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As filed with the United States Securities and Exchange Commission on May 7, 2018.

Registration Statement No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form F-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Autolus Therapeutics Limited¹

(Exact name of registrant as specified in its charter)

England and Wales

2836

Not applicable

(State or other jurisdiction of

incorporation or organization)

(Primary Standard Industrial

Classification Code Number)

(I.R.S. Employer

Identification Number)

Forest House

58 Wood Lane

White City

London W12 7RZ

United Kingdom

Tel: +44 20 3829 6230

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Corporation Service Company

1180 Avenue of the Americas, Suite 210

New York, NY 10036

+1 800 927 9801

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies of all communications, including communications sent to agent for service, should be sent to:

Darren K. DeStefano

Christian E. Plaza

Brian F. Leaf

Courtney T. Thorne

Cooley LLP

11951 Freedom Drive

Reston, VA 20190-5656

+1 703 456 8000

Ed Lukins

Edward Dyson

Thomas Goodman

Cooley (UK) LLP

Dashwood

69 Old Broad Street

London EC2M 1QS

United Kingdom

+44 20 7785 9355

Patrick O’Brien

Emily Oldshue

Ropes & Gray LLP

Prudential Tower

800 Boylston Street

Boston, MA 02199

+1 617 951 7000

Approximate date of commencement of proposed sale to public: As soon as practicable after this registration statement becomes effective.

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of ‘‘large accelerated filer,’’ ‘‘accelerated filer,’’ ‘‘smaller reporting company’’ and ‘‘emerging growth company’’ in Rule 12b-2 of the Exchange Act.


Large Accelerated Filer ☐	Accelerated Filer ☐	Non-Accelerated Filer ☒	Smaller Reporting Company ☐
		(Do not check if a smaller reporting company)	Emerging Growth Company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards^† provided to Section 7(a)(2)(B) of the Securities Act. ☒

^†	The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

CALCULATION OF REGISTRATION FEE



TITLE OF EACH CLASS OF SECURITIES TO BE REGISTERED	PROPOSED MAXIMUM AGGREGATE OFFERING PRICE(1)(2)	AMOUNT OF REGISTRATION FEE(3)
Ordinary shares, nominal value £0.00001 per share(4)	$100,000,000	$12,450.00

(1)	Estimated solely for the purpose of computing the amount of the registration fee pursuant to Rule 457(o) under the Securities Act of 1933, as amended.

(2)	Includes shares represented by American Depositary Shares, or ADSs, that are issuable upon exercise of the underwriters’ option to purchase additional shares.

(3)	Calculated pursuant to Rule 457(o) under the Securities Act of 1933, as amended, based on an estimate of the proposed maximum aggregate offering price.

(4)	These ordinary shares are represented by ADSs, each of which represents one ordinary share of the registrant. ADSs issuable upon deposit of the ordinary shares registered hereby are being registered pursuant to a separate registration statement on Form F-6 (File No. 333- ).

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to such Section 8(a), shall determine.

The information in this preliminary prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED MAY 7, 2018

PRELIMINARY PROSPECTUS

American Depositary Shares

LOGO

Representing Ordinary Shares

We are offering American Depositary Shares, or ADSs. Each ADS represents one ordinary share. The ADSs may be evidenced by American Depositary Receipts, or ADRs. This is the initial public offering of our ADSs. All of the ADSs are being sold by us.

Prior to this offering, there has been no public market for our ADSs or ordinary shares. It is currently estimated that the initial public offering price per ADS will be between $ and $ . We intend to apply to list our ADSs on The Nasdaq Global Market under the symbol “AUTL.”

Investing in our ADSs involves a high degree of risk. Before buying any ADSs, you should carefully read the discussion of material risks of investing in our ADSs in “Risk Factors” beginning on page 18 of this prospectus.

We are an “emerging growth company” as defined in Section 2(a) of the Securities Act of 1933, as amended, and, as such, will be subject to reduced public company reporting requirements. See “Prospectus Summary—Implications of Being an Emerging Growth Company and a Foreign Private Issuer” for additional information.

Neither the U.S. Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.


	PER ADS	TOTAL
Initial public offering price	$	$
Underwriting discounts and commissions(1)	$	$
Proceeds, before expenses, to Autolus Therapeutics	$	$

(1)	We have agreed to reimburse the underwriters for certain expenses. See the section titled “Underwriting” for additional information regarding underwriting compensation.

The underwriters have an option to purchase up to additional ADSs from us at the initial public offering price less the underwriting discount. The underwriters may exercise this option at any time within 30 days after the date of this prospectus.

The underwriters expect to deliver the ADSs to the purchasers on or about , 2018.


Goldman Sachs & Co. LLC		Jefferies

Wells Fargo Securities		William Blair

Prospectus dated , 2018

TABLE OF CONTENTS


MARKET, INDUSTRY AND OTHER DATA			ii
ABOUT THIS PROSPECTUS			ii
PROSPECTUS SUMMARY			1
THE OFFERING			14
SUMMARY FINANCIAL DATA			16
RISK FACTORS			18
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS			79
USE OF PROCEEDS			81
DIVIDEND POLICY			83
CORPORATE REORGANIZATION			84
CAPITALIZATION			87
DILUTION			89
SELECTED FINANCIAL DATA			91
MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS			93
BUSINESS			109
MANAGEMENT			167
RELATED PARTY TRANSACTIONS			182
PRINCIPAL SHAREHOLDERS			186
DESCRIPTION OF SHARE CAPITAL AND ARTICLES OF ASSOCIATION			189
DESCRIPTION OF AMERICAN DEPOSITARY SHARES			208
SHARES AND ADSs ELIGIBLE FOR FUTURE SALE			220
MATERIAL INCOME TAX CONSIDERATIONS			223
UNDERWRITING			233
EXPENSES OF THIS OFFERING			239
LEGAL MATTERS			240
EXPERTS			240
SERVICE OF PROCESS AND ENFORCEMENT OF LIABILITIES			240
WHERE YOU CAN FIND ADDITIONAL INFORMATION			241
INDEX TO THE FINANCIAL STATEMENTS			F-1

We are responsible for the information contained in this prospectus and any free writing prospectus we prepare or authorize. We have not, and the underwriters have not, authorized anyone to provide you with different information, and we and the underwriters take no responsibility for any other information others may give you. We are not, and the underwriters are not, making an offer to sell our ADSs in any jurisdiction where the offer or sale is not permitted. You should not assume that the information contained in this prospectus is accurate as of any date other than the date on the front cover of this prospectus, regardless of the time of delivery of this prospectus or the sale of any ADSs.

For investors outside the United States: Neither we nor the underwriters have done anything that would permit this offering or possession or distribution of this prospectus in any jurisdiction, other than the United States, where action for that purpose is required. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the ADSs and the distribution of this prospectus outside the United States.

We are incorporated under the laws of England and Wales and a majority of our outstanding securities are owned by non-U.S. residents. Under the rules of the U.S. Securities and Exchange Commission, or the SEC, we are currently eligible for treatment as a “foreign private issuer.” As a foreign private issuer, we will not be required to file periodic reports and financial statements with the SEC as frequently or as promptly as domestic registrants whose securities are registered under the Securities Exchange Act of 1934, as amended, or the Exchange Act.

MARKET, INDUSTRY AND OTHER DATA

This prospectus contains estimates, projections and other information concerning our industry, our business and the markets for our product candidates. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties, and actual events or circumstances may differ materially from events and circumstances that are assumed in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from our own internal estimates and research as well as from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

In addition, assumptions and estimates of our and our industry’s future performance are necessarily subject to a high degree of uncertainty and risk due to a variety of factors, including those described in the section titled “Risk Factors.” These and other factors could cause our future performance to differ materially from those expressed in the industry publications, as well as from our assumptions and estimates. See the section titled “Special Note Regarding Forward-Looking Statements.”

ABOUT THIS PROSPECTUS

Prior to the completion of this offering, we will undertake a corporate reorganization described in the section titled “Corporate Reorganization,” pursuant to which Autolus Limited will ultimately become a wholly owned subsidiary of Autolus Holdings (UK) Limited, which in turn will be a wholly owned subsidiary of Autolus Therapeutics Limited. Autolus Therapeutics Limited is a recently formed holding company with nominal assets and liabilities. We also intend to form another holding company, Autolus Holdings (UK) Limited. Both of these entities are or will be holding companies which have not or will not have conducted any operations prior to this offering other than acquiring the entire issued share capital of Autolus Limited and other actions incidental to their formation, the corporate reorganization and this offering.

Prior to the completion of this offering, we intend to re-register Autolus Therapeutics Limited as a public limited company and to change its name from Autolus Therapeutics Limited to Autolus Therapeutics plc.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus to the terms “Autolus Limited,” “Autolus Therapeutics Limited,” “Autolus Therapeutics plc,” “the company,” “we,” “us” and “our” refer to (i) Autolus Limited and its wholly owned U.S. subsidiary, Autolus Inc., prior to the completion of our corporate reorganization, (ii) Autolus Therapeutics Limited and its subsidiaries after the completion of our corporate reorganization and (iii) Autolus Therapeutics plc and its subsidiaries after the re-registration of Autolus Therapeutics Limited as a public limited company, which is expected to occur prior to the completion of this offering. See “Corporate Reorganization” for more information.

We own various trademark registrations and applications, and unregistered trademarks, including Autolus Limited and our corporate logo. All other trade names, trademarks and service marks of other companies appearing in this prospectus are the property of their respective holders. Solely for convenience, the trademarks and trade names in this prospectus may be referred to without the ^® and ^™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend to use or display other companies’ trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

PROSPECTUS SUMMARY

The following summary highlights information contained elsewhere in this prospectus and does not contain all of the information you should consider before investing in our ADSs. You should read the entire prospectus carefully, including “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and our financial statements and the related notes, in each case included in this prospectus before making an investment decision.

Overview

We are a biopharmaceutical company developing next-generation programmed T cell therapies for the treatment of cancer. Using our broad suite of proprietary and modular T cell programming technologies, we are engineering precisely targeted, controlled and highly active T cell therapies that are designed to better recognize cancer cells, break down their defense mechanisms and eliminate these cells. We believe our programmed T cell therapies have the potential to be best-in-class and offer cancer patients substantial benefits over the existing standard of care, including the potential for cure in some patients.

Cancers thrive on their ability to fend off T cells by evading recognition by T cells and by establishing other defense mechanisms, such as checkpoint inhibition and creating a hostile microenvironment. Our next-generation T cell programming technologies allow us to tailor our therapies to address the specific cancer we are targeting and introduce new programming modules into a patient’s T cells to give those T cells improved properties to better recognize cancer cells and overcome fundamental cancer defense mechanisms. We believe our leadership in T cell programming technologies will provide us with a competitive advantage as we look to develop future generations of T cell therapies targeting both hematological cancers and solid tumors.

Our clinical-stage pipeline comprises five programs being developed in six hematological and solid tumor indications. We expect to complete the proof-of-concept phases of four Phase 1/2 clinical trials in hematological cancer indications by early 2019. These clinical programs are adaptive and designed to allow collection of sufficient data in the expansion phase of the trials to potentially support registration. We have worldwide commercial rights to all of our programmed T cell therapies.

Our current clinical-stage programs are:


AUTO1:		a CD19-targeting programmed T cell therapy designed to improve the safety profile of the CD19 binder while maintaining its anti-leukemia activity. AUTO1 has demonstrated this anti-leukemia activity in the absence of severe cytokine release syndrome, or CRS, in a Phase 1 trial of 11 patients with pediatric relapsed or refractory acute B lymphocytic leukemia, or pediatric ALL. A Phase 1 clinical trial in adult patients with ALL is ongoing.

AUTO2:		the first dual-targeting programmed T cell therapy for the treatment of relapsed or refractory multiple myeloma targeting B-cell Maturation Antigen, or BCMA, and the transmembrane activator and CAML interactor, or TACI. We initiated a Phase 1/2 clinical trial in the third quarter of 2017.

AUTO3:		the first dual-targeting programmed T cell therapy for the treatment of relapsed or refractory diffuse large B-cell lymphoma, or DLBCL, and pediatric ALL, independently targeting B-lymphocyte antigens CD19 and CD22. We initiated separate Phase 1/2 clinical trials of AUTO3 in DLBCL and in pediatric ALL in the third quarter of 2017.



AUTO4:		a programmed T cell therapy for the treatment of peripheral T-cell lymphoma targeting TRBC1. We intend to initiate a Phase 1/2 clinical trial in the first half of 2018.

AUTO6:		a programmed T cell therapy targeting GD2 in development for the treatment of neuroblastoma. A Phase 1 clinical trial with AUTO6 is being sponsored and conducted by Cancer Research UK, or CRUK, and preliminary data has shown initial anti-tumor activity in this solid tumor indication. We are developing a next-generation product candidate, which we refer to as AUTO6 NG, incorporating additional programming modules designed to improve the efficacy, safety and persistence of AUTO6. We expect to initiate a Phase 1/2 clinical trial of AUTO6 NG in 2020.

Our most advanced product candidate, AUTO1, has an optimized engagement of the CD19 target designed to reduce the risk of severe CRS without adversely impacting efficacy. We believe that these properties may make AUTO1 a suitable candidate for the treatment of adult patients with ALL, who tend to be less tolerant of severe toxicity than children with ALL. There are currently no programmed T cell therapies approved for the treatment of adult ALL. AUTO2 and AUTO3 are designed to address a key escape route used by hematological cancers in response to T cell therapies. Cancer cells often mutate and cease to express the antigen that current therapies were designed to recognize. This loss of the target antigen leads to patient relapse. Consequently, we have developed AUTO2 and AUTO3 to employ a dual-targeting mechanism because we believe it may improve durability of treatment response and reduce the frequency of cancer relapse when compared to other currently approved single-targeting T cell therapies, including other chimeric antigen receptor, or CAR, T cell therapies and T cell engager approaches. Our product candidate AUTO4, which we are developing for the treatment of peripheral T-cell lymphoma, employs a novel and differentiated treatment approach. AUTO4 is designed to kill cancerous T cells in a manner that we believe will preserve a portion of the patient’s normal, healthy T cells to maintain immunity. AUTO2 and AUTO4 target antigens for which there is limited or no clinical data and also are programmed with a “safety switch” in order to allow us to manage toxicity by eliminating the programmed T cells if a patient experiences severe adverse side effects from the treatment. We are developing AUTO6 NG, which builds upon AUTO6 by incorporating programming modules intended to enhance efficacy and aiming to extend persistence and address the layers of defense that cancer cells deploy to evade T cell killing.

The manufacture and delivery of programmed T cell therapies to patients involves complex, integrated processes, including harvesting T cells from patients, programming the T cells ex vivo, or outside the body, multiplying the programmed T cells to obtain the desired dose, and ultimately infusing the programmed T cells back into a patient’s body. Providing T cell therapies in a commercially successful manner requires a manufacturing process that is reliable, scalable and economical. We are using a semi-automated, fully enclosed system for cell manufacturing, which is designed to provide a common platform suitable for manufacturing all of our product candidates and to allow for rapid development of our product candidates through clinical trial phases and the regulatory approval processes. In addition, this platform allows for parallel processing and the ability to scale for commercial supply in a controlled environment and at an economical cost. We plan to build internal manufacturing and supply capabilities as well as to utilize the expertise of collaborators on some of the aspects of product delivery, logistics and capacity expansion. We believe having established manufacturing processes suitable for commercialization early in the development of our T cell therapies will allow us to focus on expanding manufacturing capacity during our clinical trials.

follow-on, or next-generation, product candidates with enhanced characteristics, such as pharmacological control, insensitivity to checkpoint inhibition or other desirable features.

Recent Developments

Cash as of December 31, 2017

As of December 31, 2017, our cash and cash equivalents were $129.0 million.

Our Team

Our management team has a strong track record of accomplishment in redirected T cell therapies, gene therapy, transplantation and oncology. Their collective experience spans key areas of expertise required of a fully integrated company delivering advanced programmed T cell therapies, including fundamental innovation in therapeutic design, translational medicine and clinical development, process sciences, manufacturing and commercialization. We are led by Dr. Christian Itin, our Chairman and Chief Executive Officer. His prior experience includes serving as the chief executive officer of Micromet, Inc., a public biotechnology company acquired by Amgen Inc. in 2012 for $1.2 billion, where he led the development of blinatumomab, which in 2014 became the first redirected T cell therapy approved by the U.S. Food and Drug Administration, or FDA. Our proprietary and modular T cell programming technologies were invented by Dr. Martin Pulé, our scientific founder and Senior Vice President and Chief Scientific Officer. Dr. Pulé has been an innovator in the field of genetic engineering of T cells for cancer treatment for almost 20 years. We are backed by leading life sciences investors, including Syncona Limited, Woodford Investment Management, Arix Bioscience plc, Cormorant Asset Management, Google Ventures and Nextech Invest Ltd.

Our Pipeline

The following table summarizes key information about our programmed T cell therapy product candidates and other pipeline programs. We have retained worldwide commercial rights with respect to all of these product candidates.

LOGO

Our Strategy

Our goal is to use our broad array of proprietary and modular T cell programming technologies to become a fully integrated biopharmaceutical company offering advanced, differentiated, best-in-class programmed T cell therapies. In order to accomplish this goal, we plan to execute on the following key strategies:

•

for the treatment of DLBCL and pediatric ALL. We expect to initiate a Phase 1/2 clinical trial of AUTO4 for the treatment of peripheral T-cell lymphoma in the first half of 2018. We intend to progress each of these product candidates in parallel through clinical trials. Depending on the results we observe in our clinical trials, we believe these product candidates may be eligible for accelerated regulatory approval pathways and we may seek to achieve breakthrough therapy designation from the FDA or PRIority MEdicines, or PRIME, designation from the European Medicines Agency, or EMA.

•

Continue to innovate and develop our product pipeline using a modular approach to T cell programming. We have a broad and expanding array of programming modules that can be used to bring improved properties to T cells. These modules may lead to improved product features such as an enhanced ability to recognize cancer cells, elements to overcome fundamental cancer defense mechanisms, improved safety through pharmacological control or improved survival or persistence of the programmed T cells. By continuing to develop and deploy new modules as our knowledge of cancer defense mechanisms advances, we believe we will be well positioned to design new programmed T cell product candidates with additional cancer-fighting properties or enhanced safety features tailored to specific indications or cancer sub-types.

•

Expand our product pipeline in solid tumor indications. CRUK is conducting an exploratory Phase 1 clinical trial of AUTO6, a GD2-targeting programmed T cell therapy, which has shown initial signs of clinical activity in two pediatric patients with neuroblastoma. We have worldwide commercial rights to the Phase 1 clinical data and UCLB patents covering this program, and are planning to initiate a Phase 1/2 clinical trial of AUTO6 NG, a next-generation product candidate building upon AUTO6, in 2020. In addition, we are planning to initiate a clinical trial of AUTO7 for the treatment of prostate cancer. Both AUTO6 NG and AUTO7 are being developed to incorporate multiple programming elements designed to address certain complexities of solid tumors.

•

Scale our economical manufacturing process. We have developed our own proprietary viral vector and semi-automated cell manufacturing processes, which we are already using in our clinical-stage programs. We believe these processes are fit for commercial scale and we anticipate they will enable commercial supply at an attractive cost of goods. Manufacturing is currently conducted by, or under the supervision of, our own employees and we have established plans to increase manufacturing capacity to meet our anticipated future clinical and commercial needs.

•

Establish a focused commercial infrastructure. Our current clinical-stage product candidates are being developed for the treatment of patients with late-stage or rare hematological cancers, most of whom will be treated in specialized treatment centers or hospitals. With our experience in gene therapy, transplantation and oncology, we aim to provide high levels of service and scientific engagement at these treatment centers, and to pilot and establish systems necessary for product delivery by the time of launch.

Our Solution

There remains a critical unmet medical need for improved T cell therapies. We believe that improving efficacy and durability over the products currently on the market or in development for the treatment of cancers requires addressing target antigen loss, countering checkpoint inhibition and adding novel targets to expand the range of indications amenable to programmed T cell therapy. We

believe our clinical-stage product candidates and our approach to T cell programming have the potential to address these limitations.

We are applying our broad array of T cell programming technologies and capabilities to engineer precisely targeted, controlled and highly active T cell therapies that are designed to better recognize cancer cells, break down their defense mechanisms and attack and kill these cells. The breadth of our technology platform allows us to select from a range of programming modules, and our modular approach is designed to enable us to tailor our therapies to address the specific cancer we are targeting, or to improve an already established therapy, such as by making it suitable for outpatient use. We believe this capability represents a competitive advantage in the field and will allow us to position our product candidates to have the potential to be best-in-class.

After identifying a cancer target, we select the suite of programming modules that we believe is best suited to target that particular cancer based on our latest clinical data and the results of our cancer research. A viral vector is used to introduce combinations of these modules into the DNA of the T cells. The particular modules selected may vary, and not every product candidate, including our current product candidates, contains all categories of modules. With the exception of AUTO1, all of our product candidates contain two or more programming modules.

Advanced Targeting Technologies Used in our Modular Approach

We have developed advanced antigen targeting technologies to improve the ability of our programmed T cell therapies to selectively identify, target and destroy cancer cells and overcome shortcomings of the current generation of T cell therapies. These targeting technologies include innovative binders, novel targets, dual-targeting and pattern recognition.

Innovative Binders and Novel Targets

Binding domains allow for selective targeting of cancer cells, and the properties of binders are crucial to the performance of T cell therapies. The binders of each of our programs have been optimized, are novel binders, or bind to novel targets.

The T cells of other CD19 CAR T cell therapies that have been approved or that are in clinical development are engineered to express high affinity binders that can engage their targets for an extended period of time. This can lead to excessive T cell activation and toxicities caused by cytokine release, as well as exhaustion of the CAR T cell. The programmed T cells of AUTO1 express a CD19 binder with a fast off-rate, which refers to the rate at which a T cell disengages from a target antigen. This is similar to the off-rate of naturally occurring T cells. AUTO1, with this enhanced kinetic profile, appears to result in reduced CRS and in increased T cell engraftment compared to data reported for other CAR T cell product candidates in clinical development for ALL that use high affinity binders.

The APRIL ligand is a human single domain protein that was selected as the targeting moiety in AUTO2 because it can bind with high affinity to BCMA and to TACI, two different antigens expressed on multiple myeloma cells. Using a single binder for two targets provides for efficiencies in the T cell programming process and leaves additional capacity in the viral vector to include further programming modules.

AUTO3 includes an optimized CD22 binder. It is challenging to target CD22 for immunotherapy because of its large size and extensive posttranslational modifications. Our optimized CD22 binder combines five CAR binding domains to allow for suitable orientation and efficient target engagement compared to a traditional CAR.

The TRBC1 binder used in AUTO4 is highly selective for one of two highly related variants of the constant domain in T cell receptor beta chains. The binder allows AUTO4 to target TRBC1-positive T cell lymphoma cells without affecting healthy TRBC2-positive T cells.

AUTO6 is designed to target GD2 with an optimized anti-GD2 binder which uses a humanized targeting domain. Initial clinical data from an ongoing Phase 1 clinical trial sponsored by CRUK indicates early signs of clinical activity in the absence of neurotoxicity.

Dual-Targeting Technology

Escape from T cell recognition by losing the antigen, the very structure the programmed T cell is designed to recognize, is a fundamental defense mechanism of hematological cancers. All clinical programs targeting CD19, CD22 or BCMA in a single-target approach have reported patients relapsing with cells that no longer have detectable levels of the target antigen. The most profound impact of this defense mechanism of cancer cells was reported for children relapsing under CD19-targeting Kymriah^® treatment, with more than half the children at time of relapse showing a loss of the CD19 antigen on the recurring cancer cells.

We believe that directly targeting two antigens on a cancer cell will reduce the chances for relapse and may also improve a response in those patients with low levels of expression of a target antigen on their cancer cells. AUTO2, the first dual-targeting programmed T cell therapy for the treatment of multiple myeloma, binds to two receptors, BCMA and TACI, both of which are expressed in varying levels on the surface of multiple myeloma cancer cells. AUTO3, the first dual-targeting programmed T cell therapy for the treatment of pediatric ALL and DLBCL, targets both the CD19 and CD22 antigens, both of which are B-cell antigens with similar patterns of expression.

Pattern Recognition Technology

Programmed T cells are very powerful and must be highly selective for the cancer cells in order to avoid unwanted side effects. Particularly for the treatment of solid tumors, which have greater complexity, achieving a sufficient level of selectivity based on a single target to avoid toxicity can be challenging. For such cancers, we have developed a programming module designed to make a kill decision based on the presence of two or more targets on the cancer cell. This technology is designed to allow us to program T cells to eliminate tumor cells only if two different targets are both present on the surface of the cell, thereby sparing healthy cells that express only one of these targets in isolation. We are also developing technology that we believe will allow us to program T cells to eliminate a tumor if only the tumor target, but not a target only found on healthy cells, is present on the cancer cell.

Pharmacological Control of T Cell Activity

Management of toxicity is a critical step in the successful application of programmed T cell therapies. We have developed multiple technologies designed to pharmacologically control T cell activity. These technologies fall into two distinct categories: safety switches and tunable T cells.

Safety Switches

antibody rituximab, or Rituxan^®, which binds to the surface of the T cell and thereby triggers cell death. We use the RQR8 safety switch in our AUTO2, AUTO4 and AUTO6 programs. The next generation of our safety switches, which we plan to incorporate in our solid tumor programs, utilizes rapamycin activated Caspase 9 (rapaCasp9), a cell therapy safety switch that allows for selective elimination of programmed T cells using a single therapeutic dose of the commercially available product rapamycin, such as sirolimus or Rapamune^®. Rapamycin is a small molecule drug, which we expect will have the benefit of better tissue penetration and may require less time to take effect as compared to a monoclonal antibody-activated safety switch.

Tunable T Cells

Eliminating programmed T cells with a safety switch like RQR8 has the potential to allow the patient to recover from treatment-related side effects but also to preclude the anti-tumor activity following elimination of the programmed T cells, which could lead to relapse. To avoid this undesirable consequence of the safety switch, we are developing several programming modules that are designed to allow tunable programmed T cell responses by reducing programmed T cell activity if a patient experiences severe toxicity, while also allowing for the subsequent reactivation of programmed T cells, thereby allowing for the possibility of persistence and sustained anti-tumor activity. One such system we have developed is designed to reversibly dampen the activity of the programmed T cells by temporarily dislocating the signaling domain on the inside of the T cell from the cancer cell recognition domain with two commercially available antibiotics, tetracycline and minocycline.

Enhanced T Cell Activity Technologies

We have also developed a wide range of technologies designed to inhibit the immunosuppressive effects of the tumor microenvironment and enhance T cell persistence.

Evading Hostile Tumor Microenvironments Including Checkpoint Inhibition

Proteins expressed on tumor cells can trigger inhibitory receptors on T cells to block their ability to eliminate the tumor, such as PD-L1/PD-1 immune checkpoints. These inhibitory receptors act through a common signaling pathway inside the T cell that prevents normal T cell activation. We have developed a programming module designed to cause T cells to express a modified version of an adaptor protein, SHP2, that in preclinical studies has been shown to efficiently counteract the inhibition of T cells resulting from the PD-L1/PD-1 checkpoint interaction. Unlike methods that rely on blocking one inhibitory receptor using antibodies that are separately administered to the patient and are known to have significant side effects on their own, we have designed this programming module to be engineered into the T cells and not to require the administration of a separate pharmaceutical agent. In addition, it is designed to simultaneously disarm multiple inhibitory receptors on the cancer cell.

Enhanced T Cell Persistence

local administration of cytokines can be toxic. Therefore, we have developed a technology that is designed to deliver a cytokine signal directly inside our programmed T cells without administration of cytokines themselves. Depending on the tumor microenvironment, the cytokine persistence signal may be further enhanced by antigens secreted by the tumor. We believe our approach will be more potent and will have the potential to be less toxic, when compared to approaches that rely on systemic or local delivery of cytokines.

Advanced T Cell Programming is Key for Solid Tumor Programs

Achieving a meaningful and durable response with programmed T cell therapies in the treatment of solid tumors is more challenging than in hematological cancers for a variety of reasons. Solid tumors have fewer suitably selective, single antigen targets that can be used as a basis for tumor recognition, and solid tumors employ multiple sophisticated lines of defense to evade T cell killing.

Consequently, in order to be able to tackle the more complex biology of solid tumors, we anticipate that programmed T cell products will need to employ multiple modules of technology to overcome these challenges. With our broad array of proprietary programming modules and our ability to incorporate multiple elements into our programmed T cell product candidates, we believe we are well positioned to design these types of products and expand our pipeline into solid tumor indications, including with our development of AUTO6 NG.

Risks Associated with Our Business

Our business is subject to a number of risks of which you should be aware before making an investment decision. You should carefully consider all of the information set forth in this prospectus and, in particular, should evaluate the specific factors set forth in the section titled “Risk Factors” before deciding whether to invest in our ADSs. Among these important risks are, but such risks are not limited to, the following:

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We have incurred significant losses in every year since our inception. We expect to continue to incur losses over the next several years and may never achieve or maintain profitability.

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Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

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We will need additional funding to complete the development of our product candidates, which may not be available on acceptable terms, if at all.

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We are very early in our development efforts. All of our product candidates are in early-stage clinical development or in preclinical development. If we are unable to advance our product candidates through clinical development, obtain regulatory approval and ultimately commercialize our product candidates, or experience significant delays in doing so, our business will be materially harmed.

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Our proprietary, next-generation T cell programming technologies, our modular approach for engineering T cells and our manufacturing platform for our programmed T cell product candidates, represent emerging approaches to cancer treatment that face significant challenges and hurdles.

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Our future success is highly dependent on the regulatory approval of our current clinical-stage programmed T cell product candidates and our preclinical programs. All of our product candidates will require significant clinical or preclinical testing before we can seek regulatory approval for and launch a product commercially.

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Adverse side effects or other safety risks associated with our product candidates could delay or preclude approval, cause us to suspend or discontinue clinical trials, cause us to abandon product candidates, could limit the commercial profile of an approved label, or could result in significant negative consequences following any potential marketing approval.

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If the clinical trials of any of our product candidates fail to demonstrate safety and efficacy to the satisfaction of the FDA, the EMA or other comparable regulatory authorities, or do not otherwise produce favorable results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of our product candidates.

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We may not be able to successfully create our own manufacturing infrastructure for supply of our requirements of programmed T cell product candidates for use in clinical trials and for commercial sale.

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Our product candidates are biologics and the manufacture of our product candidates is complex and we may encounter difficulties in production, particularly with respect to process development or scaling-out of our manufacturing capabilities. If we encounter such difficulties, our ability to provide supply of our product candidates for clinical trials or our products for patients, if approved, could be delayed or stopped.

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We operate in a rapidly changing industry and face significant competition, which may result in others discovering, developing or commercializing products before or more successfully than we do.

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If we are unable to obtain and maintain patent protection for our T cell programming technologies and product candidates, or if the scope of the patent protection obtained is not sufficiently broad, our competitors could develop and commercialize technology and biologics similar or identical to ours, and our ability to successfully commercialize our technology and product candidates may be impaired.

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In connection with the audit of our financial statements as of and for the years ended September 30, 2016 and 2017 in preparation for this offering, our independent registered public accounting firm identified a material weakness in our internal control over financial reporting. If we are not able to remediate the material weakness or if we otherwise fail to maintain an effective system of internal control over financial reporting, we may not be able to accurately report our financial statements in a timely manner, which may adversely affect our business, investor confidence in our company and the market value of our ADSs.

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As an English public limited company, certain capital structure decisions will require shareholder approval, which may limit our flexibility to manage our capital structure.

Corporate Information

Autolus Therapeutics Limited was incorporated under the laws of England and Wales in February 2018. Our registered office is located at Forest House, 58 Wood Lane, White City, London W12 7RZ, United Kingdom and our telephone number is +44 20 3829 6230. Our website address is www.autolus.com. The information contained on our website is not incorporated by reference into this prospectus, and you should not consider any information contained on, or that can be accessed through, our website as part of this prospectus or in deciding whether to purchase our ADSs.

Corporate Reorganization

Prior to the completion of this offering, we will undertake a corporate reorganization pursuant to which (i) Autolus Therapeutics Limited will ultimately become the direct holding company of Autolus Holdings (UK) Limited, a new holding company we plan to incorporate prior to the completion of this offering and the indirect holding company of Autolus Limited; (ii) Autolus Holdings (UK) Limited will become the wholly owned subsidiary of Autolus Therapeutics Limited and the direct holding company of Autolus Limited; and (iii) Autolus Therapeutics Limited will re-register as a public limited company and change its name to Autolus Therapeutics plc. Pursuant to the terms of the corporate reorganization, the shareholders of Autolus Limited will exchange each of the shares held by them in Autolus Limited for the same number and class of newly issued shares of Autolus Therapeutics Limited and, as a result, Autolus Limited will become a wholly owned subsidiary of Autolus Therapeutics Limited. Following this share exchange, Autolus Holdings (UK) Limited (wholly owned by Autolus Therapeutics Limited) will acquire the entire issued share capital of Autolus Limited in exchange for an issue of shares in Autolus Holdings (UK) Limited and, as a result, Autolus Limited will become a wholly owned subsidiary of Autolus Holdings (UK) Limited. In addition, all of our outstanding series A preferred shares, B ordinary shares and C ordinary shares will convert into a single class of ordinary shares on a one-for-one basis. Please see “Corporate Reorganization” in this prospectus for more information.

The diagram below sets forth our anticipated group structure after the completion of the corporate reorganization described above and this offering:

LOGO

After the completion of our corporate reorganization and this offering, Autolus Limited will transfer, by way of a dividend in specie, the entire issued share capital of its wholly owned subsidiary, Autolus Inc., our U.S. subsidiary which was incorporated under the laws of the State of Delaware in October 2017, to its immediate parent, Autolus Holdings (UK) Limited. Following the dividend in specie,

each of Autolus Limited and Autolus Inc. will be repositioned as direct wholly owned subsidiaries of Autolus Holdings (UK) Limited.

Implications of Being an Emerging Growth Company and a Foreign Private Issuer

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, as amended. An emerging growth company may take advantage of specified reduced reporting and other burdens that are otherwise applicable generally to public companies in the United States. These provisions include:

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the ability to include only two years of audited financial statements in addition to any required interim financial statements and correspondingly reduced Management’s Discussion and Analysis of Financial Condition and Results of Operations disclosure;

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reduced executive compensation disclosure; and

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an exemption from the auditor attestation requirement in the assessment of our internal control over financial reporting pursuant to the Sarbanes-Oxley Act of 2002.

We may choose to take advantage of some but not all of these reduced disclosure requirements. We may take advantage of these provisions until we are no longer an emerging growth company. We will remain an emerging growth company until the earliest to occur of: (1) (a) the last day of the fiscal year following the fifth anniversary of the closing of this offering, (b) the last day of the fiscal year in which our annual gross revenue is $1.07 billion or more, or (c) the date on which we are deemed to be a “large accelerated filer,” under the rules of the U.S. Securities and Exchange Commission, or SEC, which means the market value of our equity securities that is held by non-affiliates exceeds $700 million as of the end of our second quarter and (2) the date on which we have issued more than $1.0 billion in non-convertible debt during the prior three-year period.

In addition, under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards until such time as those standards apply to private companies. We have elected to comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations—JOBS Act.”

Upon the completion of this offering, we will report under the Exchange Act as a non-U.S. company with foreign private issuer status. Even after we no longer qualify as an emerging growth company, as long as we qualify as a foreign private issuer under the Exchange Act, we will be exempt from certain provisions of the Exchange Act that are applicable to U.S. domestic public companies, including:

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the sections of the Exchange Act regulating the solicitation of proxies, consents or authorizations with respect to a security registered under the Exchange Act;

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the requirement to comply with Regulation Fair Disclosure, or Regulation FD, which regulates selective disclosure of material information;

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the sections of the Exchange Act requiring insiders to file public reports of their share ownership and trading activities and liability for insiders who profit from trades made in a short period of time; and

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the rules under the Exchange Act requiring the filing with the SEC of quarterly reports on Form 10-Q containing unaudited financial and other specified information, or current reports on Form 8-K upon the occurrence of specified significant events.

Both foreign private issuers and emerging growth companies are also exempt from certain more stringent executive compensation disclosure rules. Thus, even if we no longer qualify as an emerging growth company, but remain a foreign private issuer, we will continue to be exempt from the more stringent compensation disclosures required of companies that are neither an emerging growth company nor a foreign private issuer. As a result, we do not know if some investors will find our ADSs less attractive, which may result in a less active trading market for our ADSs or more volatility in the price of our ADSs.

THE OFFERING

ADSs offered by us

ADSs, each ADS representing one ordinary share.

Option to purchase additional ADSs

We have granted the underwriters an option for a period of 30 days from the date of this prospectus to purchase up to an additional ADSs from us.

Ordinary shares to be outstanding after this offering

shares (or shares if the underwriters exercise in full their option to purchase additional ADSs).

American Depositary Shares

Each ADS represents one ordinary share, nominal value £0.00001 per share. The ADSs may be evidenced by American Depositary Receipts, or ADRs. The depositary will hold the ordinary shares underlying the ADSs in a custody account with the custodian, and you will have the rights of an ADS holder or beneficial owner (as applicable) as provided in the deposit agreement among us, the depositary and holders and beneficial owners of ADSs from time to time. To better understand the terms of our ADSs, see “Description of American Depositary Shares.” We also encourage you to read the deposit agreement, the form of which is filed as an exhibit to the registration statement of which this prospectus forms a part.

Depositary

Citibank, N.A.

Custodian

Citibank, N.A. (London)

Use of proceeds

We estimate that the net proceeds to us from this offering, after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us, to be approximately $ million based on an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus.

We currently intend to use the net proceeds from this offering, together with our existing cash, as follows:

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to complete proof-of-concept phases of our Phase 1/2 clinical trials of our current clinical-stage product candidates and advance three of these product candidates through later stages of clinical development and, potentially, registration;

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to fund our research and development activities to further expand our T cell programming technologies and develop future product candidates;

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to fund our manufacturing activities to support our ongoing and future clinical trials and potential commercial launch; and

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for other general corporate purposes.

See the section titled “Use of Proceeds” for a more complete description of the intended use of proceeds from this offering.

Risk factors

See the section titled “Risk Factors” and the other information included in this prospectus for a discussion of factors you should carefully consider before deciding to invest in our ADSs.

Proposed Nasdaq Global Market listing

We intend to apply to list our ADSs on the Nasdaq Global Market under the symbol “AUTL.”

The number of our ordinary shares to be outstanding after this offering is based on 95,431,331 ordinary shares outstanding as of September 30, 2017 and gives effect to our corporate reorganization (including the conversion of all issued series A preferred shares into ordinary shares on a one-for-one basis) and excludes:

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1,816,726 ordinary shares issuable upon the exercise of share options outstanding under our 2017 Share Option Plan as of September 30, 2017, at a weighted average price of $0.16 per share;

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up to 3,626,687 ordinary shares authorized under a shareholder agreement for future issuance as an employee incentive pool, which amount includes shares underlying options that may be granted from time to time subsequent to September 30, 2017 under our 2017 Share Option Plan; and

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ordinary shares authorized for future issuance under our 2018 Equity Incentive Plan to be adopted in conjunction with this offering.

Except as otherwise indicated herein, all information in this prospectus assumes or gives effect to:

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the consummation of the transactions described under the section titled “Corporate Reorganization” in this prospectus prior to the completion of this offering;

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no exercise of outstanding options after September 30, 2017; and

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no exercise of the option granted to the underwriters to purchase additional ADSs in this offering.

SUMMARY FINANCIAL DATA

The following tables present our summary financial data. We derived the summary statement of operations and comprehensive loss data for the fiscal years ended September 30, 2016 and 2017 and the selected balance sheet data as of September 30, 2017 from our audited financial statements included elsewhere in this prospectus. We prepare our financial statements in accordance with accounting principles generally accepted in the United States, or U.S. GAAP, as issued by the Financial Accounting Standards Board, or FASB.

Our historical results are not necessarily indicative of our future results. You should read this data together with our financial statements and related notes appearing elsewhere in this prospectus and the information under the sections titled “Capitalization” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Our functional currency is the pound sterling. However, for financial reporting purposes, our financial statements, which are prepared using the functional currency, have been translated into U.S. dollars. Our assets and liabilities are translated at the exchange rates at the balance sheet date; our revenue and expenses are translated at average exchange rates and shareholders’ equity is translated based on historical exchange rates. Translation adjustments are not included in determining net income (loss) but are included in foreign exchange translation adjustment to other comprehensive loss, a component of shareholders’ equity.

Foreign currency transactions in currencies different from the functional currency are translated into the functional currency using the exchange rates prevailing at the dates of the transactions. Foreign exchange differences resulting from the settlement of such transactions and from the translation at period-end exchange rates of monetary assets and liabilities denominated in foreign currencies are recorded in general and administrative expense in the statement of operations and comprehensive loss.

As of September 29, 2017, the last business day of the year ended September 30, 2017, the representative exchange rate was £1.00 = $1.3392.


	Year Ended September 30,
	2016			2017
	(in thousands , except share and per share data)
Statement of Operations and Comprehensive Loss Data:
Grant income	$	1,212		$	1,693
Operating expenses:
Research and development		(10,436	)		(16,012	)
General and administrative		(5,152	)		(9,099	)

Total operating expenses, net		(14,376	)		(23,418	)
Other income, net		49			38

Net loss before income taxes		(14,327	)		(23,380	)
Income tax benefit		1,777			3,653

Net loss		(12,550	)		(19,727	)
Other comprehensive income (loss):
Foreign currency translation adjustment		(2,942	)		802

Total comprehensive loss	$	(15,492	)	$	(18,925	)

Basic and diluted net loss per ordinary share	$	(1.16	)	$	(1.61	)

Weighted-average basic and diluted ordinary shares		10,794,798			12,226,019

Pro forma basic and diluted net loss per share to ordinary shareholders (unaudited)				$	(0.45	)
Pro forma weighted-average basic and diluted ordinary shares (unaudited)					43,899,562


	As of September 30, 2017
	Actual		Pro Forma As Adjusted(1)
	(in thousands)
Balance Sheet Data:
Cash	$	137,070	$
Working capital(2)		137,449
Total assets		148,662
Preferred shares		1
Ordinary shares		—
Additional paid-in capital		194,351
Total shareholders’ equity		142,601

(1)

The unaudited pro forma as adjusted balance sheet data gives effect to (i) our proposed corporate reorganization, (ii) the issuance and sale of ADSs in this offering by us at an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, and the application of the net proceeds of the offering, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us, as set forth under “Use of Proceeds.” A $1.00 increase (decrease) in the assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, would increase (decrease) the pro forma as adjusted amount of each of cash, working capital, total assets and total shareholders’ equity by $ million, assuming that the number of ADSs offered by us, as set forth on the cover page of this prospectus, remains the same, and after deducting estimated underwriting discounts and commissions. An increase (decrease) of 1,000,000 in the number of ADSs offered by us, as set forth on the cover page of this prospectus, would increase (decrease) the pro forma as adjusted amount of each of cash, working capital, total assets and total shareholders’ equity by $ million, assuming the assumed initial public offering price per ADS remains the same, and after deducting estimated underwriting discounts and commissions. This pro forma as adjusted information is illustrative only and will depend on the actual initial public offering price and other terms of this offering determined at pricing.

(2)	We define working capital as current assets less current liabilities.

RISK FACTORS

Investing in our ADSs involves a high degree of risk. Before you invest in our ADSs, you should carefully consider the risks described below together with all of the other information contained in this prospectus, including our financial statements and the related notes included elsewhere in this prospectus. If any of the following risks actually occurs, our business, prospects, operating results and financial condition could suffer materially. In such event, the trading price of our ADSs could decline, which would cause you to lose all or part of your investment. Please also see “Special Note Regarding Forward-Looking Statements.”

Risks Related to Our Financial Position

We have incurred significant losses in every year since our inception. We expect to continue to incur losses over the next several years and may never achieve or maintain profitability.

We are a clinical-stage biopharmaceutical company with a limited operating history and we have incurred significant net losses since our inception in 2014. Our net loss was $12.6 million and $19.7 million for the years ended September 30, 2016 and 2017, respectively. As of September 30, 2017, we had an accumulated deficit of $47.9 million. We have funded our operations to date primarily with proceeds from the sale of our equity securities.

We have no products approved for commercial sale, have not generated any product revenue, and are devoting substantially all of our financial resources and efforts to research and development of our programmed T cell product candidates as well as to building out our manufacturing platform, T cell programming technologies and management team. Investment in biopharmaceutical product development is highly speculative because it entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate effect or an acceptable safety profile, gain regulatory approval and become commercially viable.

We expect that it will take at least several years until any of our product candidates receive marketing approval and are commercialized, and we may never be successful in obtaining marketing approval and commercializing product candidates. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. These net losses will adversely impact our shareholders’ equity and net assets and may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially as we:

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continue our ongoing and planned research and development of our current clinical-stage programmed T cell product candidates for the treatment of hematological cancers, AUTO1, AUTO2, AUTO3 and AUTO4;

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initiate preclinical studies and clinical trials for any additional product candidates that we may pursue in the future, including our planned development of additional T cell therapies for the treatment of solid tumors;

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seek to discover and develop additional product candidates and further expand our clinical product pipeline;

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seek regulatory approvals for any product candidates that successfully complete clinical trials;

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continue to scale up internal and external manufacturing capacity with the aim of securing sufficient quantities to meet our capacity requirements for clinical trials and potential commercialization;

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establish sales, marketing and distribution infrastructure to commercialize any product candidate for which we may obtain regulatory approval;

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make required milestone and royalty payments to UCL Business plc, or UCLB, the technology-transfer company of University College London, under our license agreement with UCLB pursuant to which we were granted some of our intellectual property rights;

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develop, maintain, expand and protect our intellectual property portfolio;

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acquire or in-license other product candidates and technologies;

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hire additional clinical, quality control and manufacturing personnel;

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add clinical, operational, financial and management information systems and personnel, including personnel to support our product development and planned future commercialization efforts;

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expand our operations in the United States, Europe and other geographies; and

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incur additional legal, accounting and other expenses associated with operating as a public company.

To become and remain profitable, we must succeed in developing and eventually commercializing products that generate significant revenue. This will require us to be successful in a range of challenging activities, including completing preclinical studies and clinical trials of our product candidates, obtaining regulatory approval, manufacturing, marketing and selling any products for which we may obtain regulatory approval, as well as discovering and developing additional product candidates. We may never succeed in these activities and, even if we do, may never generate revenues that are significant enough to achieve profitability.

Because of the numerous risks and uncertainties associated with the development, delivery and commercialization of complex autologous cell therapies, we are unable to accurately predict the timing or amount of expenses or when, or if, we will be able to achieve profitability. If we are required by regulatory authorities to perform studies in addition to those currently expected, or if there are any delays in the initiation and completion of our clinical trials or the development of any of our product candidates, our expenses could increase and profitability could be further delayed.

Even if we achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would depress the value of our ADSs and could impair our ability to raise capital, expand our business, maintain our research and development efforts or continue our operations. A decline in the value of our ADSs could also cause you to lose all or part of your investment.

Our limited operating history may make it difficult for you to evaluate the success of our business to date and to assess our future viability.

We are a clinical-stage biopharmaceutical company with a limited operating history. As an organization, we have not demonstrated an ability to successfully complete late-stage clinical trials, obtain regulatory approvals, manufacture our product candidates at commercial scale or arrange for a third party to do so on our behalf, conduct sales and marketing activities necessary for successful commercialization, or obtain reimbursement in the countries of sale. We may encounter unforeseen expenses, difficulties, complications, and delays in achieving our business objectives. Our very short history as an operating company makes any assessment of our future success or viability subject to significant uncertainty. If we do not address these risks successfully or are unable to transition at some point from a company with a research and development focus to a company capable of supporting commercial activities, then our business will suffer.

We will need additional funding to complete the development of our product candidates, which may not be available on acceptable terms, if at all.

We will require substantial additional funding to meet our financial needs and to pursue our business objectives. If we are unable to raise capital when needed, we could be forced to delay, reduce or altogether cease our product development programs or commercialization efforts.

We believe that the net proceeds from this offering, together with our existing cash, will enable us to fund our operating expenses and capital expenditure requirements through the completion of the proof-of-concept phases of our ongoing and planned Phase 1/2 clinical trials of our current clinical-stage product candidates, the advancement of two of these product candidates through later stages of clinical development and, potentially, registration, the funding of our research and development to further expand our T cell programming technologies and develop future product candidates, and the funding of manufacturing activities. However, this funding will not be sufficient for us to fund any of our programmed T cell product candidates through regulatory approval, and we will need to raise additional capital to complete the development and commercialization of our programmed T cell candidates and in connection with our continuing operations and other planned activities. Our future capital requirements will depend on many factors, including:

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the progress, results and costs of laboratory testing, manufacturing, preclinical and clinical development for our current and future product candidates;

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the scope, progress, results and costs of preclinical development, laboratory testing and clinical trials of other product candidates that we may pursue;

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the development requirements of other product candidates that we may pursue;

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the timing and amounts of any milestone or royalty payments we may be required to make under current or future license agreements;

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the costs of building out our infrastructure including hiring additional clinical, quality control and manufacturing personnel;

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the costs, timing and outcome of regulatory review of our product candidates;

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the costs and timing of future commercialization activities, including product manufacturing, marketing, sales and distribution, for any of our product candidates for which we receive marketing approval;

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the revenue, if any, received from commercial sales of our product candidates for which we receive marketing approval;

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the costs and timing of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending any intellectual property-related claims;

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the costs of operating as a public company; and

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the extent to which we acquire or in-license other product candidates and technologies.

Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to obtain regulatory approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our product revenues, if any, will be derived from sales of product candidates that we do not expect to be commercially available for several years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all. In addition, we may seek additional capital due to favorable market conditions or strategic considerations even if we believe we have sufficient funds for

our current or future operating plans. If we raise additional funds through collaboration and licensing arrangements with third parties, we may have to relinquish some rights to our technologies or our product candidates on terms that are not favorable to us. Any additional capital raising efforts may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize our current and future product candidates, if approved. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or altogether cease our research and development programs or future commercialization efforts.

Risks Related to the Development of Our Product Candidates

Our product candidate AUTO1, which has generated some positive preliminary data in pediatric ALL, is in early development stage for the treatment of adult ALL. We initiated Phase 1/2 clinical trials for our dual-targeting programmed T cell product candidates, AUTO2 and AUTO3, in the second half of 2017 and are currently in the Phase 1 dose-escalation phases of these clinical trials. We have not established clinical proof-of-concept for any of these product candidates. There is no assurance that these or any other future clinical trials of our product candidates will be successful or will generate positive clinical data and we may not receive marketing approval from the U.S. Food and Drug Administration, or FDA, or other regulatory agencies, including the European Medicines Agency, or EMA, for any of our product candidates. With the exception of AUTO2, we have not submitted an Investigational New Drug Application, or IND, with the FDA for our current clinical-stage product candidates, which must be in effect before commencing clinical trials in the United States. There can be no assurance that the FDA will permit the IND to go into effect in a timely manner or at all. Without the IND, we will not be permitted to conduct clinical trials in the United States.

Biopharmaceutical development is a long, expensive and uncertain process, and delay or failure can occur at any stage of any of our clinical trials. Failure to obtain regulatory approval for our product candidates will prevent us from commercializing and marketing our product candidates. The success in the development of our programmed T cell product candidates will depend on many factors, including:

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completing preclinical studies and receiving regulatory approvals or clearance for conducting clinical trials for our preclinical-stage programs;

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obtaining positive results in our clinical trials demonstrating efficacy, safety, and durability of effect of our product candidates;

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receiving approvals for commercialization of our product candidates from regulatory authorities;

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manufacturing our product candidates at an acceptable cost; and

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maintaining and growing an organization of scientists, medical professionals and business people who can develop and commercialize our products and technology.

Many of these factors are beyond our control, including the time needed to adequately complete clinical testing and the regulatory submission process. It is possible that none of our product candidates will ever obtain regulatory approval, even if we expend substantial time and resources seeking such approval. If we do not achieve one or more of these factors in a timely manner or at all, or any other factors impacting the successful development of biopharmaceutical products, we could experience significant delays or an inability to successfully develop our product candidates, which would materially harm our business.

We have concentrated our research and development efforts on our T cell technology platform using our expertise in tumor biology and cell programming, and our future success is highly dependent on the successful development and manufacture of our programmed T cell product candidates. We do not currently have any approved or commercialized products. Two of our most advanced product candidates employ a dual-targeting mechanism. By targeting two separate antigens on the cancer cell surface, we believe these product candidates have the potential to improve durability of treatment response and reduce the frequency of cancer relapse as compared to other currently available single-targeting T cell therapies. Our product candidate for the treatment of T-cell lymphoma employs a novel approach to killing malignant T cells that aims to preserve normal, healthy T cells. Some of our product candidates include a “safety switch” that is designed to allow for the elimination of the engineered T cells if a patient experiences severe adverse side effects from the treatment. However, this “safety switch” technology has not been used to date in our clinical studies, and we do not know whether it would have the intended effect if used. Additionally, as with other targeted therapies, off-tumor or off-target activity could delay development or require us to reengineer or abandon a particular product candidate. Because programmed T cell therapies represent a relatively new field of cellular immunotherapy and cancer treatment generally, developing and commercializing our product candidates subjects us to a number of risks and challenges, including:

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obtaining regulatory approval for our product candidates, as the FDA, the EMA and other regulatory authorities have limited experience with programmed T cell therapies for cancer;

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sourcing clinical and, if approved, commercial supplies of the materials used to manufacture our product candidates;

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developing programming modules with the desired properties, while avoiding adverse reactions;

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creating viral vectors capable of delivering multiple programming modules;

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developing a reliable and consistent vector and cell manufacturing process;

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establishing manufacturing capacity suitable for the manufacture of our product candidates in line with expanding enrollment in our clinical studies and our projected commercial requirements;

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achieving cost efficiencies in the scale-up of our manufacturing capacity;

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developing protocols for the safe administration of our product candidates;

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educating medical personnel regarding our programmed T cell therapies and the potential side effect profile of each of our product candidates, such as potential adverse side effects related to cytokine release syndrome;

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establishing integrated solutions in collaboration with specialty treatment centers in order to reduce the burdens and complex logistics commonly associated with the administration of T cell therapies;

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establishing sales and marketing capabilities to successfully launch and commercialize our product candidates if and when we obtain any required regulatory approvals, and risks associated with gaining market acceptance of a novel therapy if we receive approval; and

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the availability of coverage and adequate reimbursement from third-party payors for our novel and personalized therapies in connection with commercialization of any approved product candidates.

We may not be able to successfully develop our programmed T cell product candidates or our T cell programming technologies in a manner that will yield products that are safe and effective, scalable or profitable.

Additionally, because our technology involves the genetic modification of patient cells ex vivo, we are subject to additional regulatory challenges and risks, including regulatory requirements governing genetically modified organisms that have changed frequently and will likely continue to change in the future, and that may limit or delay our ability to import our product candidates into certain countries for use in clinical trials or for commercial sale even if we receive applicable marketing approvals.

Moreover, public perception and awareness of T cell therapy safety issues may adversely influence the willingness of subjects to participate in clinical trials of our product candidates, or if approved, of physicians to prescribe our products. Physicians, hospitals and third-party payors often are slow to adopt new products, technologies and treatment practices that require additional upfront costs and training. Treatment centers may not be willing or able to devote the personnel and establish other infrastructure required for the administration of programmed T cell therapies. Physicians may not be willing to undergo training to adopt this novel and personalized therapy, may decide the therapy is too complex to adopt without appropriate training and may choose not to administer the therapy. Based on these and other factors, hospitals and payors may decide that the benefits of this new therapy do not or will not outweigh its costs.

We do not have any products that have gained regulatory approval. Our business is substantially dependent on our ability to obtain regulatory approval for, and, if approved, to successfully commercialize our current clinical-stage programmed T cell product candidates and our preclinical programs. We cannot commercialize product candidates in the United States without first obtaining regulatory approval for the product from the FDA; similarly, we cannot commercialize product candidates in countries outside of the United States without obtaining regulatory approval from comparable regulatory authorities in relevant jurisdictions, such as the EMA in Europe. Before obtaining regulatory approvals for the commercial sale of any product candidate for a particular indication, we must demonstrate with substantial evidence gathered in preclinical and clinical studies, that the product candidate is safe and effective for that indication and that the manufacturing facilities, processes and controls are adequate with respect to such product candidate. To date, we have had only limited interaction with both the FDA and the EMA regarding our product candidates. Prior to seeking approval for any of our product candidates, we will need to confer with the FDA, the EMA and other regulatory authorities regarding the design of our clinical trials and the type and amount of clinical data necessary to seek and gain approval for our product candidates.

The time required to obtain approval by the FDA, the EMA and other regulatory authorities is unpredictable but typically takes many years following the commencement of preclinical studies and clinical trials and depends upon numerous factors, including the substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions. It is possible that none of our existing product candidates or any future product candidates will ever obtain regulatory approval.

Our product candidates could fail to receive regulatory approval from the FDA, the EMA or other regulatory authorities for many reasons, including:

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disagreement with the design, protocol or conduct of our clinical trials;

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failure to demonstrate that a product candidate is safe and effective for its proposed indication;

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failure of clinical trials to meet the level of statistical significance required for approval;

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failure to demonstrate that a product candidate’s clinical and other benefits outweigh its safety risks;

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disagreement with our interpretation of data from preclinical studies or clinical trials;

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insufficiency of data collected from clinical trials of our product candidates to support the submission and filing of a Biologics License Application, or BLA, or other submission or to obtain regulatory approval;

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failure to obtain approval of the manufacturing processes or our facilities;

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changes in the approval policies or regulations that render our preclinical and clinical data insufficient for approval; or

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lack of adequate funding to complete a clinical trial in a manner that is satisfactory to the applicable regulatory authority.

The FDA, the EMA or a comparable regulatory authority may require more information, including additional preclinical or clinical data to support approval, including data that would require us to perform additional clinical trials or modify our manufacturing processes, which may delay or prevent approval and our commercialization plans, or we may decide to abandon the development program. If we change our manufacturing processes, we may be required to conduct additional clinical trials or other studies, which also could delay or prevent approval of our product candidates. If we were to obtain approval, regulatory authorities may approve any of our product candidates for fewer indications than we request (including failing to approve the most commercially promising indications), may limit indications, may grant approval contingent on the performance of costly post-marketing clinical trials or other post-marketing commitments, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate.

Depending on results we observe in our clinical trials, our development strategy may include the pursuit of expedited approvals from the FDA or the EMA, such as through the accelerated approval pathway, and we may seek to achieve breakthrough therapy designation from the FDA or the PRIority Medicines, or PRIME, designation from the EMA. There is no certainty that our product candidates will qualify for breakthrough therapy or PRIME designations, nor can we assume that the clinical data obtained from trials of our product candidates will be sufficient to qualify for any expedited approval program.

Even if a product candidate were to successfully obtain approval from the FDA, the EMA or other comparable regulatory authorities in other jurisdictions, any approval might contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, or may be subject to burdensome post-approval study or risk management requirements. If we are unable to obtain regulatory approval for one of our product candidates in one or more jurisdictions, or any approval contains significant limitations, we may not be able to obtain sufficient funding to continue the development of that product or generate revenues attributable to that product candidate. Also, any regulatory approval of our current or future product candidates, once obtained, may be withdrawn. See the risk factor titled “—Even if we complete the necessary preclinical studies and clinical trials, the regulatory approval process is expensive, time-consuming and uncertain and may prevent us from obtaining approvals for the commercialization of some or all of our product candidates. As a result, we cannot predict when or if, and in which territories, we will obtain marketing approval to commercialize a product candidate.”

We may not be successful in our efforts to build a pipeline of product candidates.

A key element of our strategy is to use our expertise in tumor biology and cell programming and our proprietary and modular T cell programming technologies to develop what we believe are safer and more effective T cell therapies. Our initial focus is on the development of a pipeline of product candidates for the treatment of hematological cancers and the progression of these product candidates through clinical development. We also intend to develop follow-on, or next-generation, product candidates with additional elements of programming built into the programmed T cell product candidate to offer enhanced characteristics as compared to the earlier product generation, such as pharmacological control or insensitivity to checkpoint inhibition. However, we may not be able to develop product candidates that are safe and effective, or which compare favorably with our existing product candidates. Even if we are successful in continuing to build our pipeline and developing next-generation product candidates or expanding into solid tumor indications, the potential product candidates that we identify may not be suitable for clinical development, including as a result of lack of safety, lack of tolerability, lack of anti-tumor activity, or other characteristics that indicate that they are unlikely to be products that will receive marketing approval, achieve market acceptance or obtain reimbursements from third-party payors. If we do not successfully develop and commercialize product candidates or collaborate with others to do so, we will not be able to obtain product revenue in future periods, which could significantly harm our financial position and adversely affect the trading price of our ADSs.

Our preclinical programs may experience delays or may never advance to clinical trials, which would adversely affect our ability to obtain regulatory approvals or commercialize these programs on a timely basis or at all, which would have an adverse effect on our business.

Our product candidates AUTO5, AUTO7 and all of our next generation product candidates are still in the preclinical development stage, and the risk of failure of preclinical programs is high. Before we can commence clinical trials for a product candidate, we must complete extensive preclinical testing and studies to obtain regulatory clearance to initiate human clinical trials, including based on INDs in the United States and clinical trial applications, or CTAs, in Europe. We cannot be certain of the timely completion or outcome of our preclinical testing and studies and cannot predict if the FDA, the EMA or other regulatory authorities will accept our proposed clinical programs or if the outcome of our preclinical testing and studies will ultimately support the further development of our programs. As a result, we cannot be sure that we will be able to submit INDs or similar applications for our preclinical programs on the timelines we expect, if at all, and we cannot be sure that submission of INDs or similar applications will result in the FDA, the EMA or other regulatory authorities allowing clinical trials to begin.

Clinical trials are difficult to design and implement, involve uncertain outcomes and may not be successful.

Human clinical trials are difficult to design and implement, in part because they are subject to rigorous regulatory requirements. The design of a clinical trial can determine whether its results will support approval of a product and flaws in the design of a clinical trial may not become apparent until the clinical trial is well advanced. As an organization, we have limited experience designing clinical trials and may be unable to design and execute a clinical trial to support regulatory approval. There is a high failure rate for biologic products proceeding through clinical trials, which may be higher for our product candidates because they are based on new technology and engineered on a patient-by-patient basis. Many companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late-stage clinical trials even after achieving promising results in preclinical testing and earlier-stage clinical trials. Data obtained from preclinical and clinical activities are subject to varying interpretations, which may delay, limit or prevent regulatory approval. In addition, we may experience

regulatory delays or rejections as a result of many factors, including changes in regulatory policy during the period of our product candidate development. Any such delays could negatively impact our business, financial condition, results of operations and prospects.

Success in preclinical studies or clinical trials may not be indicative of results in future clinical trials.

Results from preclinical studies are not necessarily predictive of future clinical trial results, and interim results of a clinical trial are not necessarily indicative of final results. For example, while we have received some positive preliminary data in a clinical trial of AUTO1 in pediatric ALL, we have no clinical data for AUTO1 in adult ALL and we are in the Phase 1 dose-escalation phases of our ongoing clinical trials with AUTO2 and AUTO3, and we have treated only a small number of patients in all of these trials. For that reason, we do not know whether these candidates will be effective for the intended indications or safe in humans. Our product candidates may fail to show the desired safety and efficacy in clinical development despite positive results in preclinical studies or having successfully advanced through initial clinical trials. This failure to establish sufficient efficacy and safety could cause us to abandon clinical development of our product candidates.

We depend on enrollment of patients in our clinical trials for our product candidates. If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

Identifying and qualifying patients to participate in clinical trials of our product candidates is critical to our success. We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the study until its conclusion. The enrollment of patients depends on many factors, including:

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the patient eligibility criteria defined in the protocol;

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the number of patients with the disease or condition being studied;

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the perceived risks and benefits of the product candidate in the trial;

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clinicians’ and patients’ perceptions as to the potential advantages of the product candidate being studied in relation to other available therapies, including any new drugs that may be approved for the indications we are investigating or drugs that may be used off-label for these indications;

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the size and nature of the patient population required for analysis of the trial’s primary endpoints;

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the proximity of patients to study sites;

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the design of the clinical trial;

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our ability to recruit clinical trial investigators with the appropriate competencies and experience;

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competing clinical trials for similar therapies or other new therapeutics not involving T cell-based immunotherapy;

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our ability to obtain and maintain patient consents; and

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the risk that patients enrolled in clinical trials will drop out of the clinical trials before completion of their treatment.

In particular, some of our clinical trials will look to enroll patients with characteristics which are found in a very small population. For example, our planned clinical trials for AUTO4 will seek to enroll patients with peripheral T-cell lymphoma, a rare and heterogeneous form of non-Hodgkin lymphoma, or NHL. Other companies are conducting clinical trials with their redirected T cell therapies in multiple myeloma, pediatric relapsed or refractory acute B lymphocytic leukemia, or pediatric ALL, and relapsed or refractory diffuse large B-cell lymphoma, or DLBCL, and seek to enroll patients in their studies that may otherwise be eligible for our clinical trials, which could lead to slow recruitment and delays in our clinical programs. In addition, since the number of qualified clinical investigators is limited, we expect to conduct some of our clinical trials at the same clinical trial sites that some of our competitors use, which could further reduce the number of patients who are available for our clinical trials in these clinical trial sites. Moreover, because our product candidates represent a departure from more commonly used methods for cancer treatment, potential patients and their doctors may be inclined to use conventional therapies, such as chemotherapy and antibody therapy, rather than enroll patients in our clinical trials.

Delays in patient enrollment may result in increased costs or may affect the timing or outcome of the planned clinical trials, which could prevent completion of these clinical trials and adversely affect our ability to advance the development of our product candidates. In addition, many of the factors that may lead to a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates.

The market opportunities for certain of our product candidates may be limited to those patients who are ineligible for or have failed prior treatments and may be small, and our projections regarding the size of the addressable market may be incorrect.

Cancer therapies are sometimes characterized as first line, second line or third line, and the FDA often approves new therapies initially only for third line use. When blood cancers are detected they are treated with first line of therapy with the intention of curing the cancer. This generally consists of chemotherapy, radiation, antibody drugs, tumor targeted small molecules, or a combination of these. In addition, sometimes a bone marrow transplantation can be added to the first line therapy after the combination chemotherapy is given. If the patient’s cancer relapses, then they are given a second line or third line therapy, which can consist of more chemotherapy, radiation, antibody drugs, tumor targeted small molecules, or a combination of these, or bone marrow transplant. Generally, the higher the line of therapy, the lower the chance of a cure. With third or higher line, the goal of the therapy in the treatment of lymphoma and myeloma is to control the growth of the tumor and extend the life of the patient, as a cure is unlikely to happen. Patients are generally referred to clinical trials in these situations.

We are initially developing AUTO1 as second line therapy for patients with ALL who are considered at high risk for relapse and as third line therapy for other patients with ALL, AUTO2 as a fourth line therapy for multiple myeloma, AUTO3 as a third line therapy for DLBCL and AUTO4 as a second line therapy for TRBC1-positive T-cell lymphoma patients. If AUTO2 or AUTO3 are approved as a fourth line and third line therapy in their respective indications, we would expect to initiate a trial to potentially position either or both of the products to an earlier line of therapy, such as third line and second line, respectively. Similarly, a clinical trial with AUTO4 may be initiated to position it as a consolidation therapy after first line chemotherapy in T-cell lymphoma, but there is no guarantee that any of our product candidates, even if approved, would be approved for an earlier line of therapy. In addition, we may have to conduct additional large randomized clinical trials prior to gaining approval for the earlier line of therapy.

Our projections of both the number of people who have the cancers we are targeting, as well as the size of the patient population subset of people with these cancers in a position to receive first,

second, third and fourth line therapy and who have the potential to benefit from treatment with our product candidates, are based on our beliefs and estimates. These estimates have been derived from a variety of sources, including scientific literature, surveys of clinics, patient foundations, or market research and may prove to be incorrect. Further, new studies may change the estimated incidence or prevalence of these cancers. The number of patients may turn out to be fewer than expected. Additionally, the potentially addressable patient population for our product candidates may be limited or may not be amenable to treatment with our product candidates. For instance, in our planned clinical trials for AUTO4 we expect to initially target a small patient population that suffers from peripheral T-cell lymphoma, a rare and heterogeneous form of NHL. Even if we obtain significant market share for our product candidates, because the potential target populations are small, we may never achieve significant revenues without obtaining regulatory approval for additional indications or as part of earlier lines of therapy.

In clinical trials conducted by other companies involving CAR T cells, the most prominent acute toxicities included symptoms thought to be associated with cytokine release syndrome, or CRS, such as fever, low blood pressure and kidney dysfunction. Some patients also experienced toxicity of the central nervous system, or neurotoxicity, such as confusion, tremor, cranial nerve dysfunction, seizures and speech impairment. Adverse events with the worst grades and attributed to CAR T cells were severe and life threatening in some patients. The life threatening events were related to kidney dysfunction and neurotoxicity. Severe and life threatening toxicities occurred mostly in the first two weeks after cell infusion and generally resolved within three weeks, but several patients died in clinical trials involving CAR T cells developed by other companies and academic institutions. In initial clinical trials of AUTO1, we have observed Grade 1 and Grade 2 CRS, but no Grade 3 or higher CRS. We have also observed severe neurotoxicity in the trials. There can be no assurance that patients in future trials of AUTO1 or any of our other product candidates will not experience more severe CRS or unacceptable levels of neurotoxicity.

Our clinical trials include cancer patients who are very sick and whose health is deteriorating, and we expect that additional clinical trials of our other product candidates will include similar patients with deteriorating health. It is possible that some of these patients may experience similar adverse side effects as were observed in clinical trials conducted by other companies and academic institutions involving CAR T cells, and that some patients may die during our clinical trials for various reasons, including as a result of receiving our product candidates, because the patient’s disease is too advanced, or because the patient experiences medical problems that may not be related to our product candidate. Even if the deaths are not related to our product candidate, the deaths could affect perceptions regarding the safety of our product candidate.

Patient deaths and severe side effects caused by our product candidates, or by products or product candidates of other companies that are thought to have similarities with our therapeutic candidates, could result in the delay, suspension, clinical hold or termination of clinical trials by us, the FDA, the EMA or other regulatory authorities for a number of reasons. If we elect or are required to delay, suspend or terminate any clinical trial of any product candidates that we develop, the commercial prospects of such product candidates will be harmed and our ability to generate product revenues from any of these product candidates would be delayed or eliminated. Serious adverse events observed in clinical trials could hinder or prevent market acceptance of the product candidate at issue. Any of these occurrences may harm our business, prospects, financial condition and results of operations significantly.

We may not commercialize, market, promote or sell any product candidate without obtaining marketing approval from the FDA, the EMA or other comparable regulatory authority, and we may never receive such approvals. It is impossible to predict accurately when or if any of our product candidates will prove effective or safe in humans and will receive regulatory approval. Before obtaining marketing approval from regulatory authorities for the commercial sale of any of our product candidates, we must demonstrate through lengthy, complex and expensive preclinical testing and clinical trials that our product candidates are both safe and effective for use in each target indication. Clinical testing is expensive, difficult to design and implement, can take many years to complete and is uncertain as to outcome. A failure of one or more clinical trials can occur at any stage of testing.

We may experience numerous unforeseen events prior to, during, or as a result of, clinical trials that could delay or prevent our ability to receive marketing approval or commercialize any of our product candidates, including:

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the FDA, the EMA or other comparable regulatory authority may disagree as to the number, design or implementation of our clinical trials, or may not interpret the results from clinical trials as we do;

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regulators or institutional review boards may not authorize us or our investigators to commence a clinical trial or conduct a clinical trial at a prospective trial site;

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we may not reach agreement on acceptable terms with prospective clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different clinical trial sites;

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clinical trials of our product candidates may produce negative or inconclusive results;

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we may decide, or regulators may require us, to conduct additional clinical trials or abandon product development programs;

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the number of patients required for clinical trials of our product candidates may be larger than we anticipate, enrollment in these clinical trials may be slower than we anticipate, participants may drop out of these clinical trials at a higher rate than we anticipate or we may fail to recruit suitable patients to participate in a trial;

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our third-party contractors may fail to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all;

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regulators may issue a clinical hold, or regulators or institutional review boards may require that we or our investigators suspend or terminate clinical research for various reasons, including noncompliance with regulatory requirements or a finding that the participants are being exposed to unacceptable health risks;

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the cost of clinical trials of our product candidates may be greater than we anticipate;

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the FDA, the EMA or other comparable regulatory authorities may fail to approve our manufacturing processes or facilities;

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the supply or quality of our product candidates or other materials necessary to conduct clinical trials of our product candidates may be insufficient or inadequate;

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our product candidates may have undesirable side effects or other unexpected characteristics, particularly given their novel, first-in-human application, such as cytokine-induced toxicity and

T-cell aplasia, causing us or our investigators, regulators or institutional review boards to suspend or terminate the clinical trials; and

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the approval policies or regulations of the FDA, the EMA or other comparable regulatory authorities may significantly change in a manner rendering our clinical data insufficient for approval.

To the extent that the results of the trials are not satisfactory for the FDA, the EMA or regulatory authorities in other countries or jurisdiction to approve our BLA, Marketing Approval Application, or MAA, or other comparable application, the commercialization of our product candidates may be significantly delayed, or we may be required to expend significant additional resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates.

Our manufacturing and commercialization strategy is based on establishing a fully integrated vein-to-vein product delivery cycle. Over time, we expect to establish regional or zonal manufacturing hubs to service major markets to meet projected needs for commercial sale quantities. However, we do not currently own any facility that may be used as our clinical-scale manufacturing and processing facility and rely on the use of manufacturing suites on-site at Royal Free Hospital’s Centre for Cell, Gene and Tissue Therapeutics and King’s College London Vector Lab, where our employees currently perform or supervise viral vector manufacturing and cell processing for our product candidates.

We expect to expand our cell manufacturing capacity in the second quarter of 2018 by taking occupancy of a specialized manufacturing suite at the Cell and Gene Therapy Catapult manufacturing center in Stevenage, United Kingdom. Our long-term plan is to establish additional manufacturing sites in the United States and in Europe as needed. The implementation of this plan is subject to many risks. For example, the establishment of a cell-therapy manufacturing facility is a complex endeavor requiring knowledgeable individuals. Creating an internal manufacturing infrastructure will rely upon finding personnel with an appropriate background and training to staff and operate the facility. Should we be unable to find these individuals, we may need to rely on external contractors or train additional personnel to fill the needed roles. There are a small number of individuals with experience in cell therapy and the competition for these individuals is high.

We expect that the establishment of our own commercial cell manufacturing facilities will provide us with enhanced control of material supply for both clinical trials and the commercial market, enable the more rapid implementation of process changes, and allow for better long-term cost margins. However, we have no experience as a company in designing and operating a commercial manufacturing facility and may never be successful in developing our own manufacturing facility or capability. We may establish additional manufacturing sites as we expand our commercial footprint to multiple geographies, which may lead to regulatory delays or prove costly. Even if we are successful, our manufacturing operations could be affected by cost-overruns, unexpected delays, equipment failures, labor shortages, natural disasters, power failures and numerous other factors, or we may not be successful in establishing sufficient capacity to produce our product candidates in sufficient quantities to meet the requirements for the potential launch or to meet potential future demand, all of which could prevent us from realizing the intended benefits of our manufacturing strategy and have a material adverse effect on our business.

We may not be successful in achieving cost of goods at commercial scale that provide for an attractive margin.

We believe that our current, fully enclosed manufacturing processes are fit for commercial scale and we anticipate they will enable commercial supply at an economical cost. However, we have not yet established manufacturing capacity at commercial scale and may underestimate the cost and time required to do so, or overestimate cost reductions from economies of scale that can be realized with our manufacturing processes. We may ultimately be unable to manage the cost of goods for our product candidates to levels that will allow for a margin in line with our expectations and return on investment if and when those product candidates are commercialized.

We have developed a process for manufacturing programmed T cells in a fully enclosed system designed to minimize the risk of contamination, and we have improved the viral transduction process to help eliminate processing inconsistencies. We believe that our current processes are suitable for commercialization. While we have established a process which we believe is scalable for commercial production, each manufacturing process must be validated through the performance of process validation runs to guarantee that the facility, personnel, equipment, and process work as designed. We have not yet manufactured or processed our product candidates on a commercial scale and may not be able to do so for any of our product candidates.

We, like other manufacturers of biologic products, may encounter difficulties in production, particularly in scaling up or out, validating the production process, and assuring high reliability of the manufacturing process. These problems include delays or break-downs in logistics and shipping, difficulties with production costs and yields, quality control, and product testing, operator error, lack of availability of qualified personnel, as well as failure to comply with strictly enforced federal, state and foreign regulations.

Furthermore, if microbial, viral or other contaminations are discovered in our supply of product candidates or in the manufacturing facilities, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination. We cannot assure you that any of these or other issues relating to the manufacture of our product candidates will not occur in the future. Any delay or interruption in the supply of clinical trial supplies could delay the completion of clinical trials, increase the costs associated with maintaining clinical trial programs and, depending upon the period of delay, require us to begin new clinical trials at additional expense or terminate clinical trials completely.

The manufacture and delivery of programmed T cell therapies to patients involves complex, integrated processes, including harvesting T cells from patients, programming the T cells ex vivo, multiplying the T cells to obtain the desired dose, and ultimately infusing the T cells back into a patient’s body. As a result of the complexities, the cost to manufacture biologics in general, and our programmed T cell product candidates in particular, is generally higher than traditional small molecule chemical compounds, and the manufacturing process is less reliable and is more difficult and costly to reproduce. In addition, our manufacturing process will be susceptible to product loss or failure due to logistical issues associated with the collection of white blood cells from the patient, shipping such patient material to the manufacturing site, storing and processing such patient material, shipping the patient material with the programmed T cells back to the patient, and infusing the patient with the final

product. Other manufacturing issues include the differences in patient starting materials, inconsistency in cell growth, variability in product characteristics, interruptions in the manufacturing process, equipment or reagent failure, improper installation or operation of equipment, and vendor or operator error. Even minor deviations from normal manufacturing processes could result in reduced production yields, product defects, and other supply disruptions. If we lose, destroy or otherwise impair the patient materials at any point in the vein-to-vein supply chain, the manufacturing process for that patient will need to be restarted and the resulting delay may adversely affect that patient’s outcome due to the risk of disease progression. In addition, because our product candidates are manufactured for each particular patient, we will be required to maintain a chain of identity with respect to materials as they move from the patient to the manufacturing facility, through the manufacturing process, and back to the patient. Maintaining such a chain of identity is difficult and complex, and failure to do so could result in adverse patient outcomes, loss of product, or regulatory action including withdrawal of our products from the market. Further, as product candidates are developed through preclinical to late stage clinical trials towards approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods, are altered along the way in an effort to optimize processes and results. Such changes carry the risk that they will not achieve these intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials.

Our manufacturing facilities also require commissioning and validation activities to demonstrate that they operate as designed, and are subject to government inspections by the FDA, the EMA and other comparable regulatory authorities. If we are unable to reliably produce products to specifications acceptable to the regulatory authorities, we may not obtain or maintain the approvals we need to manufacture our products. Further, our facilities may fail to pass government inspections prior to or after the commercial launch of our product candidates, which would cause significant delays and additional costs required to remediate any deficiencies identified by the regulatory authorities. Any of these challenges could delay completion of clinical trials, require bridging clinical trials or the repetition of one or more clinical trials, increase clinical trial costs, delay approval of our product candidate, impair commercialization efforts, increase our cost of goods, and have an adverse effect on our business, financial condition, results of operations and growth prospects.

Prior treatments can alter the cancer and negatively impact chances for achieving clinical activity with our programmed T cells.

Patients with hematological cancers receive highly toxic lympho-depleting chemotherapy as their initial treatments that can impact the viability of the T cells collected from the patient and can contribute to highly variable responses to programmed T cell therapies. Patients could also have received prior therapies that target the same target antigen on the cancer cells as our intended programmed T cell product candidate and thereby lead to a selection of cancer cells with low or no expression of the target. As a result, our programmed T cell product candidates may not recognize the cancer cell and may fail to achieve clinical activity. Both of our most advanced product candidates, AUTO2 and AUTO3, may face this challenge. For example, multiple myeloma patients could have received a BCMA-targeting antibody drug conjugate (BCMA-ADC) (GSK 2857916), BCMA targeting T cell engagers like AMG-420 (Amgen) and EM-901 (Celgene), BCMA targeting CAR-T approaches like bb2121 (bluebird bio), or similar products or product candidates prior to receiving AUTO2; pediatric ALL patients could have received blinatumomab or Kymriah, or a CD19 ADC, or a CD22 targeting CAR T, or CD22 ADC, like inotuzomab, or similar products or product candidates prior to receiving AUTO3; and DLBCL patients could have received Yescarta, Kymriah, JCAR-17, inotuzomab, CD22 targeting CAR or blinatumomab, or similar products or product candidates prior to receiving AUTO3. If any of our product candidates do not achieve a sufficient level of clinical activity, we may discontinue the development of that product candidate, which could have an adverse effect on the value of our ADSs.

We may expend our limited resources to pursue a particular product candidate or indication and fail to capitalize on product candidates or indications that may be more profitable or have a greater likelihood of success.

Because we have limited financial and management resources, we focus on research programs and product candidates that we identify for specific indications. As a result, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater commercial potential. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs and product candidates for specific indications may not yield any commercially viable products. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such product candidate.

We plan to seek, but may fail to obtain “breakthrough therapy” designation from the FDA and “PRIME” designation from the EMA, and may pursue accelerated approval for some or all of our programmed T cell product candidates, which may prolong the regulatory approval process for our product candidates.

In 2012, the FDA established a breakthrough therapy designation which is intended to expedite the development and review of product candidates that treat serious or life-threatening diseases when “preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development.” The designation of a product candidate as a breakthrough therapy provides potential benefits that include more frequent meetings with FDA to discuss the development plan for the product candidate and ensure collection of appropriate data needed to support approval; more frequent written correspondence from the FDA about such things as the design of the proposed clinical trials and use of biomarkers; guidance on an efficient drug development program, beginning as early as Phase 1; organizational commitment involving senior managers; and eligibility for rolling review and priority review. The frequency of communication from the FDA is intended to allow for questions and issues to be resolved quickly, which often leads to earlier drug approval and access by patients. Similarly, the EMA has established the PRIME scheme to expedite the development and review of product candidates that show a potential to address to a significant extent an unmet medical need, based on early clinical data.

We intend to seek breakthrough therapy designation or PRIME designation for some or all of our programmed T cell product candidates that may qualify. There is no assurance that we will obtain breakthrough therapy designation, or that we will obtain access to PRIME, for any of our product candidates. Breakthrough therapy designation and PRIME eligibility do not change the standards for product approval, and there is no assurance that such designation or eligibility will result in expedited review or approval. Additionally, breakthrough therapy designation and access to PRIME can each be revoked if the criteria for eligibility cease to be met as clinical data emerges.

We may also seek accelerated approval for certain of our product candidates. Under the FDA’s fast track and accelerated approval programs, the FDA may approve a drug or biologic for a serious or life-threatening illness that provides meaningful therapeutic benefit to patients over existing treatments based upon a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. For

drugs granted accelerated approval, post-marketing confirmatory trials have been required to describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. These confirmatory trials must be completed with due diligence. Moreover, the FDA may withdraw approval of our indication approved under the accelerated approval pathway if, for example:

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the trial or trials required to verify the predicted clinical benefit of our product candidates fail to verify such benefit or do not demonstrate sufficient clinical benefit to justify the risks associated with the drug;

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other evidence demonstrates that our product candidates are not shown to be safe or effective under the conditions of use;

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we fail to conduct any required post-approval trial of our product candidates with due diligence; or

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we disseminate false or misleading promotional materials relating to the relevant product candidate.

Risks Related to our Business Operations

As a company based outside of the United States, our business is subject to economic, political, regulatory and other risks associated with international operations.

As a company based in the United Kingdom, our business is subject to risks associated with conducting business outside of the United States. Many of our suppliers and clinical trial relationships are located outside the United States. Accordingly, our future results could be harmed by a variety of factors, including:

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economic weakness, including inflation, or political instability in particular non-U.S. economies and markets;

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differing and changing regulatory requirements for product approvals;

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differing jurisdictions could present different issues for securing, maintaining or obtaining freedom to operate in such jurisdictions;

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potentially reduced protection for intellectual property rights;

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difficulties in compliance with different, complex and changing laws, regulations and court systems of multiple jurisdictions and compliance with a wide variety of foreign laws, treaties and regulations;

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changes in non-U.S. regulations and customs, tariffs and trade barriers;

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changes in non-U.S. currency exchange rates of the pound sterling, U.S. dollar, euro and currency controls;

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changes in a specific country’s or region’s political or economic environment, including the implications of the recent decision of the eligible members of the U.K. electorate for the United Kingdom to withdraw from the European Union;

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trade protection measures, import or export licensing requirements or other restrictive actions by governments;

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differing reimbursement regimes and price controls in certain non-U.S. markets;

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negative consequences from changes in tax laws;

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compliance with tax, employment, immigration and labor laws for employees living or traveling abroad, including, for example, the variable tax treatment in different jurisdictions of options granted under our share option schemes or equity incentive plans;

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workforce uncertainty in countries where labor unrest is more common than in the United States;

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litigation or administrative actions resulting from claims against us by current or former employees or consultants individually or as part of class actions, including claims of wrongful terminations, discrimination, misclassification or other violations of labor law or other alleged conduct;

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difficulties associated with staffing and managing international operations, including differing labor relations;

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production shortages resulting from any events affecting raw material supply or manufacturing capabilities abroad; and

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business interruptions resulting from geo-political actions, including war and terrorism, or natural disasters including earthquakes, typhoons, floods and fires.

Exchange rate fluctuations may materially affect our results of operations and financial condition.

Our functional currency and that of our subsidiaries is the pound sterling and our reporting currency is the U.S. dollar. Given that our functional currency and that of our subsidiaries is the pound sterling, but our reporting currency is the U.S. dollar, fluctuations in currency exchange rates between the U.S. dollar and the pound sterling could materially and adversely affect our business. There may be instances in which costs and revenue will not be matched with respect to currency denomination. Currently, we do not have any exchange rate hedging arrangements in place.

Additionally, although we are based in the United Kingdom, we source research and development, manufacturing, consulting and other services from the United States and other countries. Further, potential future revenue may be derived from the United States, countries within the euro zone, and various other countries around the world. As a result, our business and the price of our ADSs may be affected by fluctuations in foreign exchange rates not only between the pound sterling and the U.S. dollar, but also the euro and other currencies, which may have a significant impact on our results of operations and cash flows from period to period. As a result, to the extent we continue our expansion on a global basis, we expect that increasing portions of our revenue, cost of revenue, assets and liabilities will be subject to fluctuations in currency valuations. We may experience economic loss and a negative impact on earnings or net assets solely as a result of currency exchange rate fluctuations.

We will need to grow the size of our organization, and we may experience difficulties in managing this growth.

As of April 15, 2018, we had 126 employees, 122 of whom are full-time. As our development and commercialization plans and strategies develop, and as we transition into operating as a public company, we expect to need additional managerial, operational, financial and other personnel, including personnel to support our product development and planned future commercialization efforts. Future growth will impose significant added responsibilities on members of management, including:

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identifying, recruiting, integrating, maintaining and motivating additional employees;

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managing our internal development efforts effectively, including the clinical, FDA and EMA review processes for our product candidates; and

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improving our operational, financial and management controls, reporting systems and procedures.

There are a small number of individuals with experience in cell therapy and the competition for these individuals is high. Our future financial performance and our ability to commercialize our product candidates will depend, in part, on our ability to effectively manage any future growth, and our management may also have to divert a disproportionate amount of its attention away from day-to-day activities in order to devote a substantial amount of time to managing these growth activities.

If we are not able to effectively expand our organization by hiring new employees, we may not be able to successfully implement the tasks necessary to further develop and commercialize our product candidates and, accordingly, may not achieve our research, development and commercialization goals.

In addition to expanding our organization, we are increasing the size of our facilities and building out our development and manufacturing capabilities, which requires significant capital expenditures. If these capital expenditures are higher than expected, it may adversely affect our financial condition and capital resources. In addition, if the increase in the size of our facilities is delayed, it may limit our ability to rapidly expand the size of our organization in order to meet our corporate goals.

Our future success depends on our ability to retain key members of senior management and to attract, retain and motivate qualified personnel.

Our ability to compete in the highly competitive biopharmaceutical industry depends upon our ability to attract and retain highly qualified management, research and development, clinical, financial and business development personnel. We are highly dependent on our management, scientific and medical personnel, including Dr. Christian Itin, our Chief Executive Officer and Dr. Martin Pulé, our scientific founder, Senior Vice President and Chief Scientific Officer. Although we intend to enter into new employment arrangements with the members of our senior management that will be effective upon the closing of this offering, each of them may currently terminate their employment with us at any time and will continue to be able to do so after the closing of this offering. We do not maintain ‘‘key person’’ insurance for any of our employees.

Recruiting and retaining qualified scientific and clinical personnel and, if we progress the development of any of our product candidates, commercialization, manufacturing and sales and marketing personnel, will be critical to our success. The loss of the services of members of our senior management or other key employees could impede the achievement of our research, development and commercialization objectives and seriously harm our ability to successfully implement our business strategy. Furthermore, replacing members of our senior management and key employees may be difficult and may take an extended period of time because of the limited number of individuals in our industry with the breadth of skills and experience required to successfully develop, gain regulatory approval of and commercialize our product candidates. Our success also depends on our ability to continue to attract, retain and motivate highly skilled junior, mid-level and senior managers, as well as junior, mid-level and senior scientific and medical personnel. Competition to hire from this limited candidate pool is intense, and we may be unable to hire, train, retain or motivate these key personnel on acceptable terms given the competition among numerous pharmaceutical and biotechnology companies for similar personnel. We also experience competition for the hiring of scientific and clinical personnel from universities and research institutions. In addition, we rely on consultants and advisors, including scientific and clinical advisors, to assist us in formulating our research and development and commercialization strategy. Our consultants and advisors may have commitments under consulting or advisory contracts with other entities that may limit their availability to us. If we are unable to continue to attract and retain high-quality personnel, our ability to pursue our growth strategy will be limited.

If we engage in future acquisitions or strategic collaborations, this may increase our capital requirements, dilute our shareholders, cause us to incur debt or assume contingent liabilities and subject us to other risks.

From time to time, we may evaluate various acquisitions and strategic collaborations, including licensing or acquiring complementary products, intellectual property rights, technologies or businesses, as we may deem appropriate to carry out our business plan. Any potential acquisition or strategic collaboration may entail numerous risks, including:

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increased operating expenses and cash requirements;

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the assumption of additional indebtedness or contingent liabilities;

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assimilation of operations, intellectual property and products of an acquired company, including difficulties associated with integrating new personnel;

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the diversion of our management’s attention from our existing programs and initiatives in pursuing such a strategic partnership, merger or acquisition;

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retention of key employees, the loss of key personnel and uncertainties in our ability to maintain key business relationships;

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risks and uncertainties associated with the other party to such a transaction, including the prospects of that party and their existing products or product candidates and regulatory approvals; and

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our inability to generate revenue from acquired technology sufficient to meet our objectives in undertaking the acquisition or even to offset the associated acquisition and maintenance costs.

Additionally, if we undertake acquisitions, we may issue dilutive securities, assume or incur debt obligations, incur large one-time expenses and acquire intangible assets that could result in significant future amortization expenses. Moreover, we may not be able to locate suitable acquisition opportunities and this inability could impair our ability to grow or obtain access to technology or products that may be important to the development of our business.

Our internal computer systems, or those of our future collaborators or other contractors or consultants, may fail or suffer security breaches, which could result in a significant disruption of our product development programs and our ability to operate our business effectively.

Our internal computer systems and those of our current and any future collaborators and other contractors or consultants are vulnerable to damage from computer viruses, unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. While we have not experienced any significant system failure, accident or security breach to date, if such an event were to occur and cause interruptions in our operations, it could result in a disruption of our development programs and our business operations, whether due to a loss of our trade secrets or other proprietary information or other similar disruptions. For example, the loss of clinical trial data from completed or future clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. To the extent that any disruption or security breach were to result in a loss of, or damage to, our data or applications, or inappropriate disclosure of confidential or proprietary information, we could incur liability, our competitive position could be harmed and the further development and commercialization of our product candidates could be delayed.

Business disruptions could seriously harm our future revenue and financial condition and increase our costs and expenses.

Our operations, and those of our vendors and suppliers, could be subject to earthquakes, power shortages, telecommunications failures, water shortages, floods, hurricanes, typhoons, fires, extreme

weather conditions, medical epidemics and other natural or man-made disasters or business interruptions, for which we are predominantly self-insured. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses. We currently rely on third-party suppliers to produce and process our product candidates on a patient-by-patient basis. Our ability to obtain clinical supplies of our product candidates could be disrupted if the operations of these suppliers are affected by a man-made or natural disaster or other business interruption.

Risks Related to Our Dependence on Third Parties

We are dependent on licensed intellectual property, and if we were to fail to comply with our obligations under our existing and any future intellectual property licenses with third parties, we could lose license rights that are important to our business and we may not be able to continue developing or commercializing our product candidates, if approved.

We are party to an exclusive intellectual property license agreement with UCLB, the technology-transfer company of University College London, which is important to our business and under which we in-license patent rights related to 23 patent families and other intellectual property related to our business. We expect to enter into additional license agreements in the future. Our existing license agreement with UCLB imposes, and we expect that future license agreements will impose, various due diligence, milestone payment, royalty, insurance and other obligations on us. Any uncured, material breach under the UCLB license agreement could result in our loss of rights to practice the patent rights and other intellectual property licensed to us, and could compromise our development and commercialization efforts for our current or any future product candidates.

Licensing of intellectual property is of critical importance to our business and involves complex legal, business and scientific issues. For example, under our license agreement with UCLB, our exclusive license under certain of the patent rights is subject to specified exclusions. Our right to enforce any patents that may issue from such patent rights similarly excludes enforcing them in such excluded fields, and obligates us to coordinate our enforcement efforts with a licensee, if any, with rights in that excluded field. If a third party-licensee has the right to enforce those patents in their field, it could put a patent that may issue from this family at risk of being invalidated or construed narrowly, in which case we would no longer have the benefit of the patents for our own exclusivity. Disputes may arise between us and our licensors regarding intellectual property subject to a license agreement, including disputes regarding:

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the scope of rights granted under the license agreement and other interpretation-related issues;

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whether and the extent to which our technology and processes infringe on intellectual property of the licensor that is not subject to the licensing agreement;

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our rights to third parties;

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our diligence obligations with respect to the use of the licensed technology in relation to our development and commercialization of our product candidates, and what activities satisfy those diligence obligations;

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the ownership of inventions and know-how resulting from the joint creation or use of intellectual property by our licensors and us;

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our right to transfer or assign the license; and

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the effects of termination.

If disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangement on acceptable terms, we may be unable to successfully develop and

commercialize the affected product candidates. See the section of this prospectus titled “Business—Our License Agreement with UCL Business plc” for a more detailed description of our license agreement with UCLB, as well as our rights and obligations under the agreement.

We rely, and expect to continue to rely, on third parties to conduct the preclinical and clinical trials for our product candidates, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such trials or failing to comply with applicable regulatory requirements.

We depend and will continue to depend upon independent investigators and collaborators, such as universities, medical institutions, and strategic partners to conduct our preclinical and clinical trials. Agreements with such third parties might terminate for a variety of reasons, including a failure to perform by the third parties. If we need to enter into alternative arrangements, our product development activities would be delayed.

Our reliance on these third parties for research and development activities will reduce our control over these activities but will not relieve us of our responsibilities. For example, we will remain responsible for ensuring that each of our clinical trials is conducted in accordance with the general investigational plan and protocols for the trial. Moreover, the FDA requires us to comply with regulatory standards, commonly referred to as good laboratory practices, or GLP, and good clinical practices, or GCP, for conducting, recording and reporting the results of preclinical and clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. Similar regulatory requirements apply outside the United States, including the International Council for Harmonisation of Technical Requirements for the Registration of Pharmaceuticals for Human Use, or ICH. We are also required to register certain ongoing clinical trials and post the results of certain completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within specified timeframes. Failure to do so by us or third parties can result in FDA refusal to approve applications based on the clinical data, enforcement actions, adverse publicity and civil and criminal sanctions.

Furthermore, these third parties may also have relationships with other entities, some of which may be our competitors. If these third parties do not successfully carry out their contractual duties, meet expected deadlines or conduct our clinical trials in accordance with regulatory requirements or our stated protocols, we will not be able to obtain, or may be delayed in obtaining, marketing approvals for our product candidates and will not be able to, or may be delayed in our efforts to, successfully commercialize our product candidates.

In addition, principal investigators for our clinical trials may serve as scientific advisors or consultants to us from time to time and may receive cash or equity compensation in connection with such services. If these relationships and any related compensation result in perceived or actual conflicts of interest, or the FDA concludes that the financial relationship may have affected the interpretation of the trial, the integrity of the data generated at the applicable clinical trial site may be questioned and the utility of the clinical trial itself may be jeopardized, which could result in the delay or rejection by the FDA. Any such delay or rejection could prevent us from commercializing our clinical-stage product candidates or any future product candidates.

Cell-based therapies rely on the availability of reagents, specialized equipment, and other specialty materials, which may not be available to us on acceptable terms or at all. For some of these reagents, equipment, and materials, we rely or may rely on sole source vendors or a limited number of vendors, which could impair our ability to manufacture and supply our products.

Manufacturing our product candidates will require many reagents, which are substances used in our manufacturing processes to bring about chemical or biological reactions, and other specialty materials and equipment, some of which are manufactured or supplied by small companies with limited resources and experience to support commercial biologics production. We currently depend on a limited number of vendors for access to facilities and supply of certain materials and equipment used in the manufacture of our product candidates. For example, we currently use facilities and equipment at Royal Free Hospital and King’s College London for vector and cell manufacturing. In addition, we purchase equipment and reagents critical for the manufacture of our product candidates from Miltenyi GmbH and other suppliers on a purchase order basis. Some of our suppliers may not have the capacity to support commercial products manufactured under cGMP by biopharmaceutical firms or may otherwise be ill-equipped to support our needs. We also do not have supply contracts with many of these suppliers, and may not be able to obtain supply contracts with them on acceptable terms or at all. Accordingly, we may not be able to obtain key materials and equipment to support clinical or commercial manufacturing.

For some of these reagents, equipment, and materials, we rely and may in the future rely on sole source vendors or a limited number of vendors. An inability to continue to source product from any of these suppliers, which could be due to regulatory actions or requirements affecting the supplier, adverse financial or other strategic developments experienced by a supplier, labor disputes or shortages, unexpected demands, or quality issues, could adversely affect our ability to satisfy demand for our product candidates, which could adversely and materially affect our product sales and operating results or our ability to conduct clinical trials, either of which could significantly harm our business.

As we continue to develop and scale our manufacturing process, we may need to obtain rights to and supplies of certain materials and equipment to be used as part of that process. We may not be able to obtain rights to such materials on commercially reasonable terms, or at all, and if we are unable to alter our process in a commercially viable manner to avoid the use of such materials or find a suitable substitute, it would have a material adverse effect on our business.

Risks Related to Regulatory Approval of Our Product Candidates and

Other Legal Compliance Matters

Even if we complete the necessary preclinical studies and clinical trials, the regulatory approval process is expensive, time-consuming and uncertain and may prevent us from obtaining approvals for the commercialization of some or all of our product candidates. As a result, we cannot predict when or if, and in which territories, we will obtain marketing approval to commercialize a product candidate.

Our product candidates and the activities associated with their development and commercialization, including their design, research, testing, manufacture, safety, efficacy, quality control, recordkeeping, labeling, packaging, storage, approval, advertising, promotion, sale, distribution, import, export, and reporting of safety and other post-market information, are subject to comprehensive regulation by the FDA, the EMA and other comparable regulatory authorities in other jurisdictions. Failure to obtain marketing approval for a product candidate will prevent us from commercializing the product candidate. We have not received approval to market any of our product candidates from regulatory authorities in any jurisdiction. We have only limited experience in filing and

supporting the applications necessary to gain marketing approvals and may rely on third-party contract research organizations, or CROs, to assist us in this process. Securing marketing approval requires the submission of extensive preclinical and clinical data and supporting information to regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing marketing approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities by, the regulatory authorities. Our product candidates may not be effective, may be only moderately effective or may prove to have undesirable or unintended side effects, toxicities or other characteristics that may preclude our obtaining marketing approval or prevent or limit commercial use. If any of our product candidates receives marketing approval, the accompanying label may limit its approved use, which could limit sales of the product.

The process of obtaining marketing approvals, both in the United States and abroad, is expensive and may take many years, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Securing marketing approval requires the submission of extensive preclinical and clinical data and supporting information to regulatory authorities for each therapeutic indication to establish the product candidate’s safety and efficacy. Securing marketing approval also requires the submission of information about the product manufacturing process to, and inspection of manufacturing facilities by, the regulatory authorities. The FDA, the EMA or other regulatory authorities may determine that our product candidates are not safe and effective, only moderately effective or have undesirable or unintended side effects, toxicities or other characteristics that preclude our obtaining marketing approval or prevent or limit commercial use. Any marketing approval we ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable.

In addition, changes in marketing approval policies during the development period, changes in or the enactment of additional statutes or regulations, or changes in regulatory review for each submitted product application, may cause delays in the approval or rejection of an application. Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data is insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent marketing approval of a product candidate. Any marketing approval we ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable. Any marketing approval we ultimately obtain may be limited or subject to restrictions or post-approval commitments that render the approved product not commercially viable.

If we experience delays in obtaining approval or if we fail to obtain approval of our product candidates, the commercial prospects for our product candidates may be harmed and our ability to generate revenues will be impaired.

In order to market and sell our products in the European Union and any other jurisdictions, we must obtain separate marketing approvals and comply with numerous and varying regulatory requirements. The approval procedure varies among countries and can involve additional testing. The time required to obtain approval may differ substantially from that required to obtain approval from the FDA. The regulatory approval process outside the United States generally includes all of the risks associated with obtaining approval from the FDA. In addition, in many countries outside the United States, it is required that the product be approved for reimbursement before the product can be approved for sale in that country. We may not obtain approvals from regulatory authorities outside the United States on a timely basis, if at all. Approval by the FDA does not ensure approval by regulatory authorities in other countries or jurisdictions, and approval by one regulatory authority outside the

United States does not ensure approval by regulatory authorities in other countries or jurisdictions or by the FDA. However, failure to obtain approval in one jurisdiction may impact our ability to obtain approval elsewhere. We may not be able to file for marketing approvals and may not receive necessary approvals to commercialize our products in any market.

Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not mean that we will be successful in obtaining regulatory approval of our product candidates in other jurisdictions.

Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction, but a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA grants marketing approval of a product candidate, comparable regulatory authorities in other jurisdictions must also approve the manufacturing, marketing and promotion of the product candidate in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from those in the United States, including additional preclinical studies or clinical trials as clinical studies conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our products is also subject to approval.

Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. If we fail to comply with the regulatory requirements in international markets and/or to receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed.

The expected withdrawal of the United Kingdom from the European Union, commonly referred to as “Brexit,” may adversely impact our ability to obtain regulatory approvals of our product candidates in the European Union, result in restrictions or imposition of taxes and duties for importing our product candidates into the European Union, and may require us to incur additional expenses in order to develop, manufacture and commercialize our product candidates in the European Union.

In June 2016, a majority of the eligible members of the electorate in the United Kingdom voted to withdraw from the European Union in a national referendum, commonly referred to as ‘‘Brexit.’’ The withdrawal of the United Kingdom from the European Union will take effect either on the effective date of the withdrawal agreement or, in the absence of agreement, two years after the United Kingdom provides a notice of withdrawal pursuant to Article 50 of the Treaty on European Union, unless the European Council, in agreement with the United Kingdom, unanimously decides to extend this period. On March 29, 2017, the United Kingdom formally delivered the notice of withdrawal to the European Union. It appears likely that this withdrawal will involve a process of lengthy negotiations between the United Kingdom and EU Member States to determine the future terms of the United Kingdom’s relationship with the European Union. Since a significant proportion of the regulatory framework in the United Kingdom applicable to our business and our product candidates is derived from EU directives and regulations, the withdrawal could materially impact the regulatory regime with respect to the development, manufacture, importation, approval and commercialization of our product candidates in the United Kingdom or the European Union. Any delay in obtaining, or an inability to obtain, any marketing approvals, as a result of Brexit or otherwise, would prevent us from commercializing our product candidates in the United Kingdom or the European Union and restrict our ability to generate revenue and achieve and sustain profitability. In addition, we may be required to pay taxes or duties or

be subjected to other hurdles in connection with the importation of our product candidates into the European Union, or we may incur expenses in establishing a manufacturing facility in the European Union in order to circumvent such hurdles. If any of these outcomes occur, we may be forced to restrict or delay efforts to seek regulatory approval in the United Kingdom or the European Union for our product candidates, or incur significant additional expenses to operate our business, which could significantly and materially harm or delay our ability to generate revenues or achieve profitability of our business.

Even if we obtain marketing approvals for our product candidates, the terms of approvals and ongoing regulation of our products may limit how we manufacture and market our products and compliance with such requirements may involve substantial resources, which could materially impair our ability to generate revenue.

Even if marketing approval of a product candidate is granted, an approved product and its manufacturer and marketer are subject to ongoing review and extensive regulatory requirements for manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage, advertising, promotion, sampling, and recordkeeping, including the potential requirements to implement a risk evaluation and mitigation strategy, or REMS, program or to conduct costly post-marketing studies or clinical trials and surveillance to monitor the safety or efficacy of the product. We must also comply with requirements concerning advertising and promotion for any of our product candidates for which we obtain marketing approval. Promotional communications with respect to prescription drugs are subject to a variety of legal and regulatory restrictions and must be consistent with the information in the product’s approved labeling. Thus, we will not be able to promote any products we develop for indications or uses for which they are not approved. In addition, manufacturers of approved products and those manufacturers’ facilities are required to comply with extensive regulatory requirements of the FDA, the EMA and other regulatory authorities, including ensuring that quality control and manufacturing procedures conform to cGMP and other comparable regulations and standards, which include requirements relating to quality control and quality assurance as well as the corresponding maintenance of records and documentation and reporting requirements. We or our suppliers could be subject to periodic unannounced inspections by the FDA, the EMA, or other regulatory authorities to monitor and ensure compliance with cGMP.

Accordingly, assuming we receive marketing approval for one or more of our product candidates, we and suppliers will continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production, product surveillance and quality control. If we are not able to comply with post-approval regulatory requirements, we could have the marketing approvals for our products withdrawn by regulatory authorities and our ability to market any future products could be limited, which could adversely affect our ability to achieve or sustain profitability.

Thus, the cost of compliance with post-approval regulations may have a negative effect on our operating results and financial condition.

Any product candidate for which we obtain marketing approval could be subject to post-marketing restrictions or recall or withdrawal from the market, and we may be subject to penalties if we fail to comply with regulatory requirements or if we experience unanticipated problems with our product candidates, when and if any of them are approved.

The FDA and other federal and state agencies, including the U.S. Department of Justice, or DOJ, closely regulate compliance with all requirements governing prescription drug products, including requirements pertaining to marketing and promotion of products in accordance with the provisions of the approved labeling and manufacturing of products in accordance with cGMP requirements. The FDA and DOJ impose stringent restrictions on manufacturers’ communications regarding off-label use

and if we do not market our products for their approved indications, or if other of our marketing claims are deemed false or misleading, we may be subject to enforcement action. Violations of such requirements may lead to investigations alleging violations of the Food, Drug and Cosmetic Act and other statutes, including the False Claims Act and other federal and state health care fraud and abuse laws as well as state consumer protection laws.

Our failure to comply with all regulatory requirements, and later discovery of previously unknown adverse events or other problems with our products, manufacturers or manufacturing processes, may yield various results, including:

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litigation involving patients taking our products;

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restrictions on such products, manufacturers or manufacturing processes;

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restrictions on the labeling or marketing of a product;

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restrictions on product distribution or use;

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requirements to conduct post-marketing studies or clinical trials;

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warning or untitled letters;

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withdrawal of the products from the market;

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refusal to approve pending applications or supplements to approved applications that we submit;

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recall of products;

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fines, restitution or disgorgement of profits or revenues;

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suspension or withdrawal of marketing approvals;

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suspension of any ongoing clinical trials;

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damage to relationships with any potential collaborators;

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unfavorable press coverage and damage to our reputation;

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refusal to permit the import or export of our products;

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product seizure; or

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injunctions or the imposition of civil or criminal penalties.

Non-compliance by us or any future collaborator with regulatory requirements regarding safety monitoring or pharmacovigilance, and with requirements related to the development of products for the pediatric population, can also result in significant financial penalties. Similarly, failure to comply with regulatory requirements regarding the protection of personal information can also lead to significant penalties and sanctions.

Non-compliance with EU requirements regarding safety monitoring or pharmacovigilance, and with requirements related to the development of products for the pediatric population, also can result in significant financial penalties. Similarly, failure to comply with the European Union’s requirements regarding the protection of personal information can also lead to significant penalties and sanctions.

If any of these events occurs, our ability to sell such product may be impaired, and we may incur substantial additional expense to comply with regulatory requirements, which could adversely affect our business, financial condition and results of operations.

Our employees, independent contractors, principal investigators, consultants, commercial partners and vendors may engage in misconduct or other improper activities, including non-compliance with regulatory standards and requirements.

We are exposed to the risk of employee fraud or other misconduct or failure to comply with applicable regulatory requirements. Misconduct by employees and independent contractors, such as principal investigators, consultants, commercial partners, and vendors, could include failures to comply with regulations of the FDA, the EMA and other comparable regulatory authorities, to provide accurate information to such regulators, to comply with manufacturing standards we have established, to comply with healthcare fraud and abuse laws, to report financial information or data accurately or to disclose unauthorized activities to us. In particular, sales, marketing and other business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of business activities, including, but not limited to, research, manufacturing, distribution, pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Employee and independent contractor misconduct could also involve the improper use of individually identifiable information, including, without limitation, information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation.

In addition, federal procurement laws impose substantial penalties for misconduct in connection with government contracts and require certain contractors to maintain a code of business ethics and conduct. It is not always possible to identify and deter employee and independent contractor misconduct, and any precautions we take to detect and prevent improper activities may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to be in compliance with such laws. If any such actions are instituted against us, those actions could have a significant impact on our business, including the imposition of civil, criminal and administrative penalties, damages, monetary fines, disgorgement of profits, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, National Health Service in the United Kingdom, or other government supported healthcare in other jurisdictions, contractual damages, reputational harm, diminished profits and future earnings, additional reporting or oversight obligations if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with the law and curtailment or restructuring of our operations, any of which could adversely affect our ability to operate.

Our business operations and current and future relationships with healthcare professionals, principal investigators, consultants, customers and third-party payors in the United States and elsewhere may be subject, directly or indirectly, to applicable anti-kickback, fraud and abuse, false claims, physician payment transparency, health information privacy and security and other healthcare laws and regulations, which could expose us to substantial penalties.

Healthcare providers, physicians and third-party payors in the United States and elsewhere will play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our current and future arrangements with healthcare professionals, principal investigators, consultants, customers and third-party payors may expose us to broadly applicable fraud and abuse and other healthcare laws, including, without limitation, the U.S. federal Anti-Kickback Statute and the U.S. federal False Claims Act, that may constrain the business or financial arrangements and relationships through which we sell, market and distribute any product candidates for which we obtain marketing approval. In addition, we may be subject to physician payment transparency laws and patient privacy and security regulation by the U.S. federal government and by the states and foreign jurisdictions in which we conduct our business. The applicable federal, state and foreign healthcare laws that may affect our ability to operate include the following:

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the U.S. federal Anti-Kickback Statute, which prohibits, among other things, persons from knowingly and willfully soliciting, offering, receiving or providing remuneration, directly or indirectly, in cash or in kind, to induce or reward, or in return for, either the referral of an individual for, or the purchase, lease, order or recommendation of, any good, facility, item or service, for which payment may be made, in whole or in part, under federal and state healthcare programs such as Medicare and Medicaid. The term ‘‘remuneration’’ has been broadly interpreted to include anything of value. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on the one hand and prescribers, purchasers and formulary managers on the other hand. Although there are a number of statutory exceptions and regulatory safe harbors protecting certain common activities from prosecution or other regulatory sanctions, the exceptions and safe harbors are drawn narrowly, and practices that involve remuneration that are alleged to be intended to induce prescribing, purchases or recommendations may be subject to scrutiny if they do not qualify for an exception or safe harbor. Failure to meet all of the requirements of a particular applicable statutory exception or regulatory safe harbor does not make the conduct per se illegal under the federal Anti-Kickback Statute. Instead, the legality of the arrangement will be evaluated on a case-by-case basis based on a cumulative review of all its facts and circumstances. Several courts have interpreted the statute’s intent requirement to mean that if any one purpose of an arrangement involving remuneration is to induce referrals of federal healthcare covered business, the federal Anti-Kickback Statute has been violated;

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U.S. federal civil and criminal false claims laws and civil monetary penalty laws, including the federal False Claims Act, which, among other things, impose criminal and civil penalties, including through civil whistleblower or qui tam actions, against individuals or entities for, among other things, knowingly presenting, or causing to be presented, to the federal government, including the Medicare and Medicaid programs, claims for payment that are false or fraudulent or making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government. Pharmaceutical and other healthcare companies have been prosecuted under these laws for, among other things, allegedly inflating drug prices they report to pricing services, which in turn were used by the government to set Medicare and Medicaid reimbursement rates, and for allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product. In addition, certain marketing practices, including off-label promotion, may also violate false claims laws. Further, pharmaceutical manufacturers can be held liable under the False Claims Act even when they do not submit claims directly to government payors if they are deemed to “cause” the

submission of false or fraudulent claims. Criminal prosecution is also possible for making or presenting a false, fictitious or fraudulent claim to the federal government;

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the U.S. federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which created new federal criminal statutes that prohibit knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program or obtain, by means of false or fraudulent pretenses, representations or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of whether the payor is public or private, knowingly and willfully embezzling or stealing from a health care benefit program, willfully obstructing a criminal investigation of a health care offense and knowingly and willfully falsifying, concealing or covering up by any trick or device a material fact or making any materially false statements in connection with the delivery of, or payment for, healthcare benefits, items or services relating to healthcare matters;

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HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act of 2009, or HITECH, and their respective implementing regulations, which impose obligations on “covered entities,” including certain healthcare providers, health plans, and healthcare clearinghouses, as well as their respective “business associates” that create, receive, maintain or transmit individually identifiable health information for or on behalf of a covered entity, with respect to safeguarding the privacy, security and transmission of individually identifiable health information. Additionally, HITECH also created four new tiers of civil monetary penalties, amended HIPAA to make civil and criminal penalties directly applicable to business associates, and gave state attorneys general new authority to file civil actions for damages or injunctions in federal courts to enforce the federal HIPAA laws and seek attorneys’ fees and costs associated with pursuing federal civil actions;

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the U.S. federal Food, Drug and Cosmetic Act, which prohibits, among other things, the adulteration or misbranding of drugs, biologics and medical devices;

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the U.S. federal Physician Payments Sunshine Act, created under Section 6002 of Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act, or collectively, the ACA, and its implementing regulations, created annual reporting requirements for certain manufacturers of drugs, devices, biologicals and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions), to report information related for certain payments and “transfers of value” provided to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors) and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members; and

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analogous state laws and regulations and foreign laws, such as state anti-kickback and false claims laws, which may apply to sales or marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers; state and foreign laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government or to adopt compliance programs as prescribed by state laws and regulations, or that otherwise restrict payments that may be made to healthcare providers; state and foreign laws that require drug manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures; state and local laws that require the registration of pharmaceutical sales representatives; and state and foreign laws governing the privacy and security of health information in certain circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts.

Further, the ACA, among other things, amended the intent requirement of the federal Anti-Kickback Statute and certain criminal statutes governing healthcare fraud. A person or entity no longer

needs to have actual knowledge of the statute or specific intent to violate it. In addition, the ACA provided that the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the False Claims Act.

Because of the breadth of these laws and the narrowness of their exceptions and safe harbors, it is possible that our business activities can be subject to challenge under one or more of such laws. The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform. Federal and state enforcement bodies have recently increased their scrutiny of interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry.

Efforts to ensure that our internal operations and future business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial costs. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant civil, criminal and administrative penalties, including, without limitation, damages, monetary fines, individual imprisonment, disgorgement of profits, possible exclusion from participation in Medicare, Medicaid and other federal healthcare programs, contractual damages, reputational harm, diminished profits and future earnings, additional reporting or oversight obligations if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with the law and curtailment or restructuring of our operations, any of which could adversely affect our ability to operate our business and pursue our strategy. If any of the physicians or other healthcare providers or entities with whom we expect to do business, including future collaborators, are found not to be in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from participation in government healthcare programs, which could also affect our business.

Our product candidates are subject to government price controls in certain jurisdictions that may affect our revenue.

There has been heightened governmental scrutiny in the United Kingdom, United States, European Union and other jurisdictions of pharmaceutical pricing practices in light of the rising cost of prescription drugs. In the United States, such scrutiny has resulted in several recent Congressional inquiries and proposed and enacted federal legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for products. At the federal level, Congress and the Trump administration have each indicated that it will continue to seek new legislative and/or administrative measures to control drug costs. At the state level, legislatures have increasingly enacted legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Outside of the United States, particularly in the European Union, the pricing of prescription pharmaceuticals is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take considerable time after the receipt of marketing approval for a product. To obtain coverage and reimbursement or pricing approval in some countries, we may be required to conduct a clinical trial that compares the cost-effectiveness of our product candidate to other available therapies. If reimbursement of our products is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, our business could be harmed.

Recently enacted and future legislation in the United States and other countries may affect the prices we may obtain for our product candidates and increase the difficulty and cost for us to commercialize our product candidates.

In the United States and many other countries, rising healthcare costs have been a concern for governments, patients and the health insurance sector, which resulted a number of changes to laws and regulations, and may result in further legislative and regulatory action regarding the healthcare and health insurance systems that could affect our ability to profitably sell any product candidates for which we obtain marketing approval. For a detailed discussion of healthcare reform initiatives of importance to the pharmaceutical industry, see the section titled “Business—Government Regulation and Product Approval—Healthcare Reform Efforts.”

For example, the ACA was enacted in the United States in March 2010 with the stated goals of containing healthcare costs, improving quality and expanding access to healthcare, and includes measures to change health care delivery, increase the number of individuals with insurance, ensure access to certain basic health care services, and contain the rising cost of care. Since January 2017, President Trump has signed two executive orders and other directives designed to delay, circumvent, or loosen certain requirements mandated by the ACA. Concurrently, Congress has considered legislation that would repeal or repeal and replace all or part of the ACA. While Congress has not passed repeal legislation, two bills affecting the implementation of certain taxes under the ACA have been signed into law. H.R. 1: An Act to provide for reconciliation pursuant to titles II and V of the concurrent resolution on the budget for fiscal year 2018, or the Tax Cuts and Jobs Act of 2017, includes a provision repealing, effective January 1, 2019, the tax-based shared responsibility payment imposed by the ACA on certain individuals who fail to maintain qualifying health coverage for all or part of a year that is commonly referred to as the “individual mandate”. Additionally, on January 22, 2018, President Trump signed a continuing resolution on appropriations for fiscal year 2018 that delayed the implementation of certain ACA-mandated fees, including the so-called “Cadillac” tax on certain high cost employer-sponsored insurance plans, the annual fee imposed on certain health insurance providers based on market share, and the medical device excise tax on non-exempt medical devices. Further, the Bipartisan Budget Act of 2018, or the BBA, among other things, amends the ACA, effective January 1, 2019, to increase from 50% to 70% the point-of-sale discount that is owed by pharmaceutical manufacturers who participate in Medicare Part D and to close the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole”. Congress may consider other legislation to repeal or replace elements of the ACA. These executive orders and legislative actions are expected to result in increased health insurance premiums and reduce the number of people with health insurance in the United States, and have other effects that adversely affect US health insurance markets and the ability of patients to have access to therapies that our product candidates can provide.

In addition, other federal health reform measures have been proposed and adopted in the United States. For example, as a result of the Budget Control Act of 2011, providers are subject to Medicare payment reductions of 2% per fiscal year through 2027 unless additional Congressional action is taken. Further, the American Taxpayer Relief Act of 2012 reduced Medicare payments to several providers and increased the statute of limitations period for the government to recover overpayments from providers from three to five years. The Medicare Access and CHIP Reauthorization Act of 2015 also introduced a quality payment program under which certain individual Medicare providers will be subject to certain incentives or penalties based on new program quality standards. Payment adjustments for the Medicare quality payment program will begin in 2019. At this time, it is unclear how the introduction of the quality payment program will impact overall physician reimbursement under the Medicare program. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors. Further, there has been heightened governmental scrutiny in the United States of pharmaceutical pricing practices in light of the rising cost of prescription drugs and biologics.

The combination of healthcare cost containment measures, increased health insurance costs, reduction of the number of people with health insurance coverage, as well as future legislation and regulations focused on reducing healthcare costs by reducing the cost of or reimbursement and access to pharmaceutical products, may limit or delay our ability to generate revenue, attain profitability, or commercialize our products.

We are subject to the U.K. Bribery Act, the U.S. Foreign Corrupt Practices Act and other anti-corruption laws, as well as export control laws, import and customs laws, trade and economic sanctions laws and other laws governing our operations.

Our operations are subject to anti-corruption laws, including the U.K. Bribery Act 2010, or the Bribery Act, the U.S. Foreign Corrupt Practices Act of 1977, as amended, or the FCPA, the U.S. domestic bribery statute contained in 18 U.S.C. §201, the U.S. Travel Act, and other anti-corruption laws that apply in countries where we do business. The Bribery Act, the FCPA and these other laws generally prohibit us and our employees and intermediaries from authorizing, promising, offering, or providing, directly or indirectly, improper or prohibited payments, or anything else of value, to government officials or other persons to obtain or retain business or gain some other business advantage.

Under the Bribery Act, we may also be liable for failing to prevent a person associated with us from committing a bribery offense. We and those acting on our behalf operate in a number of jurisdictions that pose a high risk of potential Bribery Act or FCPA violations, and we participate in collaborations and relationships with third parties whose corrupt or illegal activities could potentially subject us to liability under the Bribery Act, FCPA or local anticorruption laws, even if we do not explicitly authorize or have actual knowledge of such activities. In addition, we cannot predict the nature, scope or effect of future regulatory requirements to which our international operations might be subject or the manner in which existing laws might be administered or interpreted.

Compliance with the Bribery Act, the FCPA and these other laws is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, anti-corruption laws present particular challenges in the pharmaceutical industry, because, in many countries, hospitals are operated by the government, and doctors and other hospital employees are considered foreign officials. Certain payments to hospitals in connection with clinical trials and other work have been deemed to be improper payments to government officials and have led to enforcement actions.

We are also subject to other laws and regulations governing our international operations, including regulations administered by the governments of the United States and the United Kingdom, and authorities in the European Union, including applicable export control regulations, economic sanctions and embargoes on certain countries and persons, anti-money laundering laws, import and customs requirements and currency exchange regulations, collectively referred to as the Trade Control laws.

There is no assurance that we will be completely effective in ensuring our compliance with all applicable anti-corruption laws, including the Bribery Act, the FCPA or other legal requirements, including Trade Control laws. If we are not in compliance with the Bribery Act, the FCPA and other anti-corruption laws or Trade Control laws, we may be subject to criminal and civil penalties, disgorgement and other sanctions and remedial measures, and legal expenses, which could have an adverse impact on our business, financial condition, results of operations and liquidity. Likewise, any investigation of any potential violations of the Bribery Act, the FCPA, other anti-corruption laws or Trade Control laws by United States, United Kingdom or other authorities could also have an adverse impact on our reputation, our business, results of operations and financial condition. Further, the failure to comply with laws governing international business practices may result in substantial civil and criminal penalties and suspension or debarment from government contracting.

If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could harm our business.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations involve the use of hazardous materials, including chemicals and biological materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties for failure to comply with such laws and regulations.

Although we maintain insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of biological or hazardous materials.

In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or production efforts. Our failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

Risks Related to the Commercialization of Our Product Candidates

If we are unable to establish sales, marketing and distribution capabilities for our product candidates, or enter into sales, marketing and distribution agreements with third parties, we may not be successful in commercializing our product candidates, if and when they are approved.

We currently plan to work to build our global commercialization capabilities internally over time such that we are able to commercialize any product candidate for which we may obtain regulatory approval. However, we currently have no sales, marketing or distribution capabilities and have no experience in marketing or distributing pharmaceutical products. To achieve commercial success for any product candidate for which we may obtain marketing approval, we will need to establish a sales and marketing organization and establish logistics and distribution processes to commercialize and deliver our product candidates to patients and healthcare providers. The development of sales, marketing and distribution capabilities will require substantial resources, will be time-consuming and could delay any product launch.

If we are unable or decide not to establish internal sales, marketing and distribution capabilities, we would have to pursue collaborative arrangements regarding the sales and marketing of our products. However, we may not be successful in entering into arrangements with third parties to sell, market and distribute our product candidates or may be unable to do so on terms that are favorable to us, or if we are able to do so, that they would be effective and successful in commercializing our products. Our product revenues and our profitability, if any, would likely to be lower than if we were to sell, market and distribute any product candidates that we develop ourselves. In addition, we would have limited control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market our product candidates effectively.

If we do not establish sales, marketing and distribution capabilities successfully, either on our own or in collaboration with third parties, we will not be successful in commercializing our product candidates in the United States or overseas.

We operate in a rapidly changing industry and face significant competition, which may result in others discovering, developing or commercializing products before or more successfully than we do.

The development and commercialization of new biopharmaceutical products is highly competitive and subject to rapid and significant technological advancements. We face competition from major multi-national pharmaceutical companies, biotechnology companies and specialty pharmaceutical companies with respect to our current and future product candidates that we may develop and commercialize in the future. There are a number of large pharmaceutical and biotechnology companies that currently market and sell products or are pursuing the development of product candidates for the treatment of cancer. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large, established companies. Potential competitors also include academic institutions, government agencies and other public and private research organizations. Due to their promising clinical therapeutic effect in clinical exploratory trials, engineered T cell therapies, redirected T cell therapies in general and antibody-drug conjugates are being pursued by multiple biotechnology and pharmaceutical companies, including Novartis AG, Gilead Sciences, Inc., or Gilead, Celgene, Janssen Biotech Inc., bluebird bio, Roche Holding AG, Seattle Genetics, Amgen Inc. and Juno Therapeutics, Inc. Our competitors may succeed in developing, acquiring or licensing technologies and products that are more effective, more effectively marketed and sold or less costly than any product candidates that we may develop, which could render our product candidates non-competitive and obsolete.

We are developing AUTO2, our dual-targeting BCMA/TACI programmed T cell product candidate, for the treatment of relapsed or refractory multiple myeloma. bluebird bio, in collaboration with Celgene, is developing a BCMA CAR T cell therapy for the treatment of multiple myeloma. Nanjing Legend Biotech is also developing a similar therapy. Nanjing Legend Biotech and Janssen Biotech, Inc., a subsidiary of Johnson & Johnson, are collaborating on the development of a similar therapy. AUTO2 is expected to compete directly with both of these therapies. We are developing AUTO3, our dual-targeting CD19/CD22 programmed T cell product candidate for the treatment of relapsed or refractory DLBCL and pediatric ALL. Novartis and Gilead have received marketing approval for their anti-CD19 CAR T cell therapy, and Juno is in the process of developing another anti-CD19 CAR T cell therapy. AUTO3 is expected to compete directly with all of these therapies. In addition, some companies, such as Cellectis, Inc., are pursuing allogeneic T cell products that could compete with our programmed T cell product candidates.

Novartis and Gilead may be successful in establishing a strong market position for their CD19-targeted CAR T cell products, and we may not be able to compete effectively against these therapies once they have been established. In addition, our competitors with development-stage programs may obtain marketing approval from the FDA, the EMA or other comparable regulatory authorities for their product candidates more rapidly than we do, and they could establish a strong market position before we are able to enter the market.

Many of our competitors, either alone or with their strategic collaborators, have substantially greater financial, technical and human resources than we do. Accordingly, our competitors may be more successful than we are in obtaining approval for treatments and achieving widespread market acceptance, which may render our treatments obsolete or non-competitive. Mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical study sites and patient registration for clinical studies, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive or better reimbursed than any products that we may commercialize. Our competitors also may obtain FDA, EMA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position for either the product or a specific indication before we are able to enter the market.

Even if any of our product candidates receives marketing approval, it may fail to achieve the degree of market acceptance by physicians, patients, third-party payors and others in the medical community necessary for commercial success.

Even if we obtain approvals from the FDA, the EMA or other comparable regulatory agencies and are able to initiate commercialization of our clinical-stage product candidates or any other product candidates we develop, the product candidate may not achieve market acceptance among physicians, patients, hospitals, including pharmacy directors, and third-party payors and, ultimately, may not be commercially successful. The degree of market acceptance of our product candidates, if approved for commercial sale, will depend on a number of factors, including:

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the clinical indications for which our product candidates are approved;

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physicians, hospitals, cancer treatment centers, and patients considering our product candidates as a safe and effective treatment;

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hospitals and cancer treatment centers establishing the infrastructure required for the administration of redirected T cell therapies;

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the potential and perceived advantages of our product candidates over alternative treatments;

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the prevalence and severity of any side effects;

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product labeling or product insert requirements of the FDA, the EMA or other regulatory authorities;

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limitations or warnings contained in the labeling approved by the FDA or the EMA;

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the timing of market introduction of our product candidates as well as competitive products;

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the cost of treatment in relation to alternative treatments;

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the amount of upfront costs or training required for physicians to administer our product candidates;

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the availability of coverage, adequate reimbursement, and pricing by third-party payors and government authorities;

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the willingness of patients to pay out-of-pocket in the absence of comprehensive coverage and reimbursement by third-party payors and government authorities;

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relative convenience and ease of administration, including as compared to alternative treatments and competitive therapies; and

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the effectiveness of our sales and marketing efforts and distribution support.

Our efforts to educate physicians, patients, third-party payors and others in the medical community on the benefits of our products, if approved, may require significant resources and may never be successful. Such efforts may require more resources than are typically required due to the complexity and uniqueness of our product candidates. Because we expect sales of our product candidates, if approved, to generate substantially all of our product revenue for the foreseeable future, the failure of our product candidates to find market acceptance would harm our business and could require us to seek additional financing.

In addition, although we are not utilizing embryonic stem cells or replication competent vectors, adverse publicity due to the ethical and social controversies surrounding the therapeutic use of such technologies, and reported side effects from any clinical trials using these technologies or the failure of such trials to demonstrate that these therapies are safe and effective, may limit market acceptance our product candidates. If our product candidates are approved but fail to achieve market acceptance among physicians, patients, hospitals, cancer treatment centers or others in the medical community, we will not be able to generate significant revenue.

Even if our products achieve market acceptance, we may not be able to maintain that market acceptance over time if new products or technologies are introduced that are more favorably received than our products, are more cost effective or render our products obsolete.

Coverage and adequate reimbursement may not be available for our current or any future product candidates, which could make it difficult for us to sell profitably, if approved.

Market acceptance and sales of any product candidates that we commercialize, if approved, will depend in part on the extent to which reimbursement for these products and related treatments will be available from third-party payors, including government health administration authorities, managed care organizations and private health insurers. Third-party payors decide which therapies they will pay for and establish reimbursement levels. Third-party payors in the United States often rely upon Medicare coverage policy and payment limitations in setting their own coverage and reimbursement policies. However, decisions regarding the extent of coverage and amount of reimbursement to be provided for any product candidates that we develop will be made on a payor-by-payor basis. One payor’s determination to provide coverage for a drug does not assure that other payors will also provide coverage and adequate reimbursement for the drug. Additionally, a third-party payor’s decision to provide coverage for a therapy does not imply that an adequate reimbursement rate will be approved. Third-party payors are increasingly challenging the price, examining the medical necessity and reviewing the cost-effectiveness of medical products, therapies and services, in addition to questioning their safety and efficacy. We may incur significant costs to conduct expensive pharmaco-economic studies in order to demonstrate the medical necessity and cost-effectiveness of our product candidates, in addition to the costs required to obtain FDA approvals. Our product candidates may not be considered medically necessary or cost-effective.

Each payor determines whether or not it will provide coverage for a therapy, what amount it will pay the manufacturer for the therapy, and on what tier of its list of covered drugs, or formulary, it will be placed. The position on a payor’s formulary, generally determines the co-payment that a patient will need to make to obtain the therapy and can strongly influence the adoption of such therapy by patients and physicians. Patients who are prescribed treatments for their conditions and providers prescribing such services generally rely on third-party payors to reimburse all or part of the associated healthcare costs. Patients are unlikely to use our products, and providers are unlikely to prescribe our products, unless coverage is provided and reimbursement is adequate to cover a significant portion of the cost of our products and their administration. Therefore, coverage and adequate reimbursement is critical to new medical product acceptance.

A primary trend in the U.S. healthcare industry and elsewhere is cost containment. Third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. We cannot be sure that coverage and reimbursement will be available for any drug that we commercialize and, if reimbursement is available, what the level of reimbursement will be. Even if favorable coverage and reimbursement status is attained for one or more product candidates for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future. Inadequate coverage and reimbursement may impact the demand for, or the price of, any drug for which we obtain marketing approval. If coverage and adequate

reimbursement are not available, or are available only to limited levels, we may not be able to successfully commercialize our current and any future product candidates that we develop.

We cannot be sure that coverage and reimbursement in the United States, the European Union or elsewhere will be available for any product that we may develop, and any reimbursement that may become available may be decreased or eliminated in the future.

Product liability lawsuits against us could cause us to incur substantial liabilities and to limit commercialization of any products that we may develop.

We face an inherent risk of product liability exposure related to the testing of our product candidates in human clinical trials and will face an even greater risk if we commercially sell any products that we may develop. If we cannot successfully defend ourselves against claims that our product candidates or products caused injuries, we will incur substantial liabilities. Regardless of merit or eventual outcome, liability claims may result in:

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reduced resources of our management to pursue our business strategy;

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decreased demand for any product candidates or products that we may develop;

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injury to our reputation and significant negative media attention;

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withdrawal of clinical trial participants;

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initiation of investigations by regulators;

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product recalls, withdrawals or labeling, marketing or promotional restrictions;

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significant costs to defend the resulting litigation;

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substantial monetary awards paid to clinical trial participants or patients;

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loss of revenue; and

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the inability to commercialize any products that we may develop.

We currently hold £1.0 million in product liability insurance coverage in the aggregate, with a per incident limit of £1.0 million, which may not be adequate to cover all liabilities that we may incur. We may need to increase our insurance coverage as we expand our clinical trials or if we commence commercialization of our product candidates. Insurance coverage is increasingly expensive. We may not be able to maintain insurance coverage at a reasonable cost or in an amount adequate to satisfy any liability that may arise.

Risks Related to Our Intellectual Property

Our success depends, in large part, on our ability to obtain and maintain patent protection in the United States, the European Union and other countries with respect to our product candidates. We seek to protect our proprietary position by filing patent applications related to our technology and product candidates in the major pharmaceutical markets, including the United States, major countries in Europe and Japan. If we do not adequately protect our intellectual property, competitors may be able to use our technologies and erode or negate any competitive advantage that we may have, which could harm our business and ability to achieve profitability.

To protect our proprietary positions, we file patent applications in the United States and other countries related to our novel technologies and product candidates that are important to our business. The patent application and prosecution process is expensive and time-consuming. We may not be able to file and prosecute all necessary or desirable patent applications at a reasonable cost or in a timely manner. We may also fail to identify patentable aspects of our research and development before it is too late to obtain patent protection. It is possible that defects of form in the preparation or filing of our patents or patent applications may exist, or may arise in the future, such as with respect to proper priority claims, inventorship, claim scope or patent term adjustments. If any current or future licensors or licensees are not fully cooperative or disagree with us as to the prosecution, maintenance or enforcement of any patent rights, such patent rights could be compromised and we might not be able to prevent third parties from making, using and selling competing products. If there are material defects in the form or preparation of our patents or patent applications, such patents or applications may be invalid and unenforceable. Moreover, our competitors may independently develop equivalent knowledge, methods and know-how. Any of these outcomes could impair our ability to prevent competition from third parties.

Prosecution of our owned and in-licensed patent portfolio is at a very early stage. No patents have issued from our pending applications in the United States, and only one patent has issued from our pending applications in Europe. Much of our patent portfolio consists of pending priority applications that are not examined and pending applications under the Patent Cooperation Treaty, or PCT. Neither priority applications nor PCT applications can themselves give rise to issued patents. Rather, protection for the inventions disclosed in these applications must be further pursued by applicable deadlines via applications that are subject to examination. As applicable deadlines for the priority and PCT applications become due, we will need to decide whether and in which countries or jurisdictions to pursue patent protection for the various inventions claimed in these applications, and we will only have the opportunity to pursue and obtain patents in those jurisdictions where we pursue protection.

It is also possible that we will fail to identify patentable aspects of our research and development output before it is too late to obtain patent protection. The patent applications that we own or in-license may fail to result in issued patents with claims that cover our current and future product candidates in the United States or in other foreign countries. Our patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless, and until, a patent issues from such applications, and then only to the extent the issued claims cover the technology.

If the patent applications we hold or have in-licensed with respect to our development programs and product candidates fail to issue, if their breadth or strength of protection is threatened, or if they fail to provide meaningful exclusivity for our current and future product candidates, it could threaten our ability to commercialize our product candidates. Any such outcome could have a negative effect on our business.

The patent position of biotechnology and pharmaceutical companies generally is highly uncertain. Changes in either the patent laws or interpretation of the patent laws in the United States and other countries may diminish the value of our patents or narrow the scope of our patent protection. In addition, the protections offered by laws of different countries vary. No consistent policy regarding the breadth of claims allowed in biotechnology and pharmaceutical patents has emerged to date in the United States or in many foreign jurisdictions. In addition, the determination of patent rights with respect to pharmaceutical compounds and technologies commonly involves complex legal and factual questions, which has in recent years been the subject of much litigation. As a result, the issuance, scope, validity, enforceability and commercial value of our patent rights, whether owned or in-licensed, are highly uncertain. Furthermore, recent changes in patent laws in the United States, may affect the scope, strength and enforceability of our patent rights or the nature of proceedings that may be brought

by or against us related to our patent rights. Additionally, the U.S. Supreme Court has ruled on several patent cases in recent years either narrowing the scope of patent protection available in certain circumstances or weakening the rights of patent owners in certain situations. In addition to increasing uncertainty with regard to our ability to obtain patents in the future, this combination of events has created uncertainty with respect to the value of patents, once obtained. Depending on decisions by the U.S. Congress, the federal courts, and the USPTO, the laws and regulations governing patents could change in unpredictable ways that could weaken our ability to obtain patents or to enforce any patents that we might obtain in the future.

We may not be aware of all third-party intellectual property rights potentially relating to our current and future our product candidates. Publications of discoveries in the scientific literature often lag behind the actual discoveries, and patent applications in the United States and other jurisdictions are typically not published until 18 months after filing, or in some cases not at all. Therefore, we cannot be certain that we or our licensors were the first to make the inventions claimed in our patents or pending patent applications, or that we or our licensors were the first to file for patent protection of such inventions. Similarly, should we own or in-license any patents or patent applications in the future, we may not be certain that we or the applicable licensor were the first to file for patent protection for the inventions claimed in such patents or patent applications. As a result, the issuance, scope, validity and commercial value of our patent rights cannot be predicted with any certainty. Moreover, we may be subject to a third-party pre-issuance submission of prior art to the U.S. Patent and Trademark Office, or USPTO, or become involved in opposition, derivation, reexamination, inter partes review or interference proceedings, in the United States or elsewhere, challenging our patent rights or the patent rights of others. An adverse determination in any such submission, proceeding or litigation could reduce the scope of, or invalidate, our patent rights, allow third parties to commercialize our technology or product candidates and compete directly with us, without payment to us, or result in our inability to manufacture or commercialize products without infringing third-party patent rights, which could significantly harm our business and results of operations.

Our pending and future patent applications, whether owned or in-licensed, may not result in patents being issued that protect our technology or product candidates, in whole or in part, or which effectively prevent others from commercializing competitive technologies and products. Even if our patent applications issue as patents, they may not issue in a form that will provide us with any meaningful protection against competing products or processes sufficient to achieve our business objectives, prevent competitors from competing with us or otherwise provide us with any competitive advantage. Our competitors may be able to circumvent our owned or licensed patents, should they issue, by developing similar or alternative technologies or products in a non-infringing manner. Our competitors may seek approval to market their own products similar to or otherwise competitive with our products. In these circumstances, we may need to defend and/or assert our patents, including by filing lawsuits alleging patent infringement. In any of these types of proceedings, a court or other agency with jurisdiction may find our patents invalid and/or unenforceable.

The issuance of a patent is not conclusive as to its inventorship, scope, validity or enforceability, and our owned and licensed patents may be challenged in the courts or patent offices in the United States and abroad. Such challenges may result in loss of exclusivity or freedom to operate or in patent claims being narrowed, invalidated or held unenforceable, in whole or in part, which could limit our ability to stop others from using or commercializing similar or identical technology and products, or limit the duration of the patent protection of our technology and products. In addition, given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such candidates might expire before or shortly after such candidates are commercialized.

Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain and could significantly harm our business.

Our commercial success depends, in part, on our ability to develop, manufacture, market and sell our product candidates and use our proprietary and modular T cell programming technology without infringing the intellectual property and other proprietary rights of third parties. Numerous third-party U.S. and non-U.S. issued patents exist in the area of biotechnology, including in the area of programmed T cell therapies and including patents held by our competitors. If any third party patents cover our product candidates or technologies, we may not be free to manufacture or commercialize our product candidates as planned.

There is a substantial amount of intellectual property litigation in the biotechnology and pharmaceutical industries, and we may become party to, or threatened with, litigation or other adversarial proceedings regarding intellectual property rights with respect to our technology or product candidates, including interference proceedings before the USPTO. Intellectual property disputes arise in a number of areas including with respect to patents, use of other proprietary rights and the contractual terms of license arrangements. Third parties may assert claims against us based on existing or future intellectual property rights and claims may also come from competitors against whom our own patent portfolio may have no deterrent effect. The outcome of intellectual property litigation is subject to uncertainties that cannot be adequately quantified in advance. Other parties may allege that our product candidates or the use of our technologies infringes patent claims or other intellectual property rights held by them or that we are employing their proprietary technology without authorization. As we continue to develop and, if approved, commercialize our current and future product candidates, competitors may claim that our technology infringes their intellectual property rights as part of business strategies designed to impede our successful commercialization. There are and may in the future be additional third-party patents or patent applications with claims to, for example, materials, compositions, formulations, methods of manufacture or methods for treatment related to the use or manufacture of any one or more of our product candidates. For example, we are aware of third-party U.S. patents that claim technology related to AUTO1. These U.S. patents will expire in 2023 and late 2024, and there are no counterpart patents in Europe or the rest of the world that extend beyond the earliest expected regulatory approval date of AUTO1. If regulatory approval is received for AUTO1, unless we are able to obtain a license or licenses to the third-party U.S. patent or patents on commercially reasonable terms or any applicable patent or patents are invalidated, held to be unenforceable, or deemed uninfringed by our activities, we currently intend to launch AUTO1 outside the United States first, and delay the commercial launch of AUTO1 in the United States until the expiration of any applicable third-party patent or patents covering AUTO1. As a result, the future commercial opportunity of AUTO1 in the United States could be adversely impacted. Moreover, we may fail to identify relevant third party patents or patent applications, or we may incorrectly conclude that the claims of an issued patent are invalid or are not infringed by our activities. Because patent applications can take many years to issue, third parties may have currently pending patent applications which may later result in issued patents that any of our product candidates may infringe, or which such third parties claim are infringed by our technologies.

If we are found to infringe a third party’s intellectual property rights, we could be forced, including by court order, to cease developing, manufacturing or commercializing the infringing product candidate or product. Alternatively, we may be required or may choose to obtain a license from such third party in order to use the infringing technology and continue developing, manufacturing or marketing the infringing product candidate. However, we may not be able to obtain any required license on commercially reasonable terms or at all. Even if we were able to obtain a license, it could be non-exclusive, thereby giving our competitors access to the same technologies licensed to us. In addition, we could be found liable for monetary damages, including treble damages and attorneys’ fees

if we are found to have willfully infringed a patent. A finding of infringement could prevent us from commercializing our product candidates or force us to cease some of our business operations. Claims that we have misappropriated the confidential information or trade secrets of third parties could have a similar negative effect on our business. Even if successful, the defense of any claim of infringement or misappropriation is time-consuming, expensive and diverts the attention of our management from our ongoing business operations.

We may need to license intellectual property from third parties, and such licenses may not be available or may not be available on commercially reasonable terms.

A third party may hold intellectual property rights, including patent rights, that are important or necessary to the development or manufacture of our product candidates. It may be necessary for us to use the patented or proprietary technology of third parties to commercialize our product candidates, in which case we would be required to obtain a license from these third parties. Such a license may not be available on commercially reasonable terms, or at all, and we could be forced to accept unfavorable contractual terms. If we are unable to obtain such licenses on commercially reasonable terms, our business could be harmed.

We may become involved in lawsuits to protect or enforce our intellectual property, which could be expensive, time-consuming and unsuccessful.

Competitors may infringe our patents, if issued, trademarks, copyrights or other intellectual property. To counter infringement or unauthorized use, we may be required to file infringement claims, which can be expensive and time-consuming and divert the time and attention of our management and scientific personnel. Any claims we assert against perceived infringers could provoke these parties to assert counterclaims against us alleging that we infringe their patents, trademarks, copyrights or other intellectual property. In addition, in a patent infringement proceeding, there is a risk that a court will decide that a patent of ours is invalid or unenforceable, in whole or in part, and that we do not have the right to stop the other party from using the invention at issue. There is also a risk that, even if the validity of such patents is upheld, the court will construe the patent’s claims narrowly or decide that we do not have the right to stop the other party from using the invention at issue on the grounds that our patents do not cover the invention. An adverse outcome in a litigation or proceeding involving our patents could limit our ability to assert our patents against those parties or other competitors, and may curtail or preclude our ability to exclude third parties from making and selling similar or competitive products. Similarly, if we assert trademark infringement claims, a court may determine that the marks we have asserted are invalid or unenforceable, or that the party against whom we have asserted trademark infringement has superior rights to the marks in question. In this case, we could ultimately be forced to cease use of such trademarks.

In any infringement litigation, any award of monetary damages we receive may not be commercially valuable. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some of our confidential information could be compromised by disclosure during litigation. In addition, there could be public announcements of the results of hearings, motions or other interim proceedings or developments and if securities analysts or investors perceive these results to be negative, it could have a substantial adverse effect on the price of our ADSs. Moreover, there can be no assurance that we will have sufficient financial or other resources to file and pursue such infringement claims, which typically last for years before they are concluded. Some of our competitors may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their greater financial resources and more mature and developed intellectual property portfolios. Even if we ultimately prevail in such claims, the monetary cost of such litigation and the diversion of the attention of our management and scientific personnel could outweigh any benefit we receive as a result of the proceedings. Accordingly, despite

our efforts, we may not be able to prevent third parties from infringing, misappropriating or successfully challenging our intellectual property rights. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a negative impact on our ability to compete in the marketplace.

We may be subject to claims by third parties asserting that we or our employees have misappropriated their intellectual property, or claiming ownership of what we regard as our own intellectual property.

Many of our employees were previously employed at universities or other biotechnology or pharmaceutical companies, and our founder and Chief Scientific Officer, Dr. Martin Pulé, is currently employed both by us and the University College London. Although we try to ensure that our employees do not use the proprietary information or know-how of third parties in their work for us, we may be subject to claims that these employees or we have inadvertently or otherwise used intellectual property, including trade secrets or other proprietary information, of any such employee’s former employer. We may also in the future be subject to claims that we have caused an employee to breach the terms of his or her non-competition or non-solicitation agreement. Litigation may be necessary to defend against these potential claims.

In addition, while it is our policy to require our employees and contractors who may be involved in the development of intellectual property to execute agreements assigning such intellectual property to us, such employees and contractors may breach the agreement and claim the developed intellectual property as their own.

Our business was founded as a spin-out from University College London. As of March 31, 2018, our current patent portfolio is comprised of 61 patent families, of which 25 patent families are in-licensed from UCLB, the technology-transfer company of University College London, and 36 patent families we own and have originated from our own research. Because we license certain of our patents from UCLB, we must rely on their prior practices with regard to the assignment of such intellectual property. Our and their assignment agreements may not be self-executing or may be breached, and we may be forced to bring claims against third parties or defend claims they may bring against us, to determine the ownership of what we regard as our intellectual property.

If we fail in prosecuting or defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. A court could prohibit us from using technologies or features that are essential to our products if such technologies or features are found to incorporate or be derived from the trade secrets or other proprietary information of the former employers. Even if we are successful in prosecuting or defending against such claims, litigation could result in substantial costs and could be a distraction to management. In addition, any litigation or threat thereof may adversely affect our ability to hire employees or contract with independent service providers. Moreover, a loss of key personnel or their work product could hamper or prevent our ability to commercialize our products.

We may be subject to claims challenging the inventorship or ownership of our owned or in-licensed patent rights and other intellectual property.

We generally enter into confidentiality and intellectual property assignment agreements with our employees, consultants, outside scientific collaborators, sponsored researchers and other advisors. However, these agreements may not be honored and may not effectively assign intellectual property rights to us. For example, disputes may arise from conflicting obligations of consultants or others who are involved in developing our technology and product candidates. Litigation may be necessary to defend against these and other claims challenging inventorship or ownership. The owners of

intellectual property in-licensed to us could also face such claims. If we or our licensors fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights, such as exclusive ownership of, or right to use, valuable intellectual property. Such an outcome could have a material adverse effect on our business. Even if we or our licensors are successful in defending against such claims, litigation could result in substantial costs and be a distraction to management and other employees.

Any trademarks we may obtain may be infringed or successfully challenged, resulting in harm to our business.

We expect to rely on trademarks as one means to distinguish any of our product candidates that are approved for marketing from the products of our competitors. We have not yet selected trademarks for our product candidates and have not yet begun the process of applying to register trademarks for our product candidates. Once we select trademarks and apply to register them, our trademark applications may not be approved. Third parties may oppose our trademark applications, or otherwise challenge our use of the trademarks. In the event that our trademarks are successfully challenged, we could be forced to rebrand our products, which could result in loss of brand recognition and could require us to devote resources to advertising and marketing new brands. Our competitors may infringe our trademarks and we may not have adequate resources to enforce our trademarks.

In addition, any proprietary name we propose to use with our clinical-stage product candidates or any other product candidate in the United States must be approved by the FDA, regardless of whether we have registered it, or applied to register it, as a trademark. The FDA typically conducts a review of proposed product names, including an evaluation of the potential for confusion with other product names. If the FDA objects to any of our proposed proprietary product names, we may be required to expend significant additional resources in an effort to identify a suitable proprietary product name that would qualify under applicable trademark laws, not infringe the existing rights of third parties and be acceptable to the FDA.

If we are unable to protect the confidentiality of our trade secrets, our business and competitive position would be harmed.

In addition to seeking patent and trademark protection for our product candidates, we also rely on trade secrets, including unpatented know-how, technology and other proprietary information, to maintain our competitive position. We seek to protect our trade secrets, in part, by entering into non-disclosure and confidentiality agreements with parties who have access to them, such as our employees, consultants, advisors and other third parties. We also enter into confidentiality and invention or patent assignment agreements with our employees and consultants. Despite these efforts, any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets. Monitoring unauthorized uses and disclosures of our intellectual property is difficult, and we do not know whether the steps we have taken to protect our intellectual property will be effective. In addition, we may not be able to obtain adequate remedies for any such breaches. Enforcing a claim that a party illegally disclosed or misappropriated a trade secret is difficult, expensive and time-consuming, and the outcome is unpredictable. In addition, some courts inside and outside the United States are less willing or unwilling to protect trade secrets.

Moreover, our competitors may independently develop knowledge, methods and know-how equivalent to our trade secrets. Competitors could purchase our products and replicate some or all of the competitive advantages we derive from our development efforts for technologies on which we do not have patent protection. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor, we would have no right to prevent them, or those to whom they communicate it, from using that technology or information to compete with us. If any of our trade

secrets were to be disclosed to or independently developed by a competitor, our competitive position would be harmed.

We may not be able to protect our intellectual property rights throughout the world.

Filing, prosecuting and defending patents on product candidates in all countries throughout the world would be prohibitively expensive, and our intellectual property rights in some countries outside the United States could be less extensive than those in the United States. In some cases, we may not be able to obtain patent protection for certain technology outside the United States. In addition, the laws of some foreign countries do not protect intellectual property rights to the same extent as federal and state laws in the United States, even in jurisdictions where we do pursue patent protection. Consequently, we may not be able to prevent third parties from practicing our inventions in all countries outside the United States, even in jurisdictions where we do pursue patent protection or from selling or importing products made using our inventions in and into the United States or other jurisdictions.

Competitors may use our technologies in jurisdictions where we have not pursued and obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection, but enforcement is not as strong as that in the United States. These products may compete with our product candidates and preclinical programs and our patents or other intellectual property rights may not be effective or sufficient to prevent them from competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in foreign jurisdictions. The legal systems of certain countries, particularly certain developing countries, do not favor the enforcement of patents, trade secrets and other intellectual property protection, particularly those relating to biotechnology products, which could make it difficult for us to stop the infringement of our patents, if pursued and obtained, or marketing of competing products in violation of our proprietary rights generally. Proceedings to enforce our patent rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our patents at risk of being invalidated or interpreted narrowly and our patent applications at risk of not issuing and could provoke third parties to assert claims against us. We may not prevail in any lawsuits that we initiate and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, our efforts to enforce our intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

Obtaining and maintaining our patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance and annuity fees on any issued patent are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patent. The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of a patent or patent application include failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If we or our licensors fail to maintain the patents and patent applications covering our products or product candidates, our competitors might

be able to enter the market, which would harm our business. In addition, to the extent that we have responsibility for taking any action related to the prosecution or maintenance of patents or patent application in-licensed from a third party, any failure on our part to maintain the in-licensed rights could jeopardize our rights under the relevant license and may expose us to liability.

Risks Related to this Offering, Our Securities and Our Status as a Public Company

An active trading market for our ADSs may not develop and you may not be able to resell your ADSs at or above the initial offering price, if at all.

This offering constitutes the initial public offering of our ADSs, and no public market has previously existed for our ADSs. We intend to apply to list our ADSs on The Nasdaq Global Market. Any delay in the commencement of trading of our ADSs on The Nasdaq Global Market would impair the liquidity of the market for the ADSs and make it more difficult for holders to sell the ADSs. If our ADSs are listed and quoted on The Nasdaq Global Market, there can be no assurance that an active trading market for the ADSs will develop or be sustained after this offering is completed. The lack of an active trading market may also reduce the fair market value of the ADSs. The initial offering price will be determined by negotiations among the lead underwriters and us. Among the factors to be considered in determining the initial public offering price are our future prospects and the prospects of our industry in general, our revenue, net income and certain other financial and operating information in recent periods, and the market prices of securities and certain financial and operating information of companies engaged in activities similar to ours. However, there can be no assurance that, following the completion of this offering, the ADSs will trade at a price equal to or greater than the initial public offering price.

The trading price of our ADSs may be volatile, and you could lose all or part of your investment.

The trading price of our ADSs following this offering is likely to be highly volatile and could be subject to wide fluctuations in response to various factors, some of which are beyond our control, including limited trading volume. The stock market in general and the market for biopharmaceutical companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies. As a result of this volatility, investors may not be able to sell their ADSs at or above the price paid for the ADSs. In addition to the factors discussed in this “Risk Factors” section and elsewhere in this prospectus, these factors include:

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the commencement, enrollment or results of our planned and future clinical trials;

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positive or negative results from, or delays in, testing and clinical trials by us, collaborators or competitors;

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the loss of any of our key scientific or management personnel;

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regulatory or legal developments in the United States, United Kingdom and other countries;

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the success of competitive products or technologies;

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adverse actions taken by regulatory agencies with respect to our clinical trials or manufacturers;

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changes or developments in laws or regulations applicable to our product candidates and preclinical program;

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changes to our relationships with collaborators, manufacturers or suppliers;

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concerns regarding the safety of our product candidates or programmed T cells in general;

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announcements concerning our competitors or the pharmaceutical industry in general;

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actual or anticipated fluctuations in our operating results;

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changes in financial estimates or recommendations by securities analysts;

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potential acquisitions, financing, collaborations or other corporate transactions;

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the results of our efforts to discover, develop, acquire or in-license additional product candidates;

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the trading volume of our ADSs on The Nasdaq Global Market;

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sales of our ADSs or ordinary shares by us, members of our senior management and directors or our shareholders or the anticipation that such sales may occur in the future;

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general economic, political, and market conditions and overall fluctuations in the financial markets in the United States or the United Kingdom;

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stock market price and volume fluctuations of comparable companies and, in particular, those that operate in the biopharmaceutical industry;

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investors’ general perception of us and our business; and

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other events and factors, many of which are beyond our control.

These and other market and industry factors may cause the market price and demand for our ADSs to fluctuate substantially, regardless of our actual operating performance, which may limit or prevent investors from selling their ADSs at or above the price paid for the ADSs and may otherwise negatively affect the liquidity of our ADSs. In addition, the stock market in general, and biopharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies.

Some companies that have experienced volatility in the trading price of their shares have been the subject of securities class action litigation. Any lawsuit to which we are a party, with or without merit, may result in an unfavorable judgment. We also may decide to settle lawsuits on unfavorable terms.

Any such negative outcome could result in payments of substantial damages or fines, damage to our reputation or adverse changes to our business practices. Defending against litigation is costly and time-consuming, and could divert our management’s attention and our resources. Furthermore, during the course of litigation, there could be negative public announcements of the results of hearings, motions or other interim proceedings or developments, which could have a negative effect on the market price of our ADSs.

If you purchase ADSs in this offering, you will suffer immediate dilution of your investment.

The initial public offering price of our ADSs is substantially higher than the pro forma as adjusted net tangible book value per ADS. Therefore, if you purchase ADSs in this offering, you will pay a price per ADS that substantially exceeds our pro forma as adjusted net tangible book value per ADS after this offering. Based on an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, you will experience immediate dilution of $ per ADS, representing the difference between our pro forma as adjusted net tangible book value per ADS after this offering and the initial public offering price per ADS. After this offering, we will also have outstanding options to purchase ordinary shares with exercise prices lower than the initial public offering price. To the extent these outstanding options are exercised, there will be further dilution to investors in this offering. For further information regarding the dilution resulting from this offering, see the section titled “Dilution” in this prospectus.

A significant portion of our total outstanding shares are restricted from immediate resale, but may be sold into the market in the near future. This could cause the market price of our ADSs to drop significantly, even if our business is doing well.

Sales of a substantial number of our ordinary shares or ADSs in the public market could occur at any time.

If our shareholders sell, or the market perceives that our shareholders intend to sell, substantial amounts of our ordinary shares or ADSs in the public market following this offering, the market price of our ADSs could decline significantly.

Upon completion of this offering, we will have outstanding ordinary shares, including ordinary shares represented by ADSs. Of these shares, the ADSs sold in this offering will be freely tradable, and additional ordinary shares will be available for sale in the public market beginning 180 days after the date of this prospectus following the expiration of lock-up agreements entered into by our shareholders in connection with the offering. The representatives of the underwriters may agree to release these shareholders from their lock-up agreements at any time and without notice, which would allow for earlier sales of shares in the public market. Sales of a substantial number of such shares upon expiration of the lock-up agreements, the perception that such sales may occur, or early release of restrictions in the lock-up agreements, could cause the market price of our ADSs to fall or make it more difficult for you to sell your ADSs at a time and price that you deem appropriate.

In addition, promptly following the completion of this offering, we intend to file one or more registration statements on Form S-8 registering the issuance of approximately ordinary shares subject to options or other equity awards issued or reserved for future issuance under our equity incentive plans. Shares registered under these registration statements on Form S-8 will be available for sale in the public market subject to vesting arrangements and exercise of options, the lock-up agreements described above and, in the case of our affiliates, the restrictions of Rule 144 under the Securities Act of 1933, as amended.

Additionally, after this offering, the holders of an aggregate of of our ordinary shares, or their transferees, will have rights, subject to some conditions, to require us to file one or more registration statements covering their shares or to include their shares in registration statements that we may file for ourselves or other shareholders. If we were to register the resale of these shares, they could be freely sold in the public market. If these additional shares are sold, or if it is perceived that they will be sold, in the public market, the trading price of our ADSs could decline.

Although we are not yet subject to the certification or attestation requirements of Section 404 of the Sarbanes-Oxley Act, in the course of auditing our financial statements as of and for the years ended September 30, 2016 and 2017 in preparation for this offering, our independent registered public accounting firm identified a material weakness related to our financial statement closing process. This material weakness primarily related to our lack of controls over the preparation and review of complex accounting issues involving significant judgment or estimates in the financial statement closing process

resulting from our in-house accounting and finance team. Currently, our finance team lacks sufficient competencies related to U.S. GAAP and SEC reporting for the purposes of timely and reliable financial reporting and relies on third-party advisors to provide assistance with financial reporting. Under standards established by the Public Company Accounting Oversight Board, a material weakness is a deficiency, or combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of a company’s annual or interim financial statements will not be prevented or detected and corrected on a timely basis. This finding relates to our lack of sufficient accounting and finance personnel and our lack of appropriate procedures and controls over the preparation of our financial statements, including sufficient financial statement close process controls as well as overall review procedures of the financial statements and disclosures. We concur with these findings.

We have commenced measures to remediate this material weakness and we are actively searching for a full-time Chief Financial Officer, as well as other finance and accounting personnel, and we plan to further develop and implement policies, processes, documentation and review control procedures relating to our financial reporting. The actions that we are taking are subject to ongoing executive management review, and will be subject to audit committee oversight. Although we intend to complete this remediation process as quickly as practicable, we cannot at this time estimate how long it will take, and our initiatives may not prove to be successful in remediating the material weakness.

If we are unable to successfully remediate our identified material weakness, if we discover additional material weaknesses, or if we otherwise are unable to report our financial statements accurately or in a timely manner, we would be required to continue disclosing such material weaknesses in future filings with the SEC, which could adversely affect our business, investor confidence in our company and the market price of our ADSs, and could subject us to litigation or regulatory enforcement actions. As a result, shareholders could lose confidence in our financial and other public reporting, which would harm our business and the market value of our ADSs.

If we fail to implement and maintain effective internal controls over financial reporting, our ability to produce accurate financial statements on a timely basis could be impaired.

Upon becoming a public company, we will be subject to reporting obligations under U.S. securities laws, including the Sarbanes-Oxley Act of 2002. Section 404(a) of the Sarbanes-Oxley Act, or Section 404(a), will require that, beginning with our second annual report following our initial public offering, management assess and report annually on the effectiveness of our internal control over financial reporting and identify any material weaknesses in our internal control over financial reporting. We expect our first Section 404(a) assessment will take place for our annual report for the fiscal year ending September 30, 2019. If we fail to remediate the material weakness identified above, our management may conclude that our internal control over financial reporting is not effective. Although Section 404(b) of the Sarbanes-Oxley Act, or Section 404(b), requires our independent registered public accounting firm to issue an annual report that addresses the effectiveness of our internal control over financial reporting, we have opted to rely on the exemptions provided in the JOBS Act, and consequently will not be required to comply with SEC rules that implement Section 404(b) until such time as we are no longer an emerging growth company.

The presence of material weaknesses could result in financial statement errors which, in turn, could lead to errors in our financial reports or delays in our financial reporting, which could require us to restate our operating results or result in our auditors issuing a qualified audit report. In order to establish, maintain and improve effective disclosure controls and procedures and internal control over financial reporting, we will need to expend significant resources and provide significant management oversight. Developing, implementing and testing changes to our internal control may require specific compliance training of our directors and employees, entail substantial costs in order to modify our

existing accounting systems, take a significant period of time to complete and divert management’s attention from other business concerns. These changes may not, however, be effective in establishing and maintaining adequate internal controls.

If either we are unable to conclude that we have effective internal control over financial reporting or, at the appropriate time, our independent auditors are unwilling or unable to provide us with an unqualified report on the effectiveness of our internal control over financial reporting as required by Section 404(b), investors may lose confidence in our operating results, the price of our ADSs could decline and we may be subject to litigation or regulatory enforcement actions. In addition, if we are unable to meet the requirements of Section 404, we may not be able to remain listed on Nasdaq.

We will have broad discretion in the use of proceeds from this offering and may invest or spend the proceeds in ways with which you do not agree and in ways that may not increase the value of your investment.

Our management will have broad discretion in the application of our cash and cash equivalents, including the net proceeds from this offering, and could spend the proceeds in ways that do not improve our results of operations or enhance the value of our ADSs. The failure by our management to apply these funds effectively could result in financial losses that could have a negative impact on our business, cause the price of our ADSs to decline and delay the development of our product candidates and preclinical program. Pending their use, we may invest our cash and cash equivalents, including the net proceeds from this offering, in a manner that does not produce income or that loses value. See the section titled “Use of Proceeds” for additional information.

Raising additional capital may cause dilution to our holders, including purchasers of our ADSs in this offering, restrict our operations or require us to relinquish rights to our technologies or product candidates.

We expect that significant additional capital may be needed in the future to continue our planned operations, including conducting clinical trials, commercialization efforts, expanded research and development activities and costs associated with operating a public company. Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through any or a combination of securities offerings, debt financings, license and collaboration agreements and research grants. If we raise capital through securities offerings, such sales may also result in material dilution to our existing shareholders, and new investors could gain rights, preferences and privileges senior to the holders of our ADSs or ordinary shares, including ADSs sold in this offering.

To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect your rights as a shareholder. Debt financing and preferred equity financing, if available, could result in fixed payment obligations, and we may be required to accept terms that restrict our ability to incur additional indebtedness, force us to maintain specified liquidity or other ratios or restrict our ability to pay dividends or make acquisitions.

If we raise additional funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may be required to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us. In addition, we could also be required to seek funds through arrangements with collaborators or others at an earlier stage than otherwise would be desirable. If we raise funds through research grants, we may be subject to certain requirements, which may limit our ability to use the funds or require us to share information from our research and development. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to

delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to a third party to develop and market product candidates that we would otherwise prefer to develop and market ourselves. Raising additional capital through any of these or other means could adversely affect our business and the holdings or rights of our shareholders, and may cause the market price of our ADSs to decline.

The rights of our shareholders may differ from the rights typically offered to shareholders of a U.S. corporation.

We are incorporated under English law. The rights of holders of ordinary shares and, therefore, certain of the rights of holders of our ADSs, are governed by English law, including the provisions of the U.K. Companies Act 2006, or the Companies Act, and by our Articles of Association. These rights differ in certain respects from the rights of shareholders in typical U.S. corporations. See the section titled “Description of Share Capital and Articles of Association—Differences in Corporate Law” in this prospectus for a description of the principal differences between the provisions of the Companies Act applicable to us and, for example, the Delaware General Corporation Law relating to shareholders’ rights and protections.

Holders of our ADSs have fewer rights than our shareholders and must act through the depositary to exercise their rights.

Holders of our ADSs do not have the same rights as our shareholders and may only exercise their voting rights with respect to the underlying ordinary shares in accordance with the provisions of the deposit agreement. Holders of the ADSs will appoint the depositary or its nominee as their representative to exercise the voting rights attaching to the ordinary shares represented by the ADSs. When a general meeting is convened, if you hold ADSs, you may not receive sufficient notice of a shareholders’ meeting to permit you to withdraw the ordinary shares underlying your ADSs to allow you to vote with respect to any specific matter. We will make all commercially reasonable efforts to cause the depositary to extend voting rights to you in a timely manner, but we cannot assure you that you will receive voting materials in time to instruct the depositary to vote, and it is possible that you, or persons who hold their ADSs through brokers, dealers or other third parties, will not have the opportunity to exercise a right to vote. Furthermore, the depositary will not be liable for any failure to carry out any instructions to vote, for the manner in which any vote is cast or for the effect of any such vote. As a result, you may not be able to exercise your right to vote and you may lack recourse if your ADSs are not voted as you request. In addition, in your capacity as an ADS holder, you will not be able to call a shareholders’ meeting.

Concentration of ownership of our ordinary shares among our existing senior management, directors and principal shareholders may prevent new investors from influencing significant corporate decisions and matters submitted to shareholders for approval.

Upon completion of this offering, members of our senior management, directors and current beneficial owners of 5% or more of our ordinary shares and their respective affiliates will, in the aggregate, beneficially own approximately % of our outstanding ordinary shares, based on the number of ordinary shares outstanding as of September 30, 2017 and assuming the issuance of ADSs in this offering. As a result, these persons, acting together, would be able to significantly influence all matters requiring shareholder approval, including the election and removal of directors, any merger, consolidation or sale of all or substantially all of our assets, or other significant corporate transactions. In addition, these persons, acting together, may have the ability to control the management and affairs of our company. Accordingly, this concentration of ownership may harm the market price of our ADSs by:

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delaying, deferring, or preventing a change in control;

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entrenching our management and/or the board of directors;

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impeding a merger, consolidation, takeover, or other business combination involving us; or

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discouraging a potential acquirer from making a tender offer or otherwise attempting to obtain control of us.

In addition, some of these persons or entities may have interests different than yours. For example, because many of these shareholders purchased their shares at prices substantially below the price at which shares are being sold in this offering and have held their shares for a longer period, they may be more interested in selling our company to an acquirer than other investors, or they may want us to pursue strategies that deviate from the interests of other shareholders.

You may not receive distributions on our ordinary shares represented by the ADSs or any value for them if it is illegal or impractical to make them available to holders of ADSs.

Although we do not have any present plans to declare or pay any dividends, in the event we declare and pay any dividend, the depositary for the ADSs has agreed to pay to you the cash dividends or other distributions it or the custodian receives on our ordinary shares or other deposited securities after deducting its fees and expenses. You will receive these distributions in proportion to the number of our ordinary shares your ADSs represent. However, in accordance with the limitations set forth in the deposit agreement, it may be unlawful or impractical to make a distribution available to holders of ADSs. We have no obligation to register under U.S. securities laws any offering of ADSs, ordinary shares or other securities received through such distributions. We also have no obligation to take any other action to permit distribution on the ADSs, ordinary shares, rights or anything else to holders of the ADSs. This means that you may not receive the distributions we make on our ordinary shares or any value from them if it is unlawful or impractical to make them available to you. These restrictions may have an adverse effect on the value of your ADSs.

Your right to participate in any future rights offerings may be limited, which may cause dilution to your holdings.

We may from time to time distribute rights to our shareholders, including rights to acquire our securities. However, we cannot make rights available to you in the United States unless we register the rights and the securities to which the rights relate under the Securities Act or an exemption from the registration requirements is available. Also, under the deposit agreement, the depositary bank will not make rights available to you unless either both the rights and any related securities are registered under the Securities Act, or the distribution of them to ADS holders is exempted from registration under the Securities Act. We are under no obligation to file a registration statement with respect to any such rights or securities or to endeavor to cause such a registration statement to be declared effective. Moreover, we may not be able to establish an exemption from registration under the Securities Act. If the depositary does not distribute the rights, it may, under the deposit agreement, either sell them, if possible, or allow them to lapse. Accordingly, you may be unable to participate in our rights offerings and may experience dilution in your holdings.

Because we do not anticipate paying any cash dividends on our ADSs in the foreseeable future, capital appreciation, if any, will be your sole source of gains and you may never receive a return on your investment.

You should not rely on an investment in our ADSs to provide dividend income. Under current English law, a company’s accumulated realized profits must exceed its accumulated realized losses (on a non-consolidated basis) before dividends can be paid. Therefore, we must have distributable profits before issuing a dividend. We have never declared or paid a dividend on our ordinary shares in

the past, and we currently intend to retain our future earnings, if any, to fund the development and growth of our business. As a result, capital appreciation, if any, on our ADSs will be your sole source of gains for the foreseeable future. Investors seeking cash dividends should not purchase our ADSs in this offering.

As a holding company, our only material assets will be our equity interests in our operating subsidiaries, and our principal source of cash flow will be distributions from such subsidiaries, which may be limited by law and/or contract in making such distributions.

We are holding company that does not conduct any business operations of our own. While we have the ability to raise additional capital through the issuance of equity securities, such as in this offering or in future equity financings, our principal source of cash flow will be distributions from our subsidiaries. Therefore, our ability to carry out our business plan, to fund and conduct our business and to pay dividends, if any, in the future will depend on the ability of our subsidiaries to generate sufficient net income and cash flow to make upstream cash distributions to us. Our subsidiaries are separate legal entities, and although we wholly own and control them, they have no obligation to make any funds available to us, whether in the form of loans, dividends or otherwise. The ability of our subsidiaries to distribute cash to us will also be subject to, among other things, restrictions that may be contained in our subsidiaries’ agreements, as entered into from time to time, availability of sufficient funds in such subsidiaries and applicable laws and regulatory restrictions. Claims of any creditors of our subsidiaries generally will have priority as to the assets of such subsidiaries over our claims and claims of our shareholders. To the extent the ability of our subsidiaries to distribute dividends or other payments to us is limited in any way, this could materially limit our ability to fund and conduct our business and pay dividends, if any.

If we are a passive foreign investment company following this offering, there could be adverse U.S. federal income tax consequences to U.S. Holders.

Under the Internal Revenue Code of 1986, as amended, or the Code, we will be a passive foreign investment company, or PFIC, for any taxable year in which (1) 75% or more of our gross income consists of passive income or (2) 50% or more of the average quarterly value of our assets consists of assets that produce, or are held for the production of, passive income. For purposes of these tests, passive income includes dividends, interest, gains from the sale or exchange of investment property and certain rents and royalties. In addition, for purposes of the above calculations, a non-U.S. corporation that directly or indirectly owns at least 25% by value of the shares of another corporation is treated as if it held its proportionate share of the assets and received directly its proportionate share of the income of such other corporation. If we are a PFIC for any taxable year during which a U.S. Holder (as defined below under “Material Income Tax Considerations—Material U.S. Federal Income Tax Considerations for U.S. Holders”) holds our ADSs, the U.S. Holder may be subject to adverse tax consequences regardless of whether we continue to qualify as a PFIC, including ineligibility for any preferred tax rates on capital gains or on actual or deemed dividends, interest charges on certain taxes treated as deferred, and additional reporting requirements.

We do not believe we were a PFIC for our taxable year ended September 30, 2017. Based on our current estimates of expected gross assets and income, we do not believe we will be a PFIC for our taxable year ending September 30, 2018. However, no assurances regarding our PFIC status can be provided for any past, current or future taxable years. The determination of whether we are a PFIC is a fact-intensive determination made on an annual basis and the applicable law is subject to varying interpretation. In particular, the characterization of our assets as active or passive may depend in part on our current and intended future business plans, which are subject to change. In addition, for our current and future taxable years, the total value of our assets for PFIC testing purposes may be determined in part by reference to the market price of our ordinary shares or ADSs from time to time,

which may fluctuate considerably. Under the income test, our status as a PFIC depends on the composition of our income which will depend on the transactions we enter into in the future and our corporate structure. The composition of our income and assets is also affected by how, and how quickly, we spend the cash we raise in any offering, including this offering. Accordingly, in its legal opinion issued in connection with this offering, our U.S. counsel expresses no opinion with respect to our PFIC status for our taxable year ended September 30, 2017, and also expresses no opinion with regard to our expectations regarding our PFIC status in the future.

If we are a PFIC, U.S. holders of our ADSs would be subject to adverse U.S. federal income tax consequences, such as ineligibility for any preferred tax rates on capital gains or on actual or deemed dividends, interest charges on certain taxes treated as deferred, and additional reporting requirements under U.S. federal income tax laws and regulations. For further discussion of the PFIC rules and the adverse U.S. federal income tax consequences in the event we are classified as a PFIC, see the section titled ‘‘Material Income Tax Considerations—Material U.S. Federal Income Considerations for U.S. Holders” in this prospectus.

If a United States person is treated as owning at least 10% of our ordinary shares, including ordinary shares represented by ADSs, such holder may be subject to adverse U.S. federal income tax consequences.

If a U.S. Holder (as defined below under “Material Income Tax Considerations—Material U.S. Federal Income Tax Considerations for U.S. Holders”) is treated as owning (directly, indirectly or constructively) at least 10% of the value or voting power of our ordinary shares, including ordinary shares represented by ADSs, such U.S. Holder may be treated as a “United States shareholder” with respect to each “controlled foreign corporation” in our group (if any). Because our group includes at least one U.S. subsidiary (Autolus Inc.), certain of our non-U.S. subsidiaries may be treated as controlled foreign corporations (regardless of whether Autolus Therapeutics plc is treated as a controlled foreign corporation). A United States shareholder of a controlled foreign corporation may be required to annually report and include in its U.S. taxable income its pro rata share of “Subpart F income,” “global intangible low-taxed income” and investments in U.S. property by controlled foreign corporations, regardless of whether we make any distributions. An individual that is a United States shareholder with respect to a controlled foreign corporation generally would not be allowed certain tax deductions or foreign tax credits that would be allowed to a United States shareholder that is a U.S. corporation. We cannot provide any assurances that we will assist investors in determining whether any of our non-U.S. subsidiaries, if any, are treated as a controlled foreign corporation or whether such investor is treated as a United States shareholder with respect to any of such controlled foreign corporations. Further, we cannot provide any assurances that we will furnish to any U.S. shareholder information that may be necessary to comply with the reporting and tax paying obligations discussed above. Failure to comply with these reporting obligations may subject you to significant monetary penalties and may prevent the statute of limitations with respect to your U.S. federal income tax return for the year for which reporting was due from starting. U.S. Holders should consult their tax advisors regarding the potential application of these rules to their investment in our ADSs.

We may be unable to use U.K. carryforward tax losses to reduce future tax payments or benefit from favorable U.K. tax legislation.

As a U.K. resident trading entity, we are subject to U.K. corporate taxation. Due to the nature of our business, we have generated losses since inception. As of September 30, 2017, we had cumulative carryforward tax losses of $22.8 million. Subject to any relevant restrictions (including those that limit the percentage of profits that can be reduced by carried forward losses and those that can restrict the use of carried forward losses where there is a change of ownership of more than half the ordinary shares of the company and a major change in the nature, conduct or scale of the trade), we

expect these to be available to carry forward and offset against future operating profits. As a company that carries out extensive research and development activities, we benefit from the U.K. research and development tax credit regime under the scheme for small and medium-sized enterprises, or SMEs, and also claim a Research and Development Expenditure Credit, or RDEC, to the extent that our projects are grant funded. Under the SME scheme, we are able to surrender some of our trading losses that arise from our qualifying research and development activities for a cash rebate of up to 33.35% of such qualifying research and development expenditures. The net tax benefit of the RDEC is expected to be 8.9% (increasing to 9.13% in financial year 2020). Qualifying expenditures largely are comprised of employment costs for research staff, consumables, outsourced CRO costs and utilities costs incurred as part of research projects. Specified subcontracted qualifying research expenditures are eligible for a cash rebate of up to 21.67%.

In the event we generate revenues in the future, we may benefit from the U.K. “patent box” regime that allows profits attributable to revenues from patents or patented products to be taxed at an effective rate of 10%. We are the exclusive licensee or owner of one patent and several patent applications which, if issued, would cover our product candidates, and accordingly, future upfront fees, milestone fees, product revenues and royalties could be taxed at this tax rate. When taken in combination with the enhanced relief available on our research and development expenditures, we expect a long-term lower effective rate of corporation tax to apply to us. If, however, there are unexpected adverse changes to the U.K. research and development tax credit regime or the “patent box” regime, or for any reason we are unable to qualify for such advantageous tax legislation, or we are unable to use net operating loss and tax credit carryforwards and certain built-in losses to reduce future tax payments, our business, results of operations, and financial condition may be adversely affected.

Future changes to tax laws could materially adversely affect our company and reduce net returns to our shareholders.

The tax treatment of the company is subject to changes in tax laws, regulations and treaties, or the interpretation thereof, tax policy initiatives and reforms under consideration and the practices of tax authorities in jurisdictions in which we operate, as well as tax policy initiatives and reforms related to the Organisation for Economic Co-Operation and Development’s, or OECD, Base Erosion and Profit Shifting, or BEPS, Project, the European Commission’s state aid investigations and other initiatives. Such changes may include (but are not limited to) the taxation of operating income, investment income, dividends received or (in the specific context of withholding tax) dividends paid. We are unable to predict what tax reform may be proposed or enacted in the future or what effect such changes would have on our business, but such changes, to the extent they are brought into tax legislation, regulations, policies or practices, could affect our financial position and overall or effective tax rates in the future in countries where we have operations, reduce post-tax returns to our shareholders, and increase the complexity, burden and cost of tax compliance.

In addition, on December 22, 2017, President Trump signed into law new legislation that significantly revises the Internal Revenue Code of 1986, as amended. The newly enacted U.S. federal income tax law, among other things, contains significant changes to corporate taxation, including reduction of the corporate tax rate from a top marginal rate of 35% to a flat rate of 21%, limitation of the tax deduction for interest expense to 30% of adjusted earnings (except for certain small businesses), limitation of the deduction for net operating losses to 80% of current year taxable income and elimination of net operating loss carrybacks, one time taxation of offshore earnings at reduced rates regardless of whether they are repatriated, elimination of U.S. tax on foreign earnings (subject to certain important exceptions), immediate deductions for certain new investments instead of deductions for depreciation expense over time, and modifying or repealing many business deductions and credits. Notwithstanding the reduction in the corporate income tax rate, the overall impact of the new federal tax law is uncertain and our business and financial condition could be adversely affected. In addition, it

is uncertain if and to what extent various states will conform to the newly enacted federal tax law. The impact of this tax reform on holders of our ADSs is also uncertain and could be adverse. We urge you to consult with your legal and tax advisors with respect to this legislation and the potential tax consequences of investing in or holding our ADSs.

Tax authorities may disagree with our positions and conclusions regarding certain tax positions, resulting in unanticipated costs, taxes or non-realization of expected benefits.

A tax authority may disagree with tax positions that we have taken, which could result in increased tax liabilities. For example, Her Majesty’s Revenue & Customs, or HMRC, the U.S. Internal Revenue Service or another tax authority could challenge our allocation of income by tax jurisdiction and the amounts paid between our affiliated companies pursuant to our intercompany arrangements and transfer pricing policies, including amounts paid with respect to our intellectual property development. Similarly, a tax authority could assert that we are subject to tax in a jurisdiction where we believe we have not established a taxable connection, often referred to as a ‘‘permanent establishment’’ under international tax treaties, and such an assertion, if successful, could increase our expected tax liability in one or more jurisdictions. A tax authority may take the position that material income tax liabilities, interest and penalties are payable by us, in which case, we expect that we might contest such assessment. Contesting such an assessment may be lengthy and costly and if we were unsuccessful in disputing the assessment, the implications could increase our anticipated effective tax rate, where applicable.

We will incur significantly increased costs as a result of operating as a company whose ADSs are publicly traded in the United States, and our management will be required to devote substantial time to new compliance initiatives.

As a public company in the United States, we will incur significant legal, accounting and other expenses that we did not incur previously. These expenses will likely be even more significant after we no longer qualify as an emerging growth company. The Sarbanes-Oxley Act, the Dodd-Frank Wall Street Reform and Consumer Protection Act, the listing requirements of Nasdaq and other applicable securities rules and regulations impose various requirements on public companies in the United States, including the establishment and maintenance of effective disclosure and financial controls and corporate governance practices. Our senior management and other personnel will need to devote a substantial amount of time to these compliance initiatives. Moreover, these rules and regulations will increase our legal and financial compliance costs and will make some activities more time-consuming and costly. For example, we expect that these rules and regulations may make it more difficult and more expensive for us to obtain director and officer liability insurance, which in turn could make it more difficult for us to attract and retain qualified senior management personnel or members for our board of directors.

However, these rules and regulations are often subject to varying interpretations, in many cases due to their lack of specificity, and, as a result, their application in practice may evolve over time as new guidance is provided by regulatory and governing bodies. This could result in continuing uncertainty regarding compliance matters and higher costs necessitated by ongoing revisions to disclosure and governance practices.

Pursuant to Section 404, we will be required to furnish a report by our senior management on our internal control over financial reporting. However, while we remain an emerging growth company, we will not be required to include an attestation report on internal control over financial reporting issued by our independent registered public accounting firm. To prepare for eventual compliance with Section 404, we will be engaged in a process to document and evaluate our internal control over financial reporting, which is both costly and challenging. In this regard, we will need to continue to

dedicate internal resources, potentially engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting, continue steps to improve control processes as appropriate, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. Despite our efforts, there is a risk that we will not be able to conclude, within the prescribed timeframe or at all, that our internal control over financial reporting is effective as required by Section 404. As described elsewhere in this Risk Factors section, our independent registered public accounting firm has identified a material weakness over our internal control over financial reporting. If we are unable to successfully remediate that identified material weakness, or if we identify other material weaknesses, it could result in an adverse reaction in the financial markets due to a loss of confidence in the reliability of our financial statements.

We are an “emerging growth company” and as a result of the reduced disclosure and governance requirements applicable to emerging growth companies, our ADSs may be less attractive to investors.

We are an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. For as long as we continue to be an emerging growth company, we may take advantage of exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies, including not being required to comply with the auditor attestation requirements of Section 404, exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. As an emerging growth company, we are able to report only two years of financial results and selected financial data compared to three and five years, respectively, for comparable data reported by other public companies. We may take advantage of these exemptions until we are no longer an emerging growth company. We could be an emerging growth company for up to five years, although circumstances could cause us to lose that status earlier, including if the aggregate market value of our ordinary shares, including ordinary shares represented by ADSs, held by non-affiliates exceeds $700 million as of the end of our second fiscal quarter before that time, in which case we would no longer be an emerging growth company as of the following September 30^th (the last day of our fiscal year). We cannot predict if investors will find our ADSs less attractive because we may rely on these exemptions. If some investors find our ADSs less attractive as a result, there may be a less active trading market for our ADSs and the price of our ADSs may be more volatile.

Under Section 107(b) of the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards until such time as those standards apply to private companies. We have irrevocably elected not to avail ourselves of this exemption from new or revised accounting standards and, therefore, we will be subject to the same new or revised accounting standards as other public companies that are not emerging growth companies.

We qualify as a foreign private issuer and, as a result, we will not be subject to U.S. proxy rules and will be subject to Exchange Act reporting obligations that permit less detailed and frequent reporting than that of a U.S. domestic public company.

Upon the closing of this offering, we will report under the Exchange Act as a non-U.S. company with foreign private issuer status. Because we qualify as a foreign private issuer under the Exchange Act, we are exempt from certain provisions of the Exchange Act that are applicable to U.S. domestic public companies, including (i) the sections of the Exchange Act regulating the solicitation of proxies, consents or authorizations in respect of a security registered under the Exchange Act; (ii) the sections of the Exchange Act requiring insiders to file public reports of their stock ownership and trading activities and liability for insiders who profit from trades made in a short period of time; and (iii) the rules under the

Exchange Act requiring the filing with the SEC of quarterly reports on Form 10-Q containing unaudited financial and other specified information, or current reports on Form 8-K upon the occurrence of specified significant events. In addition, foreign private issuers are not required to file their annual report on Form 20-F until 120 days after the end of each fiscal year, while U.S. domestic issuers that are accelerated filers are required to file their annual report on Form 10-K within 75 days after the end of each fiscal year. Foreign private issuers also are exempt from Regulation FD, aimed at preventing issuers from making selective disclosures of material information. As a result of the above, you may not have the same protections afforded to shareholders of companies that are not foreign private issuers.

If we lose our status as a foreign private issuer, we would be required to comply with the Exchange Act reporting and other requirements applicable to U.S. domestic issuers, which are more detailed and extensive than the requirements for foreign private issuers. We may also be required to make changes in our corporate governance practices in accordance with various SEC and Nasdaq rules. The regulatory and compliance costs to us under U.S. securities laws if we are required to comply with the reporting requirements applicable to a U.S. domestic issuer may be significantly higher than the cost we would incur as a foreign private issuer. As a result, we expect that a loss of foreign private issuer status would increase our legal and financial compliance costs and would make some activities highly time consuming and costly. We also expect that if we were required to comply with the rules and regulations applicable to U.S. domestic issuers, it would make it more difficult and expensive for us to obtain director and officer liability insurance, and we may be required to accept reduced coverage or incur substantially higher costs to obtain coverage. These rules and regulations could also make it more difficult for us to attract and retain qualified members of our board of directors.

As a foreign private issuer, we are permitted to adopt certain home country practices in relation to corporate governance matters that differ significantly from Nasdaq corporate governance listing standards. These practices may afford less protection to shareholders than they would enjoy if we complied fully with Nasdaq corporate governance listing standards.

We are entitled to rely on a provision in Nasdaq’s corporate governance rules that allows us to follow English corporate law and the Companies Act with regard to certain corporate governance matters. This allows us to follow certain corporate governance practices that differ in significant respects from the corporate governance requirements applicable to U.S. companies listed on Nasdaq.

We intend to continue to follow English corporate governance practices in lieu of the following corporate governance requirements of Nasdaq: (i) disclosure requirement within four business days of any determination to grant a waiver of the code of business conduct and ethics to directors and officers and (ii) requirement to obtain shareholder approval for certain issuances of securities, including shareholder approval of option plans. Therefore, our shareholders may be afforded less protection than they otherwise would have under corporate governance listing standards applicable to U.S. domestic issuers.

Shareholder protections found in provisions under the U.K. City Code on Takeovers and Mergers, or the Takeover Code, will apply if our place of management and control remains in the United Kingdom.

We believe that as of the date of this prospectus our place of central management and control is in the United Kingdom for the purposes of the jurisdictional criteria of the Takeover Code. Accordingly, we believe that we are currently subject to the Takeover Code and, as a result, our shareholders are currently entitled to the benefit of certain takeover offer protections provided under the Takeover Code, including the rules regarding mandatory takeover bids.

The Takeover Code provides a framework within which takeovers of companies are regulated and conducted. The Takeover Panel may, at any relevant time, review our place of central

management and control based on the jurisdictional criteria of the Takeover Code, and their assessment as to jurisdiction may or may not change. Absent a relevant event occurring under the Takeover Code, it is unlikely that the Takeover Panel would reassess jurisdiction in the interim. It is feasible that, in the future, due to the board’s composition, location of board meetings, changes in the Takeover Panel’s interpretation of the Takeover Code or other events, the Takeover Panel’s assessment of its jurisdiction regarding and applicability of the Takeover Code to the company may change.

The following is a brief summary of some of the most important rules of the Takeover Code:

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When either (i) a person, together with persons acting in concert with him, acquires, whether by a series of transactions over a period of time or not, an interest in shares which (when taken together with shares in which persons acting in concert with him are interested) carry 30% or more of the voting rights of a company (which percentage is treated by the Takeover Code as the level at which effective control is obtained); or (ii) any person who, together with persons acting in concert with him, is interested in shares which in the aggregate carry not less than 30% of the voting rights of a company but does not hold shares carrying more than 50% of such voting rights and such person, or any person acting in concert with him, acquires an interest in any other shares which increases the percentage of shares carrying voting rights in which he is interested, such person must make a cash offer to all other shareholders at not less than the highest price paid by the person required to make an offer or any person acting in concert with him during the 12 months before the offer was announced.

•

If an offer has been made for a company and interests in shares carrying 10% or more of the voting rights of a class have been acquired by the offeror (i.e., a bidder) in the offer period and the previous 12 months, the offer must include a cash alternative for all shareholders of that class at the highest price paid by the offeror in that period. Further, if an offeror acquires for cash any interest in shares during the offer period, a cash alternative must be made available at a price at least equal to the price paid for such shares.

•

If, after making an offer for a company, the offeror acquires an interest in shares in an offeree company (i.e., a target) at a price higher than the value of the offer, the offer must be increased accordingly.

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An offeree company must appoint a competent independent adviser whose advice on the financial terms of the offer must be made known to all the shareholders, together with the opinion of the board of directors of the offeree company.

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Favorable deals for selected shareholders are banned.

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All shareholders must be given the same information.

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Those issuing takeover circulars must include statements taking responsibility for the contents thereof.

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Profit forecasts, quantified financial benefits statements and asset valuations must be made to specified standards and must be reported on by professional advisers.

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Misleading, inaccurate or unsubstantiated statements made in documents or to the media must be publicly corrected immediately.

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Actions during the course of an offer by the offeree company, which might frustrate the offer are generally prohibited unless shareholders approve these plans. Stringent requirements are laid down for the disclosure of dealings in relevant securities during an offer.

Employees of both the offeror and the offeree company and the trustees of the offeree company’s pension scheme must be informed about an offer. In addition, the offeree company’s employee

representatives and pension scheme trustees have the right to have a separate opinion on the effects of the offer on employment appended to the offeree board of directors’ circular or published on a website.

You may face difficulties in protecting your interests, and your ability to protect your rights through the U.S. federal courts may be limited, because we are incorporated under the laws of England and Wales, conduct most of our operations outside the United States and most of our directors and senior management reside outside the United States.

We are incorporated and have our registered office in, and are currently existing under the laws of, England and Wales. In addition, most of our tangible assets are located, and most of our senior management and directors reside, outside of the United States. As a result, it may not be possible to serve process within the United States on certain directors or us or to enforce judgments obtained in U.S. courts against such directors or us based on civil liability provisions of the securities laws of the United States. As a result, it may not be possible for investors to effect service of process within the United States upon such persons or to enforce judgments obtained in U.S. courts against them or us, including judgments predicated upon the civil liability provisions of the U.S. federal securities laws.

The United States and the United Kingdom do not currently have a treaty providing for recognition and enforcement of judgments (other than arbitration awards) in civil and commercial matters. Consequently, a final judgment for payment given by a court in the United States, whether or not predicated solely upon U.S. securities laws, would not automatically be recognized or enforceable in the United Kingdom. In addition, uncertainty exists as to whether U.K. courts would entertain original actions brought in the United Kingdom against us or our directors or senior management predicated upon the securities laws of the United States or any state in the United States. Any final and conclusive monetary judgment for a definite sum obtained against us in U.S. courts would be treated by the courts of the United Kingdom as a cause of action in itself and sued upon as a debt at common law so that no retrial of the issues would be necessary, provided that certain requirements are met.

Whether these requirements are met in respect of a judgment based upon the civil liability provisions of the U.S. securities laws, including whether the award of monetary damages under such laws would constitute a penalty, is subject to determination by the court making such decision. If an English court gives judgment for the sum payable under a U.S. judgment, the English judgment will be enforceable by methods generally available for this purpose. These methods generally permit the English court discretion to prescribe the manner of enforcement.

As a result, U.S. investors may not be able to enforce against us or certain of our directors any judgments obtained in U.S. courts in civil and commercial matters, including judgments under the U.S. federal securities laws.

As an English public limited company, certain capital structure decisions will require shareholder approval, which may limit our flexibility to manage our capital structure.

We intend to alter the legal status of our company under English law from a private limited company by re-registering as a public limited company and changing our name from Autolus Therapeutics Limited to Autolus Therapeutics plc prior to the completion of this offering. English law provides that a board of directors may only allot shares (or rights to subscribe for or convertible into shares) with the prior authorization of shareholders, such authorization being up to the aggregate nominal amount of shares and for a maximum period of five years, each as specified in the articles of association or relevant shareholder resolution. The Articles of Association authorize the allotment of additional shares for a period of five years from (being the date of the adoption of the Articles of Association), which authorization will need to be renewed upon expiration (i.e., at least every five years) but may be sought more frequently for additional five-year terms (or any shorter period).

English law also generally provides shareholders with preemptive rights when new shares are issued for cash. However, it is possible for the articles of association, or for shareholders to pass a special resolution at a general meeting, being a resolution passed by at least 75% of the votes cast, to disapply preemptive rights. Such a disapplication of preemptive rights may be for a maximum period of up to five years from the date of adoption of the articles of association, if the disapplication is contained in the articles of association, or from the date of the shareholder special resolution, if the disapplication is by shareholder special resolution. In either case, this disapplication would need to be renewed by our shareholders upon its expiration (i.e., at least every five years). The Articles of Association disapply preemptive rights for a period of five years from , which disapplication will need to be renewed upon expiration (i.e., at least every five years) to remain effective, but may be sought more frequently for additional five-year terms (or any shorter period).

English law also generally prohibits a public company from repurchasing its own shares without the prior approval of shareholders by ordinary resolution, being a resolution passed by a simple majority of votes cast, and other formalities. Such approval may be for a maximum period of up to five years. See the section titled “Description of Share Capital and Articles of Association.”

If equity research analysts do not publish research or reports, or publish unfavorable research or reports, about us, our business or our market, the price and trading volume of our ADSs could decline.

The trading market for our ADSs will be influenced by the research and reports that equity research analysts publish about us and our business. We do not currently have and may never obtain research coverage by equity research analysts. Equity research analysts may elect not to provide research coverage of our ADSs after the completion of this offering, and such lack of research coverage may adversely affect the market price of our ADSs. In the event we do have equity research analyst coverage, we will not have any control over the analysts or the content and opinions included in their reports. The price of our ADSs could decline if one or more equity research analysts downgrade our ADSs or issue other unfavorable commentary or research about us. If one or more equity research analysts ceases coverage of us or fails to publish reports on us regularly, demand for our ADSs could decrease, which in turn could cause the trading price or trading volume of our ADSs to decline.

You may be subject to limitations on transfers of your ADSs.

Your ADSs are transferable on the books of the depositary. However, the depositary may close its transfer books at any time or from time to time when deemed necessary or advisable by it in good faith in connection with the performance of its duties or at our reasonable written request, subject in all cases to compliance with applicable U.S. securities laws. In addition, the depositary may refuse to deliver, transfer or register transfers of ADSs generally when our books or the books of the depositary are closed, or at any time if we or the depositary deems it advisable to do so because of any requirement of law or of any government or governmental body, or under any provision of the deposit agreement, or for any other reason.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements that involve substantial risks and uncertainties. In some cases, you can identify forward-looking statements by the words “may,” “might,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue” and “ongoing,” or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements and opinions contained in this prospectus are based upon information available to us as of the date of this prospectus and, while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. Forward-looking statements contained in this prospectus include, but are not limited to, statements about:

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the development of our product candidates, including statements regarding the timing of initiation, completion and the outcome of clinical studies or trials and related preparatory work, the period during which the results of the trials will become available and our research and development programs;

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our ability to obtain and maintain regulatory approval of our product candidates in the indications for which we plan to develop them, and any related restrictions, limitations or warnings in the label of an approved drug or therapy;

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our ability to license additional intellectual property relating to our product candidates from third parties and to comply with our existing license agreement;

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our plans to research, develop, manufacture and commercialize our product candidates;

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the timing of our regulatory filings for our product candidates;

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the size and growth potential of the markets for our product candidates;

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our ability to raise additional capital;

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our commercialization, marketing and manufacturing capabilities and strategy;

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our expectations regarding our ability to obtain and maintain intellectual property protection;

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our ability to commercialize our products in light of the intellectual property rights of others;

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our ability to attract and retain qualified employees and key personnel;

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our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

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the scalability and commercial viability of our manufacturing methods and processes;

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the success of competing therapies that are or may become available;

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whether we are classified as a PFIC for current and future periods;

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our estimates regarding future revenue, expenses and needs for additional financing; and

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our expected use of proceeds from this offering.

You should refer to the section titled “Risk Factors” for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. As a result of these factors, we cannot assure you that the forward-looking statements in

this prospectus will prove to be accurate. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all. We undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

You should read this prospectus and the documents that we reference in this prospectus and have filed as exhibits to the registration statement of which this prospectus is a part completely and with the understanding that our actual future results may be materially different from what we expect.

This prospectus also contains estimates, projections and other information concerning our industry, our business, and the markets for our product candidates. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties, and actual events or circumstances may differ materially from events and circumstances that are assumed in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from our own internal estimates and research as well as from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

In addition, assumptions and estimates of our and our industry’s future performance are necessarily subject to a high degree of uncertainty and risk due to a variety of factors, including those described in the section titled ‘‘Risk Factors.’’ These and other factors could cause our future performance to differ materially from our assumptions and estimates.

USE OF PROCEEDS

We estimate that the net proceeds from the sale of ADSs in this offering will be

$ million, or $ million if the underwriters exercise their option to purchase additional ADSs in full, based on an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, and after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us.

A $1.00 increase (decrease) in the assumed initial public offering price of $ per ADS, which is the midpoint of the range listed on the cover page of this prospectus, would increase (decrease) the net proceeds to us from this offering by $ million, assuming that the number of ADSs offered by us, as set forth on the cover page of this prospectus, remains the same. An increase (decrease) of 1,000,000 in the number of ADSs we are offering would increase (decrease) the net proceeds to us from this offering by $ million, assuming the assumed initial public offering price remains the same, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

As of September 30, 2017, we had cash of $137.1 million. We currently expect to use the net proceeds from this offering, together with our existing cash, to advance our clinical pipeline, including, specifically:

•

approximately $ to contribute to the clinical trial conducted by UCL for AUTO1 in adult ALL and complete the proof-of-concept phases of our Phase 1/2 clinical trials of AUTO2 in multiple myeloma, AUTO3 in pediatric ALL and DLBCL, and AUTO4 in peripheral T-cell lymphoma, and advance three of these product candidates through later phases of clinical development and, potentially, registration;

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approximately $ to develop AUTO3 NG and AUTO5, our earlier stage hematological programs, and AUTO6 NG and AUTO7, our product candidates targeting solid tumor indications, through completion the proof-of-concept phases of Phase 1/2 clinical trials;

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approximately $ to fund our research and development activities to further expand our T cell programming technologies and develop future product candidates and follow-on versions of our more advanced product candidates;

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approximately $ to fund our manufacturing activities to support our ongoing and future clinical trials and potential commercial launch; and

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the balance for other general corporate purposes, including general and administrative expenses, development of our commercial infrastructure and working capital.

Based on our current operational plans and assumptions, we expect that the net proceeds from this offering, combined with our current cash, will be sufficient to fund operations through , but that we will need to raise additional capital in order to commercialize our product candidates, including any potential future trials that may be required by regulatory authorities. Our expected use of net proceeds from this offering represents our current intentions based upon our present plans and business condition. As of the date of this prospectus, we cannot predict with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering or the actual amounts that we will spend on the uses set forth above. We believe opportunities may exist from time to time to expand our current business through the acquisition or in-license of complementary product candidates or programming technologies. While we have no current agreements for any specific acquisitions or in-licenses at this time, we may use a portion of the net proceeds for these purposes.

The amounts and timing of our actual expenditures will depend on numerous factors, including the progress of our clinical trials, the potential for achieving accelerated regulatory approval and the amount of cash used in our operations. We therefore cannot estimate with certainty the amount of net

proceeds to be used for the purposes described above. We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds.

Pending these uses, we plan to invest these net proceeds in short-term, interest bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the United States. The goal with respect to the investment of these net proceeds is capital preservation and liquidity so that such funds are readily available to fund our operations.

DIVIDEND POLICY

We have never declared or paid a dividend, and we do not anticipate declaring or paying dividends in the foreseeable future. We intend to retain all available funds and any future earnings to fund the development and expansion of our business. See the section titled “Risk Factors—Risks Related to this Offering, Our Securities and Our Status as a Public Company—Because we do not anticipate paying any cash dividends on our ADSs in the foreseeable future, capital appreciation, if any, will be your sole source of gains and you may never receive a return on your investment.”

Under current English law, among other things, a company’s accumulated realized profits must exceed its accumulated realized losses (on a non-consolidated basis) before dividends can be paid. Accordingly, we may only pay dividends if we have sufficient distributable reserves (on a non-consolidated basis), which are our accumulated realized profits that have not been previously distributed or capitalized less our accumulated realized losses, so far as such losses have not been previously written off in a reduction or reorganization of capital.

CORPORATE REORGANIZATION

We are a private company with limited liability incorporated pursuant to the laws of England and Wales in February 2018 as Autolus Therapeutics Limited. We were incorporated with nominal assets and liabilities for the purpose of becoming the ultimate holding company for Autolus Limited and for the purpose of consummating the corporate reorganization described herein. Autolus Limited was formed as a separate company in July 2014. Prior to the completion of this offering, we intend to form another holding company, Autolus Holdings (UK) Limited, with Autolus Holdings (UK) Limited becoming a wholly owned subsidiary of Autolus Therapeutics Limited. Autolus Therapeutics Limited and Autolus Holdings (UK) Limited are or will be holding companies which have not or will not have conducted any operations prior to this offering other than activities incidental to their formation, the corporate reorganization and this offering.

Following the completion of our corporate reorganization:

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Autolus Therapeutics Limited will ultimately become the direct holding company of Autolus Holdings (UK) Limited and the indirect holding company of Autolus Limited.

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Autolus Holdings (UK) Limited will ultimately become the wholly owned subsidiary of Autolus Therapeutics Limited and the direct holding company for Autolus Limited.

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Autolus Therapeutics Limited will re-register as a public limited company to be re-named Autolus Therapeutics plc.

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Autolus Therapeutics plc will then have three direct and indirect subsidiaries: Autolus Holdings (UK) Limited, Autolus Limited and Autolus Inc.

Therefore, investors in this offering will only acquire, and this prospectus only describes, the offering of ADSs of Autolus Therapeutics plc.

The corporate reorganization will take place in several steps, all of which will be completed prior to the completion of this offering. We refer to the following steps, which are discussed in more detail below, as our “corporate reorganization”:

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Exchange of Autolus Limited Shares for Autolus Therapeutics Limited Shares: All shareholders of Autolus Limited will exchange each of the shares held by them for the same number and class of newly issued shares of Autolus Therapeutics Limited and, as a result, Autolus Limited will become a wholly owned subsidiary of Autolus Therapeutics Limited.

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Transfer of Autolus Limited Shares to Autolus Holdings (UK) Limited: Immediately after this share exchange, Autolus Therapeutics Limited will transfer the entire issued share capital of Autolus Limited to Autolus Holdings (UK) Limited and, as a result, Autolus Limited will become a wholly owned subsidiary of Autolus Holdings (UK) Limited, which, in turn, will be a wholly owned subsidiary of Autolus Therapeutics Limited.

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Reorganization of Separate Classes of Shares of Autolus Therapeutics Limited into a Single Class of Ordinary Shares: The different classes of issued share capital of Autolus Therapeutics Limited will be reorganized into a single class of ordinary shares.

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Reduction of Capital of Autolus Therapeutics Limited, Autolus Holdings (UK) Limited and Autolus Limited: Autolus Therapeutics Limited, Autolus Holdings (UK) Limited and Autolus Limited will reduce their issued share capital pursuant to Part 17 of the Companies Act.

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Re-registration of Autolus Therapeutics Limited as a Public Limited Company and Change of Name to Autolus Therapeutics plc.

Exchange of Autolus Limited Shares for Autolus Therapeutics Limited Shares

Prior to our corporate reorganization, the share capital of Autolus Limited was divided into the following classes: series A preferred shares, B ordinary shares, C ordinary shares and deferred shares. Prior to the effectiveness of the registration statement of which this prospectus forms a part, the shareholders of Autolus Limited will exchange each of these classes of shares of Autolus Limited for the same number and class of shares in Autolus Therapeutics Limited. As a result, Autolus Therapeutics Limited will become the sole shareholder of Autolus Limited.

Transfer of Autolus Limited Shares to Autolus Holdings (UK) Limited

Following Autolus Limited becoming a wholly owned subsidiary of Autolus Therapeutics Limited, Autolus Therapeutics Limited will transfer the entire issued share capital of Autolus Limited to Autolus Holdings (UK) Limited. As a result, Autolus Limited will become a wholly owned subsidiary of Autolus Holdings (UK) Limited, which, in turn, will be a wholly owned subsidiary of Autolus Therapeutics Limited.

Reorganization of Separate Classes of Shares of Autolus Therapeutics Limited into a Single Class of Ordinary Shares

Pursuant to the terms of the articles of association of Autolus Therapeutics Limited in effect at such time, each class of shares of Autolus Therapeutics Limited will be reorganized into one class of ordinary shares of Autolus Therapeutics Limited as follows:

•

Each series A preferred share will be converted into one B ordinary share;

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Each B ordinary share will be converted into one ordinary share; and

•

Each C ordinary share will be converted into one ordinary share.

As of September 30, 2017, we had 20,935 deferred shares issued and outstanding. As part of our corporate reorganization, we will, as part of the capital reduction described below, cancel all such deferred shares. Therefore, at the time of the re-registration of Autolus Therapeutics Limited as a public company, we will have no deferred shares issued or outstanding.

Reduction of Capital of Autolus Therapeutics Limited, Autolus Holdings (UK) Limited and Autolus Limited

Autolus Therapeutics Limited, Autolus Holdings (UK) Limited and Autolus Limited will reduce their issued share capital pursuant to Part 17 of the Companies Act by way of the cancellation of shares that are issued and outstanding (including all deferred shares then issued and outstanding), reduction in the nominal value of shares issued and outstanding and/or reduction of the amounts credited to each company’s share premium account or other permitted undistributable reserve. Any such reduction of capital will be credited to each company’s reserves that are available for distribution.

Re-registration of Autolus Therapeutics Limited as a Public Limited Company and Change of Name to Autolus Therapeutics plc

Following the steps described above and prior to the completion of this offering, Autolus Therapeutics Limited will re-register as a public limited company and change its name to Autolus Therapeutics plc. Such re-registration and change of name will require certain special resolutions to be passed by the shareholders of Autolus Therapeutics Limited to approve the re-registration as a public limited company, the name change to Autolus Therapeutics plc and the adoption of new articles of association for Autolus Therapeutics plc appropriate for a public company.

Certain further resolutions will be required to be passed by the shareholders of Autolus Therapeutics plc prior to the completion of this offering, details of which are set out in the section titled “Description of Share Capital and Articles of Association.”

Therefore, upon completion of the corporate reorganization and prior to the completion of this offering, the then-current shareholders of Autolus Limited will hold an aggregate of ordinary shares of Autolus Therapeutics plc.

Post-Completion of Corporate Reorganization and this Offering

CAPITALIZATION

The following table sets forth our cash and capitalization as of September 30, 2017 on:

•

an actual basis; and

•

a pro forma as adjusted basis to give effect to (i) our corporate reorganization and (ii) the sale of ADSs in this offering.

The pro forma as adjusted calculations assume an initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us.

You should read this information together with our unaudited financial statements, audited financial statements and related notes appearing elsewhere in this prospectus and the information set forth under the sections titled “Selected Financial Data,” “Use of Proceeds” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”


	As of September 30, 2017
	Actual			Pro Forma As Adjusted(1)
	(in thousands, except share and per share data)
Cash	$	137,070		$

Shareholders’ equity:
Preferred shares, £0.00001 par value; 78,143,548 shares authorized, 78,002,897 shares issued and outstanding, actual; shares authorized, shares issued and outstanding, pro forma as adjusted		1
Ordinary shares, £0.00001 par value; 119,203,434 shares authorized, 17,428,434 shares issued and outstanding, actual; shares authorized, shares issued and outstanding, pro forma as adjusted		—
Additional paid-in capital		194,351
Accumulated other comprehensive loss		(3,849	)
Accumulated deficit		(47,902	)

Total shareholders’ equity		142,601

Total capitalization	$	142,601		$

(1)

A $1.00 increase (decrease) in the assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, would increase (decrease) pro forma as adjusted amount of each of cash, total shareholders’ equity and total capitalization by $ million, assuming that the number of ADSs offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting estimated underwriting discounts and commissions. An increase (decrease) of 1,000,000 ADSs in the number of ADSs offered by us, as set forth on the cover page of this prospectus, would increase (decrease) the pro forma as adjusted amount of each of cash, total shareholders’ equity and total capitalization by $ million, assuming no change in the assumed initial public offering price per ADS and after deducting estimated underwriting discounts and commissions.

The number of ordinary shares outstanding on a pro forma as adjusted basis in the table above does not include:

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1,816,726 ordinary shares issuable upon the exercise of share options outstanding under our 2017 Share Option Plan as of September 30, 2017, at a weighted average price of $0.16 per share;

•

ordinary shares authorized for future issuance under our 2018 Equity Incentive Plan to be adopted in conjunction with this offering.

DILUTION

If you invest in our ADSs in this offering, your ownership interest will be immediately diluted to the extent of the difference between the initial public offering price per ADS in this offering and the pro forma as adjusted net tangible book value per ADS after this offering. Dilution results from the fact that the initial public offering price per ADS is substantially in excess of the net tangible book value per ADS. As of September 30, 2017, we had a historical net tangible book value of $142.6 million, or $8.18 per ordinary share (equivalent to $8.18 per ADS). Our net tangible book value per share represents total tangible assets less total liabilities, divided by the number of ordinary shares outstanding on September 30, 2017.

After giving effect to (i) our corporate reorganization and (ii) the sale of ADSs in this offering at an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, and after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value at September 30, 2017 would have been $ per ordinary share (equivalent to $ per ADS). This represents an immediate increase in pro forma as adjusted net tangible book value of $ per ADS to new investors and immediate dilution of $ per ADS to new investors. The following table illustrates this dilution to new investors purchasing ADSs in this offering on a per ADS basis:


Assumed initial public offering price per ADS			$
Historical net tangible book value per ADS as of September 30, 2017	$	8.18
Increase in net tangible book value per ADS attributable to our corporate reorganization and this offering

Pro forma as adjusted net tangible book value per ADS as of September 30, 2017

Dilution per ADS to new investors purchasing ADSs in this offering			$

The dilution information discussed above is illustrative only and will change based on the actual initial public offering price and other terms of this offering determined at pricing. A $1.00 increase (decrease) in the assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, would increase (decrease) our pro forma as adjusted net tangible book value as of September 30, 2017 after this offering by $ per ADS, and would increase (decrease) dilution to new investors by $ per ADS, assuming that the number of ADSs offered by us, as set forth on the cover page of this prospectus, remains the same. An increase of 1,000,000 in the number of ADSs we are offering would increase our pro forma as adjusted net tangible book value as of September 30, 2017 after this offering by $ per ADS, and would decrease dilution to new investors by $ per ADS, assuming the assumed initial public offering price per ADS remains the same. A decrease of 1,000,000 in the number of ADSs we are offering would decrease our pro forma as adjusted net tangible book value as of September 30, 2017 after this offering by $ per ADS, and would increase dilution to new investors by $ per ADS, assuming the assumed initial public offering price per ADS remains the same.

If the underwriters exercise their option to purchase additional ADSs in full, the pro forma as adjusted net tangible book value per ADS after the offering would be $ , the increase in net tangible book value per ADS to existing shareholders would be $ and the immediate dilution in net tangible book value per ADS to new investors in this offering would be $ .

The following table summarizes, on the pro forma as adjusted basis described above as of September 30, 2017, the differences between the existing shareholders and the new investors in this

offering with respect to the number of ordinary shares, including ordinary shares represented by ADSs purchased from us, the total consideration paid to us and the average price per share, including ordinary shares represented by ADSs, based on an assumed initial public offering price of $ per ADS, which is the midpoint of the price range set forth on the cover page of this prospectus, before deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.


	SHARES PURCHASED⁽¹⁾				TOTAL CONSIDERATION				AVERAGE PRICE PER SHARE
	NUMBER	PERCENT			AMOUNT	PERCENT			AVERAGE PRICE PER SHARE
Existing shareholders					$				$
New investors									$

Total			100	%	$		100	%

(1)	Including ordinary shares represented by ADSs.

A $1.00 increase (decrease) in the assumed initial public offering price of $ per ADS, which is the midpoint of the price range on the cover page of this prospectus, would increase or decrease the total consideration paid by new investors by $ million and, in the case of an increase, would increase the percentage of total consideration paid by new investors by percentage points and, in the case of a decrease, would decrease the percentage of total consideration paid by new investors by percentage points, assuming that the number of ADSs offered by us, as set forth on the cover page of this prospectus, remains the same. An increase (decrease) of 1,000,000 in the number of ADSs offered by us, as set forth on the cover page of this prospectus, would increase or decrease the total consideration paid by new investors by $ million and, in the case of an increase, would increase the percentage of total consideration paid by new investors by percentage points and, in the case of a decrease, would decrease the percentage of total consideration paid by new investors by percentage points, assuming no change in the assumed initial public offering price per ADS.

If the underwriters exercise their option to purchase additional ADSs in full, the percentage of ordinary shares held by existing shareholders will decrease to % of the total number of ordinary shares outstanding after the offering, and the number of shares held by new investors will be increased to , or % of the total number of ordinary shares outstanding after this offering.

The table and discussion above exclude:

•

1,816,726 ordinary shares issuable upon the exercise of share options outstanding under our 2017 Share Option Plan as of September 30, 2017, at a weighted average price of $0.16 per share;

•

ordinary shares authorized for future issuance under our 2018 Equity Incentive Plan to be adopted in conjunction with this offering.

To the extent that outstanding options are exercised, new options are issued under our 2018 Equity Incentive Plan, or we issue additional ordinary shares or ADSs in the future, there will be further dilution to investors participating in this offering.

SELECTED FINANCIAL DATA

The following tables present our selected financial data as of the dates and for the periods indicated. We derived the selected statement of operations and comprehensive loss data for the years ended September 30, 2016 and 2017 and the selected balance sheet data as of September 30, 2016 and 2017 from our audited financial statements included elsewhere in this prospectus. We prepare our financial statements in accordance with U.S. GAAP.

Our functional currency is the pound sterling. However, for financial reporting purposes, our financial statements, which are prepared using the functional currency, have been translated into U.S. dollars. Our assets and liabilities are translated at the exchange rates at the balance sheet date, our revenue and expenses are translated at average exchange rates and shareholders’ equity is translated based on historical exchange rates. Translation adjustments are not included in determining net income (loss) but are included in foreign exchange translation adjustment to other comprehensive loss, a component of shareholders’ equity.

As of September 29, 2017, the last business day of the year ended September 30, 2017, the representative exchange rate was £1.00 = $1.3392.


	Year Ended September 30,
	2016			2017
	(in thousands, except share and per share data)
Statement of Operations and Comprehensive Loss Data:
Grant income	$	1,212		$	1,693
Operating expenses:
Research and development		(10,436	)		(16,012	)
General and administrative		(5,152	)		(9,099	)

Total operating expenses, net		(14,376	)		(23,418	)
Other income, net		49			38

Net loss before income taxes		(14,327	)		(23,380	)
Income tax benefit		1,777			3,653

Net loss	$	(12,550	)	$	(19,727	)
Other comprehensive income (loss):
Foreign currency translation adjustment		(2,942	)		802

Total comprehensive loss	$	(15,492	)	$	(18,925	)

Basic and diluted net loss per ordinary share	$	(1.16	)	$	(1.61	)

Weighted-average basic and diluted ordinary shares		10,794,798			12,226,019

Pro forma basic and diluted net loss per share to ordinary shareholders (unaudited)				$	(0.45	)
Pro forma weighted-average basic and diluted ordinary shares (unaudited)					43,889,562


	As of September 30,
	2016		2017
	(in thousands)
Balance Sheet Data:
Cash	$	28,059	$	137,070
Working capital(1)		28,191		137,449
Total assets		34,180		148,662
Preferred shares		—		1
Ordinary shares		—		—
Additional paid-in capital		63,513		194,351
Total shareholders’ equity		30,687		142,601

(1)	We define working capital as current assets less current liabilities.

MANAGEMENT’S DISCUSSION AND ANALYSIS

OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

You should read the following discussion and analysis of our financial condition and results of operations together with section titled “Selected Financial Data” and our financial statements and related notes appearing elsewhere in this prospectus. Some of the information contained in this discussion and analysis or set forth elsewhere in this prospectus, including information with respect to our plans and strategy for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those set forth in the “Risk Factors” section of this prospectus, our actual results could differ materially from the results described in or implied by these forward-looking statements. Please also see the section titled “Special Note Regarding Forward-Looking Statements.”

In February 2018, Autolus Therapeutics Limited was incorporated under the laws of England and Wales to become the holding company for Autolus Limited pursuant to our corporate reorganization. See “Corporate Reorganization.” Prior to this offering, Autolus Therapeutics Limited has only engaged in activities incidental to its formation, the corporate reorganization and this offering. Accordingly, a discussion and analysis of the results of operations and financial condition of Autolus Therapeutics Limited for the period of its operations prior to the corporate reorganization would not be meaningful and are not presented. Following the corporate reorganization, the historical consolidated financial statements of Autolus Therapeutics plc will be retrospectively adjusted to include the historical financial results of Autolus Limited for all periods presented.

Overview

We are a biopharmaceutical company developing next-generation programmed T cell therapies for the treatment of cancer. Using our broad suite of proprietary and modular T cell programming technologies, we are engineering precisely targeted, controlled and highly active T cell therapies that are designed to better recognize cancer cells, break down their defense mechanisms and attack and kill these cells. We believe our programmed T cell therapies have the potential to be best-in-class and offer cancer patients substantial benefits over the existing standard of care, including the potential for cure in some patients.

Since our inception in July 2014, we have devoted substantially all of our resources to conducting preclinical studies and clinical trials, organizing and staffing our company, business planning, raising capital and establishing our intellectual property portfolio. We do not have any products approved for sale and have not generated any revenue from product sales. We have funded our operations to date primarily with sales of our equity securities. Through September 30, 2017, we have received net proceeds of $176.4 million from sales of our equity securities. We do not expect to generate significant revenue unless and until we obtain marketing approval for and commercialize one of our product candidates.

Since our inception, we have incurred operating losses. Our net loss was $12.6 million and $19.7 million for the years ended September 30, 2016 and 2017, respectively. As of September 30, 2017, we had an accumulated deficit of $47.9 million.

We expect to continue to incur significant expenses for the foreseeable future as we advance our product candidates through preclinical and clinical development, seek regulatory approval and pursue commercialization of any approved product candidates. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution. In addition, we may incur expenses in

connection with the in-license or acquisition of additional product candidates. Furthermore, following the closing of this offering, we expect to incur additional costs associated with operating as a public company, including significant legal, accounting, investor relations and other expenses that we did not incur as a private company.

As a result, we will need substantial additional funding to support our continuing operations and pursue our growth strategy. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through the sale of equity, debt financings or other capital sources, including potential collaborations with other companies or other strategic transactions. We may be unable to raise additional funds or enter into such other agreements or arrangements when needed on favorable terms, or at all. If we fail to raise capital or enter into such agreements as, and when, needed, we may have to significantly delay, scale back or discontinue the development and commercialization of one or more of our drug candidates or delay our pursuit of potential in-licenses or acquisitions.

As of September 30, 2017, we had cash on hand of $137.1 million. We believe that the anticipated net proceeds from this offering, together with our existing cash, will enable us to fund our operating expenses and capital expenditure requirements for at least the next months. We have based this estimate on assumptions that may prove to be wrong, and we could deplete our available capital resources sooner than we expect. See “—Liquidity and Capital Resources.”

Recent Developments

Cash as of December 31, 2017

As of December 31, 2017, our cash and cash equivalents were $129.0 million.

Components of Our Results of Operations

Grant Income

Grant income consists of proceeds from government research grants used to perform specific research and development activities. We recognize grant income over the period in which we recognize the related costs covered under the terms and conditions of the grant. We have received grants from the U.K. government, which are repayable under certain circumstances, including breach or noncompliance with the terms of the grant. For grants with refund provisions, we review the grant to determine the likelihood of repayment. If the likelihood of repayment of the grant is determined to be remote, then the grant is recognized as grant income.

Operating Expenses

Research and Development Expenses

Research and development expenses consist of costs incurred in connection with the research and development of our product candidates, which are partially offset by research and development expenditure tax credits provided by Her Majesty’s Revenue & Customs, or HMRC. We expense research and development costs as incurred. These expenses include:

•

expenses incurred under agreements with contract research organizations, or CROs, as well as investigative sites and consultants that conduct our clinical trials, preclinical studies and other scientific development services;

•

manufacturing scale-up expenses and the cost of acquiring and manufacturing preclinical and clinical trial materials;

•

employee-related expenses, including salaries, related benefits, travel and share-based compensation expense for employees engaged in research and development functions;

•

expenses incurred for outsourced professional scientific development services;

•

costs for laboratory materials and supplies used to support our research activities;

•

allocated facilities costs, depreciation and other expenses, which include rent and utilities; and

•

upfront, milestone and management fees for maintaining licenses under our third-party licensing agreements.

We recognize external development costs based on an evaluation of the progress to completion of specific tasks using information provided to us by our service providers.

Our direct research and development expenses are tracked on a program-by-program basis for our product candidates and consist primarily of external costs, such as fees paid to outside consultants and CROs in connection with our preclinical development, manufacturing and clinical development activities. Our direct research and development expenses by program also include fees incurred under license agreements. We do not allocate employee costs or facility expenses, including depreciation or other indirect costs, to specific programs because these costs are deployed across multiple programs and, as such, are not separately classified. We use internal resources primarily to oversee research and development as well as for managing our preclinical development, process development, manufacturing and clinical development activities.

The table below summarizes our research and development expenses incurred by program:


	Year Ended September 30,
	2016		2017		Change
	(in thousands)
Direct research and development expenses by program:
AUTO2	$	1,379	$	1,782	$	403
AUTO3		446		1,733		1,287
AUTO4		102		1,153		1,051
AUTO5		—		317		317

Total direct research and development expense		1,927		4,985		3,058
Research and discovery and unallocated costs:
Personnel related (including share-based compensation)		4,638		6,984		2,346
License fees		1,481		38		(1,443	)
Indirect research and development expense		2,390		4,005		1,615

Total research and development expenses	$	10,436	$	16,012	$	5,576

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. As a result, we expect that our research and development expenses will increase substantially over the next few years as we increase personnel costs, initiate and conduct additional clinical trials and prepare regulatory filings related to our product candidates. We also expect to incur additional expenses related to milestone, royalty payments and maintenance fees payable to third parties with whom we have entered into license agreements to acquire the rights related to our product candidates.

The successful development and commercialization of our product candidates is highly uncertain. At this time, we cannot reasonably estimate or know the nature, timing and costs of the efforts that will

be necessary to complete the clinical development of any of our product candidates or when, if ever, material net cash inflows may commence from sales of any of our product candidates. This uncertainty is due to the numerous risks and uncertainties associated with development and commercialization activities, including the uncertainty of:

•

the scope, progress, outcome and costs of our clinical trials and other research and development activities, including establishing an appropriate safety profile with IND-directed studies;

•

successful patient enrollment in, and the initiation and completion of, clinical trials;

•

the timing, receipt and terms of any marketing approvals from applicable regulatory authorities;

•

establishing commercial manufacturing capabilities or making arrangements with third-party manufacturers;

•

development and timely delivery of commercial-grade drug formulations that can be used in our clinical trials and for commercial manufacturing;

•

obtaining, maintaining, defending and enforcing patent claims and other intellectual property rights;

•

significant and changing government regulation;

•

launching commercial sales of our product candidates, if and when approved, whether alone or in collaboration with others;

•

maintaining a continued acceptable safety profile of the product candidates following approval; and

•

significant competition and rapidly changing technologies within the biopharmaceutical industry.

We may never succeed in achieving regulatory approval for any of our product candidates. We may obtain unexpected results from our clinical trials. We may elect to discontinue, delay or modify clinical trials of some product candidates or focus on others. Any changes in the outcome of any of these variables with respect to the development of our product candidates in clinical development could mean a significant change in the costs and timing associated with the development of these product candidates. For example, if the European Medicines Agency, or EMA, or the U.S. Food and Drug Administration, or FDA, or another regulatory authority were to delay our planned start of clinical trials or require us to conduct clinical trials or other testing beyond those that we currently expect or if we experience significant delays in enrollment in any of our planned clinical trials, we could be required to expend significant additional financial resources and time on the completion of clinical development of that product candidate. Commercialization of our product candidates will take several years and millions of dollars in development costs.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries, related benefits, travel and share-based compensation expense for personnel in executive, finance, legal and administrative functions. General and administrative expenses also include allocated facility-related costs, patent filing and prosecution costs and professional fees for marketing, insurance, legal, consulting, accounting and audit services.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support the planned development of our product candidates. We also anticipate that we will incur increased accounting, audit, legal, regulatory and compliance costs and director and officer insurance premiums, as well as higher investor and public relations expenses, associated with being a public company. Additionally, if we believe a regulatory approval of one of our

product candidates appears likely, we would anticipate an increase in payroll and expense as a result of our preparation for commercial operations, especially as it relates to the sales and marketing of our product candidate.

Other Income (Expense)

Other income consists primarily of interest earned on our cash balances held at a commercial bank. Other expense consists primarily of foreign currency transaction losses.

Income Tax Benefit

We are subject to corporate taxation in the United Kingdom. Due to the nature of our business, we have generated losses since inception. Our income tax credit recognized represents the sum of the research and development tax credits recoverable in the United Kingdom and income tax payable in the United States.

As a company that carries out extensive research and development activities, we benefit from the U.K. research and development tax credit regime under the scheme for small or medium-sized enterprises, or SMEs, and also claim a Research and Development Expenditure Credit, or RDEC, to the extent that our projects are grant funded. Under the SME regime, we are able to surrender some of our trading losses that arise from our qualifying research and development activities for a cash rebate of up to 33.35% of such qualifying research and development expenditure. The net tax benefit of the RDEC is expected to be 8.9% (increasing to 9.13% in financial year 2020). We meet the conditions of the SME regime, but also can make claims under the RDEC regime to the extent that our projects are grant funded. Qualifying expenditures largely comprise employment costs for research staff, consumables, outsourced CRO costs and utilities costs incurred as part of research projects. Certain subcontracted qualifying research and development expenditures are eligible for a cash rebate of up to 21.67%. A large portion of costs relating to our research and development, clinical trials and manufacturing activities are eligible for inclusion within these tax credit cash rebate claims.

We may not be able to continue to claim research and development tax credits under the SME regime in the future after we become a U.S. public company because we may no longer qualify as a small or medium-sized company. However, we should continue to be able to make claims under the RDEC regime.

Unsurrendered U.K. losses may be carried forward indefinitely to be offset against future taxable profits, subject to numerous utilization criteria and restrictions. The amount that can be offset each year is limited to £5.0 million plus an incremental 50% of U.K. taxable profits. After accounting for tax credits receivable, there were accumulated tax losses for carry forward in the United Kingdom of $22.8 million as of September 30, 2017.

In the event we generate revenues in the future, we may benefit from the new U.K. “patent box” regime that allows profits attributable to revenues from patents or patented products to be taxed at effective rate of 10%.

Value Added Tax, or VAT, is broadly charged on all taxable supplies of goods and services by VAT-registered businesses. Under current rates, an amount of 20% of the value, as determined for VAT purposes, of the goods or services supplied is added to all sales invoices and is payable to HMRC. Similarly, VAT paid on purchase invoices is generally reclaimable from HMRC.

Results of Operations

Comparison of the Years Ended September 30, 2016 and 2017

The following table summarizes our results of operations for the years ended September 30, 2016 and 2017:


	Year Ended September 30,
	2016			2017			Change
Grant income	$	1,212		$	1,693		$	481
Operating expenses:
Research and development		(10,436	)		(16,012	)		(5,576	)
General and administrative		(5,152	)		(9,099	)		(3,947	)

Total operating expenses, net		(14,376	)		(23,418	)		(9,042	)

Other income, net		49			38			(11	)

Net loss before income tax		(14,327	)		(23,380	)		(9,053	)
Income tax benefit		1,777			3,653			1,876

Net loss	$	(12,550	)	$	(19,727	)	$	(7,177	)

Grant Income

Grant income increased from $1.2 million for the year ended September 30, 2016 to $1.7 million for the year ended September 30, 2017. The increase of $0.5 million related to an increase in research grant income as we received an additional research grant from the U.K. government to fund additional projects in 2017.

Research and Development Expenses

Research and development expenses increased from $10.4 million for the year ended September 30, 2016 to $16.0 million for the year ended September 30, 2017. The increase of $5.6 million consisted primarily of an increase in salaries, bonuses and benefits of $2.3 million due to an overall increase in headcount as we advanced toward the commencement of clinical trials and manufacturing of our products candidates and additional share-based compensation expense, an increase of $3.1 million primarily related to direct costs associated with the additional activities necessary to prepare and activate clinical trial sites and with our viral vector and cell manufacturing processes for patients enrolled in the clinical trials for each of our research programs AUTO2, AUTO3, AUTO4 and AUTO5. In addition, our indirect costs increased by $1.6 million to support the functions of our research programs due to an increase in general laboratory use of $0.5 million, an increase in overhead costs of $0.3 million, an increase of $0.3 million in rent fees related to our laboratory facilities, an increase of $0.3 million in lab equipment depreciation and an increase of $0.2 million related to other research and development costs. The overall increases were partially offset by higher license fees of $1.4 million in the year ended September 30, 2016 resulting from the issuance of 1,000,000 B ordinary shares to UCL Business plc in March 2016; there were no such expenses recognized in 2017.

General and Administrative Expenses

General and administrative expenses increased from $5.2 million for the year ended September 30, 2016 to $9.1 million for the year ended September 30, 2017. The increase of $3.9 million consisted primarily of an increase in salaries, bonuses and benefits of $2.2 million due to an overall increase in headcount and the recognition of additional share-based compensation, an increase in legal and professional fees of $0.8 million related to new equity incentive plans and activities related to preparations for becoming a public company, an increase of $0.4 million related to other administrative expenses, an increase in corporate costs of $0.3 million related to the overall growth of the business and an increase in depreciation of $0.2 million.

Income Tax Benefits

Income tax benefits increased from $1.8 million for the year ended September 30, 2016 to $3.7 million for the year ended September 30, 2017 due to additional U.K. research and development tax credits receivable from HMRC. Research and development credits are obtained at a maximum rate of 33.35% of our qualifying research and development expenses, and the increase in the net credit was primarily attributable to an increase in our eligible research and development expenses.

Liquidity and Capital Resources

Since our inception, we have not generated any product revenue and have incurred operating losses and negative cash flows from our operations. We expect to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates through preclinical and clinical development, seek regulatory approval and pursue commercialization of any approved product candidates. We expect that our research and development and general and administrative costs will increase in connection with our planned research activities. As a result, we will need additional capital to fund our operations until such time as we can generate significant revenue from product sales.

We do not currently have any approved products and have never generated any revenue from product sales or otherwise. We have funded our operations to date primarily with proceeds from government grants and sales of our preferred and ordinary shares. Through September 30, 2017, we have received aggregate net cash proceeds of $176.4 million from sales of our equity securities. As of September 30, 2017, we had cash and cash equivalents of $137.1 million.

We currently have no ongoing material financing commitments, such as lines of credit or guarantees, that are expected to affect our liquidity over the next five years, other than our lease obligations described below.

Cash Flows

The following table summarizes our cash flows for each of the periods presented:


	Year Ended September 30,
	2016			2017
	(in thousands)
Net cash used in operating activities	$	(9,849	)	$	(16,360	)
Net cash used in investing activities		(1,855	)		(2,876	)
Net cash provided by financing activities		32,222			127,686
Effect of exchange rate changes on cash		(2,662	)		561

Net increase in cash	$	17,856		$	109,011

Net Cash Used in Operating Activities

During the year ended September 30, 2017, operating activities used $16.4 million of cash, resulting from our net loss of $19.7 million, net cash used in changes in our operating assets and liabilities of $0.8 million, partially offset by non-cash charges of $4.2 million. Net cash used in changes in our operating assets and liabilities for the year ended September 30, 2017 consisted primarily of a $2.3 million increase in prepaid expenses and other assets, partially offset by a $1.1 million increase in accrued expenses and a $0.4 million increase in accounts payable.

During the year ended September 30, 2016, operating activities used $9.8 million of cash, resulting from our net loss of $12.6 million, net cash used in changes in our operating assets and

liabilities of $1.2 million, partially offset by non-cash charges of $3.9 million. Net cash used in changes in our operating assets and liabilities for the year ended September 30, 2016 consisted primarily of a $2.0 million increase in prepaid expenses and other current assets, partially offset by $0.3 million increase in accrued expenses and a $0.5 million increase in accounts payable.

Net Cash Used in Investing Activities

During the years ended September 30, 2016 and 2017, we used $1.9 million and $2.9 million, respectively, of cash in investing activities, all of which consisted of purchases of property and equipment.

Net Cash Provided by Financing Activities

During the years ended September 30, 2016 and 2017, net cash provided by financing activities was $32.2 million and $127.7 million, respectively, in each case consisting of net cash proceeds from our sale and issuance of preferred shares.

Funding Requirements

We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we advance the preclinical activities and clinical trials of our product candidates. Our expenses will increase as we:

•

seek regulatory approvals for any product candidates that successfully complete preclinical and clinical trials;

•

establish a sales, marketing and distribution infrastructure in anticipation of commercializing of any product candidates for which we may obtain marketing approval and intend to commercialize on our own or jointly;

•

hire additional clinical, medical, and development personnel;

•

expand our infrastructure and facilities to accommodate our growing employee base; and

•

maintain, expand and protect our intellectual property portfolio.

Our primary uses of capital are, and we expect will continue to be, compensation and related expenses, clinical costs, external research and development services, laboratory and related supplies, legal and other regulatory expenses, and administrative and overhead costs. Our future funding requirements will be heavily determined by the resources needed to support development of our product candidates.

Following this offering, we will be a publicly traded company and will incur significant legal, accounting and other expenses that we were not required to incur as a private company. In addition, the Sarbanes-Oxley Act of 2002, as well as rules adopted by the SEC and The Nasdaq Stock Market, requires public companies to implement specified corporate governance practices that are currently inapplicable to us as a private company. We expect these rules and regulations will increase our legal and financial compliance costs and will make some activities more time-consuming and costly.

We expect that our existing cash resources will enable us to fund our current operating expenses and capital expenditure requirements for at least the next 12 months. We expect that these cash resources, together with anticipated net proceeds from this offering will enable us to fund our current and planned operating expenses and capital expenditure requirements for at least the next months. We have based these estimates on assumptions that may prove to be wrong, and we could

100

utilize our available capital resources sooner than we expect. If we receive regulatory approval for our other product candidates, we expect to incur significant commercialization expenses related to product manufacturing, sales, marketing and distribution, depending on where we choose to commercialize. We may also require additional capital to pursue in-licenses or acquisitions of other product candidates.

Because of the numerous risks and uncertainties associated with research, development and commercialization of pharmaceutical product candidates, we are unable to estimate the exact amount of our working capital requirements. Our future funding requirements will depend on and could increase significantly as a result of many factors, including:

•

the scope, progress, outcome and costs of our clinical trials and other research and development activities;

•

the costs, timing, receipt and terms of any marketing approvals from applicable regulatory authorities;

•

the costs of future activities, including product sales, medical affairs, marketing, manufacturing and distribution, for any of our product candidates for which we receive marketing approval;

•

the revenue, if any, received from commercial sale of our products, should any of our product candidates receive marketing approval;

•

the costs and timing of hiring new employees to support our continued growth;

•

the costs of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending intellectual property-related claims; and

•

the extent to which we in-license or acquire additional product candidates or technologies.

Until such time, if ever, that we can generate product revenue sufficient to achieve profitability, we expect to finance our cash needs through equity offerings. To the extent that we raise additional capital through the sale of equity, your ownership interest will be diluted. If we raise additional funds through other third-party funding, collaborations agreements, strategic alliances, licensing arrangements or marketing and distribution arrangements, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market products or product candidates that we would otherwise prefer to develop and market ourselves.

Contractual Obligations and Commitments

The following table summarizes our contractual obligations as of September 30, 2017 and the effects that such obligations are expected to have on our liquidity and cash flows in future periods:


	Payments Due by Period
	Total		Less than 1 Year		1 to 3 Years		4 to 5 Years		More than 5 Years
	(in thousands)
Operating Lease Obligations⁽¹⁾	$	7,397	$	1,025	$	2,769	$	876	$	2,727

(1)	Amounts in the table reflect minimum payments due for our leases of office, laboratory and manufacturing space and payments required to reimburse the landlord for leasehold improvements related to operating leases.

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Operating lease obligations relate to our leased corporate headquarters and manufacturing space. We entered into a lease for our corporate headquarters in September 2015 and, as part of this agreement, exercised an option to lease additional space in October 2016. Both leases expire in May 2025 with options to early terminate in September 2020. Prior to the lease commencement date of both leases, we, in conjunction with the landlord, made improvements to the leased space. The total cost of these improvements were funded by the landlord with a portion of the cost to be reimbursed by us over the term of the leases. In September 2017, we also entered into a lease for manufacturing space for a term through May 15, 2021, at which time we will have the option to renew or terminate the lease.

We enter into contracts in the normal course of business with CROs and other third parties for clinical trials and preclinical research studies and testing. These contracts are generally cancelable by us upon prior notice. Payments due upon cancellation consist only of payments for services provided or expenses incurred, including noncancelable obligations of our service providers, up to the date of cancellation. These payments are not included in the preceding table, as the amount and timing of such payments are not known.

We have not included any contingent payment obligations that we may incur upon achievement of clinical, regulatory and commercial milestones, as applicable, or royalty payments that we may be required to make under our license agreement with UCL Business plc, as the amount, timing and likelihood of such payments are not known.

Critical Accounting Policies and Significant Judgments and Estimates

Our financial statements are prepared in accordance with U.S. GAAP. The preparation of our financial statements and related disclosures requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions or conditions.

While our significant accounting policies are described in more detail in Note 2 to our financial statements appearing at the end of this prospectus, we believe that the following accounting policies are those most critical to the judgments and estimates used in the preparation of our financial statements.

Share-Based Compensation

Under the company’s shareholder agreements, we are authorized to issue C ordinary shares, as well as options and other securities exercisable for or convertible into C ordinary shares, as incentives to our employees and directors. To the extent such incentives are in the form of share options, the options are granted pursuant to the terms of our 2017 Share Option Plan, or the 2017 Plan. Options granted under the 2017 Plan, as well as restricted C shares granted as employee incentives, typically vest over a four-year service period with 25% of the award vesting on the first anniversary of the commencement date and the balance vesting monthly over the remaining three years, unless the awards contain specific performance vesting provisions. For equity awards issued that have both a performance vesting condition and a services condition, or performance awards, once the performance criteria is achieved, the performance awards are then subject to a four-year service vesting with 25% of the performance award vesting on the first anniversary of the performance condition being achieved, with the balance vesting monthly over the remaining three years. For certain members of senior

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management and directors, the board has approved an alternative vesting schedule for the equity awards. The options granted under the 2017 Plan generally expire 10 years from the date of grant. We expect our share-based compensation expense for awards granted to employees, directors and other service providers to increase in future periods due to the planned increases in our headcount.

Valuation of Share Options

We estimate the fair value of each share option grant using the Black-Scholes option pricing model, which requires the input of subjective assumptions, including assumptions about the expected life of share-based awards and share price volatility. In addition, as a privately held company, one of the most subjective inputs into the Black-Scholes option pricing model is the estimated fair value of our ordinary shares.

As a privately held company, our share price does not have sufficient historical volatility for us to adequately assess the fair value of the share option grants. As a result, our management considered the historical volatility of other comparable publicly traded companies and, based on this analysis, concluded that a volatility range of 68.61% to 68.93% was appropriate for the valuation of our share options. We intend to continue to consistently apply this methodology using the same comparable companies until a sufficient amount of historical information regarding the volatility of our own share price as a public company becomes available.

The expected life of the option, beginning with the option grant date, was used in valuing our share options. The expected life used in the calculation of share-based payment expense is the time from the grant date to the expected exercise date. The life of the options depends on the option expiration date, volatility of the underlying shares and vesting features.

The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods that are approximately equal to the expected term of the award.

The grant date fair value of restricted share awards is calculated based on the grant date fair value of the underlying ordinary shares. As there has been no public market for our ordinary shares or ADSs to date, the fair value of the underlying ordinary shares has historically been determined by our board of directors based upon information available to it at the time of grant. Our board of directors considered numerous objective and subjective factors in the assessment of fair value, including reviews of our business and financial condition, the conditions of the industry in which we operate and the markets that we serve and general economic, market and U.S. and global capital market conditions, the lack of marketability of our ordinary shares, the likelihood of achieving a liquidity event for the ordinary shares, the status of our clinical trials and preclinical studies relating to our product candidates and third-party valuations of our ordinary shares. Our board has generally considered the most persuasive evidence of fair value to be the prices at which our securities were sold in an arm’s-length transaction.

Valuation of Ordinary Shares

There are significant judgments and estimates inherent in the determination of the fair value of our ordinary shares. These judgments and estimates include assumptions regarding our future operating performance, the likelihood and time to complete an initial public offering or other liquidity event, the related company valuations associated with such events, and the determinations of the appropriate valuation methods. If we had made different assumptions, our share-based payment expense, loss for the year and total comprehensive loss, on both an absolute and per-share basis, could have been significantly different.

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We are a private company with no active public market for our ordinary shares. In the course of preparing for this offering, we performed valuations, with the help of a third-party valuation specialist, on a retrospective basis, of our ordinary shares as of various dates. These valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation, or the Practice Aid. Upon the completion of this proposed offering, it will no longer be necessary to estimate the fair value of our ordinary shares in connection with our accounting for share-based payment expenses, as the fair value of our ordinary shares will be determinable by reference to the trading price of our ADSs on the Nasdaq Global Market.

Our valuations performed for dates between October 1, 2015 and September 30, 2017 resulted in fair values of our B and C ordinary shares as depicted in the table below:


Valuation Date	Fair Value per B Ordinary Share⁽¹⁾		Fair Value per C Ordinary Share⁽¹⁾
March 2, 2016	$	1.22	$	1.42
April 26, 2017		1.09		1.29
September 25, 2017		1.47		1.74

(1)	The per share amounts were translated into U.S. dollars using the average exchange rate as of the valuation dates noted.

In conducting the valuations, we considered all objective and subjective factors that we believed to be relevant for each valuation conducted, including our best estimate of our business condition, prospects and operating performance at each valuation date. Within the valuations performed, a range of factors, assumptions and methodologies were used. The significant factors included:

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the lack of an active public market for our ordinary shares;

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our results of operations, financial position and the status of our research and preclinical development efforts;

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the material risks related to our business;

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our business strategy;

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the market performance of publicly traded companies in the life sciences and biotechnology sectors;

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the likelihood of achieving a liquidity event for the holders of our ordinary shares, such as an initial public offering, given prevailing market conditions; and

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any recent contemporaneous valuations of our ordinary shares prepared in accordance with methodologies outlined in the Practice Aid.

Our retrospective valuations were prepared in accordance with the guidelines in the Practice Aid, which prescribes several valuation approaches for determining the value of an enterprise, such as the cost, market and income approaches, and various methodologies for allocating the value of an enterprise to its capital structure and specifically the ordinary shares. After considering the market approach, the income approach and the asset-based approach, we utilized the market approach to determine the estimated fair value of our ordinary shares based on its determination that this approach was most appropriate for a clinical-stage biopharmaceutical company at this point in its development.

Valuations of ordinary shares performed as of the valuation dates referenced above were prepared using a market approach, based on precedent transactions in the shares, to estimate our

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total equity value. Our total equity value was estimated using an option-pricing backsolve method, or OPM, which used a combination of market approaches and an income approach to estimate our enterprise value. An income approach is used to estimate value based on the present value of future economic benefits that are expected to be produced by the entity. A market approach is used to estimate value through the analysis of recent sales of comparable assets or business entities.

The OPM derives an equity value such that the value indicated for the C ordinary shares is consistent with the investment price, and it provides an allocation of this equity value to each class of our securities. The OPM treats the various classes of ordinary shares as call options on the total equity value of a company, with exercise prices based on the value thresholds at which the allocation among the various holders of a company’s securities changes. Under this method, each class of shares has value only if the funds available for distribution to shareholders exceed the value of the share liquidation preferences of the class or classes of shares with senior preferences at the time of the liquidity event. Key inputs into the OPM calculation include the valuation of forward contracts, expected time to liquidity and volatility.

Options Granted

The following table sets forth by grant date the number of shares subject to options granted from October 1, 2015 through September 30, 2017, the per share exercise price of the options, the fair value per ordinary share on each grant date, and the per share estimated fair value of the options:


Grant Date	Number of Shares Subject to Options Granted		Per Share Exercise Price of Options		Fair Value per Ordinary Share on Grant Date⁽¹⁾		Per Share Fair Value of Options⁽¹⁾
April 21, 2017		686,848	$	0.00001	$	1.29	$	1.29
July 24, 2017		1,087,378		0.25		1.29		1.13
September 17, 2017		43,236		0.25		1.74		1.56

(1)	The per share amounts were translated into U.S. dollars using the average exchange rates of the valuation dates noted.

Restricted C Ordinary Shares Granted

The following table sets forth by grant date the number of restricted C ordinary shares granted from October 1, 2015 through September 30, 2017 and the fair value per ordinary share on each grant date:


Grant Date	Number of Restricted C Ordinary Shares Granted		Fair Value per Ordinary Share on Grant Date⁽¹⁾
November 24, 2015		36,127	$	1.13
January 26, 2016		11,116		1.13
February 5, 2016		794		1.13
March 2, 2016		2,693,235		1.42
March 23, 2016		1,000		1.42
April 18, 2016		111,923		1.42
May 17, 2016		286,273		1.42
July 19, 2016		12,897		1.42
September 21, 2016		257,125		1.42
November 29, 2016		1,402		1.42
April 21, 2017		1,643,884		1.29
July 24, 2017		400,000		1.29

(1)	The per share amounts were translated into U.S. dollars using the average exchange rates of the valuation dates noted.

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Share-based compensation expense totaled $2.3 million and $3.2 million for the years ended September 30, 2016 and 2017, respectively. As of September 30, 2017, we had $5.1 million of unrecognized compensation cost related to unvested restricted employee and non-employee incentive shares and share options outstanding, which is expected to be recognized over a weighted-average period of 3.5 years.

Income Taxes

We account for income taxes under the asset and liability method which includes the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in our financial statements. Under this approach, deferred taxes are recorded for the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. The provision for income taxes represents income taxes paid or payable for the current year plus deferred taxes. Deferred taxes result from differences between the financial statements and tax bases of our assets and liabilities, and are adjusted for changes in tax rates and tax laws when changes are enacted. The effects of future changes in income tax laws or rates are not anticipated.

We are subject to corporation taxes in the United Kingdom. The calculation of our tax provision involves the application of U.K. tax law and requires judgement and estimates.

We evaluate the realizability of our deferred tax assets at each reporting date, and we establish a valuation allowance when it is more likely than not that all or a portion of our deferred tax assets will not be realized.

The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income of the same character and in the same jurisdiction. We consider all available positive and negative evidence in making this assessment, including, but not limited to, the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies. In circumstances where there is sufficient negative evidence indicating that our deferred tax assets are not more likely than not realizable, we establish a valuation allowance.

We use a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate tax positions taken or expected to be taken in a tax return by assessing whether they are more likely than not sustainable, based solely on their technical merits, upon examination, and including resolution of any related appeals or litigation process. The second step is to measure the associated tax benefit of each position as the largest amount that we believe is more likely than not realizable. Differences between the amount of tax benefits taken or expected to be taken in our income tax returns and the amount of tax benefits recognized in our financial statements represent our unrecognized income tax benefits, which we either record as a liability or as a reduction of deferred tax assets.

Deferred Tax and Current Tax Credits

Tax on the profit or loss for the year comprises current and deferred tax. Tax is recognized in the statement of operations, except to the extent that it relates to items recognized directly in equity, in which case it is recognized in equity. Current tax is the expected tax payable on the taxable income or loss for the year, using tax rates enacted or substantively enacted at the balance sheet date, and any adjustment to tax payable in respect of previous years. Tax credits are accrued for the year based on calculations that conform to the U.K. research and development tax credit regime, under both the SME and large company regimes. We meet the conditions of the SME regime, but also can make claims under the RDEC regime to the extent that our projects are grant funded.

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Deferred tax is recognized on temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for taxation purposes. The amount of deferred tax is based on the expected manner of realization or settlement of the carrying amount of assets and liabilities, using tax rates enacted or substantively enacted at the balance sheet date. A deferred tax asset is recognized only to the extent that it is probable that future taxable profits will be available against which the asset can be utilized. No deferred tax assets are recognized on our losses carried forward and other attributes because there is currently no indication that we will make sufficient profits to utilize these attributes.

JOBS Act

On April 5, 2012, the Jumpstart Our Business Startups Act, or the JOBS Act, was enacted. The JOBS Act provides that, among other things, an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. As an emerging growth company, we have irrevocably elected not to take advantage of the extended transition period afforded by the JOBS Act for implementation of new or revised accounting standards and, as a result, we will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth public companies.

In addition, we intend to rely on the other exemptions and reduced reporting requirements provided by the JOBS Act. Subject to certain conditions set forth in the JOBS Act, we are entitled to rely on certain exemptions as an “emerging growth company,” we are not required to, among other things, (i) provide an auditor’s attestation report on our system of internal controls over financial reporting pursuant to Section 404(b), (ii) provide all of the compensation disclosure that may be required of non-emerging growth public companies under the Dodd-Frank Wall Street Reform and Consumer Protection Act, (iii) comply with any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation or a supplement to the auditor’s report providing additional information about the audit and the financial statements (auditor discussion and analysis), and (iv) disclose certain executive compensation-related items such as the correlation between executive compensation and performance and comparisons of the chief executive officer’s compensation to median employee compensation. These exemptions will apply for a period of five years following the completion of this offering or until we no longer meet the requirements of being an emerging growth company, whichever is earlier.

Off-Balance Sheet Arrangements

We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined in the rules and regulations of the Securities and Exchange Commission.

Recently Issued Accounting Pronouncements

A description of recently issued accounting pronouncements that may potentially impact our financial position and results of operations is disclosed in Note 2, “Summary of Significant Accounting Policies,” to our financial statements appearing at the end of this prospectus.

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Quantitative and Qualitative Disclosures about Market Risk

We are exposed to market risks in the ordinary course of our business, which are principally limited to interest rate fluctuations and foreign currency exchange rate fluctuations. We maintain significant amounts of cash and cash equivalents that are in excess of federally insured limits in various currencies, placed with one or more financial institutions for varying periods according to expected liquidity requirements.

Interest Rate Risk

As of September 30, 2017, we had cash of $137.1 million. Our exposure to interest rate sensitivity is impacted by changes in the underlying U.K. bank interest rates. Our surplus cash has been invested in interest-bearing savings accounts from time to time. We have not entered into investments for trading or speculative purposes. Due to the conservative nature of our investment portfolio, which is predicated on capital preservation of investments with short-term maturities, we do not believe an immediate one percentage point change in interest rates would have a material effect on the fair market value of our portfolio, and therefore we do not expect our operating results or cash flows to be significantly affected by changes in market interest rates.

Foreign Currency Exchange Risk

We maintain our financial statements in our functional currency, which is pounds sterling. Monetary assets and liabilities denominated in currencies other than the functional currency are translated into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary assets and liabilities denominated in foreign currencies are translated into the functional currency at the exchange rates prevailing at the date of the transaction. Exchange gains or losses arising from foreign currency transactions are included in the determination of net income (loss) for the respective periods. We recorded exchange losses of $10,000 and $25,000 for the years ended September 30, 2016 and 2017, respectively.

For financial reporting purposes, our financial statements are prepared using the functional currency and translated into U.S. dollars. Assets and liabilities are translated at the exchange rates at the balance sheet dates, revenue and expenses are translated at the average exchange rates during the reporting period and shareholders’ equity amounts are translated based on historical exchange rates on the date of the applicable transaction. Translation adjustments are not included in determining net income (loss) but are included in foreign exchange adjustment to accumulated other comprehensive loss, a component of shareholders’ equity.

We do not currently engage in currency hedging activities in order to reduce our currency exposure, but we may begin to do so in the future. Instruments that may be used to hedge future risks include foreign currency forward and swap contracts. These instruments may be used to selectively manage risks, but there can be no assurance that we will be fully protected against material foreign currency fluctuations.

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BUSINESS

Overview

Our current clinical-stage programs are:


AUTO1:		a CD19-targeting programmed T cell therapy designed to improve the safety profile of the CD19 binder while maintaining its anti-leukemia activity. AUTO1 has demonstrated this anti-leukemia activity in the absence of severe cytokine release syndrome, or CRS, in a Phase 1 trial of 11 patients with pediatric relapsed or refractory acute B lymphocytic leukemia, or pediatric ALL. A Phase 1 clinical trial in adult patients with ALL is ongoing.

AUTO2:		the first dual-targeting programmed T cell therapy for the treatment of relapsed or refractory multiple myeloma targeting B-cell Maturation Antigen, or BCMA, and the transmembrane activator and CAML interactor, or TACI. We initiated a Phase 1/2 clinical trial in the third quarter of 2017.

AUTO3:		the first dual-targeting programmed T cell therapy for the treatment of relapsed or refractory diffuse large B-cell lymphoma, or DLBCL, and pediatric ALL, independently targeting B-lymphocyte antigens CD19 and CD22. We initiated separate Phase 1/2 clinical trials of AUTO3 in DLBCL and in pediatric ALL in the third quarter of 2017.

AUTO4:		a programmed T cell therapy for the treatment of peripheral T-cell lymphoma targeting TRBC1. We intend to initiate a Phase 1/2 clinical trial in the first half of 2018.

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AUTO6:		a programmed T cell therapy targeting GD2 in development for the treatment of neuroblastoma. A Phase 1 clinical trial with AUTO6 is being sponsored and conducted by Cancer Research UK, or CRUK, and preliminary data has shown initial anti-tumor activity in this solid tumor indication. We are developing a next-generation product candidate, which we refer to as AUTO6 NG, incorporating additional programming modules designed to improve the efficacy, safety and persistence of AUTO6. We expect to initiate a Phase 1/2 clinical trial of AUTO6 NG in 2020.

We anticipate that the market for T cell therapies will be characterized by rapid cycling of product improvements. We believe our modular approach to T cell programming and the common manufacturing platform used across all our T cell therapies will position us to more quickly develop follow-on, or next-generation, product candidates with enhanced characteristics, such as pharmacological control, insensitivity to checkpoint inhibition or other desirable features.

Our management team has a strong track record of accomplishment in redirected T cell therapies, gene therapy, transplantation and oncology. Their collective experience spans key areas of

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expertise required of a fully integrated company delivering advanced programmed T cell therapies, including fundamental innovation in therapeutic design, translational medicine and clinical development, process sciences, manufacturing and commercialization. We are led by Dr. Christian Itin, our chairman and Chief Executive Officer. His prior experience includes serving as the Chief Executive Officer of Micromet, Inc., a public biotechnology company acquired by Amgen Inc. in 2012 for $1.2 billion, where he led the development of blinatumomab, which in 2014 became the first redirected T cell therapy approved by the U.S. Food and Drug Administration, or FDA. Our proprietary and modular T cell programming technologies were invented by Dr. Martin Pulé, our scientific founder and Senior Vice President and Chief Scientific Officer. Dr. Pulé has been an innovator in the field of genetic engineering of T cells for cancer treatment for almost 20 years. We are backed by leading life sciences investors, including Syncona Limited, Woodford Investment Management, Arix Bioscience plc, Cormorant Asset Management, Google Ventures and Nextech Invest Ltd.

Our Pipeline

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Our Strategy

Our goal is to use our broad array of proprietary and modular T cell programming technologies to become a fully integrated biopharmaceutical company offering advanced, differentiated, best-in-class

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programmed T cell therapies. In order to accomplish this goal, we plan to execute on the following key strategies:

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Simultaneously develop our four current clinical-stage product candidates for the treatment of hematological cancers. In March 2018, we licensed global rights to develop and commercialize AUTO1 from UCL Business plc, or UCLB, which we plan to develop for the treatment of adult ALL in collaboration with University College London, or UCL. We are co-funding a Phase 1 clinical trial of AUTO1 in adult ALL being conducted by UCL, which is designed to establish proof-of-concept in 2018. In 2017, we commenced a Phase 1/2 clinical trial for AUTO2 for the treatment of multiple myeloma and Phase 1/2 clinical trials for AUTO3 for the treatment of DLBCL and pediatric ALL. We expect to initiate a Phase 1/2 clinical trial of AUTO4 for the treatment of peripheral T-cell lymphoma in the first half of 2018. We intend to progress each of these product candidates in parallel through clinical trials. Depending on the results we observe in our clinical trials, we believe these product candidates may be eligible for accelerated regulatory approval pathways and we may seek to achieve breakthrough therapy designation from the FDA or MEdicines, or PRIME, designation from the European Medicines Agency, or EMA.

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Background on T Cells and Cancer Treatment Approaches

Cancers originate from individual cells that have developed mutations in essential cellular programs, driving increased cell division and growth. A key control mechanism to detect and eliminate such cells is the patient’s own T cells. T cells are a type of white blood cells used by the human immune system to defend the body against infectious pathogens and cancerous cells. Using their T cell receptor like a molecular scanner, T cells are able to discriminate between normal human cells and ones that contain a mutation that alters their function. If the T cell recognizes an altered cell, it becomes activated and kills that particular cell. For a cancer to grow to the detriment of the patient, cancer cells evolve mechanisms to evade recognition by, or establish other defenses against, T cells.

T Cell Activation- and Redirection-Based Therapies

Cancer immunotherapy treatment requires the activation and expansion of cancer-specific T cells, which kill cancer cells by recognizing antigen targets expressed on cancer cells. Studies have shown that tumors develop escape mechanisms that prevent T cell-mediated destruction through immune checkpoint proteins, which shut down anti-tumor immunity. Clinical trials have shown that treatment with immune checkpoint inhibitors can restore T cell activity and results in durable clinical responses. These observations have led to the FDA approval of several checkpoint inhibitors including ipilimumab (anti-CTLA-4), nivolumab (anti-PD-1), pembrolizumab (anti-PD-1), durvalumab (anti-PD-L1) and atezolizumab (anti-PD-L1). Treatment with checkpoint inhibitors has shown the ability to activate CD8+ T cells, shrink tumors, and improve patient survival. While these approaches collectively represented major advances in cancer treatment, they all lack active redirection of the patient’s T cells to the cancer, eventually limiting clinical activity.

More recently, redirected T cell therapies that are designed to give the patient’s T cells a new specificity to recognize cancer cells have been developed. The first approved product of this class is a bi-specific T cell engager called blinatumomab (Blincyto^®) from Amgen Inc. Blinatumomab targets the CD19 antigen on the surface of B cells and cancers derived from B cells. Blinatumomab received an accelerated approval for the treatment of patients with relapsed or refractory B cell acute lymphoblastic leukemia, or B-ALL, in 2014, followed by a full approval for all age groups in B-ALL in 2017. In 2017, the first two genetically programmed redirected T cell therapies were approved, both also targeting CD19, CAR-T therapy Kymriah^® by Novartis AG for pediatric B-ALL and Yescarta^® by Kite Pharma, Inc. (acquired by Gilead Sciences, Inc.) for DLBCL. All three of these therapies received breakthrough therapy designation and showed high response rates and, in a subset of patients, prolonged treatment effects. For those patients experiencing a relapse, the common causes for relapse are insufficient survival of the programmed T cells, loss of the CD19 target on the cancer cells and upregulation of checkpoint inhibitor PD-L1 on the cancer cells.

In view of the limitations of current therapies, there remains a critical unmet medical need for improved T cell therapies. We believe that improving efficacy and durability over the products currently on the market or in development for the treatment of cancers requires addressing target antigen loss, countering checkpoint inhibition and adding novel targets to expand the range of indications amenable to programmed T cell therapy. We believe our clinical-stage product candidates and our approach to T cell programming have the potential to address these limitations.

Programmed T Cell Therapies

Process of T Cell Programming

Existing programmed T cell therapies for oncology have focused on engineering CAR T cells. CARs are membrane-bound proteins, combining the tumor-recognition properties of an antibody with

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the naturally occurring T cell activation mechanism. CARs are designed such that a portion on the outside of the T cell binds to a structure on the surface of a cancer cell and a portion on the inside of a T cell transmits an activating signal and leads the T cell to attack the cancer cell. The actual steps to create CAR T cells start with leukapheresis, a process in which white blood cells are collected from the patient and separated from the blood. The sample is then enriched by stimulating the T cells, which causes them to replicate. During that process, a viral gene vector is used to introduce the genetic information encoding the CAR into the DNA of the T cells. T cells then read this information and produce CARs on their cell surface. The programmed T cells are then infused back into the patient intravenously following a short course of chemotherapy to condition the bone marrow to accept the programmed T cells. This process is illustrated in the graphic below.

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Limitations of Current T Cell Immunotherapies

Although existing T cell immunotherapies, including CAR T therapies, have shown significant efficacy in hematological malignancies, the extent and duration of the treatment effects and disease remission remain unknown. Optimizing the targeting module of a programmed T cell may enhance its effect and safety. Also, in response to targeted therapies, cancer cells often mutate and cease to express the antigen the therapy was designed to recognize. This loss of target antigen leads to patient relapse. Additionally, numerous challenges, including lack of T cell persistence and upregulation of checkpoint inhibitors, represent significant hurdles that need to be addressed by new therapies. T cell immunotherapies also have the capacity to elicit toxicities including CRS, neurologic toxicity and the elimination of normal cells via on-target off tumor recognition. Further, manufacturing T cells can be prohibitively costly if the manufacturing process is not appropriately designed to support parallel

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processing and automation. Finally, realization of the potential of this approach across a broad range of solid tumor types will require multiple technology solutions in order to address limitations of the current generation of therapies. Our broad array of proprietary and modular T cell programming technologies are designed to address these limitations.

Our Solution: Advanced T Cell Programming using a Modular Approach

Our programming modules are designed to provide a host of key benefits as described in the table below:

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After identifying a cancer target, we select the suite of programming modules that we believe is best suited to target that particular cancer based on our latest clinical data and the results of our cancer research. The particular modules selected may vary, and not every product candidate, including our current product candidates, contain all categories of modules. A viral vector is used to introduce combinations of these modules into the DNA of the T cells, as depicted in the graphic below. With the exception of AUTO1, all of our product candidates contain two or more programming modules.

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Advanced Targeting Technologies Used in our Modular Approach

Innovative Binders and Novel Targets

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Programmed T Cell Product Delivery Cycle T cells are shipped to cell manufacturing facility Leukapheresis T Cell Programming T cells are extracted from the patient at the treatment center or leukapheresis center A viral vector introduces genetic information that causes T cells to express CARs or exhibit other properties Infusion Expansion of Programmed T Cells Programmed T cells are administered to the patient at the treatment center Programmed T cells replicate through natural cell division until desired dose level is reached Programmed T cells are shipped Back to treatment center C Autolus 2018

Dual-Targeting Technology

Escape from T cell recognition by losing the antigen, the very structure the programmed T cell is designed to recognize, is a fundamental defense mechanism of hematological cancers. All clinical programs targeting CD19, CD22 or BCMA in a single-target approach have reported patients relapsing with cells that no longer have detectable levels of the target antigen. The most profound impact of this defense mechanism of cancer cells was reported for children relapsing under CD19-targeting Kymriah treatment, with more than half the children at time of relapse showing a loss of the CD19 antigen on the recurring cancer cells.

Pattern Recognition Technology

Pharmacological Control of T Cell Activity

Safety Switches

Also referred to as “off switches” or “suicide switches,” safety switches selectively eliminate the programmed T cells and are intended to be triggered in the event a patient suffers certain serious adverse events related to the T cell therapy, such as CRS or neurotoxicity. We incorporate the RQR8 safety switch into some of our programmed T cell product candidates, which allows us to selectively eliminate the programmed T cells by the administration of the commercially available monoclonal antibody rituximab, or Rituxan^®, which binds to the surface of the T cell and thereby triggers cell death. We use the RQR8 safety switch in our AUTO2, AUTO4 and AUTO6 programs. The next generation of our safety switches, which we plan to incorporate in our solid tumor programs, utilizes rapamycin activated Caspase 9 (rapaCasp9), a cell therapy safety switch that allows for selective elimination of programmed T cells using a single therapeutic dose of the commercially available product rapamycin, such as sirolimus or Rapamune^®. Rapamycin is a small molecule drug, which we expect will have the benefit of better tissue penetration and may require less time to take effect as compared to a monoclonal antibody-activated safety switch.

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Advanced Programming Modules Eliminating cancer cells based Advanced Targeting Dual Targeting on the recognition of either of two disease-specific antigens Pattern Recognition Elimination of cancer cells based on recognition of patterns of two or more antigens Pharmacological Control Safety Switches Elimination of programmed T cells by administration of an antibody or small molecule Tunable Tcells Reversible reduction in the activity of programmed T cells by administration of a small molecule Enhanced T Cell Activity Immune Checkpoint Blockade Expression of modified SH P2 adaptor protein to counteract immune checkpoint inhibition Enhanced Tcell Persistence Delivery of a cytokine signal directly into our programmed T cell to enhance persistence in response to tumor-secreted antigens Key Intended Benefits Reduce the risk for antigen negative relapse Support a response in patients with low levels of target antigen Enhance selectivity for the tumor Spare healthy cells and avoids unwanted side effects Remove the therapy in the event the patient suffers a severe adverse event or chronic toxicity Dampen activity of the therapy to manage the patient through periods of acute toxicities such as CRS or neurotoxicity Prevent shutdown of T cell activity by tumor m icroenvironment Acting across a range of immune checkpoint pathways Continued stimulation to help programmed T cell survive and persist for extended periods of time Enhance activity against solid tumors

Tunable T Cells

Enhanced T Cell Activity Technologies

We have also developed a wide range of technologies designed to inhibit the immunosuppressive effects of the tumor microenvironment and enhance T cell persistence.

Evading Hostile Tumor Microenvironments Including Checkpoint Inhibition

Proteins expressed on tumor cells can trigger inhibitory receptors on T cells to block their ability to eliminate the tumor, such as PD-L1/PD-1 immune checkpoints. These inhibitory receptors act through a common signaling pathway inside the T cell that prevents normal T cell activation. We have developed a programming module designed to cause T cells to express a modified version of an adaptor protein, SHP2, that in preclinical studies has been shown to efficiently counteracts the inhibition of T cells resulting from the PD-L1/PD-1 checkpoint interaction. Unlike methods that rely on blocking one inhibitory receptor using antibodies that are separately administered to the patient and are known to have significant side effects on their own, we have designed this programming module to be engineered into the T cells and not to require the administration of a separate pharmaceutical agent. In addition, it is designed to simultaneously disarm multiple inhibitory receptors on the cancer cell.

Enhanced T Cell Persistence

Programmed T cell therapies that target hematological malignancies are regularly stimulated by engaging tumor and normal cells in the bone marrow and lymph tissue. This continued stimulation helps the programmed T cell survive and persist, allowing them to attack the tumor for an extended period of time. One of the challenges of targeting some solid tumors is the lack of such easily accessible stimulation for programmed T cells, leading to poor persistence and a weak anti-tumor activity. Programmed T cell therapies have been co-administered with cytokines that boost T cell activity and persistence in an attempt to enhance their effect on solid tumors. However, systemic or local administration of cytokines can be toxic. Therefore, we have developed a technology that is designed to deliver a cytokine signal directly inside our programmed T cells without administration of cytokines themselves. Depending on the tumor microenvironment, the cytokine persistence signal may be further enhanced by antigens secreted by the tumor. We believe our approach will be more potent and will have the potential to be less toxic, when compared to approaches that rely on systemic or local delivery of cytokines.

Advanced T Cell Programming is Key for Solid Tumor Programs

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Consequently, in order to be able to tackle the more complex biology of solid tumors, we anticipate that programmed T cell products will need to employ multiple modules of technology to overcome these challenges. With our broad array of proprietary programming modules and our ability to incorporate multiple elements into our programmed T cell product candidates, we believe we are well positioned to design these types of product candidates and expand our pipeline into solid tumor indications, including with our development of AUTO6 NG.

Our Pipeline

The following table summarizes key information about our clinical-stage programmed T cell product candidates and other pipeline programs.

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Our Product Candidates for the Treatment of Hematological Cancers

Our four clinical-stage product candidates targeting hematological cancers are AUTO1, AUTO2, AUTO3 and AUTO4. We have an additional product candidate, AUTO5, in preclinical development.

AUTO1: Our Programmed T Cell Therapy for the Treatment of ALL

Introduction to AUTO1

CD19 is a protein expressed by B cell lymphomas and leukemia. CD19 CAR T cell therapies have proven effective in treating leukemia and lymphoma, with efficacy dependent on engraftment and

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expansion of the CAR T cells. However, rapid activation and expansion of CAR T cells can result in CRS, which in some cases can be life-threatening, particularly for elderly patients and patients with higher tumor burden that have a poor tolerance for toxicity. Furthermore, excessive activation of CAR T cells can lead to cell exhaustion and limit their persistence, which may impact the durability of therapeutic effect. AUTO1 is an investigational therapy in which a patient’s T cells are genetically modified to express a novel CD19-specific binder designed to reduce cytokine release-related side effects.

AUTO1, currently the subject of separate Phase 1 trials in pediatric ALL and adult ALL, has been designed to recognize CD19 and interact with the target with a fast off-rate. This property allows the AUTO1 cells to efficiently recognize cancer cells, inject cytotoxic proteins to initiate the natural self-destruction process present in all human cells and then rapidly disengage from them in order to engage the next cancer cell, a process also known as serial killing. Rapid disengagement from the target antigen is expected to minimize excessive activation of the programmed T cells, reduce toxicity and may also reduce T cell exhaustion. Our academic partner, UCL, is conducting a Phase 1 clinical trial in pediatric ALL patients, named the CARPALL trial, evaluating the safety and efficacy of AUTO1. Preliminary results from the CARPALL trial observed to date suggest high levels of therapeutic activity without Grade 3 or 4 CRS, which are considered to be severe CRS, and without needing to administer tocilizumab to neutralize IL-6, a prominent cytokine causing CRS.

Clinical Experience in Phase 1 Clinical Trial in Pediatric ALL

Most of the clinical experience with AUTO1 to date has been in the Phase 1 CARPALL trial that was initiated by UCL in the second quarter of 2016. The CARPALL trial is a single-arm, open label, multi-center trial enrolling patients aged 24 years or younger with high-risk relapsed or refractory CD19 positive B-lineage ALL. Currently, the clinical trial is being conducted at sites in the United Kingdom. The main objective of the trial is to evaluate the safety and efficacy of AUTO1 when administered at a dose of 1 million cells/kg.

As of October 3, 2017, 11 patients were treated in the CARPALL trial. The clinical data shows substantial engraftment and expansion with a high percentage of AUTO1 cells detected in peripheral blood. Furthermore, we observed persistence of AUTO1 cells in peripheral blood, based on a polymerase chain reaction, or PCR, assay, at comparable levels as those reported for Kymriah at the 12-month time point.

Preliminary data from the CARPALL trial suggests a favorable safety profile for AUTO1. In the CARPALL trial, Grade 1 or 2 CRS has been observed in all patients, but no Grade 3 or higher CRS has been observed as of October 3, 2017. In addition, in the CARPALL trial, no patient has needed or received tocilizumab or admission to an intensive care unit for the management of CRS. Additionally, the severe neurotoxicity rate (Grade 3 or higher) in AUTO1 is currently 9%. The only case of severe neurotoxicity in the CARPALL trial was determined by the trial investigator to be primarily attributed to fludarabine, a chemotherapy agent that was administered to the patient in a prior course of treatment and as part of intrathecal therapy for central nervous system, or CNS, disease and during the conditioning in advance of the administration of AUTO1. In the CARPALL trial, 45% of patients experienced cytopenias (Grade 3 or higher) persisting beyond 30 days. In the ELIANA trial, the pivotal trial supporting the approval of Kymriah, 47% of patients treated with Kymriah experienced Grade 3 or higher CRS and the severe neurotoxicity rate (Grade 3 or higher) was 13%. Cytopenias (Grade 3 or higher) lasting longer than one month were 32% for Kymriah.

While the comparative interpretation of safety and efficacy are limited by the small number of patients in the CARPALL trial (n=11), AUTO1 has been observed to be active with an overall minimal residual disease-negative complete response, or MRD-negative CR, rate at one month of 91%, which

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is in line with what is observed with other CD19 CAR T cell products. In the CARPALL trial, event free survival, or EFS, at six months was 53%. EFS for Kymriah was reported to be 73% at six months. Although we believe these safety observations from the CARPALL trial are promising, no definitive conclusions regarding safety or effectiveness can be drawn between these two studies given the investigational stage of AUTO1, the small study size, differing study designs between the CARPALL and ELIANA trials, and other factors.

Clinical Development of AUTO1 in Adult ALL

Background of Adult ALL

AUTO1 is being tested in a Phase 1 clinical trial for the treatment of adult ALL, which according to the American Cancer Society is predicted to affect approximately 5,960 adults in the United States in 2018. Combination chemotherapy enables 90% of adult patients to experience CR. Despite this, and in contrast to pediatric ALL, the prognosis of adult ALL is still poor and has not changed significantly during the last two to three decades, with long-term remission rates limited to 30–40%. Approximately 50% of all adult ALL patients will relapse, and data from the Medical Research Council’s UKALL12/ECOG 2993 study, published in 2007, found that five-year overall survival, or OS, rate in adults who relapse following standard multi-agent chemotherapy is 7%. The only curative option for relapsed or refractory ALL consists of achieving a second CR by salvage therapy followed by an allogeneic hematopoietic stem cell transplant, or allo-HSCT. Without allo-HSCT, a subsequent relapse occurs in nearly all patients. However, less than half of patients achieve a second CR, and therefore only a subset will be eligible for this procedure. Even then, less than one-third of patients receiving the transplant are expected to sustain long-term disease-free survival. Further, allo-HSCT is associated with severe morbidity and significant mortality. Many patients with relapsed or refractory ALL will have been maximally treated with chemotherapy, and often do not achieve a second CR with standard-of-care chemotherapy in order to be eligible for allo-HSCT.

Recently, two new targeted therapies have shown promise in the treatment of adult ALL: blinatumomab and inotuzumab ozogamicin. Both of these therapies achieve high CR rates but durability is limited. In a randomized Phase 3 clinical trial of blinatumomab in heavily pretreated B-cell precursor ALL, the blinatumomab arm achieved a CR rate of 44%, of which 76% also achieved MRD-negative CR, and the median duration of remission was 7.3 months. The median OS in those patients, though significantly improved compared to chemotherapy, was still only 7.7 months. Similarly, in a Phase 3 clinical trial of inotuzumab ozogamicin, a higher percentage of patients achieved MRD-negative CR when treated with inotuzumab compared to standard-of-care chemotherapy, but the median duration of remission was 4.6 months and median OS was 7.7 months.

CD19 CAR T cell therapies have been tested in pediatric ALL patients and have shown sustained responses without allo-HSCT. In adult ALL, however, one of the major challenges has been severe toxicity, including death due to CAR T cell-mediated toxicity observed in the clinical trials of these products. AUTO1 has been designed to reduce toxicity but still sustain durable CRs, and we believe it has the potential to become a standalone therapy for adult ALL.

Phase 1 Clinical Trial in Adult ALL

In the first quarter of 2018, our academic partner UCL initiated a single-arm, open label, multi-center Phase 1 clinical trial of AUTO1, named the ALLCAR19 trial, in patients aged 16 to 65 years of age with high-risk, relapsed or refractory CD19 positive B-lineage ALL. The clinical trial is currently being conducted at sites in the United Kingdom. The ALLCAR19 trial is currently recruiting patients and is expected to enroll approximately 20 patients. The main objective of the trial is to evaluate the safety and the feasibility of manufacturing AUTO1 at the planned dose. The trial will also evaluate the efficacy and durability of patient responses.

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The trial employs an intra-patient dose escalation design. The initial dose fraction is dependent on disease burden in the bone marrow. Patients with low levels of leukemia in the bone marrow, measured as less than or equal to 20% bone marrow infiltration at baseline (< 20% BM Blast) will receive a higher first dose of 100 million AUTO1 cells, while those with higher disease levels of greater than 20% bone marrow infiltration at baseline (> 20% BM Blast) will receive lower first dose of 10 million AUTO1 cells. If no severe toxicity occurs following the first dose, the remainder of the cells are administered on the ninth day. This approach is intended to reduce the risks of severe CRS and severe neurotoxicity without compromising on the promising results observed in the CARPALL trial.

Prior to receiving AUTO1, all enrolled patients will receive a course of chemotherapy with fludarabine for three days and cyclophosphamide for one day ending 3 days before the initial AUTO1 infusion. This pre-treatment is designed to reduce the number of normal T cells in the body and condition the patients for therapy.

The graphic below depicts the dosing schematic of the ALLCAR19 Phase 1 clinical trial:

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Development Strategy for Adult ALL

Based on the anticipated enrollment rates, UCL expects to report preliminary results from the ALLCAR19 trial in late 2018 or first half of 2019. If the preliminary data is positive in terms of improved safety and efficacy, we intend to seek breakthrough therapy designation from the FDA for AUTO1 based on the significant medical unmet need among these patients.

We are currently transitioning cell manufacturing for AUTO1 from using an open manufacturing platform to manufacture AUTO1 to using our current closed and semi-automated manufacturing platform. This is the same manufacturing platform we use to manufacture all of our product candidates. However, unlike our other hematological cancer product candidates, AUTO1 is based on a lentiviral vector. If the transition of the manufacturing process of AUTO1 is successful and if supported by positive clinical data from the ALLCAR19 trial, then we intend to initiate a multicenter, single-arm Phase 2 trial of AUTO1 in adult ALL. The final number of patients to be enrolled in the trial and the trial endpoints will be determined based on feedback from regulatory authorities.

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AUTO2: Our Programmed T Cell Therapy for the Treatment of Multiple Myeloma

Introduction to AUTO2

We are developing AUTO2, the first dual-targeting programmed T cell product candidate binding to two targets on multiple myeloma cells. AUTO2 uses a human ligand, known as APRIL, which binds to two antigens, BCMA and TACI, both of which are expressed on the surface of multiple myeloma cancer cells.

Background of Multiple Myeloma

Multiple myeloma is a plasma cell cancer that is responsible for approximately 10% of all hematological malignancies. According to data from the Global Burden of Disease Study 2015, multiple myeloma affected 488,000 people globally and resulted in 101,100 deaths in 2015. The American Cancer Society estimates that in the United States in 2018, approximately 30,700 new cases will be diagnosed and approximately 12,770 deaths are expected to occur from multiple myeloma. Most people in the United States who are diagnosed with multiple myeloma are 65 years old or older, with less than 1% of cases diagnosed in people younger than 35 years old. Without treatment, typical survival is seven months. With currently available treatments, survival is usually four to five years, with a five-year survival rate of approximately 49%.

Treatment choices for multiple myeloma vary with the aggressiveness of the disease and related prognostic factors. Newly diagnosed patients in good physical health with active disease generally receive high-dose chemotherapy with autologous stem cell transplantation, or ASCT. Eligibility for ASCT is established primarily by age and comorbidities. When transplantation is not an option, treatment traditionally consists of systemic chemotherapy, with adjunctive use of radiation.

The therapeutic landscape of multiple myeloma has changed significantly in the past decade with the introduction of novel immunomodulatory agents, such as lenalidomide, as well as monoclonal antibodies, such as daratumumab, and proteasome inhibitors, including bortezomib and carfilzomib. The past decade has also seen major progress in the understanding of the molecular oncogenesis of plasma cell neoplasms, which has significantly influenced the clinical management of multiple myeloma. Despite these major advances, most cases of multiple myeloma have remained incurable. A considerable number of multiple myeloma patients ultimately experience a final tumor relapse without any additional, effective treatment option. Patients with relapsed or refractory disease typically have a poor prognosis.

Emerging therapeutic approaches include an array of product candidates that target BCMA on multiple myeloma cells, including an antibody drug conjugate and redirected T cell therapies such as T cell engagers and CAR T cell therapies. Despite recent progress, there remains significant unmet clinical need among patients with multiple myeloma, with approximately 11,240 deaths attributed to the disease in the United States in 2015. Our programmed T cell product candidate, AUTO2, is the first dual-targeting approach, which we believe has the potential to lead to higher levels of efficacy and durability of effect compared to other products and redirected T cell therapies that bind to BCMA alone.

Advantage of Dual Targeting

In a study we conducted in collaboration with UCL, multiple myeloma cells from 50 patients were evaluated for the presence of BCMA and TACI. As shown in the following graphic, BCMA was expressed on all of the multiple myeloma cells, while TACI was expressed on approximately 78% of the multiple myeloma cells. As the graph below illustrates, there is high variability in the degree of BCMA expression in multiple myeloma patients.

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BCMA and TACI Expression on Multiple Myeloma Cells

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We believe that a therapeutic approach that targets TACI, in addition to BCMA, would be potentially more effective than current therapies that target BCMA alone, because of the increased target antigen expression. We believe that this dual-targeting approach could overcome limitations of current single-targeting BCMA-targeting therapies, which have been demonstrated to be less effective for patients whose BCMA levels are low. Academic literature has shown that remaining myeloma cells from patients who had a partial response to a single-targeting BCMA-targeting therapy showed low BCMA intensity on tumor cells that remained post-treatment as compared with baseline, indicating the inability to target and eradicate low BCMA expressing multiple myeloma cells. This may result in recurrence of the disease. Additionally, we believe that a programmed T cell therapy that targets BCMA and TACI may potentially overcome the challenges resulting from antigen loss, which is another evasion mechanism of multiple myeloma whereby the cancer cells cease expressing the target antigen and a reported shortcoming of current single-targeting BCMA-targeting therapies.

Clinical Development of AUTO2 for Multiple Myeloma

To capitalize on the possibility of better durability than existing therapies while aiming to maintain a similar safety profile, we conducted preclinical testing and subsequently initiated our clinical development program evaluating AUTO2 in patients with multiple myeloma who have failed multiple lines of prior therapy.

Preclinical Studies of AUTO2

We have studied AUTO2 in in vitro preclinical studies and in animal models of disease. In these studies, administration of AUTO2 resulted in selective and highly effective killing of a human multiple myeloma cell line that naturally expressed both BCMA and TACI. This selective activity was also observed with cell lines expressing either BCMA or TACI at physiological levels, even at conditions of a

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low ratio of targets to AUTO2 cells. Similar outcomes were observed with primary multiple myeloma cancer cells isolated directly from several multiple myeloma patients, including under conditions where access to BCMA was blocked.

In mouse studies modeling multiple myeloma, a single dose of AUTO2 resulted in rapid tumor regression and disease clearance. Toxicological assessments and histological examination of tissues revealed that there were no treatment-related toxicities in treated animals, indicating that targeting TACI may not present a greater risk of off-tumor toxicities than targeting BCMA alone.

In one of our preclinical in vivo studies of AUTO2, 12 mice were injected with tumor cells expressing both BCMA and TACI and were monitored for tumor burden using two methods for quantifying specific cell populations: (i) biological luminescence imaging, or BLI, and (ii) flow cytometry, a technology that measures the number and percentage of cells in a blood sample as well as cell characteristics. Thirteen days after tumor injection, one cohort was treated with AUTO2 and the other cohort, which is referred to as the control, was left untreated. The mice images below show the tumor burden of the two cohorts of mice, both prior to treatment and at 11 days after treatment. The images show the significant reduction of tumor burden observed in the mice that received AUTO2.

Reduction of Tumor Burden in In Vivo Mouse Model

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In another one of our preclinical in vivo studies of AUTO2, 21 mice were injected with a mixture of tumor cells that expressed either BCMA only or TACI only, and were monitored by BLI and flow cytometry for tumor burden. Of the three cohorts of mice, one cohort was treated with AUTO2, one cohort was treated with T cells engineered with a CAR targeting BCMA and one cohort, which is referred to as the control, was left untreated. The mice images below show the tumor burden of the three cohorts, both prior to treatment and at nine days after treatment. The images show that there was significant clearance of the tumor cells in the cohort treated with AUTO2, while the BCMA-targeting CAR T cell cohort was not able to achieve similar levels of clearance. While both AUTO2 and the BCMA-targeting CAR T cells reduced BCMA-expressing cells, only the mice that received AUTO2 showed a substantial reduction in TACI-expressing cells. The figures below the images show the clearance of BCMA-expressing cells and TACI-expressing cells in each cohort.

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Reduction of Tumor Burden in In Vivo Mouse Model

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Phase 1/2 Clinical Trial

In the third quarter of 2017, we initiated a single-arm, open label, multi-center Phase 1/2 clinical trial of AUTO2 in patients with advanced multiple myeloma who have failed at least three prior therapies or are refractory to two of the major traditional classes of cancer treatments, such as chemotherapy, proteasome inhibitors, immunomodulatory agents and monoclonal antibodies. Additionally, the patients are not being selected based on BCMA or TACI antigen expression. We refer to this trial as the APRIL Trial. The trial is initially being conducted at three major hospitals in the United Kingdom. We expect to initiate additional clinical trial sites in the Netherlands and the United States during 2018. In order to initiate clinical trial sites located in the United States, we submitted an Investigational New Drug, or IND, application to the FDA in the second quarter of 2018.

The main objective of the Phase 1 portion of the trial is to evaluate safety and to determine a recommended dose for the Phase 2 portion of the trial. The main objective of the Phase 2 portion will be to further evaluate the safety of the treatment and to evaluate efficacy endpoints, such as overall response rate and complete response rate. Efficacy will be measured based on consensus criteria developed by the International Myeloma Working Group, or IMWG. These criteria take into account the malignant myeloma protein, or M-protein, present in blood and urine, the presence of malignant plasma cells in bone marrow, and other parameters. Further, the efficacy endpoints in our trial have previously been used in clinical trials of other multiple myeloma products that have been approved by the FDA.

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We have designed the trial to evaluate up to four dose levels of AUTO2, beginning with a low starting dose of 15 million cells. We elected to initiate testing of AUTO2 at this low level based in part upon this trial being the first in human administration of programmed T cells targeting TACI. Assuming that we do not observe any dose limiting toxicities, or DLT, the dose escalation phase of the trial will continue in cohorts of three to six patients, each receiving higher doses ranging from 75 million cells up to a maximum of 450 million cells. Once a recommended dose has been established, we intend to enroll 30 patients in the Phase 2 portion of the trial. If we obtain positive data and after consultation with regulatory authorities, we intend to enlarge the trial size.

Prior to receiving AUTO2, all enrolled patients will receive a three-day course of intravenous chemotherapy with fludarabine and cyclophosphamide ending three to four days before AUTO2 infusion. This pre-treatment is designed to reduce the number of normal T cells in the body and condition the patients for programmed T cell therapy.

The graphic below depicts the trial design of the Phase 1/2 clinical trial:

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As of April 23, 2018, five patients were dosed in the trial. One patient received a dose of 15 million AUTO2 cells, three patients received 75 million AUTO2 cells and one patient received a dose of 225 million AUTO2 cells. No safety signals were observed in these patients and we have begun enrolling patients in the third cohort at the next higher dose level of 225 million AUTO2 cells. All of the evaluable patients had low BCMA expression. One patient had high TACI expression and the other patients had moderate to low TACI expression. Of the first four evaluable patients, three had a best response of stable disease, or SD, at the end of month one. One patient has an ongoing SD at the end of month six, and three patients progressed at months three, two and one, respectively. The fifth patient is not yet evaluable. The activity of AUTO2 observed at the dose levels up to 75 million cells is comparable to the data reported in other Phase 1 clinical trials of BCMA CAR T cell product candidates.

To date, AUTO2 has been well tolerated, with adverse events consistent with those observed with other CAR T cell therapies. To date, the most common adverse events have included cytopenias or a mild fever associated with CRS. Additionally, there has been one serious adverse event of Grade 4 neutropenia deemed by the trial investigator to be related to AUTO2. No DLT, neurotoxicity, liver, kidney or cardiac toxicities, or TACI-related unexpected toxicity incidents deemed by the trial investigator to be related to AUTO2 have been observed to date.

Development Strategy for AUTO2

We anticipate completing the Phase 1 dose escalation phase of the trial in the first half of 2019 and establish a recommended dose for the Phase 2 portion of the trial. Once a recommended dose has been established, we expect to commence the Phase 2 portion.

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During the Phase 2 portion of the trial, we will evaluate preliminary efficacy endpoints, such as overall response rate and complete response rate, and depending on the preliminary efficacy results, we may consider expanding the trial into a single-arm trial that, subject to discussions with regulatory authorities, may be a registrational trial. The final number of patients to be enrolled in the trial, specific endpoints and other aspects of the design of the trial will be determined based on feedback from regulatory authorities. We will also consider conducting clinical trials to evaluate AUTO2 as a potential earlier line treatment for multiple myeloma based on emerging data.

Future Generations for AUTO2

We believe our modular approach to T cell programming and the common manufacturing platform used across all our T cell therapies will position us to more quickly develop next-generation product candidates with enhanced characteristics such as pharmacological control, insensitivity to checkpoint inhibition or other desirable features. Building on our prior clinical work and using our advanced T cell programming, we are developing next-generation product candidates of AUTO2 with the intent of providing an improved safety, efficacy and durability profile. One next-generation version of AUTO2 is being developed as a tunable version of the earlier-generation product candidate. Using a clinically approved small molecule, this system is designed to reversibly dampen the activity of the programmed T cells by temporarily dislocating the signaling domain on the inside of the T cell from the cancer cell recognition domain, in order to manage the patient through periods of acute toxicities such as CRS or neurotoxicity. Another next-generation version of AUTO2 is being developed to include a modified SHP2 adaptor protein designed to counteract immune checkpoint inhibition. A decision to advance such product candidates into clinical development will depend, in part, on the emerging safety and efficacy profile of AUTO2.

AUTO3: Our Programmed T Cell Therapy for the Treatment of Pediatric ALL and Adult DLBCL

Introduction to AUTO3

We are developing AUTO3, the first dual-targeting programmed T cell product candidate that targets B cell antigens CD19 and CD22, for the treatment of pediatric patients with relapsed or refractory ALL, as well as the treatment of adult patients with DLBCL.

To our knowledge, AUTO3 is the only programmed T cell product candidate in development that simultaneously targets both CD19 and CD22. By simultaneously targeting both B cell antigens, we believe the novel molecular design of AUTO3 addresses a major limitation of current CAR T cell products that target only CD19 or CD22 that is the loss of the target antigen on the surface of the cancer cell, which leads to relapse of the cancer.

Background of Pediatric ALL

Pediatric ALL is a type of cancer in which the bone marrow makes too many immature lymphocytes, which are a type of white blood cell. According to the American Cancer Society, ALL is most common in early childhood, peaking between two and four years of age. As per the National Cancer Institute Surveillance, Epidemiology and End Results statistics database, there are approximately 3,400 new cases of pediatric ALL diagnosed in the United States each year.

The current standard of care for both pediatric and adult ALL patients is a standard regimen of combination chemotherapy. Pediatric patients typically respond well to the complex first-line treatment. According to the American Cancer Society, the five-year survival rate for children with ALL is more than 85% overall. However, 10 to 20% of pediatric ALL patients relapse with chemotherapy-resistant disease. These patients are re-treated with intensive chemotherapy, and those that respond well

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proceed to receiving an allogenic stem cell transplant, or SCT. However, SCT is associated with significant long-term morbidity due to the risk of developing graft-versus-host disease, or GVHD, and treatment-related mortality, although the risk of death declines with better post-transplant management.

Patients with high-risk clinical or genetic features including gene abnormalities, as well as those who have an inadequate response to initial chemotherapy, typically do poorly and receive a more intensive therapy regimen, with a five-year OS rate of approximately 15%. Patients relapsing after SCT have a very poor prognosis. Long-term survival rates are only approximately 10 to 20% among patients receiving a second SCT and negligible in those unable to proceed to a second transplant.

There is a significant unmet need in pediatric patients with high-risk relapsed or refractory ALL. CD19 CAR T cell therapies have been developed for these patients, with an 80 to 90% complete response rate observed. However, at six months after treatment, approximately 40% of the patients relapse. In one study of CD19-targeting Kymriah treatment, approximately two-thirds of relapses were determined to have been due to loss of CD19 on the target cells.

Clinical Development of AUTO3 for Pediatric ALL

We conducted preclinical testing of AUTO3 and subsequently initiated our clinical development program of AUTO3 for pediatric ALL. Clinical trials of AUTO3 are designed to evaluate AUTO3 in pediatric patients with ALL that is refractory or in second or later relapse.

Preclinical Studies of AUTO3

We have evaluated AUTO3 in preclinical in vitro and in vivo animal models of disease. In these studies, AUTO3 cells targeting both CD19 and CD22 were observed to eliminate tumor cells expressing these antigens. The specificity and functionality of the CD19/CD22 programmed T cells was established in vitro using the relevant human cell line. In addition, the dual targeting AUTO3 cells had similar functionality relative to the single CD19 and CD22 CAR T cells. Moreover, the ability of the dual targeting AUTO3 cells to efficiently kill CD19-negative variants was confirmed in an in vitro model of antigen-escape, a common mechanism of relapse in patients following treatment with a CD19 targeting CAR T cell therapy.

In an in vivo tumor xenograft mouse model using immune-compromised mice, we also observed that AUTO3 cells caused rapid tumor regression and disease clearance. The humanized CD19 and CD22 antigen-binding fragments do not cross the species barrier from human to mouse, which restricts the ability to assess off-tumor effects in mice. However, we conducted a standard human tissue cross-reactivity, or TCR, study to assess potential off-target activity and no unexpected cross-reactivity was observed.

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The preclinical study design and the results of the in vivo efficacy studies are shown in the graphic below. In the study, two cohorts of six mice received injections of tumor cells expressing both target antigens and were monitored by BLI and flow cytometry for tumor burden. Of the two cohorts of mice, one cohort was treated with AUTO3 and the other cohort, which is referred to as the control, was treated with normal T cells. The images below show the tumor burden in the mice in each cohort, both prior to treatment and at 14 days after treatment. The images show the significant reduction in tumor burden in the cohort treated with AUTO3.

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Individual data for each mouse is shown in the graphics below and the lines in the right and left graphics represent the mean value in each. In the graph on the left, the dot plots show a representative staining from the spleen or the bone marrow of the control cohort of mice compared to the cohort treated with AUTO3. The same tumor cells and T cells were used in the control cohort as for the AUTO3 cohort, except that the T cells were not transduced with the CAR construct. The graph on the right shows the typical expansion of the AUTO3 cells that would be expected to accompany the elimination of the tumor in humans based on comparable cells/kg.

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Phase 1/2 Clinical Trial in Pediatric ALL

In the third quarter of 2017, we initiated a single-arm, open label, multi-center Phase 1/2 clinical trial of AUTO3 in patients up to 24 years of age with high-risk relapsed or refractory B-lineage ALL. We refer to this trial as the Amelia Trial and we expect to enroll up to 54 patients. If we observe positive data and after consultation with regulatory authorities, we intend to enlarge the trial size. Currently, the clinical trial is being conducted at sites in the United Kingdom, and we expect to submit an IND application to the FDA in the third quarter of 2018 in order to open additional trial sites in the United States. The trial is enrolling patients who have not previously received any CAR T cell therapy, as well as those who have received CD19-targeting CAR T cell therapy but have relapsed due to loss of the CD19 target protein.

The main objective of the Phase 1 portion of the trial is to evaluate the safety of AUTO3 and to determine a recommended dose for the Phase 2 portion. The main objective of the Phase 2 portion will be to further evaluate the safety of the treatment and to evaluate the efficacy endpoints, such as complete response rate and MRD-negative complete response rate, or MRD-negative CRR. Response rates will be as assessed by flow cytometry and polymerase chain reaction, or PCR.

In the Phase 1 portion, the trial is designed to test up to three dose levels, 1 million, 3 million and 5 million AUTO3 cells/kg. Within each dose level, patients will be enrolled in two different cohorts based on the level of leukemia in their bone marrow. Those with low levels of leukemia burden in the bone marrow will receive a single dose at the relevant dose level, while those with higher disease levels will receive a split dose divided into two infusions, administered five to ten days apart, to reduce the risks of toxicity associated with cytokine release. Once a recommended dose has been established, we intend to enroll at least 24 patients in the Phase 2 portion of the trial.

Prior to receiving AUTO3, all enrolled patients will receive a course of chemotherapy with fludarabine for four days and cyclophosphamide for two days ending three days before AUTO3 infusion. This pre-treatment is designed to reduce the number of normal T cells in the body and condition the patients for therapy.

The graphic below depicts the trial design of the Phase 1/2 clinical trial:

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As of April 19, 2018, six patients have been dosed in the trial. The first dose cohort consisted of three patients at the dose level of 1 million AUTO3 cells/kg, with one of the three patients receiving a

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split dose. The second dose cohort consisted of three patients at the dose level of 3 million AUTO3 cells/kg, with two of the three patients receiving a split dose and the third patient receiving a single dose.

To date, AUTO3 has generally been well tolerated and no DLT or severe CRS have been observed. The four evaluable patients at the first and second dose levels experienced transient cytopenias that mostly resolved by the end of month one. Two patients experienced mild CRS.

The patient in the first dose cohort of the trial received a split-dose schedule due to a high disease burden only received the first portion of the split dose totaling 300,000 AUTO3 cells/kg. The patient experienced a worsening of CNS symptoms following administration of AUTO3, but has since significantly improved. The adverse event was assessed by the treating physician as unrelated to AUTO3 treatment, arising from intrathecal chemotherapy treatment received by the patient prior to dosing with AUTO3. Following this event, the trial protocol was changed to add a four-week washout period after the last intrathecal chemotherapy, which is intended to reduce future recurrences of such events.

Two of the three evaluable patients treated at the 1 million cells/kg dose, including the patient who only received the first portion of the split dose totaling 300,000 AUTO3 cells/kg, developed MRD-negative CR at the end of month one. However, bone marrow molecular relapse was observed at month five and at month three, respectively. The third patient in the first dose cohort did not respond and had progressive CD19- and CD22-positive leukemia at week six. In the second dose cohort, the first of three patients dosed was evaluable as of April 19, 2018. This patient, who received a split dose, also achieved an MRD negative CR. The other two patients are not yet evaluable for response.

Development Strategy for Pediatric ALL

Based on our anticipated enrollment rates for the trial, we anticipate completing the Phase 1 dose escalation phase of the trial and to report preliminary results from the trial in late 2018 or early 2019. If the preliminary efficacy data are positive in both leukemia and CD19 or CD22 negative relapsed leukemia patients, we intend to seek breakthrough designation from the FDA for AUTO3 based on the significant medical unmet need among these patients.

If the preliminary efficacy data from the Phase 2 portion of the trial are positive, we intend to discuss with the FDA the possibility of converting the Phase 2 portion into a single-arm trial that, subject to discussions with regulatory authorities, may be a registrational trial, with separate cohorts for CD19 CAR-naïve and CD19-negative patients. The final number of patients to be enrolled in the trial, specific endpoints, and other aspects of the design of the trial will be determined based on feedback from regulatory authorities. If the response rate and relapse free survival is compelling, we intend to submit a biologics license application, or BLA, for accelerated approval in patients with high-risk relapsed or refractory ALL or in patients with second or later B-ALL relapse.

Background of DLBCL

Non-Hodgkin lymphoma, or NHL, consists of a diverse group of malignant neoplasms. According to the American Cancer Society, DLBCL is the most common subtype of NHL, accounting for approximately one-third of the approximately 72,000 adult NHL patients diagnosed in 2017 in the United States. DLBCL arises from a mature B cell that generally express CD19 and CD22 antigens on the surface. DLBCL is classified as an aggressive lymphoma, in which survival is measured in months rather than years.

First-line therapy usually consists of a chemotherapy regimen known as R-CHOP, which combines the monoclonal antibody rituximab with the drugs cytoxan, adriamycin, vincristine and

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prednisone. Approximately 50% to 60% of DLBCL patients are cured with first-line therapy and do not have recurrence of their lymphoma.

For patients who relapse or are refractory to first-line therapy, the current standard of care for second-line therapy consists of a platinum-based chemotherapy regimen with rituximab. These second-line chemotherapy regimens are either R-ICE, consisting of rituximab, ifosfamide, carboplatin and etoposide, or R-DHAP, consisting of rituximab, dexamethasone, cytarabine and cisplatin. Patients who respond to second-line therapy may go on to receive autologous hematopoietic stem cell transplantation, or HSCT. Patients who are not candidates for HSCT or those who do not respond to second-line therapy or who relapse after HSCT are typically treated with a third-line salvage chemotherapy. These patients have a poor prognosis, and treatment is generally palliative to try to prevent further cancer growth without the intent to cure.

Indolent lymphomas account for 40% of all NHL cases. The subtypes of indolent lymphoma, including follicular lymphoma and others, initially respond well to chemotherapy or antibody therapy, or a combination of both. However, in patients with progressive disease or relapse after complete remission, there is no defined standard of care, and such patients are generally encouraged to participate in clinical trials whenever possible. Relapsed patients who are symptomatic or need treatment are usually treated with chemotherapy, which is unfortunately not curative. Additionally, a minority of these patients are eligible to receive HSCT, which provides long-term disease free survival in some cases.

Clinical Development of AUTO3 for Adult DLBCL

We have designed AUTO3 to address limitations of current therapies for DLBCL. Simultaneous targeting of both CD19 and CD22 antigens is designed to reduce CD19 antigen negative disease relapses as seen in a third of the patients relapsing after treatment with Yescarta. Our clinical trial design also includes the administration of three doses of an anti-checkpoint inhibitor, designed to address tumor relapse due to upregulation of checkpoints in DLBCL patients treated with CAR T cell therapy. We are initially developing AUTO3 as a third-line therapy for DLBCL.

In September 2017, we initiated a single-arm, open label, multi-center Phase 1/2 clinical trial of AUTO3, followed by limited duration of consolidation with an anti-PD-1 antibody. The trial is enrolling adult DLBCL patients who have chemotherapy refractory disease or with relapsed disease after two lines of prior therapy. We refer to this trial as the Alexander Trial and we expect to enroll approximately 100 patients in the trial, which is initially conducted at sites in the United Kingdom. We plan to open additional trial sites in Europe and the United States in 2018. Additionally, we expect to submit an IND application to the FDA in 2018.

The primary objective of the Phase 1 portion of the trial is to evaluate the safety of AUTO3 in lymphoma patients and to determine a recommended dose for the Phase 2 portion. The primary objective of the Phase 2 portion will be to further evaluate the safety of the treatment and to evaluate the efficacy endpoints, such as overall response rate and complete response rate.

We have designed the trial to evaluate three dose levels, with patients enrolled at each dose level receiving a single infusion of AUTO3. The initial cohort of six to 12 patients will receive an infusion of 50 million cells of AUTO3/kg. Assuming that we do not observe any DLT, the dose escalation phase of the trial will continue to open cohorts of three to six patients, receiving higher doses of 150 million cells/kg and 300 million cells/kg. Prior to receiving AUTO3, enrolled patients will receive a three-day course of chemotherapy with fludarabine and cyclophosphamide ending three to four days before AUTO3 infusion. This pre-treatment is designed to reduce the number of normal inhibitory T cells in the body and to condition the patients for therapy. In addition to receiving AUTO3, all but the first three patients

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at the lowest dose will also receive the anti-PD1 antibody pembrolizumab two weeks after AUTO3 infusion. The anti-PD1 antibody will be given every three weeks, for a total of three doses of 200 mg each. Once a recommended dose has been established, we intend to enroll 81 patients in the Phase 2 portion of the trial.

The graphic below depicts the trial design of the Phase 1/2 clinical trial:

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As of April 19, 2018, three patients were dosed at the starting dose of 50 million AUTO3 cells. No DLTs have been observed and no severe CRS have been noted. One patient experienced mild grade CRS treated with tocilizumab, and another patient developed delayed Grade 3 neurotoxicity at week seven, who has since fully recovered.

The three patients were evaluable for response. The first patient had a mixed response classified as progressive disease. This patient had weak CD19 expression and no CD22 expression on the tumor cells. The second patient, who had low CD19 expression and normal CD22 expression on the tumor cells, had a partial response at month one but progressed at month three. The third patient, who expressed only CD19 on the tumor cells and was negative for CD22 expression, had a complete response at the one month assessment.

Further enrollment into the trial’s 50 million dose cohort is ongoing, with the additional patients receiving consolidation therapy with three doses of Keytruda^®. Upon successful completion of this cohort, the next higher dose level of 150 million cells followed by Keytruda consolidation will be opened. Based on the three patients treated thus far in the first dose cohort of this clinical trial, AUTO3 has shown clinical responses in a patient whose tumor cells expressed CD22 but had low CD19 expression, and in a patient whose tumor cells expressed CD19, but not CD22. We believe this preliminary data supports our belief that the dual-targeting approach of AUTO3 may prove to be beneficial for a broader number of DLBCL patients than a single targeting CD19 CAR T cell therapy.

Development Strategy for Adult DLBCL

Based on our anticipated enrollment rates for the trial, we anticipate completing the Phase 1 dose escalation phase of the trial in the first quarter of 2019. Based on the observations from the Phase 1 portion of the trial, we plan to establish a recommended dose for the Phase 2 portion of the trial. Once a recommended dose has been established, we expect to commence the Phase 2 portion.

If the safety and efficacy data from the Phase 2 portion of our ongoing trial are positive, we plan to submit a BLA to the FDA and seek accelerated approval of AUTO3 as a third-line therapy for

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DLBCL patients. If AUTO3 is approved as a third-line therapy for DLBCL, we would expect to initiate a trial to potentially position AUTO3 as a second-line therapy. Such a trial may include a randomized trial of AUTO3 followed by limited anti-PD1 consolidation versus standard of care followed by auto transplant. We may also pursue additional trials including a randomized trial of standard of care based upon advice from regulatory authorities or in order to move to an earlier line of therapy.

Other Potential Indications and Future Generations for AUTO3

In addition, we plan to investigate the activity of AUTO3 in other aggressive and indolent lymphomas, such as follicular lymphoma, primary mediastinal B-cell lymphoma, mantle cell lymphoma and chronic lymphocytic leukemia. We will also consider consolidation of AUTO3 with anti-PD1 antibodies and other agents in these indications.

We believe our modular approach to T cell programming and the common manufacturing platform used across all our T cell therapies will position us to more quickly develop next-generation product candidates with enhanced characteristics such as pharmacological control, insensitivity to checkpoint inhibition or other desirable features. Building on our prior clinical work and using our advanced T cell programming, we are developing next-generation product candidates of AUTO3 with the intent of providing an improved safety, efficacy and durability profile. One next-generation version of AUTO3 is being developed as a tunable version of the earlier-generation product candidate. Using a clinically approved small molecule, this system is designed to reversibly dampen the activity of the programmed T cells by temporarily dislocating the signaling domain on the inside of the T cell from the cancer cell recognition domain, in order to manage the patient through periods of acute toxicities such as CRS or neurotoxicity. Another next-generation version of AUTO3 is being developed to include a modified SHP2 adaptor protein in order to counteract immune checkpoint inhibition, which may eliminate the need for the separate administration of anti-PD1/PDL-1 antibodies. A decision to advance such products into clinical development will depend, in part, on the emerging safety and efficacy profile of AUTO3.

AUTO4 and AUTO5: Our Programmed T-Cell Lymphoma Program

Introduction to AUTO4 and AUTO5

We are developing two programmed T cell product candidates, AUTO4 and AUTO5, as potential treatments for T-cell lymphomas. We are developing these product candidates with a unique targeting approach that is designed to avoid the severe immunosuppression typically associated with current treatment options for this disease.

T cells have one of two functionally identical genes, known as TRBC1 and TRBC2. A normal T cell population contains a mix of cells expressing either TRBC1 or TRBC2. Both forms are active and provide the body with natural immunity, including antiviral immunity. Because T-cell lymphomas are clonal tumors that develop from a single T cell, they are either entirely TRBC1-positive or entirely TRBC2-positive. Currently available products for the treatment of T-cell lymphoma indiscriminately target all T cells, leading to the severe immunosuppression associated with these treatments.

We have designed AUTO4 as a programmed T cell to specifically target and deplete cells expressing TRBC1, while preserving healthy T cells that express TRBC2, and we are designing AUTO5 to specifically target and deplete cells expressing TRBC2, while preserving healthy T cells that express TRBC1. A normal T cell population consists of varying amounts of TRBC1-positive and TRBC2-positive T cells. Based on the typical distribution of TRBC1-positive and TRBC2-positive T cells, we believe that patients treated with AUTO4 or AUTO5 should be left with a population of healthy, functional T cells, which provides the immune system of these patients the ability to respond

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with these remaining healthy T cells to bacterial and viral infections and other pathogens. In addition, both product candidates will have a built-in safety switch designed to eliminate the programmed T cells in the event a patient suffers certain serious adverse events related to the T cell therapy, such as CRS or neurotoxicity.

The graphic below illustrates the targeting mechanism of action and intended therapeutic effect of AUTO4 and AUTO5.

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Companion Diagnostic for AUTO4 and AUTO5

We are developing a proprietary diagnostic test to distinguish between TRBC1-positive T cells and TRBC2-positive T cells. When a patient presents with T-cell lymphoma, this diagnostic is designed to test the patient’s tumor to assess whether the tumor is TRBC1-positive or TRBC2-positive, which will determine whether the patient is potentially a candidate to receive AUTO4 or AUTO5.

Background of T-Cell Lymphoma

T-cell lymphoma is a rare and heterogeneous form of NHL, representing approximately 10 to 20% of NHL cases and 3 to 4% of all hematological malignancies. While T-cell lymphoma is a smaller percentage of all lymphomas as compared to B cell lymphomas, T-cell lymphoma is an aggressive disease with a very poor prognosis for patients. Most T-cell lymphomas are peripheral T-cell lymphomas, or PTCL, the initial indication for which we are developing AUTO4. We estimate that PTCL affects approximately 2,900 patients in the United States each year. PTCL generally involves high-grade tumors and occurs at a similar age as aggressive B cell lymphomas, with a relatively high proportion of patients becoming rapidly unwell with malaise and fevers. The five-year survival rate ranges from 18% to 24%. The three most common subtypes of PTCL are peripheral T-cell lymphoma not otherwise specified, or PTCL-NOS, anaplastic large-cell lymphoma, or ALCL, and angioimmunoblastic T-cell lymphoma, or AITL, together accounting for approximately 70% of all PTCLs in the United States.

The first-line treatment for PTCL consists of the combination chemotherapy CHOP, consisting of cyclophosphamide, vincristine, doxorubicin and prednisolone. However, treatment with chemotherapy

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introduces toxicity concerns, including low blood cell counts, nausea, vomiting, diarrhea, hair loss, mouth sores, and increased risk of infections. Additionally, with CHOP chemotherapy, complete response rates are lower than in DLBCL and relapse is more common. In many treatment centers, CHOP chemotherapy is consolidated with high-dose chemotherapy and autologous or allogenic stem cell transplantation.

Little is understood in terms of treatment guidance for the other PTCL subtypes and these lymphomas lack clear treatment guidelines. A large proportion of T-cell lymphoma patients are refractory to or relapse following treatment with standard therapies and there remains a need to develop an effective therapy for this currently unmet need.

Unlike B cell lymphomas, T-cell lymphomas have not benefited from advances in immunotherapeutic approaches. This is mainly due to the lack of therapeutic development in T-cell lymphomas to identify suitable target antigens to distinguish malignant T cells from normal T cells. While a similar problem exists with B cell lymphomas, targeting a pan B cell antigen is an acceptable strategy, as the concomitant depletion of the normal B cell compartment is well tolerated, and some targeted approaches may be ameliorated by the administration of immunoglobulin. In contrast, targeting a pan T cell antigen would result in severe immunosuppression, where there is currently no available rescue medication. Some competitors that are pursuing this approach are planning to include an allogenic SCT as a rescue following removal of all T cells. There is currently no programmed T cell therapy that is being developed as a standalone treatment.

Preclinical Studies

We have evaluated AUTO4 in pre-clinical in vitro studies and in animal models of disease. The specificity and functionality of AUTO4 was established in vitro using the relevant cell line and primary human cells. In these studies, the AUTO4 cells selectively and effectively eliminated TRBC1-expressing tumor cells. The activity of AUTO4 was also established in vivo in a tumor xenograft mouse model using immune-compromised mice where the AUTO4 cells caused tumor regression and disease clearance by selectively and effectively killing target cancer cells.

In one in vivo mouse study, 16 mice were injected with a mixture of fluorescently labelled cells that expressed either TRBC1 only or TRBC2 only, and were monitored by flow cytometry for tumor burden. Of the two cohorts of mice, one cohort was treated with AUTO4 and the other cohort was treated with mock-transduced treatment cells, which is referred to as the control. The graphic below shows the depletion of TRBC1 and TRBC2 in each cohort at the termination of the study, six days after treatment. These results showed that AUTO4 was able to deplete TRBC1-expressing cells but not TRBC2-expressing cells, which confirmed the TRBC1 specificity of AUTO4.

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In another in vivo mouse study, 16 mice were injected with tumor cells expressing TRBC1 and were monitored by BLI and flow cytometry for tumor burden. Of the two cohorts of mice, one cohort was treated with AUTO4 and the other cohort was treated with normal T cells, which is referred to as the control. The mice images below show tumor burden in each cohort both prior to treatment and at 13 days after treatment. The images and the figures below the images show that the cohort treated with AUTO4 experienced significant reduction in tumor burden compared to the control cohort. The blue coloring in the mice scans below depict tumor burden at the time of injection, which is equal across the two cohorts. At 13 days following treatment, the control cohort showed increase in tumor burden, which is reflected by the red and green coloring in the images and correlates with tumor cell density. The AUTO4 cohort, however, showed disappearance of luminescence, which is represented by lack of blue coloring and correlates with a significant decrease of tumor burden.

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Although these mouse models are restricted in their ability to show what off-tumor effects may be experienced in humans, a standard human TCR study was used to assess potential off-target activity, and no cross-reactivity was observed beyond the expected tissue distribution of T cells. Collectively, these findings suggest that no off-target toxicity is anticipated.

Clinical Development of AUTO4 and AUTO5

Because AUTO4 and AUTO5 represent a novel approach to treating T-cell lymphomas, our development strategy for these product candidates will be based on initially commencing a Phase 1/2 clinical trial of AUTO4 for the treatment of TRBC1-positive T-cell lymphoma. Prior to initiation of the Phase 1/2 trial, a diagnostic test for the identification of TRBC1 and TRBC2 may be required. If we are able to establish proof-of-concept in AUTO4, we plan to commence a similar Phase 1/2 clinical trial of AUTO5 for the treatment of TRBC2-positive T-cell lymphoma.

Planned Phase 1/2 Clinical Trial of AUTO4

We are planning to conduct a single-arm, open label, multi-center Phase 1/2 clinical trial in patients with PTCL-NOS, AITL and ALCL, the three most common subtypes of PTCL that express TRBC1, which patients have failed, or have relapsed disease following, at least one prior therapy. We have received approval from the Medicines and Healthcare products Regulatory Agency, or MHRA, and expect to commence a Phase 1/2 trial in the first half of 2018. The trial will initially be conducted at sites in the United Kingdom. Provided that safety and efficacy data is satisfactory in the initial patients in the trial, we intend to submit an IND and initiate additional sites in the United States.

The main objective of the Phase 1 portion of the trial is to evaluate the safety of AUTO4 and to determine a recommended dose for the Phase 2 portion of the trial. The main objective of the Phase 2 portion will be to further evaluate the safety of the treatment and evaluate efficacy endpoints, such as overall response rate and CR rate.

We have designed the trial to evaluate up to three dose levels of AUTO4, beginning with a low dose of 25 million AUTO4 cells/kg in cohorts of three to six patients. Assuming that we do not observe any DLT, the dose escalation phase of the trial will continue to higher doses of 75 million AUTO4 cells/kg and 225 million AUTO4 cells/kg. Based on emerging data, we may also consider split dose regimens. We expect that we will enroll a total of up to 25 patients in the Phase 1 portion of the trial. Once a recommended dose has been identified in the Phase 1 portion of the trial, we intend to treat up to 30 patients in the Phase 2 portion of the trial.

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The graphic below depicts the trial design of the Phase 1/2 clinical trial:

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Development Strategy for AUTO4

Based on our expected enrollment rates for the trial, we anticipate completing the Phase 1 dose escalation phase of the trial in late 2019 or early 2020. If the preliminary efficacy data from the Phase 2 portion of the trial is positive, we intend to discuss with the FDA the possibility of converting the Phase 2 portion into a single-arm trial that, subject to discussions with regulatory authorities, may be a registrational trial. The final number of patients to be enrolled in the trial, specific endpoints and other aspects of the design of the trial will be determined based on feedback from regulatory authorities. If the safety and efficacy data from the Phase 2 portion of the trial are positive, we plan to submit a BLA and seek accelerated approval of AUTO4 as a second-line therapy for TRBC1-positive T-cell lymphoma patients.

Development Strategy for AUTO5

If we are able to establish proof-of-concept of our programmed T cell therapeutic approach to treating T-cell lymphoma in our planned Phase 1/2 clinical trial of AUTO4, we plan to initiate a Phase 1/2 clinical trial of AUTO5 for the treatment of TRBC2-positive T-cell lymphoma. While we have not yet developed the protocol for the AUTO5 trial, we expect that the trial design would be similar to the AUTO4 trial.

Our Solid Tumor Programs

Solid tumors present a particular challenge to CAR T cell therapies, since solid tumors tend to fend off T cells with upregulation of checkpoint inhibition and a hostile microenvironment. In addition, contrary to hematological cancer cells that are readily accessible to programmed T cells in the circulating blood of a patient, solid tumors are more difficult for programmed T cells to track down in sufficient numbers to impact the disease. In addition, the persistence of programmed T cells tends to be limited, which also leads to a reduced effect on solid tumor cells. In addition to the programs we are currently pursuing described below, we intend to continue to evaluate other possible solid tumor indications.

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AUTO6: Neuroblastoma Program

Introduction to AUTO6 and AUTO6 NG

We have been granted an exclusive, worldwide license under our license agreement with UCLB to AUTO6 (1RG-CART), a programmed T cell product candidate targeting the glycosphingolipid GD2. CRUK is conducting an exploratory Phase 1 clinical trial of AUTO6 in pediatric patients with neuroblastoma. We are developing a next-generation product candidate, which we refer to as AUTO6 NG, incorporating additional programming modules designed to improve efficacy, safety and persistence of AUTO6. We expect to initiate two Phase 1/2 clinical trials of AUTO6 NG, with the first clinical trial expected to commence in late 2019 and the second clinical trial expected to commence in 2020.

Background of Neuroblastoma

Neuroblastoma is a cancer that develops from immature nerve cells found in several areas of the body, and most commonly arises in and around the adrenal glands, which have similar origins to nerve cells and sit atop the kidneys. However, neuroblastoma can also develop in other areas of the abdomen and in the chest, neck and near the spine, where groups of nerve cells exist. Neuroblastoma most commonly affects children age five or younger, though it may rarely occur in older children. According to the American Cancer Society, there are approximately 700 new cases of neuroblastoma each year in the United States.

Preclinical Studies of AUTO6

In preclinical in vitro studies, AUTO6 selectively, effectively and efficiently killed GD2-expressing tumor cells while sparing cells that did not express GD2. In addition, the RQR8 safety switch activation by rituximab was tested in vitro, where the addition of rituximab was shown to activate the safety switch and eliminate the programmed T cells from the culture, and residual cells did not possess any intrinsic anti-GD2 activity. This safety switch activation was also observed in vivo in a mouse model, where the murine analogue of rituximab was able to deplete the GD2-targeting programmed T cell product candidate from the bone marrow, blood, lymph node and spleen of animals that had previously been engrafted with programmed T cells.

Phase 1 Dose Escalation Trial of AUTO6 by CRUK in Relapsed or Refractory Neuroblastoma

In the first quarter of 2016, CRUK initiated a single-arm Phase 1 dose escalation trial of AUTO6 in relapsed or refractory neuroblastoma at two pediatric cancer centers in the United Kingdom. The trial will evaluate the safety profile of AUTO6 and will determine the recommended dose for a Phase 2 clinical trial. The Phase 1 trial is also evaluating escalating intensity of the pre-conditioning regimen along with AUTO6 dose escalation. CRUK plans to enroll 15 to 27 patients in this trial.

To date, twelve patients with relapsed or refractory neuroblastoma with measurable disease in bone (n=11), bone marrow (n=7) or soft tissue sites (n=9) have been enrolled. Ten patients have been treated, with the first six patients receiving a dose of 10 million AUTO6 cells/m², four without preconditioning, one with cyclyophosphamide alone and one with a combination of cyclyophosphamide and fludarabine, or cy/flu. A further three patients were treated with a dose of 100 million AUTO6 cells/m² with cy/flu preconditioning. In the next cohort, a further patient was treated with a dose of one billion AUTO6 cells/m² with cy/flu preconditioning. The trial is continuing to enroll patients at the dose of one billion AUTO6 cells/m².

No DLT has been observed so far. In patients treated at the first dose level, AUTO6 could not be detected in peripheral blood, and no clinical responses were seen. In contrast, expansion of AUTO6 cells was detected by flow cytometry and qPCR in the four patients treated at the 100 million AUTO6

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cells/m² and one billion AUTO6 cells/m² dose levels. One patient at the 100 million AUTO6 cells/m² dose developed Grade 2 CRS at day five and biochemical evidence of tumor lysis at day 21. Disease reassessment on day 28 showed response in many sites of bone/bone marrow disease as measured by MIBG scintigraphy, commonly known as an MIBG Scan, and near complete tumor clearance in the bone marrow, which at baseline was heavily infiltrated with neuroblastoma cells. Disease progression occurred on day 45, at which time AUTO6 cells were no longer detectable by flow cytometry. A second patient, at the one billion AUTO6 cells/m² dose, also developed Grade 1 CRS accompanied by anti-tumor activity at the site of the tumor in the neck. The anti-tumor activity was accompanied by signs of inflammation on the skin overlying the tumor, consistent with immune activity.

Based on the current preliminary data from this Phase 1 trial, on-target anti-tumor activity of AUTO6 was observed in two pediatric patients, in bone, soft tissue and bone marrow disease sites at a ³ 100 million AUTO6 cells/m² dose. We believe this is the first anti-GD2 CAR T cell product candidate that has shown significant expansion, CRS and tumor lysis syndrome in a solid tumor indication. More importantly, anti-tumor activity was noted in the absence of neurotoxicity or pain syndrome.

Clinical Development Strategy of AUTO6 NG for Neuroblastoma

With achievement of proof-of-concept in CRUK’s ongoing Phase 1 trial, we believe it is possible to safely target GD2-expressing cancers or tumors with a CAR. We are currently developing a next-generation T cell product candidate, which we refer to as AUTO6 NG, which builds on AUTO6 by incorporating additional programming modules intended to enhance the efficacy, safety and persistence of AUTO6.

Because GD2 is expressed in numerous pediatric and adult tumors including neuroblastoma, osteosarcoma, soft tissue sarcoma, melanoma, astrocytoma and small cell lung cancer, or SCLC, our clinical development strategy is to develop AUTO6 NG in parallel in neuroblastoma and in additional indications. To that end, we are planning to initiate two Phase 1/2 trials. The first trial will be in pediatric patients and is expected to commence in late 2019 and the second one will be in adult patients and is expected to commence in 2020.

In the first Phase 1/2 trial, we plan to enroll pediatric patients with relapsed or refractory neuroblastoma and osteosarcoma. Osteosarcoma is the most common type of bone cancer in children and teens, with approximately 800 to 900 new cases diagnosed each year in the United States, the majority of which will be GD2 positive. Following evaluation of safety and selection of the recommended Phase 2 dose, we plan to initiate the three-arm Phase 2 portion of the clinical trial, which will enroll patients with neuroblastoma, osteosarcoma and other GD2-positive tumors, respectively, in each individual arm of the trial. If the preliminary efficacy data from the Phase 2 portion of the trial based on appropriate criteria for individual tumor types is positive in one or more arms, we intend to discuss with the FDA the possibility of converting the Phase 2 portion into a registrational trial, with separate arms for each indication. The final number of patients to be enrolled in the trial and endpoints for each individual indication will be determined based on feedback from regulatory authorities.

The second Phase 1/2 trial, evaluating AUTO6 NG in adults, will be staggered with the first Phase 1/2 trial in order to incorporate learnings from the early dose cohorts of the first Phase1/2 trial in pediatric patients. We anticipate that prior to initiation of this second Phase 1/2 trial, a diagnostic assay for GD2 assessment may be needed. This trial will enroll adult patients with metastatic melanoma, SCLC and other GD2-positive malignancies and who have received at least one prior therapy. Melanoma is one of the most common types of cancer, with approximately 90,000 new cases diagnosed each year in the United States. SCLC accounts for about 10-15% of all lung cancer cases, with 30,000 new cases diagnosed each year in the United States. It has been reported that approximately half of the patients are positive for the GD2 antigen.

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Healthy T Cells Healthy T-cells express either of two alternative forms of the T Cell Receptor and are a mixture of TRBC1 positive cells and TRBC2 positive cells T Cell Lymphomas T-celll ymphomas are clonal and are either TRBC1 or TRBC2 positive. Patients are identified as TRBC1 or TRBC2 positive using a companion diagnostic test and assigned the appropriate treatment. T Cell Therapy Treatment with AUTO4 eliminates the TRBC1 positive cells. Treatment with AUTO5 eliminates the TRBC2 positive cells. Normal Immunity AUTO4 and AUTO5 are designed to eliminate lymphoma, while sparing non-targeted cells, which would allow these non-targeted cells to divide and help preserve immunity.

Following selection of the recommended Phase 2 dose, we plan to initiate the three-arm Phase 2 portion of the clinical trial, which will enroll patients with melanoma, SCLC and other GD2-positive tumors, respectively, in each individual arm of the trial. If the preliminary efficacy data such as overall response rate from the Phase 2 portion of the trial is promising in one or more arms, we intend to discuss with the FDA the possibility of converting the Phase 2 portion into a single-arm registration trial, with separate arms for each indication. The final number of patients to be enrolled in the trial and endpoints for each individual indication will be determined based on feedback from regulatory authorities.

AUTO7—Prostate Cancer Program

We are in preclinical development of AUTO7, a programmed T cell product candidate designed to target and treat prostate cancer. According to the American Cancer Society, other than skin cancer, prostate cancer is the most common cancer in American men, with approximately 165,000 new cases diagnosed each year. This program incorporates enhanced safety modules including our small molecule mediated safety switch and enhanced T cell activity modules that we are developing to overcome the immunosuppressive effects of the tumor microenvironment and enhance T cell persistence. We have incorporated a technology in AUTO7 that is designed to deliver a cytokine signal directly inside our programmed T cells. This cytokine persistence signal is further enhanced by engagement with antigens secreted by the tumor. We intend to initiate our clinical development of AUTO7 in 2020. We anticipate starting a Phase 1/2 trial in patients with metastatic castration-resistant prostate cancer to evaluate the safety and identify the optimum Phase 2 dose of AUTO7 in the Phase 1 part of the trial and preliminary efficacy in the Phase 2 portion of the trial.

Manufacture and Delivery of Programmed T Cell Therapies to Patients

We are devoting significant resources to process development and manufacturing in order to optimize the safety and efficacy of our product candidates, as well as to reduce our per unit manufacturing costs and time to market if we obtain regulatory approval for any of our programmed T cell product candidates.

The manufacture and delivery of programmed T cell therapies to patients involves complex, integrated processes, including harvesting T cells from patients, manufacturing viral vectors with nucleic acid content encoded with our programming modules, manufacturing programmed T cells using the viral vectors ex vivo, multiplying the T cells to obtain the desired dose, and ultimately infusing the T cells back into a patient’s body.

Commercial success in T cell therapies requires a manufacturing process that is reliable, scalable and economical. We have established a manufacturing process that is scalable and serves as a manufacturing platform designed to support rapid development of our programmed T cell therapy product candidates through clinical trial phases and regulatory approval processes. We are using a semi-automated, fully enclosed system for cell manufacturing, which is designed to provide a common platform suitable for manufacturing all of our product candidates. This platform allows for parallel processing and the ability to scale for commercial supply in a controlled environment and at an economical cost. We have improved the viral transduction process to help eliminate processing inconsistencies.

Our manufacturing and logistics process is designed to ensure that product integrity is maintained during shipment along with accurate tracking and tracing of shipments. We plan to build internal manufacturing and supply capabilities as well as to utilize the expertise of collaborators on some of the aspects of product delivery, logistics and capacity expansion.

Our manufacturing and commercialization strategy requires a fully integrated vein-to-vein product delivery cycle. We believe having established manufacturing processes suitable for commercialization

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early in the development of our T cell therapies will allow us to focus on expanding manufacturing capacity during our clinical trials. Over time, we expect to establish regional manufacturing hubs to meet projected product requirements for commercialization. We believe that anticipated future commercial requirements can be met, although we cannot be certain that we will be successful in establishing manufacturing sites in a manner that would not result in significant delay or material additional costs.

We believe our scalable closed-system manufacturing process, along with our proprietary and modular T cell programming technologies, would be challenging and costly for potential competitors to replicate.

Manufacturing Agreements

We have entered into manufacturing agreements with Royal Free Hospital and King’s College London for vector and cell manufacturing. Our employees currently perform or supervise the viral vector manufacturing and cell processing at manufacturing suites on-site at the Royal Free Hospital and King’s College London, respectively, which have Current Good Manufacturing Practice, or cGMP, compliant manufacturing facilities. The manufacturing agreements governing these arrangements also provide for access to services including quality management systems, qualified persons for product release, office space, frozen storage and warehousing services.

We expect to expand our cell manufacturing capacity in 2018 by taking occupancy of a manufacturing suite at the Cell and Gene Therapy Catapult in Stevenage, United Kingdom. Our agreement with the Cell and Gene Therapy Catapult provides for access to an architecturally and operationally segregated manufacturing suite to manufacture the programmed T cell product candidates for our clinical trials.

In March 2018, we entered into a strategic, long-term supply agreement with Miltenyi Biotec GmbH, or Miltenyi, for the supply and support to us of Miltenyi’s CliniMACS Prodigy® instruments, reagents and disposables for the manufacture of our programmed T cell therapies for preclinical and clinical use and, if approved, for commercial use. Under the supply agreement, we will provide Miltenyi with regularly scheduled rolling forecasts of our anticipated purchase requirements on a product-by-product and country-by-country basis. Within our rolling forecasts, there is a period of time referred to as the “firm zone” in which we are obligated to purchase, and Miltenyi has agreed to provide, the number of products we have specified for that period, subject to specified conditions and limitations. We also are subject to specified annual de minimis purchase amounts. The supply agreement also sets forth procedures to ensure continuity of supply to us of Miltenyi’s products, both during the clinical phase and any future commercial phase of our product candidates. After the initial term of the agreement, we have two separate options to renew the agreement for an additional term. The supply agreement contains customary termination provisions, allowing for termination by a party upon the other party’s uncured material breach, upon the other party’s bankruptcy or insolvency or upon the other party being subject to an extended period of force majeure events. We may also terminate the supply agreement upon advance written notice, if we decide to suspend or discontinue the development or commercialization of our product candidates. The supply agreement is governed under the laws of Germany.

Commercialization

Given our stage of development, we have not yet established a commercial organization or distribution capabilities. We are developing our clinical-stage programs for the treatment of patients with late-stage or rare hematological cancers and solid tumors, most of whom are treated in specialized treatment centers or hospitals. With our experience in gene therapy, transplantation and

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oncology, we aim to provide high levels of service and scientific engagement at these treatment centers, and to pilot and establish systems necessary for product delivery by the time of launch. We believe this approach will require less investment in commercial infrastructure compared to the current standard of care. By focusing on these centers, we can begin to build our commercialization capabilities with limited resources.

We have retained worldwide commercial rights for our product candidates. We currently plan to build our global commercialization capabilities internally over time such that we are able to commercialize any product candidate for which we may obtain regulatory approval. We may selectively pursue strategic collaborations with third parties in order to maximize the commercial potential of our product candidates. We generally expect to launch any of our products that receive regulatory approval in the United States first, followed by the European Union and then in other major markets. For AUTO1, we expect to commercialize first in markets outside the United States where we receive regulatory approvals, with a launch following regulatory approval in the United States occurring after the earlier of either the expected expiration of any applicable third-party patents covering AUTO1 in 2023 and late 2024, the invalidation of such patents or the receipt of a license to such patents on commercially reasonable terms. See “Risk Factors–Risks Related to our Intellectual Property–Third parties may initiate legal proceedings alleging that we are infringing their intellectual property rights, the outcome of which would be uncertain and could significantly harm our business.”

Intellectual Property

Intellectual property is of vital importance in our field and in biotechnology generally. We seek to protect and enhance proprietary technology, inventions and improvements that are commercially important to the development of our business by seeking, maintaining and defending patent rights, whether developed internally or licensed from third parties. We will also seek to rely on regulatory protection afforded through orphan drug designations, data exclusivity, market exclusivity and patent term extensions where available.

Our intellectual property estate, which includes in-licensed intellectual property and intellectual property that we own, is designed to provide multiple layers of protection. For example, we are pursuing patent protection for core constructs used in our product candidates, various methods of treatment for particular therapeutic indications using our approach, specific product candidates, innovative manufacturing processes, and constructs that may be used in future product candidates to improve the ability of our programmed T cells to better recognize and kill cancer cells. A portion of our patent portfolio is directed to certain current product candidates or technologies deployed in certain product candidates, and the remainder of the portfolio is directed to alternative approaches, technologies or modules that are not currently deployed in our current product candidates.

As of March 31, 2018, our current patent portfolio is comprised of 61 patent families, of which 25 patent families are in-licensed from UCLB and 36 patent families we own and have originated from our own research. Although our patent portfolio is, generally, at an early stage, and does not yet include any granted U.S. patents, and includes 34 patent families that consist solely of priority applications or PCT applications that are not yet subject to examination, we believe that our current patent portfolio, together with our ongoing efforts to develop and patent new technologies, will provide us with substantial intellectual property protection for our product candidates and other technologies that are not currently deployed in our product candidates.

As of March 31, 2018, we had one patent that has issued from our pending applications in Europe and covers the RQR8 safety switch. This patent is in-licensed from UCLB and has a statutory

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expiration date in April 2033. This patent includes claims directed to the RQR8 composition of matter, as well as methods of making cells that include the RQR8 safety switch and methods of using the RQR8 safety switch. A corresponding Australian patent has also issued.

Commercially or strategically important non-U.S. jurisdictions in which certain patent applications that we have in-licensed are currently pending include: Europe, Australia, Canada, Japan, China, Brazil, Chile, Israel, India, Republic of Korea, Hong Kong, Mexico, New Zealand, Russian Federation, Singapore, South Africa, Colombia, Peru, Cuba, Indonesia, Malaysia and Philippines.

Our strategy is to develop and obtain additional intellectual property covering innovative manufacturing processes and methods for genetically engineering T cells expressing new constructs with properties that are designed to improve the ability of our programmed T cells to recognize and kill cancer cells. To support this effort, we have established expertise and development capabilities focused in the areas of T cell programming, preclinical and clinical research and development, and manufacturing and manufacturing process scale-up, and we expect that our ongoing research and development activities will yield additional patentable inventions and patent applications that will expand our intellectual property portfolio.

The term of individual patents depends upon the legal term of the patents in the countries in which they are obtained. In most countries in which we file, the patent term is 20 years from the date of filing of the first non-provisional application to which priority is claimed. In the United States, a patent’s term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the U.S. Patent and Trademark Office in granting a patent, or may be shortened if a patent is terminally disclaimed over an earlier-filed patent. The term of a patent that covers an FDA-approved drug may also be eligible for a patent term restoration of up to five years under the Hatch-Waxman Act, which is designed to compensate for the patent term lost during the FDA regulatory review process. The length of the patent term restoration is calculated based on the length of time the drug is under regulatory review. A patent term restoration under the Hatch-Waxman Act cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be restored. Moreover, a patent can only be restored once, and thus, if a single patent is applicable to multiple products, it can only be extended based on one product. Similar provisions are available in Europe and certain other foreign jurisdictions to extend the term of a patent that covers an approved drug. If and when possible, we expect to apply for patent term extensions for patents covering our product candidates or their methods of use.

Our commercial success may depend in part on our ability to obtain and maintain patent and other proprietary protection for commercially important technology, inventions and know-how related to our business, defend and enforce our patents, preserve the confidentiality of our trade secrets, and operate without infringing the valid enforceable patents and proprietary rights of third parties. Our ability to stop third parties from making, using, selling, offering to sell or importing our products may depend on the extent to which we have rights under valid and enforceable patents or trade secrets that cover these activities. With respect to both licensed and company-owned intellectual property, we cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications filed by us in the future, nor can we be sure that any patents, if granted, will be commercially useful in protecting our commercial products and methods of manufacturing the same. Development and commercialization of products can be subject to substantial delays and it is possible that, at the time of commercialization, any patent covering the product has expired or will be in force for only a short period of time following commercialization. Numerous third-party U.S. and non-U.S. issued patents exist in the area of programmed T cell therapies, including patents held by our competitors. We cannot predict with any certainty if any third-party U.S. or foreign patent rights, or other proprietary rights, will be deemed infringed by the use of our technology. Nor can we predict with certainty which, if any, of these rights will or may be asserted against us by third-

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parties. Should we need to defend ourselves against any such claims, substantial costs may be incurred. Furthermore, parties making such claims may be able to obtain injunctive or other equitable relief, which could effectively block our ability to develop or commercialize some or all our products in the United States, European Union and other major markets.

We may rely, in some circumstances, on trade secrets to protect our technology. However, trade secrets can be difficult to protect. We seek to protect our proprietary technology and processes, in part, by entering into confidentiality agreements with our employees, consultants, scientific advisors and contractors. We also seek to preserve the integrity and confidentiality of our data and trade secrets by maintaining physical security of our premises and physical and electronic security of our information technology systems. While we have confidence in these individuals, organizations and systems, agreements or security measures may be breached, and we may not have adequate remedies for any breach. In addition, our trade secrets may otherwise become known or be independently discovered by competitors. To the extent that our consultants, contractors or collaborators use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions.

Our License Agreement with UCL Business plc

In September 2014, we entered into an exclusive license agreement with UCLB, the technology-transfer company of UCL, for the development and commercialization rights to certain T cell programming modules. The license agreement was amended and restated in March 2016 to also include certain development and commercialization rights to improvements and new T cell programming modules. The license agreement was further amended and restated in March 2018 to include a license to AUTO1, for which UCL is conducting Phase 1 clinical trials in pediatric and adult ALL patients. Under the license agreement, subject to certain limitations, exceptions and retained rights of UCLB, we received an exclusive license of certain patent rights and know-how owned by UCLB covering T cell programming modules. The licensed rights cover our AUTO1, AUTO2, AUTO3, AUTO4/5 and AUTO6 targeting modules, as well as additional T cell programming modules and technologies, including dual-targeting technology, pattern recognition technology, safety switches (including RQR8), tunable T cells, manufacturing processes as well as certain technology for evading tumor microenvironments. We also have option rights and rights of first negotiation to obtain an exclusive license for development and commercialization rights to certain new T cell programming modules.

In exchange for the rights under the original license agreement, we granted UCLB 4,769,994 B ordinary shares. We also agreed to pay a management fee, milestone payments and royalties upon future net sales of any products that use the in-licensed rights. The management fee of £120,000 is payable in equal installments on the first four anniversaries of our entry into the original license agreement. In exchange for the additional rights we received in March 2016 when the license agreement was amended, we granted UCLB an additional 1,000,000 B ordinary shares and made a one-time payment of £150,000. In exchange for the additional rights we received in March 2018 when the license agreement was further amended, we made an initial payment of £1.5 million and we are obligated to pay an additional £0.5 million in connection with UCLB’s transfer of clinical data to us.

Under the license agreement, we are obligated to pay UCLB milestone payments upon the receipt of specified regulatory approvals in an aggregate amount of £35.5 million, the start of commercialization in an aggregate amount of £18 million, and the achievement of net sales levels in an aggregate amount of £51 million. On a per-product basis, these milestone payments range from £1 million to £18.5 million, depending on which T cell programming modules are used in the product achieving the milestone. Under the terms of the license, we have the right to grant sublicenses to third parties, subject to certain restrictions. If we receive any income in connection with such sublicenses,

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we must pay UCLB a percentage of the income allocable to the value of the sublicensed intellectual property rights ranging from low twenties to mid-single digits, decreasing based on the development expenses incurred by us or the passage of time. UCLB has retained the right to use the licensed T cell programming modules for academic research purposes at UCL and with other academic institutions, subject to certain restrictions.

Upon commercialization of any of our products that use the in-licensed patent rights, we are obligated to pay UCLB a flat royalty for each licensed product ranging from the low- to mid-single digits, depending on which technologies are deployed in the licensed product, based on worldwide annual net sales of each licensed product, subject to certain reductions, including for the market entry of competing products and for loss of patent coverage of licensed products. We may deduct from the royalties payable to UCLB half of any payments made to a third party to obtain a license to such third party’s intellectual property that is necessary to exploit any licensed products. Once net sales of a licensed product have reached a certain specified threshold, we may exercise an option to buy out UCLB’s rights to the remaining milestone payments, royalty payments, and sublicensing revenue payments for such licensed product, on terms to be negotiated at the time.

We may acquire ownership of the licensed patent rights under the license agreement (with the exception of the RQR8 patent rights and certain other patent rights) at any time following our listing on a public stock exchange. Our payment and diligence obligations would remain unaffected by the assignment of the licensed patent rights to us.

Under the license agreement, we are solely responsible, at our expense, for developing the products that use the in-licensed patent rights and obtaining all regulatory approvals for such products worldwide. We are also solely responsible, at our expense, for commercializing the products worldwide after receiving regulatory approval. Further, we are obligated to use commercially reasonable efforts to develop certain products using the patent rights pertaining to the T cell programming modules we have licensed from UCLB. Failure to achieve diligence obligations may result in loss of exclusivity or termination of the license on a program-by-program basis.

The license agreement expires on a product-by-product and country-by-country basis upon the expiration of the royalty term with respect to each product in each country. We may unilaterally terminate the license agreement for any reason upon advance notice to UCLB. Either party may terminate the license agreement for the uncured material breach by the other party or for the insolvency of the other party. If UCLB terminates the license agreement following our insolvency or our material breach of the agreement, or if we terminate the agreement unilaterally, all rights and licenses granted to us will terminate, and all patent rights and know-how transferred to us pursuant to the agreement will revert back to UCLB, unless and to the extent we have exercised our option to acquire ownership of the licensed patent rights. In addition, UCLB has the right to negotiate with us for the grant of an exclusive license to our improvements to the T cell programming modules we have licensed on terms to be agreed upon at the time.

Competition

Presently, the biotechnology and pharmaceutical industries put significant resources in developing novel and proprietary therapies for the treatment of cancer. While we believe that our differentiated product candidates and scientific expertise in the field of cellular immunotherapy provide us with competitive advantages, we face potential competition from various sources, including larger and better-funded pharmaceutical, specialty pharmaceutical and biotechnology companies, as well as from academic institutions, governmental agencies and public and private research institutions. We anticipate that we will face intense and increasing competition as new drugs and therapies enter the

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market and advanced technologies become available. Due to their promising clinical therapeutic effect in clinical exploratory trials, advanced T cell therapies are being pursued by multiple biotechnology and pharmaceutical companies, including Novartis, Gilead, Celgene, Janssen Biotech Inc., bluebird bio, Roche Holding AG, Seattle Genetics, Amgen Inc. and Juno Therapeutics.

In particular, Novartis and Gilead have received marketing approval for their anti-CD19 CAR T cell therapy, and Juno is in the process of developing another anti-CD19 CAR T cell therapy. These companies and products will compete directly with AUTO3, our dual-targeting CD19/CD22 programmed T cell product candidate.

bluebird bio, in collaboration with Celgene, is developing a BCMA CAR T cell therapy for the treatment of multiple myeloma. Nanjing Legend Biotech and Janssen Biotech, Inc., a subsidiary of Johnson & Johnson, are collaborating on the development of a similar therapy. Both of these therapies will compete directly with AUTO2, our dual-targeting BCMA/TACI programmed T cell product candidate. In addition, some companies, such as Cellectis, Inc., are pursuing allogeneic T cell products that could compete with our programmed T cell product candidates.

While we believe that other known types of immunotherapies may potentially be used in conjunction with CAR T cell therapies, such as checkpoint inhibitors, to enhance efficacy, we do not currently expect substantial direct competition from these other types of immunotherapies. However, we cannot predict whether other types of immunotherapies may be enhanced and show greater efficacy, and we may have direct and substantial competition from such immunotherapies in the future. In addition, more effective small molecules, cancer vaccines and other approaches may be developed and used as first line or second line treatments, which would reduce the opportunity for our programmed T cell therapies.

Many of our competitors, either alone or with their strategic collaborators, have substantially greater financial, technical and human resources than we do. Accordingly, our competitors may be more successful than we are in obtaining approval for treatments and achieving widespread market acceptance and may render our treatments obsolete or non-competitive. Mergers and acquisitions in the biotechnology and pharmaceutical industries may result in even more resources being concentrated among a smaller number of our competitors. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical study sites and patient registration for clinical studies, as well as in acquiring technologies complementary to, or necessary for, our programs. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies.

We anticipate that we will face intense and increasing competition as new products and therapies enter the market and advanced technologies become available. We expect any treatments that we develop and commercialize to compete on the basis of, among other things, efficacy, safety, delivery, price and the availability of reimbursement from government and other third-party payers.

Government Regulation and Product Approval

As a biopharmaceutical company, we are subject to extensive regulation. Our programmed T cell product candidates, if approved, will be regulated as biologics. With this classification, commercial

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production of our products will need to occur in registered and licensed facilities in compliance with current Good Manufacturing Practices, or cGMPs, for biologics.

Human immunotherapy products are a new category of therapeutics. The FDA categorizes human cell- or tissue-based products as either minimally manipulated or more than minimally manipulated, and has determined that more than minimally manipulated products require clinical trials to demonstrate product safety and efficacy and the submission of a Biologics License Application, or BLA, for marketing authorization.

Government authorities in the United States (at the federal, state and local level) and in other countries and jurisdictions, including the European Union, extensively regulate, among other things, the research, development, preclinical and clinical testing, manufacturing, quality control, labeling, packaging, storage, record-keeping, promotion, advertising, sale, distribution, post-approval monitoring and reporting, marketing and export and import of biopharmaceutical products such as those we are developing. Our product candidates must be approved by the FDA before they may be legally marketed in the United States and by the appropriate foreign regulatory agency before they may be legally marketed in foreign countries. Generally, our activities in other countries will be subject to regulation that is similar in nature and scope as that imposed in the United States, although there can be important differences. Additionally, some significant aspects of regulation in Europe are addressed in a centralized way, but country-specific regulation remains essential in many respects. The process for obtaining regulatory marketing approvals and the subsequent compliance with applicable federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources.

U.S. Product Development Process

In the United States, the FDA regulates biological products under the Public Health Service Act, or PHSA, and the Federal Food, Drug and Cosmetic Act, or FDCA, and implementing regulations. Products are also subject to other federal, state and local statutes and regulations. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources. Failure to comply with the applicable U.S. requirements at any time during the product development process, approval process or after approval, may subject an applicant to administrative or judicial sanctions. FDA sanctions could include, among other actions, refusal to approve pending applications, withdrawal of an approval, a clinical hold, warning letters and similar public notice of alleged non-compliance with laws, product recalls or withdrawals from the market, product seizures, total or partial suspension of production or distribution, fines, refusals of government contracts, restitution, disgorgement of profits, or civil or criminal penalties. Any agency or judicial enforcement action could have a material adverse effect on us. The process required by the FDA before a biological product may be approved for marketing in the United States generally involves the following:

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completion of preclinical laboratory tests and animal studies according to Good Laboratory Practices, or GLPs, and applicable requirements for the humane use of laboratory animals or other applicable regulations;

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submission to the FDA of an Investigational New Drug Application, or IND, which must become effective before human clinical trials may begin;

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performance of adequate and well-controlled human clinical trials according to the FDA’s regulations commonly referred to as Good Clinical Practices, or GCPs, and any additional requirements for the protection of human research subjects and their health information, to establish the safety and efficacy of the proposed biological product for its intended use;

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preparation and submission to the FDA of a Biologics License Application, or BLA, for marketing approval that includes substantive evidence of safety, purity, and potency from results of nonclinical testing and clinical trials;

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satisfactory completion of one or more FDA inspections of the manufacturing facility or facilities where the biological product is produced to assess compliance with cGMP to assure that the facilities, methods and controls used in product manufacture are adequate to preserve the biological product’s identity, strength, quality and purity and, if applicable, the FDA’s current Good Tissue Practices, or GTPs, for the use of human cellular and tissue products;

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potential FDA audit of the nonclinical study and clinical trial sites that generated the data in support of the BLA;

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payment of user fees for FDA review of the BLA; and

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FDA acceptance, review and approval, or licensure, of the BLA, which might include review by an advisory committee, a panel typically consisting of independent clinicians and other experts who provide recommendations as to whether the application should be approved and under what conditions.

Before testing any biological product candidate, including our product candidates, in humans, the product candidate must undergo rigorous the preclinical testing. Preclinical tests, also referred to as nonclinical studies, include laboratory evaluations as well as in vitro and animal studies to assess the potential safety and efficacy of the product candidate. After sufficient preclinical testing has been conducted, the conduct of the preclinical tests must comply with federal regulations and requirements including GLPs. The clinical trial sponsor must submit an IND to the FDA before clinical testing can begin in the United States. An IND must contain the results of the preclinical tests, manufacturing information, analytical data, any available clinical data or literature, a proposed clinical protocol, an investigator’s brochure, a sample informed consent form, and other materials. Clinical trial protocols detail, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria, and the parameters to be used to monitor subject safety, including stopping rules that assure a clinical trial will be stopped if certain adverse events should occur. Each protocol and any amendments to the protocol must be submitted to the FDA as part of the IND. Some preclinical testing, such as toxicity studies, may continue even after the IND is submitted.

The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA raises concerns or questions regarding the proposed clinical trials or places the trial on a clinical hold within that 30-day time period. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. The FDA may also impose clinical holds on a biological product candidate at any time before or during clinical trials due to safety concerns or non-compliance. If the FDA imposes a clinical hold, trials may not recommence without FDA authorization and then only under terms authorized by the FDA. Accordingly, we cannot be sure that submission of an IND will result in the FDA allowing clinical trials to begin, or that, once begun, issues will not arise that suspend or terminate such trials.

Further, each clinical trial must be reviewed and approved by an independent institutional review board, or IRB, at or servicing each institution at which the clinical trial will be conducted. An IRB is charged with protecting the welfare and rights of trial participants and considers such items as whether the risks to individuals participating in the clinical trials are minimized and are reasonable in relation to anticipated benefits. The IRB also approves the form and content of the informed consent that must be signed by each clinical trial subject or his or her legal representative and must monitor the clinical trial until completed. Clinical trials involving recombinant or synthetic nucleic acid molecules also must be reviewed by an institutional biosafety committee, or IBC, a local institutional committee that reviews and oversees basic and clinical research conducted at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment.

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Clinical trials involve the administration of the biological product candidate to healthy volunteers or patients under the supervision of qualified investigators, generally physicians not employed by or under the trial sponsor’s control. Clinical trials must be conducted and monitored in accordance with the FDA’s regulations comprising the GCP requirements, including the requirement that all research patients provide informed consent.

Human clinical trials are typically conducted in three sequential phases that may overlap or be combined:

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Phase 1. The biological product is initially introduced into healthy human subjects and tested for safety. In the case of some products for severe or life-threatening diseases, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing is often conducted in patients with the target disease or condition.

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Phase 2. The biological product is evaluated in a limited patient population to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases and to determine dosage tolerance, optimal dosage and dosing schedule.

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Phase 3. Clinical trials are undertaken to further evaluate dosage, clinical efficacy, potency, and safety in an expanded patient population, generally at geographically dispersed clinical trial sites. These clinical trials are intended to generate enough data to statistically evaluate the efficacy and safety of the product for approval, to establish the overall risk to benefit profile of the product and to provide an adequate basis for product labeling.

Phase 1, Phase 2 and Phase 3 clinical trials may not be completed successfully within any specified period, if at all.

Post-approval clinical trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These clinical trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication, particularly for long-term safety follow-up.

During all phases of clinical development, regulatory agencies require extensive monitoring and auditing of all clinical activities, clinical data, and clinical trial investigators. Annual progress reports detailing the results of the clinical trials must be submitted to the FDA. Written IND safety reports must be promptly submitted to the FDA, the NIH and the investigators for serious and unexpected adverse events, any findings from other studies, tests in laboratory animals or in vitro testing that suggest a significant risk for human patients, or any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor’s initial receipt of the information. The FDA or the sponsor or its data safety monitoring board, an independent group of experts that evaluates study data for safety and makes recommendations concerning continuation, modification, or termination of clinical trials, may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research patients are being exposed to an unacceptable health risk, including risks inferred from other unrelated immunotherapy trials. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the biological product has been associated with unexpected serious harm to patients.

Because this is a relatively new and expanding area of novel therapeutic interventions, there can be no assurance as to the length of the trial period, the number of patients the FDA will require to be enrolled in the trials in order to establish the safety, efficacy, purity and potency of immunotherapy products, or that the data generated in these trials will be acceptable to the FDA to support marketing approval.

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Concurrently with clinical trials, companies usually complete additional nonclinical studies and must also develop additional information about the physical characteristics of the biological product as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. To help reduce the risk of the introduction of adventitious agents with use of biological products, the PHSA emphasizes the importance of manufacturing control for products whose attributes cannot be precisely defined. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the sponsor must develop methods for testing the identity, strength, quality, potency and purity of the final biological product. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the biological product candidate does not undergo unacceptable deterioration over its shelf life.

U.S. Review and Approval Processes

After the completion of clinical trials of a biological product, FDA approval of a BLA must be obtained before commercial marketing of the biological product. The BLA must include results of product development, laboratory and animal studies, human trials, information on the manufacture and composition of the product, proposed labeling and other relevant information. The testing and approval processes require substantial time and effort and there can be no assurance that the FDA will accept the BLA for filing and, even if filed, that any approval will be granted on a timely basis, if at all as the FDA has significant discretion to approve or reject the BLA and to require additional preclinical or clinical studies.

Under the Prescription Drug User Fee Act, or PDUFA, as amended, each BLA must be accompanied by a significant user fee. The FDA adjusts the PDUFA user fees on an annual basis. PDUFA also imposes an annual program fee for approved biological products. Fee waivers or reductions are available in certain circumstances, including a waiver of the application fee for the first application filed by a small business. Additionally, no user fees are assessed on BLAs for products designated as orphan drugs, unless the product also includes a non-orphan indication.

Within 60 days following submission of the application, the FDA reviews a BLA submitted to determine if it is substantially complete before the agency accepts it for filing. The FDA may refuse to file any BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the BLA must be resubmitted with the additional information. The resubmitted application also is subject to review before the FDA accepts it for filing. Once the submission is accepted for filing, the FDA begins an in-depth substantive review of the BLA. The FDA reviews the BLA to determine, among other things, whether the proposed product is safe, potent, and/or effective for its intended use, and has an acceptable purity profile, and whether the product is being manufactured in accordance with cGMP to assure and preserve the product’s identity, safety, strength, quality, potency and purity. The FDA may refer applications for novel biological products or biological products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions. During the biological product approval process, the FDA also will determine whether a Risk Evaluation and Mitigation Strategy, or REMS, is necessary to ensure that the benefits of the product outweigh its risks and to assure the safe use of the biological product, which could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. FDA determines the requirement for a REMS, as well as the specific REMS provisions, on a case-by-case basis. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS. The FDA will not approve a BLA without a REMS, if required.

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Before approving a BLA, the FDA will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. For immunotherapy products, the FDA also will not approve the product if the manufacturer is not in compliance with the GTPs, to the extent applicable. These are FDA regulations and guidance documents that govern the methods used in, and the facilities and controls used for, the manufacture of human cells, tissues, and cellular and tissue based products, or HCT/Ps, which are human cells or tissue intended for implantation, transplant, infusion, or transfer into a human recipient. The primary intent of the GTP requirements is to ensure that cell and tissue based products are manufactured in a manner designed to prevent the introduction, transmission and spread of communicable disease. FDA GTP regulations also require tissue establishments to register and list their HCT/Ps with the FDA and, when applicable, to evaluate donors through screening and testing. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure that the clinical trials were conducted in compliance with IND trial requirements and GCP requirements. To assure cGMP, GTP and GCP compliance, an applicant must incur significant expenditure of time, money and effort in the areas of training, recordkeeping, production, and quality control.

Notwithstanding the submission of relevant data and information, the FDA may ultimately decide that the BLA does not satisfy its regulatory criteria for approval and deny approval. If the agency decides not to approve the BLA in its present form, the FDA will issue a Complete Response Letter, which generally outlines the specific deficiencies in the BLA identified by the FDA and may require additional clinical or other data or impose other conditions that must be met in order to secure final approval of the application. The deficiencies identified may be minor, for example, requiring labeling changes, or major, for example, requiring additional clinical trials. Even with the submission of additional information, the FDA may ultimately decide that the application does not satisfy the regulatory criteria for approval. If a Complete Response Letter is issued, the applicant may either resubmit the BLA, addressing all of the deficiencies identified in the letter, or withdraw the application.

If a product receives regulatory approval, the approval is limited to the conditions of use (e.g., patient population, indication) described in the application.

Further, the FDA may require that certain contraindications, warnings or precautions be included in the product labeling, or otherwise limit the scope of any approval. In addition, the FDA may require post marketing clinical trials, sometimes referred to as Phase 4 clinical trials, designed to further assess a biological product’s safety and effectiveness, and testing and surveillance programs to monitor the safety of approved products that have been commercialized. After approval, many types of changes to the approved product, such as adding new indications, manufacturing changes and additional labeling claims, are subject to further testing requirements and FDA review and approval.

In addition, under the Pediatric Research Equity Act, or PREA, a BLA or supplement to a BLA must contain data to assess the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of data or full or partial waivers.

Post-Approval Requirements

Any products for which we receive FDA approvals are subject to continuing regulation by the FDA, including, among other things, record-keeping requirements, reporting of adverse experiences with the product, providing the FDA with updated safety and efficacy information, product sampling and distribution requirements, and complying with FDA promotion and advertising requirements, which include, among others, standards for direct-to-consumer advertising, restrictions on promoting products

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for uses or in patient populations that are not described in the product’s approved uses (known as “off-label use”), limitations on industry-sponsored scientific and educational activities, and requirements that important safety information and material facts related to the product be disclosed. Although physicians may prescribe legally available products for off-label uses, if the physicians deem to be appropriate in their professional medical judgment, manufacturers may not market or promote such off-label uses. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability.

In addition, quality control and manufacturing procedures must continue to conform to applicable manufacturing requirements after approval to ensure the long-term stability of the product. We rely, and expect to continue to rely, on third parties for the production of clinical and commercial quantities of our products in accordance with cGMP regulations. cGMP regulations require among other things, quality control and quality assurance as well as the corresponding maintenance of records and documentation and the obligation to investigate and correct any deviations from cGMP. Manufacturers and other entities involved in the manufacture and distribution of approved products are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP and other laws. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain cGMP compliance. Discovery of problems with a product after approval may result in restrictions on a product, manufacturer, or holder of an approved BLA, including, among other things, recall or withdrawal of the product from the market.

The FDA also may require post-marketing testing, known as Phase 4 testing, and surveillance to monitor the effects of an approved product. Discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, with manufacturing processes, or the failure to comply with applicable FDA requirements can have negative consequences, including adverse publicity, judicial or administrative enforcement, complete withdrawal from the market, product recalls, warning letters from the FDA, mandated corrective advertising or communications with doctors, product seizure or detention, injunctions, and civil or criminal penalties, among others. Newly discovered or developed safety or effectiveness data may require changes to a product’s approved labeling, including the addition of new warnings and contraindications, and also may require the implementation of other risk management measures. Also, new government requirements, including those resulting from new legislation, may be established, or the FDA’s policies may change, which could delay or prevent regulatory approval of our products under development.

U.S. Marketing Exclusivity

The Biologics Price Competition and Innovation Act, or BPCIA, amended the PHSA to authorize the FDA to approve similar versions of innovative biologics, commonly known as biosimilars. Biosimilars are approved pursuant to an abbreviated pathway whereby applicants need not submit the full slate of preclinical and clinical data, and approval is based in part on the FDA’s findings of safety, purity, and potency for the original biologic (i.e., the reference product). Original BLAs are eligible to receive 12 years of exclusivity from the time of first licensure of the product, which prevents the FDA from approving any biosimilars to the reference product through the abbreviated pathway, but does not prevent approval of BLAs that are accompanied by a full data package and that do not rely on the reference product. A biosimilar may be approved if the product is highly similar to the reference product notwithstanding minor differences in clinically inactive components and there are no clinically meaningful differences with the reference product in terms of the safety, purity, and potency.

Pediatric exclusivity is another type of regulatory market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existing exclusivity periods and patent terms. This six-month

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exclusivity, which runs from the end of other exclusivity protection or patent term, may be granted based on the voluntary completion of a pediatric trial in accordance with an FDA-issued “Written Request” for such a trial.

Coverage, Pricing and Reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any product candidates for which we obtain regulatory approval. In the United States and markets in other countries, sales of any products for which we receive regulatory approval for commercial sale will depend, in significant part, on the extent to which third-party payors provide coverage, and establish adequate reimbursement levels for such products. In the United States, third-party payors include federal and state healthcare programs, private managed care providers, health insurers and other organizations. The process for determining whether a third-party payor will provide coverage for a product may be separate from the process for setting the price of a product or for establishing the reimbursement rate that such a payor will pay for the product. Third-party payors may limit coverage to specific products on an approved list, also known as a formulary, which might not include all of the FDA-approved products for a particular indication. Third-party payors are increasingly challenging the price, examining the medical necessity of and reviewing the cost-effectiveness of medical products, therapies and services, in addition to questioning their safety and efficacy.

Reimbursement may impact the demand for, and/or the price of, any product candidate which obtains marketing approval. Even if coverage and reimbursement is obtained for a given product candidate by a third-party payor, the resulting reimbursement payment rates may not be adequate or may require co-payments that patients find unacceptably high. Patients who are prescribed medications for the treatment of their conditions, and their prescribing physicians, generally rely on third-party payors to reimburse all or part of the costs associated with those medications. Patients are unlikely to use a product, and physicians may be less likely to prescribe a product, unless coverage is provided and reimbursement is adequate to cover all or a significant portion of the cost of the product. Therefore, coverage and adequate reimbursement is critical to new drug product acceptance.

Different pricing and reimbursement schemes exist in other countries. In the EU, governments influence the price of pharmaceutical products through their pricing and reimbursement rules and control of national health care systems that fund a large part of the cost of those products to consumers. Some jurisdictions operate positive and negative list systems under which products may only be marketed once a reimbursement price has been agreed. To obtain reimbursement or pricing approval, some of these countries may require the completion of additional clinical trials that compare the cost-effectiveness of a particular product candidate to currently available therapies. Other member states allow companies to fix their own prices for medicines, but monitor and control company profits. In addition, in some countries, cross-border imports from low-priced markets exert a commercial pressure on pricing within a country.

The downward pressure on health care costs in general, particularly prescription drugs and biologics, has become very intense. Governments have shown significant interest in implementing cost-containment programs, including price controls, restrictions on reimbursement and requirements for substitution of generic products. As a result, increasingly high barriers are being erected to the entry of new products. The marketability of any product candidates for which we receive regulatory approval for commercial sale may suffer if the government and third-party payors fail to provide adequate coverage and reimbursement. In addition, emphasis on managed care in the United States has increased and we expect will continue to increase the pressure on healthcare pricing. Coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

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Health Care Laws Governing Interactions with Healthcare Providers

In addition to FDA restrictions on marketing of pharmaceutical products, several other types of state and federal laws restrict our business activities, including certain marketing practices. These laws include, without limitation, anti-kickback laws, false claims laws, data privacy and security laws, as well as transparency laws regarding payments or other items of value provided to healthcare providers.

The federal healthcare program Anti-Kickback Statute prohibits, among other things, knowingly and willfully offering, paying, soliciting or receiving remuneration, directly or indirectly, in cash or in kind, to induce or reward, or in return for, purchasing, leasing, ordering or arranging for the purchase, lease or order of any healthcare item, good, facility or service reimbursable, in whole o