As filed with the Securities and Exchange Commission on October 13, 2022.

Registration No. 333–267579

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1

to

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Prime Medicine, Inc.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of incorporation or organization) 2836
(Primary Standard Industrial Classification Code Number) 84-3097762
(I.R.S. Employer Identification No.)

Prime Medicine, Inc.

21 Erie Street

Cambridge, MA 02139

(617) 564-0013

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

Keith Gottesdiener, M.D.

President and Chief Executive Officer

Prime Medicine, Inc.

21 Erie Street

Cambridge, MA 02139

(617) 465-0013

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

Copies to:

Kingsley L. Taft
Marishka DeToy
Goodwin Procter LLP
100 Northern Avenue
Boston, Massachusetts 02210
(617) 570-1000 Richard D. Truesdell, Jr.
Roshni Banker Cariello
Davis Polk & Wardwell LLP
450 Lexington Avenue
New York, New York 10017
(212) 450-4000

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

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, as amended, check the following box.  o

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

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.  o

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.   o

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 Securities Exchange Act of 1934.

Large Accelerated filer	o	Accelerated filer	o
Non-accelerated filer	x	Smaller reporting company	x
		Emerging growth company	x

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 pursuant to Section 13(a) of the Exchange Act.    o

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

The information in this preliminary prospectus is not complete and may be changed. We may not sell these securities until the Securities and Exchange Commission declares our registration statement effective. This preliminary prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Subject to completion, dated October 13, 2022

Preliminary prospectus

8,900,000 Shares

Common stock

This is an initial public offering of shares of common stock by Prime Medicine, Inc. We are offering 8,900,000 shares of common stock. We expect that the initial public offering price will be between $16.00 and $18.00 per share.

Prior to this offering, there has been no public market for our shares. We have applied to list our common stock on The Nasdaq Global Market under the symbol “PRME.”

We are an “emerging growth company” and a “smaller reporting company” under the federal securities laws and, as such, we have elected to comply with certain reduced public company reporting requirements for this prospectus and for future filings.

	Per share	Total
Initial public offering price	$	$
Underwriting discounts and commissions(1)	$	$
Proceeds, before expenses, to Prime Medicine, Inc.	$	$

__________________

(1)See “Underwriting” beginning on page 271 of this prospectus for additional information regarding underwriting compensation.

We have granted the underwriters an option for a period of 30 days to purchase an additional 1,335,000 shares of our common stock from us at the initial public offering price, less underwriting discounts and commissions.

Investing in our common stock involves a high degree of risk. Before buying any shares, you should read carefully the discussion of the material risks of investing in our common stock under the heading “Risk Factors” starting on page 17 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The underwriters expect to deliver the shares of common stock to the purchasers on or about                , 2022.

J.P. Morgan Goldman Sachs & Co. LLC Morgan Stanley Jefferies

                     , 2022

Table of contents

	Page
Prospectus Summary	1
The Offering	13
Summary Financial Data	15
Risk Factors	17
Special Note Regarding Forward-Looking Statements	84
Use of Proceeds	86
Dividend Policy	88
Capitalization	89
Dilution	91
Management’s Discussion and Analysis of Financial Condition and Results of Operations	94
Business	126
Management	228
Executive Compensation	238
Director Compensation	252
Certain Relationships and Related Person Transactions	254
Principal Stockholders	257
Description of Capital Stock	260
Shares Eligible for Future Sale	265
Material U.S. Federal Income Tax Considerations for Non-U.S. Holders	267
Underwriting	271
Legal Matters	283
Experts	283
Where You Can Find More Information	283
Index to Consolidated Financial Statements	F-1

We have not, and the underwriters have not, authorized anyone to provide any information or to make any representation other than those contained in this prospectus, any amendment or supplement to this prospectus or any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the shares of common stock offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus, any amendment or supplement to this prospectus or any applicable free writing prospectus is current only as of its date, regardless of its time of delivery or any sale of shares of our common stock. Our business, financial condition, results of operations and prospects may have changed since that date.

For investors outside the United States: We have not, and the underwriters have not, done anything that would permit this offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. 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 shares of common stock and the distribution of this prospectus outside the United States.

Market data and certain other statistical information used throughout this prospectus are based on independent industry publications, governmental publications, reports by market research firms, or other independent sources that we believe to be reliable sources. Industry publications and third-party research, surveys, and studies generally indicate that their information has been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. We are responsible for all of the disclosure contained in this prospectus, and we believe that these sources are reliable; however, we have not independently verified the

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information contained in such publications. While we are not aware of any misstatements regarding any third-party information presented in this prospectus, their estimates, in particular, as they relate to projections, involve numerous assumptions, are subject to risks and uncertainties, and are subject to change based on various factors, including those discussed under the section entitled “Risk Factors” and elsewhere in this prospectus. Some data are also based on our good faith estimates.

We intend to apply for various trademarks that we use in connection with the operation of our business. This prospectus may also contain trademarks, service marks and trade names of third parties, which are the property of their respective owners. Our use or display of third parties’ trademarks, service marks, trade names or products in this prospectus is not intended to, and does not imply a relationship with, or endorsement or sponsorship by us. Solely for convenience, the trademarks, service marks and trade names referred to in this prospectus may appear without the TM or SM symbols, but the omission of such references is not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the right of the applicable owner of these trademarks, service marks and trade names.

Through and including                 , 2022 (25 days after the date of this prospectus), all dealers that buy, sell or trade our common stock, whether or not participating in this offering, may be required to deliver a prospectus. This delivery requirement is in addition to the obligation of dealers to deliver a prospectus when acting as underwriters and with respect to their unsold allotments or subscriptions.

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PROSPECTUS SUMMARY

This summary highlights information contained in greater detail elsewhere in this prospectus and does not contain all of the information that you should consider in making your investment decision. Before investing in our common stock, you should carefully read this entire prospectus, including our consolidated financial statements and the related notes thereto included elsewhere in this prospectus. You should also consider, among other things, the information set forth under the sections entitled “Risk Factors,” “Special Note Regarding Forward-Looking Statements,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” in each case included elsewhere in this prospectus. Unless the context otherwise requires, we use the terms “Prime Medicine,” the “Company,” “we,” “us,” “our,” and similar designations in this prospectus to refer to Prime Medicine, Inc. and, where appropriate, our subsidiary.

Overview

We are a biotechnology company committed to delivering a new class of differentiated one-time curative genetic therapies, Prime Editors, to address the widest spectrum of diseases by deploying our Prime Editing technology, which we believe is a versatile, precise, efficient and broad gene editing technology.

Genetic mutations implicated in disease are diverse and can range from errors of a single base, known as point mutations, to errors that extend beyond a single base, such as insertions, deletions, duplications, or combinations thereof. We believe the ability to alter the human genome at the foundational level may confer the greatest therapeutic impact on human disease.

Gene editing, including platforms such as Prime Editing, is a novel technology that is not yet clinically validated for human therapeutic use. Over the last decade, the field of genetic medicine has evolved tremendously, with groundbreaking advances in gene therapy, cell therapy, RNA therapy, and, more recently, gene editing. These technologies represent dramatic advancements for genetic therapies, but lack the versatility to precisely and efficiently correct the diverse range of mutations or DNA alterations implicated in disease.

Prime Medicine was co-founded by a world-renowned leader in the field of gene editing, David Liu, Ph.D. Dr. Liu was joined as co-founder by Andrew Anzalone, M.D., Ph.D., who conceived of and developed Prime Editing technology. Drawn by the promise of Prime Editing’s ability to transform the field of gene editing, we have assembled a diverse team that has grown to more than 150 people as of September 30, 2022. There are no current plans for Dr. Liu to be an officer or director of our company following this offering. He is expected to continue to provide consulting services to us pursuant to a consulting agreement, which has a current term that runs through September 2025 and accommodates a previous commitment with respect to Beam Therapeutics Inc., which could result in or may create the appearance of a conflict of interest. He is also expected to retain his position and affiliation with the Broad Institute, Inc., Howard Hughes Medical Institute and Harvard University.

On September 20, 2022, we achieved a major milestone as the United States Patent and Trademark Office, or the USPTO, issued U.S. Patent 11,447,770, or the ‘770 Patent, covering methods of using Prime Editors. The Broad Institute, Inc., or Broad Institute, prepared, filed and prosecuted the ‘770 Patent. While Broad Institute is the owner of the ‘770 Patent, it is exclusively licensed to us under the terms of the license agreement with Broad Institute. The ‘770 Patent is the first issued Prime Editing patent in our licensed patent portfolio and we believe it will be instrumental in protecting our Prime Editing platform and pipeline of gene editing programs.

We believe our in-licensed and company-owned Prime Editing technology has transformative potential that could change the course of how disease is treated and overcome the challenges associated with current genetic therapies. We in-license our Prime Editing technology pursuant to a license agreement with Broad Institute. In addition, the license agreement grants us certain rights and licenses under certain patent rights Broad Institute owns or controls, including a license to the ‘770 Patent, which covers Prime Editing technology and expires in 2040. The licenses are limited to the field of prevention or treatment of human disease, and most licenses granted to us under the license agreement are further limited to the prevention or treatment of human disease by editing (including modifying or converting) or targeting DNA ex vivo, in vivo, or through xeno transplantation methods, which we refer to as the Prime Broad Field. For more information regarding the scope of our rights and obligations under this

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license agreement, see the section titled “Business—Our License and Collaboration Agreements—License rights under the Broad License Agreement.”

Our Prime Editing Platform

Prime Editing technology, as developed by Dr. Liu and Dr. Anzalone, has broad theoretical potential therapeutic applications. For example, Prime Editing technology has the ability to repair diverse mutations, including all types of point mutations, deletion mutations, insertion and duplication mutations and insertion-deletion mutations. Our analysis of more than 75,000 pathological, or disease-causing, mutations found in the National Center for Biotechnology Information ClinVar Database shows that those addressable by Prime Editing technology account for approximately 90 percent of genetic variants associated with disease. As such, we believe Prime Editing technology has the theoretical potential for repairing approximately 90 percent of known disease-causing mutations across many organisms, organs and cell types. Because biotechnology companies can only initiate therapeutic programs for a subset of pathogenic mutations and the associated diseases, we have chosen to strategically focus on disease settings where we believe that Prime Editing technology could offer compelling advantages over both current standard-of-care and novel therapeutic modalities in development. Currently, at Prime Medicine, we are leveraging the breadth of our in-licensed Prime Editing technology to focus on our current portfolio of 18 therapeutic programs.

Prime Editors also have the ability to create permanent modifications at their natural genomic location, resulting in durable edits that are passed on to daughter cells, and retain their native physiological control. Our next generation gene editing technology is capable of a wide variety of precise, predictable and efficient genetic outcomes at the targeted sequence, while minimizing unwanted bystander edits and off-target edits and avoiding double-stranded DNA breaks. Our Prime Editors are designed to make only the right edit at the right position within a gene.

Our novel Prime Editors have two main components that act together to edit DNA: (i) a Prime Editor protein, comprising a fusion between a Cas protein and a reverse transcriptase enzyme, and (ii) a pegRNA, that targets the Prime Editor to a specific genomic location and provides a template for making the desired edit to the target DNA sequence. Prime Editing leverages the established DNA-targeting capabilities of CRISPR-Cas proteins modified to nick, but not cause double-stranded DNA breaks, and combines these with the DNA synthesis capabilities of reverse transcriptase enzymes, which have been engineered to efficiently and precisely copy a pegRNA-encoded edited sequence into target DNA.

Illustration of Editing Mechanism by Prime Editor – No Double-Stranded DNA Breaks

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If nuclease gene editing approaches are “scissors” for the genome, and base editors are “pencils,” erasing and rewriting a subset of single letters in the gene, then Prime Editing is a “word processor,” searching for the correct location and replacing or repairing a wide variety of target DNA.

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We believe Prime Editing is a versatile, precise, efficient and broad gene editing technology with the following key advantages:

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An important element of our capability is leveraging high-throughput screening and machine learning, coupled with automation of workflow, to build a data-driven model for designing optimized Prime Editing systems that can potentially accelerate our therapeutic candidate development and enhance efficiency. We have also optimized individual subcomponents of our Prime Editors to enhance their capability beyond first generation Prime Editing. Some notable developments include engineered pegRNAs and DNA mismatch repair modulation to further enhance efficiency of our Prime Editors where appropriate, and expanding the array of gene edits by incorporating recent innovations in Prime Editing, including dual-flap Prime Editing and targeted integration, deletion and inversion of gene-sized DNA.

We believe that we have built a leading position in Prime Editing by consolidating technology and intellectual property in the field, as well as by establishing extensive internal capabilities to deliver on the promise of this next generation gene editing technology.

Our Strategy

Our goal is to transform the lives of patients with debilitating diseases through the application of our ground-breaking Prime Editing platform and technology. Our key focus is on patients. We are committed to developing safe and efficient therapeutics using Prime Editing approaches to address high unmet need across a broad spectrum of diseases, from rare genetic diseases to severe, chronic and acute diseases, and ultimately to prevent disease before it occurs. Key components of our strategy are as follows:

•Deliver the broadest potential of Prime Editing in the service of patients.

•Deploy our technology to extend the application of one time potentially curative therapeutics to areas that we believe were not addressable before.

•Advance our pipeline while simultaneously enhancing, validating and enabling our Prime Editing platform.

•Continue to push the frontier of innovation in gene editing by optimizing and expanding our Prime Editing technology and capabilities.

•Opportunistically evaluate synergistic and value-creating partnerships to maximize the broad potential of our platform.

•Lead with our culture of integrity, ethics, innovation and respect in everything we do.

Our Portfolio

To maximize the potential of our Prime Editing technology to provide one-time curative genetic therapies to the broadest set of diseases possible, we have purposefully built a diversified portfolio organized around four strategic indication categories, each set of indications chosen to deliver a different strategic goal:

•Immediate target indications: Deliberately chosen as potentially the fastest, most direct path to demonstrate technological success of Prime Editing in patients. We are initially focusing on diseases of the blood via ex vivo delivery to hematopoietic stem cells, or HSCs, and on diseases of the liver, the eye and the ear.

•Differentiation target indications: Aimed to create therapeutics to address the underlying cause of severe genetic diseases with therapeutics that we believe could not have been created before, especially using other gene-editing approaches. These include repeat expansion diseases, or diseases where expansion of pathological DNA repeats results in serious disease.

•“Blue sky” indications: Intended to push new and innovative technological developments in Prime Editing and extend its application beyond rare genetic diseases and towards our goal of more broadly addressing human disease. These programs remain in the early stages of conception and will become an increasing focus over the next few years.

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•“March up the chromosome” approaches: Represents opportunities to deliver upon our overarching vision to ultimately treat all patients with a disease and correct the full set of mutations in a particular gene. This category overlaps with other strategic indication categories, where most of our disclosed indications across other categories have a plan that can accommodate expansion opportunities to address additional mutations in that disease.

To unlock the full potential of our Prime Editing technology across a wide range of therapeutic applications, we are pursuing a comprehensive suite of clinically validated delivery modalities in parallel. For a given tissue type, we intend to use the delivery modality with the most compelling biodistribution. Our initial, immediate programs rely on three distinct delivery methodologies: (a) electroporation for efficient delivery to blood cells and immune cells ex vivo; (b) lipid nanoparticles, or LNPs, for non-viral in vivo delivery to the liver and potentially other organs in the future; and (c) adeno-associated viruses, or AAV, for viral delivery in vivo to the eye, ear and potentially the central nervous system, or CNS, and muscle.

We have constructed our portfolio of 18 therapeutic programs, including one partnered program, across our first two strategic indication categories in disease settings where the unique characteristics of Prime Editing could offer compelling advantages over current standard-of-care and novel therapeutic modalities in development. Our current portfolio includes the following 18 programs:

Key Achievements and Upcoming Milestones

We have established preclinical proof-of-concept in vivo with long term engraftment of ex vivo Prime Edited human CD34 cells in mice in our partnered sickle cell disease program, where we have precisely corrected the disease-causing mutation. This program is closely followed by Prime Editing for patients with chronic granulomatous disease where we have designed Prime Editors with high levels of correction of the disease-causing mutation in the cells that must be targeted, and also achieved long-term engraftment. We have demonstrated Prime Editing of cells in vitro at predicted therapeutically relevant levels for all of our remaining named programs. We have designed proprietary high throughput methods to identify highly efficient Prime Editors and have advanced the reach and efficiency of the Prime Editing technology. We have incorporated dual-flap in Prime Editing technology enabling us to establish Prime Editors with greater than 75 percent precise removal of pathological expansion repeats in five different repeat expansion diseases.

We expect that key upcoming events will continue to drive the Prime Medicine platform forward. The following outlines a summary of select ongoing activities and next steps for Prime Medicine. All our in vivo studies are preliminary to date. We will continue to expand preclinical proof-of-concept in vivo, including data from in vivo

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rodent studies and non-human primate studies in several programs in 2023. If successful, we expect to next initiate IND-enabling studies for several of our lead programs with the first IND filing potentially as early as 2024, and with the potential for additional IND filings as early as 2025. Since we are in early stages of product candidate development, we will provide an update on our timelines moving forward. We also anticipate continuing to name additional programs as they advance over the next few years.

Selected Pipeline Programs

To highlight the breadth and diversity of our 18 programs, detailed below are selected example programs currently in development in unique target tissues. For a more detailed review of all of our pipeline programs, see the section entitled “Business.”

Chronic Granulomatous Disease – Correcting the NCF Gene via ex vivo Electroporation of Hematopoietic Stem Cells

Chronic granulomatous disease, or CGD, is a rare inherited hematologic disorder that results in a failure of immune defense against extracellular pathogens. In CGD patients, myeloid cells lack a functional NADPH oxidase, or NOX2, complex, which renders patients susceptible to prolonged and recurrent bacterial and fungal infections and inflammatory complications. CGD causative mutations occur in approximately one in 200,000 births in the United States, and most children are diagnosed within the first three years of life.

We are using Prime Editing in in vitro studies to precisely correct the ΔGT mutation in one copy of the NCF1 gene to restore p47phox protein expression and NOX2 activity. We have identified a series of Prime Editor complexes that demonstrate approximately 55 percent precise correction at the NCF gene in the target cells, or human primary HSCs. Following cloning of myeloid-differentiated clones after 14 days, clonal analysis showed that nearly 90 percent of clones had received at least one precise corrective edit to ΔGT. This greatly exceeds the approximately 15 percent precise editing target threshold that is predicted to provide a clinical benefit. We have demonstrated that we can restore NOX2 protein function in patient-derived myeloid cells as a result of Prime Editing, and show long-term and high-level engraftment of the edited CD34 cells in bone marrow in mice.

Wilson’s Disease – Correcting the ATP7B Gene via LNP Delivery to the Liver

Wilson’s disease, or WD, is a devastating rare disease of the liver, with manifestations throughout the body, that is caused by copper accumulation. Most people are diagnosed with WD between ages five and 35 years. We estimate it affects at least 25,000, with some studies suggesting more than 50,000 patients in the United States and Europe annually. WD is caused by mutations in both genomic copies of the ATP7B gene, which encodes a copper transporter that removes excess copper. Two predominant mutations have been described in Wilson’s disease:

1.H1069Q, found in approximately 40 percent of all patients in the United States and 18 to 72 percent of all patients in Europe; and

2.R778L, frequently found in Asian patients and those of Asian ancestry, reported in 46 percent of Chinese, 38 percent of Korean, and 25 percent of Japanese Wilson’s disease patients.

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Our initial approach to WD is to correct the prevalent mutations ATP7B H1069Q and R778L in hepatocytes of the liver at their genomic location. Correction of the gene in the liver should address all aspects of the disease, by normalizing the process in which the body removes copper in the liver. We have identified Prime Editors that demonstrate precise correction of H1069Q ATP7B in 75 percent of cells in human hepatocyte lines and have observed similar results in primary human hepatocytes with the R778L mutation. This high level of precise editing in primary hepatocytes meets our threshold for predicted clinically relevant effects, and results in significant protection from copper toxicity in cell-based assays. We are currently conducting preclinical studies to confirm the ability to correct the human R778L sequence and the human H1069Q sequence in mouse models, using LNP technology.

Retinitis Pigmentosa Caused by Rhodopsin Mutations – Correcting the RHO gene via AAV Delivery to the Eye

Retinitis pigmentosa, or RP, is a subset of related inherited retinal diseases, or IRDs, where disease progression is characterized by loss of night vision in childhood or early adulthood, followed by loss of peripheral vision in adulthood characterized by constricting visual field, and eventual loss of central vision leading to blindness later in life. One of the most common IRDs is autosomal dominant RP, or adRP, caused by mutations in RHO which encodes the light sensitive Rhodopsin protein, or RhoP, expressed by rod photoreceptors of the retina. The disease is dominant, or manifests even with mutations to just one of the two gene copies in the genome. Approximately six to seven thousand patients have adRP in the United States caused by RHO mutations. We are initially focused on one predominant mutation, P23H; the P23H mutation is highly prevalent in the United States, causing disease in approximately 30 percent of all patients (approximately 2,000-2,500).

Our initial approach to adRP is to correct the RHO P23H mutation in rod photoreceptors of the retina at their natural genomic location. We believe a Prime Editor that corrects P23H will also correct rarer, nearby P23L and P23A mutations. Natural history studies suggest that correction of only 25 percent of rod photoreceptors would have an important clinical impact, because when 25 percent or more of rods are preserved, there is full preservation of cone photoreceptors that are critical to central vision. We have identified Prime Editors that demonstrate approximately 65 percent precise correction of the RHO P23H mutant locus. We are currently conducting preclinical studies to confirm that Prime Editing of P23H will correct healthy donor human retinal explants. We also plan to evaluate our approach in non-human primate studies where the Prime Editors will be delivered by subretinal injections to mimic the anticipated route of administration in the clinic.

Friedreich’s Ataxia: Correcting Repeat Expansions in the FXN Gene

Friedreich’s Ataxia, or FRDA, is a multisystem, autosomal recessive neurodegenerative disorder affecting the central and peripheral nervous systems as well as the heart and other organs. FRDA significantly reduces survival for patients, with the mean age of death being 39 years. FRDA is characterized by progressive ataxia, or lack of muscle control or coordination of voluntary movements, with mean age at onset of approximately five to 16 years. FRDA is caused by GAA-repeat nucleotide sequence expansions in intron 1 of the FXN gene encoding the frataxin protein, which plays important roles in mitochondria. The expanded repeats occur early in the gene, and cause disruptions in transcribing the FXN gene into RNA resulting in low levels of the frataxin protein. In the United States, it is estimated that around 4,000 individuals are affected by FRDA, while there are 15,000 to 94,000 patients globally.

Our Prime Editing technology enables us to precisely remove the expanded repeat sequences that cause FRDA. Our initial experiments are encouraging. Using the dual-flap technology with a Prime Editor targeted both upstream, or before the GAA pathological repeats, and downstream, or after the repeats, we have precisely removed the repeat sequence from intron 1 of the FXN gene to restore normal FXN regulation with 60-77 percent efficiency. In addition, in our models in donor- and patient-derived induced Pluripotent Stem Cells, or iPSCs, we measure the amount of frataxin expression in both FRDA patient cells, as well as cells derived from healthy donors. As expected, we demonstrated that patient cells have low levels of frataxin, and healthy donor cells have high levels of frataxin. When we Prime Edited the FRDA patient cells in this model, Prime Editors restored levels of frataxin towards that seen in healthy donor cells. In addition, based on in vitro studies conducted in patient dorsal root ganglia, or DRGs, we observed that our Prime Editors restored their normal function.

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We have established preliminary methods to deliver Prime Editors to terminally differentiated cardiomyocytes and plan to establish editing and functional recovery of frataxin expression in this cell system. Then, to ultimately deliver Prime Editors to heart and other tissues, we expect initially to rely on the tropism of AAV capsids, each optimized to deliver our Prime Editors to the central nervous system or heart. We are currently optimizing the AAVs for expression in neurons and glial cells as our first focus.

Myotonic Dystrophy – Correcting Repeat Expansions in the DMPK Gene

Myotonic Dystrophy type 1, or DM1, is a common autosomal dominant muscular dystrophy among people of European ancestry and is principally a muscle disease affecting skeletal and cardiac muscle but has multisystem manifestations. Patients often initially present with muscle weakness. DM1 is caused by expanded CTG repeats in the 3’ UTR of one copy of the DMPK gene. When transcribed into RNA, the expanded repeat nucleotides in the case of DM1 sequester critical splicing factors, thereby preventing the correct function of many genes that regulate cell function. Recent newborn screening studies indicate that the true prevalence of DM1 is 1:2,100 (approximately 140,000 patients in the United States).

Our dual-flap Prime Editing technology enables the removal of the expanded repeat sequences that cause disease. Our goal in DM1 is to leverage our Prime Editing technology to precisely remove the repeat sequence from the UTR region of the DMPK gene, to restore DMPK regulation and expression of DMPK protein back to normal levels. The primary target tissues are cardiac and skeletal muscle, which we believe could have a transformative effect on patients; CNS is an important secondary target tissue. We have performed screens to identify pegRNA pairs that achieve highly efficient and precise removal of the expanded repeats and have demonstrated precise removal of pathological repeats from the DMPK gene. We have established precise removal of the smaller number of repeats in healthy cell lines with more than 80 percent efficiency. In patient derived stem cells, which contain approximately 1,600 pathological repeats, we have demonstrated precise removal of repeats, with our best Prime Editors achieving more than 90 percent precise editing and removal of the pathological repeats.

We are developing patient-derived stem cell-based models of disease. As a first step, we have acquired patient fibroblasts and generated iPSCs and cardiomyocytes in which to evaluate dual-flap Prime Editing. We have established preclinical methods to deliver Prime Editors to terminally differentiated cardiomyocytes and aim to establish editing and functional recovery in this cell system. In parallel, we will perform similar experiments in patient-derived skeletal muscle cells.

Risks Associated with Our Business

•We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.

•We will need substantial additional funding. If we are unable to raise capital when needed, we will be forced to delay, reduce, eliminate or prioritize among our research and product development programs or future commercialization efforts.

•Gene editing, including platforms such as Prime Editing, is a novel technology that is not yet clinically validated for human therapeutic use. The approach we are taking to discover and develop novel therapeutics is unproven and may never lead to marketable products. We may incur unexpected costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of any product candidates.

•Clinical drug development involves a lengthy and expensive process, with an uncertain outcome. Because gene editing is novel and the regulatory landscape that will govern our potential product candidates is uncertain and may change, we cannot predict the time and cost of obtaining regulatory approval, if we receive it at all, for our potential product candidates.

•We may enter into collaborations with collaborators and strategic partners such as Beam Therapeutics or other third parties for the research, development, delivery, manufacturing and commercialization of Prime Editing technology and certain of the product candidates we may develop. If any such collaborations are

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not successful, we may not be able to capitalize on the market potential of our Prime Editing platform or product candidates.

•If conflicts arise between us and our collaborators or strategic partners, these parties may act in a manner adverse to us and could limit our ability to implement our strategies.

•If we are unable to obtain and maintain patent and other intellectual property protection for any product candidates we develop and for our Prime Editing technology, or if the scope of the patent and other intellectual property protection obtained is not sufficiently broad, third parties could develop and commercialize products and technology similar or identical to ours and our ability to successfully commercialize any product candidates we may develop and our Prime Editing technology may be adversely affected.

•Our rights to develop and commercialize our Prime Editing platform technology and product candidates are subject to the terms and conditions of licenses granted to us by others. If we fail to comply with our obligations in the agreements under which we license intellectual property rights from third parties or otherwise experience disruptions to our business relationships with our licensors, we could lose license rights that are important to our business.

•Our in-licensed issued patent, owned and in-licensed patent applications and other intellectual property may be subject to priority, inventorship or ownership disputes and similar proceedings. If we or our licensors are unsuccessful in any of these proceedings, we may be required to obtain licenses from third parties, which may not be available on commercially reasonable terms or at all, or to cease the development, manufacture and commercialization of one or more of our product candidates, which could have a material adverse impact on our business. With respect to our licenses from Broad Institute:

◦Our licenses are subject to Broad Institute’s inclusive innovation model, pursuant to which Broad Institute retains the right, in certain circumstances, to grant to third parties (other than specified competitors of ours) licenses under the licensed patent rights that would otherwise fall within the scope of the exclusive license granted to us.

◦All gene targets, which are any human genes to which a program is directed, are subject to Broad Institute’s march-in license, which means Broad Institute has the right to terminate our license to gene targets under certain conditions and could make one or more gene targets unavailable to us. However, once we initiate a program for a gene target, in accordance with the terms of such license agreement, Broad Institute loses the right to use its march-in license for such gene target, provided we continue to use commercially reasonable efforts to continue to progress such development. As such, we believe that Broad Institute cannot exercise its march-in license with respect to any of our current programs for gene targets because such programs have been initiated in accordance with the terms and requirements of such license agreement.

•The intellectual property landscape around the technologies we use or plan to use, including gene editing technology, is highly dynamic, and third parties may initiate legal proceedings alleging that we are infringing, misappropriating, or otherwise violating their intellectual property rights, the outcome of which would be uncertain and may prevent, delay or otherwise interfere with our product discovery and development efforts.

•The FDA, the EMA and the National Institutes of Health, or NIH, have demonstrated caution in their regulation of gene therapy treatments, and ethical and legal concerns about gene therapy and genetic testing may result in additional regulations or restrictions on the development and commercialization of any product candidates we may develop, which may be difficult to predict.

•Our future success depends on our ability to retain our President and Chief Executive Officer, our Co-Founders, our Chief Scientific Officer, our Chief Technical Officer and other key executives and to attract, retain and motivate qualified personnel.

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•We expect to expand our research, development, delivery, manufacturing, commercialization, regulatory and future sales and marketing capabilities over time, and as a result, we may encounter difficulties in managing our growth, which could disrupt our operations.

•We have identified a material weakness in our internal control over financial reporting. If we fail to remediate this material weakness or identify additional material weaknesses in the future or otherwise fail to maintain effective internal control over financial reporting in the future, we may not be able to accurately report our financial condition or results of operations which may adversely affect investor confidence in us and, as a result, the value of our common stock.

Corporate Information

We were incorporated under the laws of the State of Delaware in September 2019 under the name Prime Medicine, Inc. Our principal executive offices are located at 21 Erie Street, Cambridge, MA 02139, and our telephone number is (617) 564-0013.

We have one subsidiary, Prime Medicine Massachusetts Securities Corp., formed in October 2020 under the laws of the Commonwealth of Massachusetts.

Our website address is https://www.primemedicine.com. The information contained in or accessible from our website is not incorporated into this prospectus, and you should not consider it part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

Implications of Being an Emerging Growth Company and a Smaller Reporting Company

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

•being permitted to present only two years of audited financial statements, in addition to any required unaudited interim financial statements, with correspondingly reduced “Management’s discussion and analysis of financial condition and results of operations” disclosure in this prospectus;

•reduced disclosure about our executive compensation arrangements;

•not being required to hold advisory votes on executive compensation or to obtain stockholder approval of any golden parachute arrangements not previously approved;

•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; and

•an exemption from compliance with the requirements of the Public Company Accounting Oversight Board regarding the communication of critical audit matters in the auditor’s report on the financial statements.

We may take advantage of these exemptions for up to five years or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenues of $1.24 billion or more; (ii) the last day of our fiscal year following the fifth anniversary of the date of the completion of this offering; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the Securities and Exchange Commission, or the SEC. We may choose to take advantage of some but not all of these exemptions. We have taken advantage of reduced reporting requirements in this prospectus. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock. Additionally, the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. This allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to avail

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ourselves of this exemption and, therefore, while we are an emerging growth company we will not be subject to new or revised accounting standards at the same time that they become applicable to other public companies that are not emerging growth companies. As a result of this election, our financial statements may not be comparable to those of other public companies that comply with new or revised accounting pronouncements as of public company effective dates. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.

We are also a “smaller reporting company,” meaning that the market value of our shares held by nonaffiliates plus the proposed aggregate amount of gross proceeds to us as a result of this offering is less than $700 million and our annual revenue was less than $100 million during the most recently completed fiscal year. We may continue to be a smaller reporting company after this offering if either (i) the market value of our shares held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year and the market value of our shares held by nonaffiliates is less than $700 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company, we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.

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THE OFFERING

Shares of common stock offered by us	8,900,000 shares.
Shares of our common stock to be outstanding after this offering	94,336,033 shares (or 95,671,033 shares if the underwriters exercise their option to purchase additional shares in full).
Underwriters’ option to purchase additional shares	We have granted the underwriters a 30-day option to purchase up to 1,335,000 additional shares of our common stock at the initial public offering price, less underwriting discounts and commissions on the same terms as set forth in this prospectus.
Use of proceeds	We estimate that the net proceeds to us from the sale of 8,900,000 shares of our common stock in this offering will be approximately $136.2 million, or $157.3 million if the underwriters exercise their option to purchase additional shares in full, assuming an initial public offering price of $17.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. We intend to use the net proceeds of this offering, together with our existing cash and cash equivalents and short-term investments: (i) for continued research and development of our Prime Editing portfolio, including preclinical studies and advancement through potential preclinical proof-of-concept; (ii) for IND-enabling studies and the potential initiation of clinical studies for certain of our current therapeutic programs; (iii) for continued advancement of our Prime Editing platform and discovery-stage research for other potential programs; (iv) to develop our early-stage manufacturing processes and build out our dedicated chemistry facility; and (v) for general corporate purposes. See “Use of Proceeds.”
Proposed Nasdaq Global Market symbol	“PRME”
Risk factors	Investment in our common stock involves substantial risks. You should read this prospectus carefully, including the section entitled “Risk Factors” and the consolidated financial statements and the related notes to those statements included in this prospectus, before investing in our common stock.

The number of shares of our common stock outstanding after this offering is based on 85,436,033 shares (which includes 11,995,985 shares of unvested restricted common stock) of our common stock outstanding as of June 30, 2022, after giving effect to the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of our common stock upon the completion of this offering, and excludes:

•58,903 shares of common stock issued after June 30, 2022 upon the exercise of stock options under our 2019 Stock Option and Grant Plan;

•3,593,533 shares of common stock issuable upon the exercise of stock options outstanding as of June 30, 2022, with a weighted-average exercise price of $4.82 per share under our 2019 Stock Option and Grant Plan;

•516,269 shares of common stock issuable upon the exercise of stock options granted after June 30, 2022, with a weighted-average exercise price of $7.96 per share under our 2019 Stock Option and Grant Plan;

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•1,818,210 shares of common stock reserved for issuance under our 2019 Stock Option and Grant Plan as of June 30, 2022, which shares will cease to be available for issuance at the time our 2022 Stock Option and Incentive Plan becomes effective;

•8,041,688 shares of common stock reserved for future issuance under our 2022 Stock Option and Incentive Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective and which includes an aggregate of 511,500 shares of common stock issuable upon the exercise of stock options which will be granted to certain of our executive officers, directors, and other employees at the time of effectiveness of the 2022 Stock Option and Incentive Plan with an exercise price equal to the initial public offering price per share; and

•971,350 shares of common stock reserved for future issuance under our 2022 Employee Stock Purchase Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective.

Except as otherwise noted, all information in this prospectus:

•reflects the automatic conversion of all outstanding shares of our preferred stock into an aggregate of 51,923,764 shares of our common stock, which will occur upon the closing of this offering;

•gives effect to a 1-for-3.10880 reverse stock split of our common stock effected on October 12, 2022;

•assumes no exercise of the underwriters’ option to purchase up to 1,335,000 additional shares of common stock in this offering;

•assumes no exercise of the outstanding options and restricted stock described above; and

•assumes the filing of our third amended and restated certificate of incorporation immediately prior to the closing of this offering and the effectiveness of our amended and restated bylaws upon the effectiveness of the registration statement of which this prospectus is a part.

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SUMMARY FINANCIAL DATA

You should read the following summary consolidated financial data together with our consolidated financial statements and the related notes appearing at the end of this prospectus and the “Management’s Discussion and Analysis of Financial Condition and Results of Operations” section of this prospectus. We have derived the consolidated statement of operations data for the period from September 13, 2019 (inception) to December 31, 2019, the years ended December 31, 2020 and 2021 from our audited consolidated financial statements appearing at the end of this prospectus. The consolidated statement of operations data for the six months ended June 30, 2021 and 2022 and the consolidated balance sheet data as of June 30, 2022 have been derived from our unaudited financial statements appearing at the end of this prospectus and have been prepared on the same basis as the audited consolidated financial statements. In the opinion of management, the unaudited data reflect all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the financial information in those statements. Our historical results are not necessarily indicative of the results that may be expected in any future period.

	Period from September 13, 2019 (Inception) to December 31,		Year Ended December 31,				Six Months Ended June 30,
	2019		2020		2021		2021		2022
	(in thousands, except share and per share data)
Consolidated Statement of Operations Data:
Related party collaboration revenue	$	—	$	5,210	$	—	$	—	$	—
Operating expenses:
Research and development(1)	920		2,980		70,550		10,261		32,617
General and administrative	1,252		3,162		13,924		3,710		13,586
Total operating expenses	2,172		6,142		84,474		13,971		46,203
Loss from operations	(2,172)		(932)		(84,474)		(13,971)		(46,203)
Other income (expense):
Change in fair value of preferred stock tranche right liability	(353)		(10,904)		(74,319)		(74,319)		—
Change in fair value of anti-dilution obligation	—		(700)		(6,681)		(6,681)		—
Change in fair value of related party short-term investment	—		10,867		(391)		9,429		(8,208)
Other income, net(2)	—		126		12		1		249
Total other expense, net	(353)		(611)		(81,379)		(71,570)		(7,959)
Net loss before income taxes	(2,525)		(1,543)		(165,853)		(85,541)		(54,162)
Provision for (benefit from) income taxes	4		1,867		(486)		503		(974)
Net loss	(2,529)		(3,410)		(165,367)		(86,044)		(53,188)
Accretion of preferred stock to redemption value	(265)		(1,645)		(1,468)		(1,468)		—
Cumulative dividend on preferred stock	—		—		(17,284)		(4,559)		(12,517)
Net loss attributable to common stockholders	$	(2,794)	$	(5,055)	$	(184,119)	$	(92,071)	$	(65,705)
Net loss per share attributable to common stockholders, basic and diluted(3)	$	(1.88)	$	(1.91)	$	(14.19)	$	(9.04)	$	(3.31)
Weighted-average common shares outstanding, basic and diluted(3)	1,486,931		2,639,717		12,973,495		10,184,747		19,871,750
Pro forma net loss per share attributable to common stockholders, basic and diluted (unaudited)(4)					$	(2.55)			$	(0.74)
Pro forma weighted-average common shares outstanding, basic and diluted (unaudited)(4)					64,897,259				71,795,514

___________________

(1)Includes related party amounts of $45, $150 and $42,170 for the period from September 13, 2019 (inception) to December 31, 2019 and for the years ended December 31, 2020 and 2021, respectively. See Note 14 to our consolidated financial statements appearing at the end of this prospectus.

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(2)Includes related party amount of $126 for the year ended December 31, 2020. See Note 14 to our consolidated financial statements appearing at the end of this prospectus.

(3)See Note 13 to our consolidated financial statements included elsewhere in this prospectus for details on the calculation of basic and diluted net loss per share attributable to common stockholders.

(4)Pro forma basic and diluted net loss per share attributable to common stockholders has been prepared to give effect to adjustments to our capital structure arising in connection with the completion of this offering and is calculated by dividing the pro forma net loss attributable to common stockholders by the pro forma weighted-average common shares outstanding for the period. The unaudited pro forma net loss attributable to common stockholders used in the calculation of unaudited pro forma basic and diluted net loss per share attributable to common stockholders adjusts net loss attributable to common stockholders to remove the accretion of preferred stock to redemption value and cumulative dividends on preferred stock for the year ended December 31, 2021 because the calculation gives effect to the automatic conversion of all shares of our preferred stock outstanding as of December 31, 2021 into shares of common stock as if such conversion had occurred on January 1, 2021. Pro forma weighted-average common shares outstanding is computed by adjusting the weighted-average common shares outstanding to give pro forma effect to the automatic conversion of all shares of our preferred stock outstanding as of December 31, 2021 into shares of common stock as if such conversion had occurred on January 1, 2021. For the year ended December 31, 2021, weighted-average common shares outstanding includes the impact of the 1,101,525 shares we were obligated to issue to Myeloid as of December 24, 2021, the date of the agreement. Pro forma basic and diluted net loss per share attributable to common stockholders does not include the effect of the shares expected to be sold in this offering.

	As of June 30, 2022
	Actual		Pro Forma(1)		Pro Forma As Adjusted(2)
	(in thousands)
Consolidated Balance Sheet Data(1):
Cash and cash equivalents	$	92,239	$	92,239	$	231,430
Working capital(3)	157,772		157,772		297,207
Total assets	247,597		247,597		383,562
Total liabilities	46,860		46,860		46,616
Convertible preferred stock	395,800		—		—
Total stockholders' equity (deficit)	(195,063)		200,737		336,946

___________________

(1)The pro forma balance sheet data gives effect to the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of our common stock upon the completion of this offering.

(2)The pro forma as adjusted balance sheet data gives effect to (i) the pro forma adjustments set forth in footnote (1) above and (ii) the issuance and sale of 8,900,000 shares of our common stock in this offering at an assumed initial public offering price of $17.00 per share, which is the midpoint of the price range set forth on the cover page of this prospectus, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Each $1.00 increase (decrease) in the assumed initial public offering price of $17.00 per share, 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 and cash equivalents, working capital, total assets and total stockholders’ equity (deficit) by $8.3 million, assuming that the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Each increase (decrease) of 1,000,000 shares in the number of shares 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 and cash equivalents, working capital, total assets and total stockholders’ equity (deficit) by $15.8 million, assuming no change in the assumed initial public offering price per share and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

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

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RISK FACTORS

Investing in our common stock involves a high degree of risk. You should carefully consider the risks and uncertainties described below together with all of the other information contained in this prospectus, including our consolidated financial statements and related notes appearing at the end of this prospectus, before deciding to invest in our common stock. If any of the events or developments described below were to occur, our business, prospects, operating results and financial condition could suffer materially, the trading price of our common stock could decline and you could lose all or part of your investment. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently believe to be immaterial may also adversely affect our business.

Risks Related To Our Financial Position and Need for Additional Capital

We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.

Since inception, we have incurred significant operating losses. Our net loss was $2.5 million, $3.4 million, $165.4 million, $86.0 million, and $53.2 million for the period from September 13, 2019 (inception) to December 31, 2019, the years ended December 31, 2020 and 2021, and the six months ended June 30, 2021 and 2022, respectively. As of June 30, 2022, we had an accumulated deficit of $224.6 million. We have financed our operations primarily through private placements of our preferred stock. Substantially all of our losses have resulted from expenses incurred in connection with our research and development and from general and administrative costs associated with our operations. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. The net losses we incur may fluctuate significantly from quarter to quarter. We anticipate that our expenses will increase substantially if and as we:

•continue our current research programs and preclinical development of any product candidates we identify;

•seek to identify additional research programs and product candidates;

•initiate preclinical studies and clinical trials for any product candidates we may identify;

•experience any delays or interruptions due to the ongoing COVID-19 pandemic, including delays in preclinical testing and clinical trials or interruptions in the supply chain for any future product candidates;

•further develop our in-licensed and company-owned gene editing platform, which we call our Prime Editing platform;

•maintain, expand, enforce, defend and protect our intellectual property portfolio and provide reimbursement of third-party expenses related to our patent portfolio;

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

•develop, maintain and enhance a sustainable, scalable, reproducible and transferable manufacturing process for the product candidates we may develop;

•ultimately establish a sales, marketing and distribution infrastructure to commercialize any therapies for which we may obtain marketing approval;

•hire additional research and development personnel;

•hire clinical and commercial personnel;

•add operational, financial and management information systems and personnel, including personnel to support our product development;

•acquire or in-license product candidates, intellectual property and technologies;

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•establish and maintain collaborations;

•should we decide to do so, build and maintain a commercial-scale current Good Manufacturing Practices, or cGMP, manufacturing facility; and

•operate as a public company.

We have not initiated clinical development of any potential product candidate and expect that it will be many years, if ever, before we have a product candidate ready for commercialization. To become and remain profitable, we must develop and, either directly or through collaborators, eventually commercialize a therapy or therapies with market potential. This will require us to be successful in a range of challenging activities, including identifying product candidates, completing preclinical studies and clinical trials of product candidates, obtaining marketing approval for these product candidates, manufacturing, marketing and selling those therapies for which we may obtain marketing approval and satisfying any post-marketing requirements. We may never succeed in these activities and, even if we do, may never generate revenues that are significant or large enough to achieve profitability.

We have transitioned from research and development to early preclinical development for our most advanced potential product candidate. Because of the numerous risks and uncertainties associated with developing Prime Editing product candidates, we are unable to predict the extent of any future losses or when we will become profitable, if at all. If we do 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 decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company could also cause you to lose all or part of your investment.

We will need substantial additional funding. If we are unable to raise capital when needed, we will be forced to delay, reduce, eliminate or prioritize among our research and product development programs or future commercialization efforts.

We expect our expenses to continue to increase in connection with our ongoing activities, particularly as we identify, continue the research and development of, initiate preclinical studies and clinical trials of, and seek marketing approval for, product candidates. Because we have limited financial and managerial resources, we have prioritized our research programs and lead optimization efforts in specific indications among many potential options. Specifically, our initial development programs target blood, liver, eye, and neuromuscular indications, amongst others. As a result of this prioritization, we may forego or delay pursuit of opportunities with other product candidates or for other indications that later prove to have greater clinical or commercial potential and we may need to reprioritize our focus in the future. 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 therapies.

In addition, if we obtain marketing approval for any product candidates we may develop, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution to the extent that such sales, marketing, manufacturing and distribution are not the responsibility of a collaborator. Furthermore, upon the closing of this offering, we expect to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on attractive terms, we would be forced to delay, reduce or eliminate our research and product development programs or future commercialization efforts.

As of June 30, 2022, our cash and cash equivalents and short-term investments were $180.6 million, excluding restricted cash, or $194.1 million, including restricted cash. We estimate that the net proceeds of this offering will be approximately $136.2 million, assuming an initial public offering price of $17.00 per share, the midpoint of the price range set forth on the cover of this prospectus, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. We believe our existing cash and cash equivalents and short-term investments, together with the net proceeds from this offering, will be sufficient to fund our operating expenses and capital expenditure requirements into 2025. However, our operating plan may change as a result of factors currently

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unknown to us, and we may need to seek funding sooner than planned. Our future capital requirements will depend on many factors, including those discussed in the risk factor entitled “We have incurred significant losses since inception. We expect to incur losses for the foreseeable future and may never achieve or maintain profitability.”

Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our ability to develop and commercialize any product candidates we may develop. We cannot be certain that additional funding will be available on acceptable terms or at all. We have no committed source of additional capital and, if we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may have to significantly delay, scale back or discontinue the development or commercialization of any product candidates or other research and development initiatives. Our license and collaboration agreements and any future collaboration agreements may also be terminated if we are unable to meet the payment or other obligations under the agreements. We could be required to seek collaborators for potential product candidates earlier than we would otherwise plan or on terms that are less favorable than might otherwise be available. We could also be required to relinquish or license our rights to product candidates on unfavorable terms in certain markets where we otherwise would seek to pursue development or commercialization ourselves.

Raising additional capital may cause dilution to our stockholders, including purchasers of common stock in this offering, restrict our operations or require us to relinquish rights to our technologies or product candidates we may develop.

Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. We do not have any committed external source of funds. 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 common stockholder. Debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, declaring dividends and possibly other restrictions. In addition, if we raise funds through additional license and collaboration agreements, strategic alliances or licensing arrangements with third parties, we may have to relinquish valuable rights to our intellectual property, technologies, future revenue streams, research programs or product candidates we may develop, or we may have to grant licenses on terms that may not be favorable to us.

Our short 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 an early-stage company. We were founded in September 2019 and commenced operations in July 2020. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, acquiring and developing our platform and technology and identifying and beginning to advance preclinical testing of potential product candidates. All of our programs are still in the research or preclinical stage of development and their risk of failure is high. We have not yet demonstrated an ability to initiate or successfully complete any clinical trials, including large-scale, pivotal clinical trials, obtain marketing approvals, manufacture a commercial-scale therapy, arrange for a third party to do so on our behalf or conduct sales and marketing activities necessary for successful commercialization. Typically, it takes about 10 to 15 years to develop a new therapy from the time it is discovered to when it is available for treating patients.

Our limited operating history, particularly in light of the rapidly evolving gene editing field, may make it difficult to evaluate our technology and industry and predict our future performance. Our very short history as an operating company makes any assessment of our future success or viability subject to significant uncertainty. We will encounter risks and difficulties frequently experienced by very early stage companies in rapidly evolving fields. If we do not address these risks successfully, our business will suffer.

In addition, as a new business, we may encounter other unforeseen expenses, difficulties, complications, delays, and other known and unknown factors. We will need to transition from a company with a research focus to a company capable of supporting commercial activities. We may not be successful in such a transition.

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We have never generated revenue from product sales and may never become profitable.

Our ability to generate revenue from product sales and achieve profitability depends on our ability, alone or with collaborative partners, to successfully complete the development of, and obtain the regulatory approvals necessary to commercialize, product candidates we may identify for development. We do not anticipate generating revenues from product sales for many years, if ever. Our ability to generate future revenues from product sales depends heavily on our, or our collaborators’, ability to successfully:

•identify product candidates and successfully complete research development of any product candidates we may identify;

•seek and obtain regulatory and marketing approvals for any product candidates for which we complete clinical trials;

•launch and commercialize any product candidates for which we may obtain regulatory and marketing approval by establishing a sales force, marketing and distribution infrastructure, or alternatively, collaborating with a commercialization partner;

•qualify for adequate coverage and reimbursement by government and third-party payors for any product candidates for which we may obtain regulatory and marketing approval;

•establish and maintain supply and manufacturing relationships with third parties that can provide adequate, in both amount and quality, products and services to support clinical development and the market demand for any product candidates for which we obtain regulatory and marketing approval;

•develop, maintain and enhance a sustainable, scalable, reproducible and transferable manufacturing process for the product candidates we may develop;

•address competing technological and market developments;

•negotiate favorable terms in any collaboration, licensing or other arrangements into which we may enter and performing our obligations in such collaborations;

•receive market acceptance by physicians, patients, healthcare payors, and others in the medical community;

•maintain, protect, enforce, defend and expand our portfolio of intellectual property and other proprietary rights, including patents, trade secrets and know-how;

•defend against third party intellectual property claims of infringement, misappropriation or other violation; and

•attract, hire and retain qualified personnel.

Our expenses could increase beyond expectations if we are required by the U.S. Food and Drug Administration, or the FDA, the European Medicines Agency, or the EMA, or other regulatory authorities to perform clinical and other studies in addition to those that we currently anticipate. Even if one or more of the product candidates we may develop are approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product candidate. Additionally, such products may become subject to unfavorable pricing regulations, third-party reimbursement practices or healthcare reform initiatives. Even if we are able to generate revenues from the sale of any approved product candidates, we may not become profitable and may need to obtain additional funding to continue operations.

Our future ability to utilize our net operating loss carryforwards and certain other tax attributes may be limited.

Since our inception, we have incurred losses and we may never achieve profitability. To the extent that we continue to generate taxable losses, under current law, our unused U.S. federal net operating losses, or NOLs, may be carried forward to offset a portion of future taxable income, if any. Additionally, we continue to generate business tax credits, including research and development tax credits, which generally may be carried forward to

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offset a portion of future taxable income, if any, subject to expiration of such credit carryforwards. Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, if a corporation undergoes an “ownership change,” generally defined as one or more shareholders or groups of shareholders who own at least 5 percent of the corporation’s equity increasing their equity ownership in the aggregate by more than 50 percentage points (by value) over a three-year period, the corporation’s ability to use its pre-change NOLs and other pre-change tax attributes (such as research and development tax credits) to offset its post-change income or taxes may be limited. Similar rules may apply under state tax laws. Our prior equity offerings and other changes in our stock ownership may have resulted in such ownership changes in the past. In addition, we may experience ownership changes in the future as a result of this offering or subsequent shifts in our stock ownership, some of which are outside of our control. As a result, if we earn net taxable income, our ability to use our pre-change NOLs or other pre-change tax attributes to offset U.S. federal taxable income may be subject to limitations, which could potentially result in increased future tax liability to us. Additional limitations on our ability to utilize our NOLs to offset future taxable income may arise as a result of our corporate structure whereby NOLs generated by our subsidiary may not be available to offset taxable income earned by our subsidiary. There is a risk that due to changes under the tax law, regulatory changes or other unforeseen reasons, our existing NOLs or business tax credits could expire or otherwise be unavailable to offset future income tax liabilities. At the state level, there may also be periods during which the use of NOLs or business tax credits is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. For these reasons, we may not be able to realize a tax benefit from the use of our NOLs or tax credits, even if we attain profitability.

We face risks related to health epidemics, pandemics and other widespread outbreaks of contagious disease, including the ongoing COVID-19 pandemic, which could significantly disrupt our operations, impact our financial results or otherwise adversely impact our business.

Significant outbreaks of contagious diseases and other adverse public health developments could have a material impact on our business operations and operating results. For example, the spread of COVID-19 has and identification of new variants of COVID-19 have affected segments of the global economy and our operations. As a result of the ongoing COVID-19 pandemic or similar public health crises that may arise, we may experience disruptions that could adversely impact our operations, research and development, and as we continue developing, any preclinical studies, clinical trials and manufacturing activities we may conduct, some of which may include:

•delays or disruptions in research programs, preclinical studies, clinical trials or investigational new drug, or IND-enabling studies that we or our collaborators may conduct;

•interruption or delays in the operations of the FDA, the EMA and comparable foreign regulatory agencies;

•interruption of, or delays in receiving and distributing, supplies of drug substance and drug product from our contract manufacturing organizations, or CMOs, to preclinical or clinical research sites or delays or disruptions in any preclinical studies or clinical trials performed by contract research organizations, or CROs;

•limitations imposed on our business operations by local, state or federal authorities to address a pandemic or similar public health crises, including if facilities and materials are commandeered under the Defense Production Act of 1950 or equivalent foreign legislation; and

•business disruptions caused by potential workplace, laboratory and office closures and an increased reliance on employees working from home, disruptions to or delays in ongoing laboratory experiments and operations, staffing shortages, travel limitations, and cybersecurity and data accessibility or security issues.

For example, our laboratory-based personnel have been unable to maximize use of our existing laboratory space due to restrictions on density of people and other aspects of our work have been limited by the need for our staff to isolate.

In addition, the trading prices for biopharmaceutical companies have been highly volatile as a result of the ongoing COVID-19 pandemic and we may face similar volatility in our stock price after we complete this public offering. We cannot predict the scope and severity of any economic recovery after the COVID-19 pandemic abates,

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including following any additional “waves” or other intensifying of the pandemic. If we or any of the third parties with whom we engage were to experience additional shutdowns or other business disruptions, our ability to conduct our business in the manner and on the timelines presently planned could be materially and negatively affected, which could have a material adverse impact on our business, financial condition, our results of operations and prospects. Furthermore, the COVID-19 pandemic could exacerbate the other risks described in this section. For additional information regarding the impact of the ongoing COVID-19 pandemic, see the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Impact of COVID-19 on Our Operations.”

Risks Related To Discovery, Development and Commercialization

Gene editing, including platforms such as Prime Editing, is a novel technology that is not yet clinically validated for human therapeutic use. The approach we are taking to discover and develop novel therapeutics is unproven and may never lead to marketable products. We may incur unexpected costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of any product candidates.

We are focused on developing therapies utilizing gene editing technology, which is new and largely unproven. The Prime Editing technologies that we have licensed and that we are utilizing in our research programs have not yet been clinically tested, nor are we aware of any clinical trials for safety or efficacy having been completed by third parties using Prime Editing or similar technologies. The scientific evidence to support the feasibility of developing product candidates based on gene editing technologies is both preliminary and limited. Successful development of product candidates will require us to safely deliver a gene editor into target cells, optimize the efficiency and specificity of such product candidates and ensure the therapeutic selectivity of such product candidates. We may need to address other safety issues as well, and to demonstrate the full value of these products, we will need to achieve these goals with single administration and demonstrate a permanent correction. There can be no assurance that our Prime Editing platform will achieve these goals, lead to the development of genetic therapies or be successful in solving any or all of these issues.

Our future success is highly dependent on the successful development of gene editing technologies, cellular delivery methods and therapeutic applications of that technology. We may decide to alter or abandon our initial programs as new data become available and we gain experience in developing gene editing therapeutics. We cannot be sure that our technologies will yield satisfactory products that are safe and effective, scalable or profitable in our initial indications or any other indication we pursue. Adverse developments in the clinical development efforts of other gene editing technology companies could adversely affect our efforts or the perception of any product candidates we may develop by both investors and regulatory authorities.

Similarly, other gene therapy approaches may be determined to be more attractive than Prime Editing. Moreover, if we decide to develop gene editing technologies other than those involving Prime Editing, we cannot be certain we will be able to obtain rights to such technologies. Although both of our co-founders have entered into agreements with us pursuant to which they assign any inventions to us with respect to the services they perform for us, such assignment obligations are subject to certain limitations, and do not extend to their work in other fields or to the intellectual property arising from their employment with their respective academic and research institutions. To obtain intellectual property rights assigned by our co-founders to such institutions, we would need to enter into license agreements with such institutions, such as the Broad Institute, Inc., or Broad Institute, Howard Hughes Medical Institute, or HHMI, and Harvard University, or Harvard, which may not be available on commercially reasonable terms or at all. Additionally, our consulting agreement with David Liu is subject to (i) the policies and regulations of certain institutions and (ii) certain agreements between such co-founder and certain third parties, including Beam Therapeutics Inc., or Beam Therapeutics. Any of these factors could reduce or eliminate our commercial opportunity and could have a material adverse effect on our business, financial condition, results of operations and prospects.

Development activities in the field of gene editing are currently subject to a number of risks, including risks related to the ownership and use of certain intellectual property rights that are subject to patent interference proceedings in the United States and opposition proceedings in Europe. For additional information regarding the

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risks that may apply to our and our licensors’ intellectual property rights, see the section entitled “—Risks Related To Our Intellectual Property” for more information.

Additionally, public perception and related media coverage relating to the adoption of new therapeutics or novel approaches to treatment, as well as ethical concerns related specifically to gene editing, may adversely influence the willingness of subjects to participate in clinical trials, or, if any therapeutic is approved, of physicians and patients to accept these novel and personalized treatments. Physicians, health care providers and third-party payors often are slow to adopt new products, technologies and treatment practices, particularly those that may also require additional upfront costs and training. Physicians may not be willing to undergo training to adopt these novel and potentially personalized therapies, may decide the particular therapy is too complex or potentially risky to adopt without appropriate training, and may choose not to administer the therapy. Furthermore, due to health conditions, genetic profile or other reasons, certain patients may not be candidates for the therapies. In addition, responses by federal and state agencies, Congressional committees and foreign governments to negative public perception, ethical concerns or financial considerations may result in new legislation, regulations or medical standards that could limit our ability to develop or commercialize any product candidates, obtain or maintain regulatory approval or otherwise achieve profitability. New government requirements may be established that could delay or prevent regulatory approval of any product candidates we may develop. It is impossible to predict whether legislative changes will be enacted, regulations, policies or guidance changed, or interpretations by agencies or courts changed, or what the impact of such changes, if any, may be. Based on these and other factors, health care providers and payors may decide that the benefits of these new therapies do not or will not outweigh their costs.

Clinical drug development involves a lengthy and expensive process, with an uncertain outcome. Because gene editing is novel and the regulatory landscape that will govern our potential product candidates is uncertain and may change, we cannot predict the time and cost of obtaining regulatory approval, if we receive it at all, for our potential product candidates.

The time required to obtain approval for any of our potential product candidates from the FDA, the EMA or other comparable foreign regulatory authorities is unpredictable but typically takes many years following the commencement of clinical trials and depends upon numerous factors, including the substantial discretion of regulatory authorities. For more information on the regulatory approval process, see “Business—Government Regulation.” Clinical trials may fail to demonstrate that our product candidates are safe for humans and effective for indicated uses. Even if initial clinical trials in any of our product candidates we may develop are successful, such product candidates may fail to show the desired safety and efficacy in later stages of clinical development despite having successfully advanced through preclinical studies and initial clinical trials. There is a high failure rate for drugs and biologics proceeding through clinical trials. A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in later stage clinical trials even after achieving promising results in earlier stage clinical trials.

Because gene editing is novel, the regulatory requirements that will govern any novel gene editing product candidates we develop may continue to evolve. Within the broader genetic therapy field, a limited number of gene therapy products have received marketing authorization from the FDA and the EMA to date. Even with respect to more established products that fit into the categories of gene therapies or cell therapies, the regulatory landscape is still developing. Regulatory requirements governing gene therapy products and cell therapy products have changed frequently and may continue to change in the future. Moreover, there is substantial, and sometimes uncoordinated, overlap in those responsible for regulation of existing gene therapy products and cell therapy products. For example, in the United States, the FDA has established the Office of Tissues and Advanced Therapies within its Center for Biologics Evaluation and Research, or CBER, to consolidate the review of gene therapy and related products, and the Cellular, Tissue and Gene Therapies Advisory Committee to advise CBER on its review. Gene therapy clinical trials may also be subject to review and oversight by an institutional biosafety committee, or IBC, a local institutional committee that reviews and oversees certain basic and clinical research conducted at the institution participating in the clinical trial. Although the FDA decides whether individual gene therapy protocols may proceed, the review process and determinations of other reviewing bodies, such as an IBC, can impede or delay the initiation of a clinical trial, even if the FDA has reviewed the trial and approved its initiation.

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The same applies in the European Union. The EMA’s Committee for Advanced Therapies, or CAT, is responsible for assessing the quality, safety and efficacy of advanced-therapy medicinal products (i.e. gene therapy, somatic-cell therapy or tissue-engineered medicines). The role of the CAT is to prepare a draft opinion on an application for marketing authorization for a gene therapy medicinal candidate that is submitted to the Committee for Medicinal Products for Human Use, or CHMP, before CHMP adopts its opinion which is submitted to the European Commission for the final decision on whether to grant a marketing authorization or not. In the European Union, the EMA publishes guidelines for the development and evaluation of gene therapy medicinal products to assist in preparing marketing authorization applications, however these are continually under review. The EMA may issue new guidelines concerning the development and marketing authorization for gene therapy medicinal products and require that we comply with these new guidelines.

Adverse developments in post-marketing experience or in clinical trials conducted by others of gene therapy products, cell therapy products or products developed through the application of gene editing technology may cause the FDA, the EMA and other regulatory bodies to revise the requirements for development or approval of our potential product candidates or limit the use of products utilizing gene editing technologies, either of which could materially harm our business. In addition, the clinical trial requirements of the FDA, the EMA and other regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of the potential products. The regulatory approval process for novel product candidates can be more expensive and take longer than for other, better known or more extensively studied pharmaceutical or other product candidates. Regulatory agencies administering existing or future regulations or legislation may not allow production and marketing of products utilizing gene editing technology in a timely manner or under technically or commercially feasible conditions. In addition, regulatory action or private litigation could result in expenses, delays or other impediments to our research programs or the commercialization of resulting products.

The regulatory review committees and advisory groups described above and the new guidelines they promulgate may lengthen the regulatory review process, require us to perform additional studies or trials, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval and commercialization of these treatment candidates or lead to significant post-approval limitations or restrictions. As we advance our research programs and develop future product candidates, we will be required to consult with these regulatory and advisory groups and to comply with applicable guidelines. If we fail to do so, we may be required to delay or discontinue development of any product candidates we identify and develop.

Because we are developing product candidates in the field of genetic medicines in which there is little clinical experience, there is increased risk that the FDA, the EMA or other regulatory authorities may not consider the endpoints of our clinical trials to provide clinically meaningful results and that these results may be difficult to analyze.

In order to proceed into clinical development of any product candidates we identify, we will need to submit INDs or clinical trial applications to regulatory authorities and obtain regulatory clearance to commence clinical development. Because the product candidates we identify are based on novel gene-editing technology, we may be unsuccessful in obtaining clearance from regulatory authorities to proceed into clinical development. In order to commence clinical development, we will need to identify success criteria and endpoints such that the FDA, the EMA or other regulatory authorities will be able to determine the clinical efficacy and safety profile of any product candidates we may develop. As we are initially seeking to identify and develop product candidates to treat diseases in which there is little clinical experience using new technologies, and while we may have opportunities to discuss our clinical development plans with regulatory authorities prior to commencing clinical development, there is heightened risk that the FDA, the EMA or other regulatory authorities may not consider the clinical trial endpoints that we propose to provide clinically meaningful results (reflecting a tangible benefit to patients). In addition, the resulting clinical data and results may be difficult to analyze. Even if the FDA does find our success criteria to be sufficiently validated and clinically meaningful, we may not achieve the pre-specified endpoints to a degree of statistical significance. This may be a particularly significant risk for many of the genetically defined diseases for which we plan to develop product candidates because many of these diseases such as Friedreich’s Ataxia have small patient populations, and designing and executing a rigorous clinical trial with appropriate statistical power is more difficult than with diseases that have larger patient populations. Furthermore, even if we do achieve the pre-specified

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criteria, we may produce results that are unpredictable or inconsistent with the results of the non-primary endpoints or other relevant data. The FDA also weighs the benefits of a product against its risks, and the FDA may view the efficacy results in the context of safety as not being supportive of regulatory approval. Other regulatory authorities in the European Union and other countries may make similar comments with respect to these endpoints and data. Any product candidates we may develop will be based on a novel technology that makes it difficult to predict the time and cost of development and of subsequently obtaining regulatory approval. No gene editing therapeutic product has been approved in the United States or in Europe. Within the broader genome product field, only a limited number of gene therapy products, such as uniQure N.V.’s Glybera and Abecma from Bristol Myers Squibb and bluebird bio, have received marketing authorization or marketing approval from the European Commission or the FDA. Some of these products have taken years to register and have had to deal with significant issues in their post-marketing experience.

We are very early in our development efforts and may not be successful in identifying and developing potential product candidates. It will be many years before we or our collaborators commercialize a product candidate or generate any revenues, if ever.

The success of our business depends primarily upon our ability to identify, develop and commercialize product candidates. We are very early in our development efforts and have focused our research and development efforts to date on our Prime Editing platform, developing our Prime Editors and identifying our initial targeted disease indications. Although we believe we can demonstrate many of the key advantages of Prime Editing, because we are very early in our development efforts, we are not yet certain of the results we may achieve, which may be important for registration and commercialization of our products. Such uncertainties include but are not limited to the actual size of the set of pathogenic mutations we can address, the level of editing efficiency we can produce, the degree of unwanted byproducts we may encounter, our ability to achieve editing success in a single administration or the permanence of our edits. We have also not yet shown that preclinical editing efficacy can result in clinically important effects, nor that results of biomarker studies in our preclinical models can translate into positive results in clinical trials. One particular form of Prime Editing that uses recombinases to insert targeted “gene-sized” DNA into the genome, is in an even earlier stage of research and development than our immediate target indications and our differentiation indications. We believe this promising form of Prime Editing needs more than one source of DNA as a template and may deliver with less efficacy.

All of our product development programs are still in the research or preclinical stage of development. Our research methodology may be unsuccessful in identifying potential product candidates, our potential product candidates may be shown to have harmful side effects in preclinical in vitro experiments or animal model studies, they may not show promising signals of therapeutic effect in such experiments or studies or they may have other characteristics that may make the product candidates impractical to manufacture, unmarketable, or unlikely to receive marketing approval. We have not achieved preclinical proof of concept for our programs and there is no guarantee that we will achieve it. Our proposed delivery methods with potential product candidates have never been evaluated in human clinical trials. Moreover, we are not aware of any clinical trials involving Prime Editing technology. Our ability to generate product revenue, which we do not expect will occur for many years, if ever, will depend heavily on the successful development and eventual commercialization of any product candidates we may develop, which may never occur. We currently generate no revenue from sales of any product, and we may never be able to develop or commercialize a marketable product.

In addition, although we believe Prime Editing will position us to rapidly expand our portfolio of product candidates beyond the initial product candidates we may develop after only minimal changes to the product candidate construct, we have not yet successfully developed any product candidate and our ability to expand our portfolio may never materialize.

Commencing clinical trials in the United States is also subject to acceptance by the FDA of our IND application and finalizing the trial design based on discussions with the FDA and other regulatory authorities. Even after we receive and incorporate guidance from these regulatory authorities, the FDA or other regulatory authorities could disagree that we have satisfied their requirements to commence our clinical trial or change their position on the acceptability of our trial design or the clinical endpoints selected, which may require us to complete additional

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studies or trials or impose stricter approval conditions than we currently expect. There are equivalent processes and risks applicable to clinical trial applications in other countries, including in Europe.

Some of our approaches may require interaction and approval from regulatory authorities beyond the specific requirements for individual product candidates. For example, our “march up the chromosome” personalized medicine approach may require the use of basket clinical studies, studies where more than one mutation in a disease are studied in a single clinical trial or even studies where mutations in different diseases are studied in a single clinical trial. Some of our approaches may also require studying more than one Prime Editor under a single IND or applying for registration for a suite of Prime Editor products to allow broad therapeutic coverage for a wide range of mutations in a single disease. It is also possible that using Prime Editing approaches in a wider, healthier population, as we propose in our “Blue Sky” approaches, may require different safety and regulatory thresholds from those required for smaller, more critically ill groups of patients.

Even if we complete the necessary clinical trials, we cannot predict when, or if, we will obtain regulatory approval to commercialize our potential product candidates in the United States or any other jurisdiction, if at all, and any such approval may be for a more narrow indication than we seek. In addition, clinical trials conducted in one country may not be accepted by regulatory authorities in other countries, and regulatory approval in one country does not guarantee regulatory approval in any other country. We may conduct one or more of our clinical trials with one or more trial sites that are located outside the United States. Although the FDA may accept data from clinical trials conducted outside the United States, acceptance of these data is subject to conditions imposed by the FDA, and there can be no assurance that the FDA will accept data from trials conducted outside of the United States. If the FDA does not accept the data from any trial that we conduct outside the United States, it would likely result in the need for additional trials, which would be costly and time-consuming and could delay or permanently halt our development of the applicable product candidates. Similarly, marketing approval by the FDA in the United States, if obtained, does not ensure approval by regulatory authorities in other countries or jurisdictions. Approval processes vary among countries and can involve additional product candidate testing and validation and additional administrative review periods.

Commercialization of any product candidates we may develop will also require obtaining manufacturing supply, capacity and expertise; building of a commercial organization; and significant marketing efforts. If we do not successfully commercialize any product candidates we may develop, we could experience a material harm to our business.

We may find it difficult to enroll patients in our clinical trials given the limited number of patients who have the diseases any product candidates we identify or develop are intended to target. If we experience delays or difficulties in the enrollment of patients in clinical trials, our clinical development activities and our receipt of necessary regulatory approvals could be delayed or prevented.

Although we are currently in preclinical development, as we progress our programs we may not be able to initiate or continue clinical trials for any product candidates we identify or develop if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA, the EMA or other analogous regulatory authorities outside the United States, or as needed to provide appropriate statistical power for a given trial. Enrollment may be particularly challenging for some of the rare genetically defined diseases we are targeting in our most advanced programs. In addition, if patients are unwilling to participate in our gene editing trials because of negative publicity from adverse events related to the biotechnology, gene therapy or gene editing fields, competitive clinical trials for similar patient populations, clinical trials in competing products or for other reasons, the timeline for recruiting patients, conducting studies and obtaining regulatory approval of our potential product candidates may be delayed. Moreover, some of our competitors may have ongoing clinical trials for product candidates that would treat the same indications as our potential product candidates, and patients who would otherwise be eligible for our clinical trials may instead enroll in clinical trials of our competitors’ product candidates.

Patient enrollment is also affected by other factors, some of which may include:

•severity of the disease under investigation;

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•size of the patient population and process for identifying patients, including proximity and availability of clinical trial sites for prospective patients with conditions that have small patient pools;

•design of the trial protocol, including efforts to facilitate timely enrollment in clinical trials;

•availability and efficacy of approved medications for the disease under investigation;

•availability of genetic testing for potential patients and ability to monitor patients adequately during and after treatment;

•ability to obtain and maintain patient informed consent;

•risk that enrolled patients will drop out before completion of the trial;

•eligibility and exclusion criteria for the trial in question;

•perceived risks and benefits of the product candidate under trial and gene editing as a therapeutic approach; and

•patient referral practices of physicians.

In addition, our ability to successfully initiate, enroll and complete a clinical trial in any foreign country is subject to numerous risks unique to conducting business in foreign countries, some of which may include:

•difficulty in establishing or managing relationships with CROs and physicians;

•different standards for the conduct of clinical trials;

•different standard-of-care for patients with a particular disease;

•difficulty in locating qualified local consultants, physicians and partners; and

•potential burden of complying with a variety of foreign laws, medical standards and regulatory requirements, including the regulation of pharmaceutical and biotechnology products and treatment and of gene editing technologies.

Enrollment delays in our clinical trials may result in increased development costs for our potential product candidates, which would cause the value of our Company to decline and limit our ability to obtain additional financing. If we or our collaborators have difficulty enrolling a sufficient number of patients to conduct our clinical trials as planned, we may need to delay, limit or terminate ongoing or planned clinical trials or entire clinical programs, any of which would have an adverse effect on our business, financial condition, results of operations and prospects.

The gene editing field is relatively new and is evolving rapidly. We are focusing our research and development efforts on gene editing using Prime Editing technology, but other gene editing technologies may be discovered that provide significant advantages over Prime Editing, which could materially harm our business.

To date, we have focused our efforts on our Prime Editing platform. However, there are numerous other companies advancing gene editing and gene therapy product candidates that are in preclinical or clinical development. Some of these other companies have previously undertaken research and development of gene editing technologies using clustered regularly interspaced short palindromic repeats, or CRISPR, or other forms such as base editing, zinc finger nucleases, or ZFNs, engineered meganucleases and transcription activator-like effector nucleases, or TALENs, but to date none has obtained marketing approval for a product candidate. There can be no certainty that Prime Editing technology will lead to the development of genetic therapies or that other gene editing technologies will not be considered better or more attractive for the development of therapies. For example, transposons, or “jumping genes,” can insert themselves into different places in the genome and carry specific DNA sequences to specific sites without the need for making double-stranded breaks in DNA, although such methods currently cannot target specific locations. In addition, Beam Therapeutics is developing novel base editing

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technology. We have entered into a collaboration and license agreement with Beam Therapeutics, under which we grant Beam Therapeutics certain exclusive and non-exclusive rights in our Prime Editing technology in certain fields. Our license grant to Beam Therapeutics does not cover all fields and applications of Prime Editing and we retain the majority of rights to use the licensed Prime Editing technology outside of the fields licensed to Beam Therapeutics. It is possible that base editing or other gene editing technology developed by Beam Therapeutics will be competitive with our business, and it is also possible that such editing technology may be considered more attractive than Prime Editing. Therefore, Beam Therapeutics may develop competing products using such technology. For more information regarding our agreement with Beam Therapeutics, see “Business—Our License and Collaboration Agreements—Strategic relationship with Beam Therapeutics.”

Similarly, other new gene editing technologies that have not been discovered yet may be determined to be more attractive than Prime Editing. Moreover, if we decide to develop gene editing technologies other than those involving Prime Editing, we cannot be certain we will be able to obtain rights to such technologies. Although both of our co-founders who currently provide consulting and advisory services to us in the area of gene editing technologies have entered into agreements with us pursuant to which they assign to us any inventions with respect to the services they perform for us, such obligations are subject to limitations and do not extend to their work in other fields or to the intellectual property arising from their employment with their respective academic and research institutions. To obtain intellectual property rights assigned by these co-founders to such institutions, such as Broad Institute, HHMI and Harvard, we would need to enter into license agreements with such institutions, which may not be available on commercially reasonable terms or at all. Additionally, our consulting agreement with David Liu is subject to (i) the policies and regulations of certain institutions and (ii) certain agreements between such co-founder and certain third parties, including Beam Therapeutics. Furthermore, although our co-founders have long-term supporting or employment roles with us, a financial stake in our success and, in certain cases, non-competition clauses in their consulting or employment agreements, such non-competition obligation is limited to the field of any and all gene editing and technology. Therefore it is possible that they may in the future develop new technologies that are outside of the field of their non-competition obligations but may be competitive to our business. In addition, other companies may use Prime Editing to develop product candidates in areas they believe are not covered under our foundational licensed issued patent, patent applications or know-how. There are also a number of large pharmaceutical and biotechnology companies that currently market and sell products or are pursuing the development of products for the treatment of the disease indications for which we have research programs, using approaches other than gene editing approaches. Any of these factors could reduce or eliminate our commercial opportunity, and could have a material adverse effect on our business, financial condition, results of operations and prospects.

We are very early in our development efforts, and we have not yet completed IND-enabling studies or initiated clinical development of any product candidate. As a result, we expect it will be many years before we commercialize any product candidate, if ever. If we are unable to advance our current or future product candidates into and through clinical trials, obtain marketing approval and ultimately commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

We are very early in our development efforts and have focused our research and development efforts to date on research efforts and preclinical development. Currently, all of our programs are still in the research or preclinical stage of development. Our ability to generate product revenues, which we do not expect will occur for many years, if ever, will depend heavily on the successful development, marketing approval and eventual commercialization of our product candidates, which may never occur. We have not yet generated revenue from product sales or otherwise, and we may never be able to develop or commercialize a marketable product.

Commencing clinical trials in the United States is subject to acceptance by the FDA of an IND and finalizing the trial design based on discussions with the FDA and other regulatory authorities. In the event that the FDA requires us to complete additional preclinical studies or we are required to satisfy other FDA requests prior to commencing clinical trials, the start of our first clinical trials may be delayed or we may be unsuccessful obtaining clearance to proceed into clinical development. Even after we receive and incorporate guidance from these regulatory authorities, the FDA or other regulatory authorities could disagree that we have satisfied their requirements to commence any clinical trial or change their position on the acceptability of our trial design or the clinical endpoints selected, which may require us to complete additional preclinical studies or clinical trials, delay

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the enrollment of our clinical trials, abandon our clinical development plans or meet stricter approval conditions than we currently expect. There are equivalent processes and risks applicable to clinical trial applications in other countries, including countries in the European Union.

Commercialization of any product candidates we may develop will require preclinical and clinical development; regulatory and marketing approval in multiple jurisdictions, including by the FDA and the EMA; manufacturing supply, capacity and expertise; a commercial organization; and significant marketing efforts. The success of product candidates we may identify and develop will depend on many factors, including the following:

•timely and successful completion of preclinical studies, including toxicology studies, biodistribution studies and minimally efficacious dose studies in animals, where applicable;

•effective INDs or comparable foreign applications that allow commencement of our planned clinical trials or future clinical trials for any product candidates we may develop;

•successful enrollment and completion of clinical trials, including under the FDA’s current Good Clinical Practices, or GCPs, current Good Laboratory Practices, or GLPs, and any additional regulatory requirements from foreign regulatory authorities;

•positive results from our future clinical trials that support a finding of safety and effectiveness and an acceptable risk-benefit profile in the intended populations;

•receipt of marketing approvals from applicable regulatory authorities;

•establishment of arrangements through our own facilities or with third-party manufacturers for clinical supply and, where applicable, commercial manufacturing capabilities;

•establishment, maintenance, defense and enforcement of patent, trademark, trade secret and other intellectual property protection or regulatory exclusivity for any product candidates we may develop;

•commercial launch of any product candidates we may develop, if approved, whether alone or in collaboration with others;

•acceptance of the benefits and use of our product candidates we may develop, including method of administration, if and when approved, by patients, the medical community and third-party payers;

•effective competition with other therapies;

•maintenance of a continued acceptable safety, tolerability and efficacy profile of any product candidates we may develop following approval; and

•establishment and maintenance of healthcare coverage and adequate reimbursement by payers.

If we do not succeed in one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize any product candidates we may develop, which would materially harm our business. If we are unable to advance our product candidates to clinical development, obtain regulatory approval and ultimately commercialize our product candidates, or experience significant delays in doing so, our business will be materially harmed.

We have not tested any of our proposed delivery methods or gene editing approaches in clinical trials and any favorable results we may have may not be predictive of results that may be observed in later preclinical studies or clinical trials. If our potential product candidates, our Prime Editing technology or the delivery modes we rely on to administer them lack efficacy or cause serious adverse events, undesirable side effects or unexpected characteristics, such results could delay or prevent regulatory approval of the product candidates, limit the commercial potential or result in significant negative consequences following any potential marketing approval.

We are developing a broad set of delivery technologies to support our Prime Editing programs. This will lead to significant challenges to develop a corresponding set of technical capabilities in support of these programs. In

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particular, a variety of serious adverse events, undesirable side effects or unexpected characteristics may occur. Such events, side effects or characteristics could delay or prevent regulatory approval of any product candidates we may develop, limit the commercial potential or result in significant negative consequences following any potential marketing approval. In addition, our Prime Editing technology itself, may lead to other issues, such as inability to deliver the desired efficacy or safety-related consequences as it is tested in clinical trials.

We have not tested any of our proposed delivery methods in clinical trials and any favorable results we may have may not be predictive of results that may be observed in later preclinical studies or clinical trials. Furthermore, we have not generated any clinical trial results to date. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their product candidates. Many product candidates that initially showed promise in early stage testing for treating a variety of diseases have later been found to lack efficacy or to cause side effects that prevented further clinical development of the product candidates.

Moreover, there have been only a very limited number of clinical trials involving the use of any gene editing technologies and none involving gene editing technology similar to our Prime Editing technology. It is impossible to predict when or if any product candidates we may develop will prove safe in humans. In the genetic therapy field, there have been several significant adverse events from gene therapy treatments in the past, including both the impact of the technology for editing, as well as the delivery methods used to convey the gene editing technology. These include a variety of safety concerns, including reported cases of leukemia, other cancers, significant morbidities and death. There can be no assurance that gene editing technologies such as our Prime Editing technology or the delivery methods we plan to use will not cause such undesirable side effects.

We cannot be sure that our Prime Editing technology or any of our planned delivery methods will not result in adverse effects in the long-term, such as improper editing of a patient’s DNA that leads to lymphoma, leukemia, other cancers or other aberrantly functioning cells or other as yet unidentified findings. Many times, side effects manifest or are only detectable after investigational products are tested in larger scale, pivotal clinical trials or, in some cases, after they are made available to patients on a commercial scale after approval. FDA guidance advises that patients treated with gene therapies undergo long-term follow-up observation for identification of potential adverse events for as long as 15 years. If additional clinical or long-term follow-up experience indicates that any of our potential product candidates have side effects or cause serious or life-threatening side effects, the development of the product candidate may fail or be delayed, or, if the product candidate has received regulatory approval, such approval may be revoked or limited. It is also possible that serious or life-threatening side effects may cause significant delay or altered perception of any product candidates we may develop, even if we are able to later show these effects are unrelated to our product candidates. Any adverse events may cause us to delay, limit or terminate other planned clinical trials, for example any that use a similar delivery method or those that use similar aspects of Prime Editing, any of which would have a material adverse effect on our business, financial condition, results of operations and prospects. In addition, many product candidates that initially showed promise in early-stage testing have later been found to cause later side effects that prevented further clinical development of the product candidates.

Additionally, a significant risk in any gene editing product candidate is that “off-target” edits, or edits far from the intended site of gene editing, may occur, which could cause serious adverse events, undesirable side effects or unexpected characteristics. One major causative factor leading to “off target” edits is the formation of double-strand breaks during gene editing. If double-strand breaks were to occur, they can also lead to decreased cell viability in edited cells, and an increase large deletions or structural rearrangements of DNA, chromosomal translocations or joining of one chromosome to another. In certain uses of Prime Editing, such as the use of dual flaps methods, or in some cases of use of nick-guide RNAs, more than one edit occurs along the target site. Although our preliminary data suggests otherwise, it is possible that the use of these variations of Prime Editing could result in adverse effects similar to those observed with double-strand breaks. However, our current understanding of our mechanism of action, which is designed to prevent double-strand breaks with Prime Editing, and preliminary data in our experiments suggest this risk may be low. We have performed initial experiments using assays that can detect off-target edits, even when such edits occur at very low frequencies. Using these assays, as well as reviewing published results, off-target edits have been noted. Except for initial experiments, we have not yet performed these

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experiments with our potential product candidates, so it is possible that we will detect more such off-target edits. However, our current information is limited, and we cannot be certain that Prime Editing with any product candidates we may develop will not cause rare double-strand breaks or that off-target editing will not occur and cause serious adverse events in any of our future clinical trials. Furthermore, the lack of observed serious side effects in any preclinical studies to date does not guarantee that such side effects will not occur in human clinical trials of any product candidates we may develop, which would adversely impact our product development programs and business.

There is also the potential risk of delayed adverse events following exposure to Prime Editing therapy due to the permanence of edits to DNA or due to other components of product candidates used to carry the genetic material. In addition, because Prime Editing makes a permanent change, the therapy cannot be withdrawn, even after a side effect is observed. These risks also apply to “on-target” mis-edits, also often called “indels,” or edits that are not intended but occur at the target site of gene correction, which might also have all of the above consequences, as well as yet unforeseen adverse effects.

Although we and others have demonstrated the ability to engineer gene editors which are designed to improve the specificity of their edits in a laboratory setting, we cannot be sure that our engineering efforts will be effective in any product candidates that we may develop. For example, we might not be able to engineer an editor to make the desired change, could diminish the effectiveness of an edit that we make or lead to adverse effects. To date, these types of adverse effects have not been observed in our ongoing experiments and programs. Some Prime Editing approaches, such as those that use mismatch repair, or MMR, inhibition, may potentially also lead to adverse effects. Since our inhibition of MMR for use in Prime Editing is likely to be transient, lasting at most hours to days, we believe the risk related to MMR inhibition is small.

We also cannot be sure that our Prime Editing technology or any of our planned delivery methods will not result in adverse effects including allergic reactions, other changes in safety parameters, increases in liver function tests or many other potential concerns noted in clinical trials. It is also possible that our Prime Editors or our delivery methods will result in significant immunogenicity that may lead to adverse effects and could also prevent any chance of reapplication of a delivery method, or gene editing method in the future, if needed.

In certain of our programs, we plan to use lipid nanoparticles, or LNPs, to deliver our Prime Editors. LNPs have been shown to induce oxidative stress in the liver at certain doses, as well as initiate systemic inflammatory responses that can be fatal in some cases. While we aim to continue to optimize our LNPs, there can be no assurance that our LNPs will not have undesired effects. Our LNPs could contribute, in whole or in part, to one or more of the following: immune reactions, infusion reactions, complement reactions, opsonation reactions, antibody reactions including IgA, IgM, IgE or IgG or some combination thereof, or reactions to the PEG from some lipids or PEG otherwise associated with the LNP. Certain aspects of our investigational therapies may induce immune reactions from either the mRNA or the lipid as well as adverse reactions within liver pathways or degradation of the mRNA or the LNP, any of which could lead to significant adverse events in one or more of our future clinical trials. Many of these types of side effects have been seen for legacy LNPs. There may be uncertainty as to the underlying cause of any such adverse event, which would make it difficult to accurately predict side effects in future clinical trials and would result in significant delays in our programs.

Our viral vectors including adeno-associated viruses, or AAVs, or lentiviruses, which are relatively new approaches used for disease treatment, also have known side effects, and for which additional risks could develop in the future. In past clinical trials that were conducted by others with non-AAV vectors, several significant side effects were caused by gene therapy treatments, including reported cases of leukemia and death. Other potential side effects could include an immunologic reaction and insertional oncogenesis, which is the process whereby the insertion of a functional gene near a gene that is important in cell growth or division results in uncontrolled cell division, which could potentially enhance the risk of malignant transformation. AAV vectors may also persist in the cell for long periods, potentially permanently, and may result in long-term adverse effects. If the vectors we use demonstrate a similar side effect or other adverse events, we may be required to halt or delay further clinical development of any potential product candidates. Furthermore, the FDA has stated that lentiviral vectors possess characteristics that may pose high risks of delayed adverse events. Such delayed adverse events may occur in other viral vectors, including AAV vectors, at a lower rate.

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In addition to side effects and adverse events caused by any product candidates we may develop, the conditioning, administration process or related procedures which may be used in our electroporation pipeline also can cause adverse side effects and adverse events. A gene therapy patient is generally administered cytotoxic drugs to remove stem cells from the bone marrow to create sufficient space in the bone marrow for the modified stem cells to engraft and produce new cells. This procedure compromises the patient’s immune system. In the future, if we are unable to demonstrate that such adverse events were caused by the conditioning regimens used, administration process or related procedure, the FDA, the EMA or other regulatory authorities could order us to cease further development of, or deny approval of, any product candidates we may develop for any or all target indications. Even if we are able to demonstrate that adverse events are not related to the drug product or the administration of such drug product, such occurrences could affect patient recruitment, the ability of enrolled patients to complete the clinical trial or the commercial viability of any product candidates that obtain regulatory approval.

We are subject to additional development challenges and risks due to the novel nature of our gene editing technology.

Because our in vivo technology may involve gene editing across multiple cell and tissue types, we are subject to many of the challenges and risks that other gene editing therapeutics and gene therapies face, some of which may include:

•regulatory guidance governing gene and gene editing therapy products have changed and may continue to change in the future;

•to date, only a limited number of products that involve in vivo gene transfer have been approved globally;

•improper modulation of a gene sequence, including unintended editing events or insertion of a sequence into certain locations in a patient’s chromosome, could lead to cancer, other aberrantly functioning cells or other diseases, including death;

•corrective expression of a missing protein in a patient’s cells could result in the protein being recognized as foreign and lead to a sustained immunological reaction against the expressed protein or expressing cells, which could be severe or life-threatening; and

•regulatory agencies may require extended follow-up observation periods of patients who receive treatment using gene editing products such as the FDA’s recommended 15-year follow-up observation period for such patients, which will require us to adopt such observation periods for any product candidates we develop if required by the relevant regulatory agencies, which could vary by country or region.

Furthermore, because any ex vivo product candidates we may develop involve editing human cells and then delivering modified cells to patients, we are subject to many of the challenges and risks that engineered cell therapies face. For example, clinical trials using engineering cell-based gene therapies require complex logistics for autologous therapies and such personalized manufacturing may be inefficient and cost-prohibitive, which could lead to delays or even termination of our product development programs in the future which could materially harm our business.

We may also consider additional delivery modes, which may carry additional known and unknown risks.

We may also consider additional delivery modes, which may carry additional known and unknown risks. For example, we intend to use novel split intein technology for AAV gene therapy that allows us to deliver the Prime Editor and guide RNA construct by co-infection with two viruses, where each virus contains one half of the editor. The scientific evidence to support the feasibility of developing product candidates based on this technology is both preliminary and limited. We also intend to use LNPs to deliver some of our Prime Editors. While LNPs have been used to deliver smaller molecules, such as RNAi, they have not been clinically proven to deliver large RNA molecules, such as the ones we intend to use for our Prime Editors. Furthermore, as with many AAV-mediated gene therapy approaches, certain patients’ immune systems might prohibit the successful delivery, thereby potentially limiting treatment outcomes of these patients. Even if initial clinical trials in any of our potential product candidates we may develop are successful, these product candidates we may develop may fail to show the desired safety and

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efficacy in later stages of clinical development despite having successfully advanced through preclinical studies and initial clinical trials.

In the future, if we are unable to demonstrate that any of the above adverse events were caused by factors other than our product candidates or our delivery methods, the FDA, the EMA or other regulatory authorities could order us to cease further development of, or deny approval of, any product candidates we are able to develop for any or all targeted indications. Even if we are able to demonstrate that all future serious adverse events are not product- and/or delivery-related, such occurrences could affect patient recruitment or the ability of enrolled patients to complete the trial or may cause significant delays to our programs and potential registration. Moreover, if we elect, or are required, to delay, suspend or terminate any clinical trials, the commercial prospects of such product candidates may be harmed and our ability to generate product revenues from any of these product candidates may be delayed or eliminated. Any of these occurrences may harm our ability to identify and develop product candidates, and may harm our business, financial condition, result of operations and prospects significantly.

We face significant competition in an environment of rapid technological change, and there is a possibility that our competitors may achieve regulatory approval before us or develop therapies that are safer or more advanced or effective than ours, which may harm our financial condition and our ability to successfully market or commercialize any product candidates we may develop.

The development and commercialization of new drug products is highly competitive. Moreover, the gene editing field is characterized by rapidly changing technologies, significant competition and a strong emphasis on intellectual property. We will face competition with respect to any product candidates that we may seek to develop or commercialize in the future from major pharmaceutical companies, specialty pharmaceutical companies and biotechnology companies worldwide. Potential competitors also include academic institutions, government agencies and other public and private research organizations that conduct research, seek patent or other intellectual property protection and establish collaborative arrangements for research, development, manufacturing and commercialization.

There are a number of large pharmaceutical and biotechnology companies that currently market and sell products or are pursuing the development of products for the treatment of the disease indications for which we have research programs. Some of these competitive products and therapies are based on scientific approaches that are the same as or similar to our approach, while others are based on entirely different approaches.

There are several companies utilizing CRISPR/Cas9 nuclease technology, including Caribou Biosciences, Inc., Editas Medicine, Inc., CRISPR Therapeutics AG, Intellia Therapeutics, Inc. and Graphite Bio, Inc., among others. Several additional companies such as Sangamo Therapeutics, Inc., Precision BioSciences, Inc. and bluebird bio, Inc. utilize alternative nuclease-based genome editing technologies, including ZFNs, engineered meganucleases and TALENs. Beam Therapeutics utilizes base editing technology. In addition, other private companies such as Tessera Therapeutics, Inc. and Tome Biosciences, Inc. have announced their work in recombinase DNA and RNA gene writers, although little is known publicly about their science or portfolio. Other companies have announced intentions to enter the gene editing field, such as Moderna, Inc. and Pfizer Inc. Most recently, new epigenetic editing companies have emerged, such as Chroma Medicine, Inc. and Tune Therapeutics, Inc. In addition, we face competition from companies utilizing gene therapy, oligonucleotides and cell therapy therapeutic approaches. Several companies such as Arbor Biotechnologies, Inc., Scribe Therapeutics Inc., Mammoth Biosciences, Inc. and Metagenomi, Inc. are actively searching for novel genome editing components and have reported the discovery of new DNA-cutting enzymes. Other companies are active in LNP delivery technologies and advancing those into therapeutics using genetic therapies, including Recode Therapeutics, Inc., Verve Therapeutics, Inc., Generation Bio Co. and Beam Therapeutics, among others.

Any product candidates that we successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future that are approved to treat the same diseases for which we may obtain approval for any product candidates we may develop. This may include other types of therapies, such as small molecule, antibody and/or protein therapies.

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Many of our current or potential competitors, either alone or with their collaboration partners, may have significantly greater financial resources and expertise in research and development, manufacturing, conducting preclinical studies and clinical trials, obtaining regulatory approvals and marketing approved products than we do. Mergers and acquisitions in the pharmaceutical, biotechnology and gene therapy industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs. Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize product candidates that are safer, more effective, have fewer or less severe side effects, are more convenient, or are less expensive than any product candidates that we may develop or that would render any product candidates that we may develop obsolete or non-competitive. Our competitors also may obtain FDA or other regulatory approval for their product candidates more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. Additionally, technologies developed by our competitors may render our potential product candidates uneconomical or obsolete, and we may not be successful in marketing any product candidates we may develop against competitors.

In addition, as a result of the expiration or successful challenge of our patent or other intellectual property rights, we could face risks relating to our ability to successfully prevent or delay launch of competitors’ products. The availability of our competitors’ products could limit the demand and the price we are able to charge for any product candidates that we may develop and commercialize.

Adverse public perception of genetic therapies and of gene editing and Prime Editing in particular, may negatively impact regulatory approval of, and/or demand for, our potential products.

Our potential therapeutic products involve editing the human genome and making permanent changes that may not be reversible. The clinical and commercial success of our potential products will depend in part on public understanding and acceptance of the use of gene editing therapy for the prevention or treatment of human diseases. Public attitudes may be influenced by claims that gene editing is unsafe, unethical or immoral, and, consequently, any product candidates we may develop may not gain the acceptance of the public or the medical community. Moreover, our success will depend upon physicians prescribing, and their patients being willing to receive, treatments that involve the use of product candidates we may develop in lieu of, or in addition to, existing treatments with which they are already familiar and for which greater clinical data may be available.

In addition, gene editing technology is subject to public debate and heightened regulatory scrutiny due to ethical concerns relating to the application of gene editing technology to human embryos or the human germline. For example, academic scientists in several countries, including the United States, have reported on their attempts to edit the gene of human embryos as part of basic research. In addition, in November 2018, Dr. Jiankui He, a Chinese biophysics researcher who was an associate professor in the Department of Biology of the Southern University of Science and Technology in Shenzhen, China, reportedly claimed he had created the first human genetically edited babies, twin girls. This claim, and another that Dr. He had helped create a second gene-edited pregnancy, was subsequently confirmed by Chinese authorities and was negatively received by the public, in particular those in the scientific community. News reports indicate that Dr. He was sentenced to three years in prison and fined $430,000 in December 2019 by the Chinese government for illegal medical practice in connection with such activities. In the wake of the claim, the World Health Organization established a new advisory committee to create global governance and oversight standards for human gene editing. The Alliance for Regenerative Medicine also released principles for the use of gene editing in therapeutic applications endorsed by a number of companies that use gene editing technologies.

Moreover, in an annual worldwide threat assessment report delivered to the U.S. Congress in February 2016, the U.S. Director of National Intelligence stated that research into gene editing that is conducted under different regulatory standards than those of Western countries probably increases the risk of the creation of potentially harmful biological agents or products, including weapons of mass destruction. He noted that given the broad

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distribution, low cost and accelerated pace of development of gene editing technology, its deliberate or unintentional misuse could have far-reaching economic and national security implications.

Although we do not, and will not use our technologies to edit human embryos or the human germline, such public debate about the use of gene editing technologies in human embryos and heightened regulatory scrutiny could prevent or delay our development of product candidates. More restrictive government regulations or negative public opinion would have a negative effect on our business or financial condition and may delay or impair our development and commercialization of product candidates or demand for any product candidates we may develop. Adverse events in our preclinical studies or clinical trials or those of our competitors or of academic researchers utilizing gene editing technologies, even if not ultimately attributable to product candidates we may identify and develop, and negative publicity could result in increased governmental regulation, unfavorable public perception, potential regulatory delays in the testing or approval of potential product candidates we may identify and develop, stricter labeling requirements for those product candidates that are approved, and a decrease in demand for any such product candidates.

If the market opportunities for any product candidates we may develop are smaller than we believe they are, our potential revenues may be adversely affected and our business may suffer. Because the target patient populations for many of the product candidates we may develop are small, we must be able to successfully identify patients and achieve market acceptance in the medical community in order to secure a significant market share to maintain profitability and growth.

We focus our research and product development on treatments for rare genetically defined diseases. Many of the product candidates we may develop are expected to target a single, often predominant mutation; as a result, the relevant patient population may therefore be small. Although we believe we can expand beyond our immediate target indications, this approach will require regulatory approval as discussed in the risk factor entitled “We are very early in our development efforts and may not be successful in identifying and developing potential product candidates. It will be many years before we or our collaborators commercialize a product candidate or generate any revenues, if ever.” Our projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with product candidates we may develop, are based on estimates. These estimates may prove to be incorrect and new studies may change the estimated incidence or prevalence of these diseases. The number of patients in the United States, Europe and elsewhere may turn out to be lower than expected, and patients may not be amenable to treatment with the product candidates we may develop, or may become increasingly difficult to identify or gain access to, all of which would adversely affect our business, financial condition, results of operations and prospects. Additionally, because of the potential that any product candidates we develop could cure a target disease, we may not receive recurring revenues from patients and may deplete the patient population prevalence through curative therapy.

Clinical trial and product liability lawsuits against us could divert our resources and could cause us to incur substantial liabilities and to limit commercialization of any products that we may develop.

We will face an inherent risk of clinical trial and product liability exposure related to the testing of our product candidates in human clinical trials, and we will face an even greater risk if we commercially sell any products that we may develop. While we currently have no products in clinical trials or that have been approved for commercial sale, the future use of product candidates by us in clinical trials, and the sale of any approved products in the future, may expose us to liability claims. These claims might be made by patients that use the product, healthcare providers, pharmaceutical companies or others selling such products. 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:

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

•termination of clinical trials;

•injury to our reputation and significant negative media attention;

•withdrawal of clinical trial participants;

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•significant costs to defend any related litigation;

•substantial monetary awards to trial participants or patients;

•loss of revenue;

•reduced resources of our management to pursue our business strategy; and

•the inability to commercialize any products that we may develop.

We currently do not hold any clinical trial liability insurance coverage. We may need to obtain 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 obtain and maintain insurance coverage at a reasonable cost or in an amount adequate to satisfy any liability that may arise. If a successful clinical trial or product liability claim or series of claims is brought against us for uninsured liabilities or in excess of insured liabilities, our assets may not be sufficient to cover such claims and our business operations could be impaired.

If we or any contract manufacturers and suppliers we engage fail to comply with environmental, health, and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

We and any contract manufacturers and suppliers we engage are subject to numerous federal, state, and local environmental, health, and safety laws, regulations, and permitting requirements, including those governing laboratory procedures; the generation, handling, use, storage, treatment, and disposal of hazardous and regulated materials and wastes; the emission and discharge of hazardous materials into the ground, air, and water; and employee health and safety. Our operations involve the use of hazardous and flammable materials, including chemicals and biological and radioactive materials. Our operations also produce hazardous waste. 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. Under certain environmental laws, we could be held responsible for costs relating to any contamination at our current or past facilities and at third-party facilities. We also could incur significant costs associated with civil or criminal fines and penalties.

Compliance with applicable environmental laws and regulations may be expensive, and current or future environmental laws and regulations may impair our research and product development efforts. In addition, we cannot entirely eliminate the risk of accidental injury or contamination from these materials or wastes. Although we maintain workers’ compensation 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 carry specific biological or hazardous waste insurance coverage (under which we currently have an aggregate of approximately $2.0 million in coverage). However, in the event of contamination or injury, we could be held liable for damages or be penalized with fines in an amount exceeding our resources, and our clinical trials or regulatory approvals could be suspended, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

In addition, we may incur substantial costs in order to comply with current or future environmental, health, and safety laws, regulations, and permitting requirements. These current or future laws, regulations, and permitting requirements may impair our research, development, or production efforts. Failure to comply with these laws, regulations, and permitting requirements also may result in substantial fines, penalties, or other sanctions or business disruption, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

Any third-party contract manufacturers and suppliers we engage will also be subject to these and other environmental, health, and safety laws and regulations. Liabilities they incur pursuant to these laws and regulations could result in significant costs or an interruption in operations, which could have a material adverse effect on our business, financial condition, results of operations, and prospects.

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Genetic therapies are novel, and any product candidates we develop may be complex and difficult to manufacture. We could experience delays in satisfying regulatory authorities or production problems that result in delays in our development programs, limit the supply of the product candidates we may develop or otherwise harm our business.

Any product candidates we may develop will likely require processing steps that are more complex than those required for most chemical pharmaceuticals. For example, one component of our Prime Editors is guide RNA, known as a Prime Editing guide RNA, or pegRNA we currently obtain from partners and vendors; future needs could require additional pegRNA lengths or increased purity, beyond what our partners and vendors can currently supply. Moreover, unlike chemical pharmaceuticals, the physical and chemical properties of a biologic such as the product candidates we intend to develop generally cannot be fully characterized. As a result, assays of the finished product candidate may not be sufficient to ensure that the product candidate will perform in the intended manner. Problems with the manufacturing process, even minor deviations from the normal process, could result in product defects or manufacturing failures that result in lot failures, product recalls, product liability claims, insufficient inventory or potentially delay progression of our potential IND filings. If we successfully develop product candidates, we may encounter problems achieving adequate quantities and quality of clinical-grade materials that meet the FDA, the EMA or other comparable applicable foreign standards or specifications with consistent and acceptable production yields and costs. For example, the current approach of manufacturing AAV vectors may fall short of supplying required number of doses needed for advanced stages of preclinical studies or clinical trials, and the FDA may ask us to demonstrate that we have the appropriate manufacturing processes in place to support the higher-dose group in our preclinical studies or clinical trials. In addition, any product candidates we may develop will require complicated delivery methods, such as electroporation, LNPs or viral vectors, each of which will introduce additional complexities in the manufacturing process.

In addition, the FDA, the EMA and other regulatory authorities may require us to submit samples of any lot of any approved product together with the protocols showing the results of applicable tests at any time. Under some circumstances, the FDA, the EMA or other regulatory authorities may require that we not distribute a lot until the agency authorizes its release. Slight deviations in the manufacturing process, including those affecting quality attributes and stability, may result in unacceptable changes in the product that could result in lot failures or product recalls. Lot failures or product recalls could cause us to delay clinical trials or product launches, which could be costly to us and otherwise harm our business, financial condition, results of operations and prospects.

Furthermore, we intend to use novel technology for gene editing. Our novel Prime Editors have two main components that act together to edit DNA: (i) a Prime Editor protein, comprising a fusion between a Cas protein and a reverse transcriptase enzyme, and (ii) a pegRNA, that targets the Prime Editor to a specific genomic location and provides a template for making the desired edit to the target DNA sequence. Prime Editing leverages the established DNA-targeting capabilities of CRISPR-Cas proteins modified to nick, but not cause double-stranded DNA breaks, and combines these with the DNA synthesis capabilities of reverse transcriptase enzymes, which have been engineered to efficiently and precisely copy a pegRNA-encoded edited sequence into target DNA. The scientific evidence to support the feasibility of developing product candidates based on this technology is both preliminary and limited and has yet to be produced at a clinical scale.

We also may encounter problems hiring and retaining the experienced scientific, quality control and manufacturing personnel needed to manage our manufacturing process, which could result in delays in our production or difficulties in maintaining compliance with applicable regulatory requirements.

Given the nature of biologics manufacturing there is a risk of contamination during manufacturing. Any contamination could materially harm our ability to produce product candidates on schedule and could harm our results of operations and cause reputational damage. Some of the raw materials that we anticipate will be required in our manufacturing process are derived from biologic sources. Such raw materials are difficult to procure and may be subject to contamination or recall. A material shortage, contamination, recall or restriction on the use of biologically derived substances in the manufacture of any product candidates we may develop could adversely impact or disrupt the commercial manufacturing or the production of clinical material, which could materially harm our development timelines and our business, financial condition, results of operations and prospects.

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Any problems in our manufacturing process or the facilities with which we contract could make us a less attractive collaborator for potential partners, including larger pharmaceutical companies and academic research institutions, which could limit our access to additional attractive development programs. Problems in third-party manufacturing process or facilities also could restrict our ability to ensure sufficient clinical material for any clinical trials we may be conducting or are planning to conduct and meet market demand for any product candidates we develop and commercialize.

If preclinical studies or clinical trials of any product candidates we may identify and develop fail to demonstrate safety and efficacy to the satisfaction of regulatory authorities or do not otherwise produce positive results, we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of such product candidates.

Before obtaining marketing approval from regulatory authorities for the sale of any product candidates we may identify and develop, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy in humans. 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. The outcome of preclinical testing and early clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results.

Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses. Many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their product candidates.

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

•delays in reaching a consensus with regulators on trial design;

•regulators, institutional review boards, or IRBs, or independent ethics committees may not authorize us or our investigators to commence a clinical trial or conduct a clinical trial at a prospective trial site;

•delays in reaching or failing to reach agreement on acceptable clinical trial contracts or clinical trial protocols with prospective CROs and clinical trial sites;

•clinical trials of any product candidates we may develop may produce negative or inconclusive results, and we may decide, or regulators may require us, to conduct additional clinical trials or abandon product development or research programs;

•difficulty in designing well-controlled clinical trials due to ethical considerations which may render it inappropriate to conduct a trial with a control arm that can be effectively compared to a treatment arm;

•difficulty in designing clinical trials and selecting endpoints for diseases that have not been well-studied and for which the natural history and course of the disease is poorly understood;

•the number of patients required for clinical trials of any product candidates we may develop may be larger than we anticipate; enrollment of suitable participants in these clinical trials, which may be particularly challenging for some of the rare genetically defined diseases we are targeting in our most advanced programs, may be delayed or slower than we anticipate; or patients may drop out of these clinical trials at a higher rate than we anticipate;

•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;

•regulators, IRBs, or independent ethics committees may require that we or our investigators suspend or terminate clinical research or clinical trials of any product candidates we may develop for various reasons, including noncompliance with regulatory requirements, a finding of undesirable side effects or other

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unexpected characteristics, or that the participants are being exposed to unacceptable health risks or after an inspection of our clinical trial operations or trial sites;

•the cost of clinical trials of any product candidates we may develop may be greater than we anticipate;

•the supply or quality of any product candidates we may develop or other materials necessary to conduct clinical trials of any product candidates we may develop may be insufficient or inadequate, including as a result of delays in the testing, validation, manufacturing, and delivery of any product candidates we may develop to the clinical sites by us or by third parties with whom we have contracted to perform certain of those functions;

•delays in having patients complete participation in a trial or return for post-treatment follow-up;

•clinical trial sites dropping out of a trial;

•selection of clinical endpoints that require prolonged periods of clinical observation or analysis of the resulting data;

•occurrence of serious adverse events associated with any product candidates we may develop that are viewed to outweigh their potential benefits;

•occurrence of serious adverse events in trials of the same class of agents conducted by other sponsors; and

•changes in regulatory requirements and guidance that require amending or submitting new clinical protocols.

If we or our collaborators are required to conduct additional clinical trials or other testing of any product candidates we may develop beyond those that we currently contemplate, if we or our collaborators are unable to successfully complete clinical trials or other testing of any product candidates we may develop, or if the results of these trials or tests are not positive or are only modestly positive or if there are safety concerns, we or our collaborators may:

•be delayed in obtaining marketing approval for any such product candidates we may develop or not obtain marketing approval at all;

•obtain approval for indications or patient populations that are not as broad as intended or desired;

•obtain approval with labeling that includes significant use or distribution restrictions or safety warnings, including boxed warnings;

•be subject to changes in the way the product is administered;

•be required to perform additional clinical trials to support approval or be subject to additional post-marketing testing requirements;

•have regulatory authorities withdraw, or suspend, their approval of the product or impose restrictions on its distribution in the form of a Risk Evaluation and Mitigation Strategy, or REMS, or through modification to an existing REMS;

•be sued; or

•experience damage to our reputation.

Product development costs will also increase if we or our collaborators experience delays in clinical trials or other testing or in obtaining marketing approvals. We do not know whether any clinical trials will begin as planned, will need to be restructured, or will be completed on schedule, or at all. Significant clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize any product candidates we may develop, could allow our competitors to bring products to market before we do, and could impair our ability to

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successfully commercialize any product candidates we may develop, any of which may harm our business, financial condition, results of operations, and prospects.

Social media campaigns and demand for expanded access to our potential product candidates could negatively affect our reputation and harm our business.

We are developing product candidates in areas of unmet medical need where there are currently limited or no available therapeutic options and may receive requests in the future for right to try access or expanded access on a compassionate use basis to certain of our potential product candidates. It is possible for individuals or groups to target companies with disruptive social media campaigns related to a request for access to unapproved drugs for patients with significant unmet medical need. If we experience a similar social media campaign regarding our decision to provide or not provide access to any of our potential product candidates under an expanded access policy, our reputation may be negatively affected and our business may be harmed.

In addition, some patients who receive access to drugs prior to their commercial approval through compassionate use, expanded access programs or right to try access have life-threatening illnesses and have exhausted all other available therapies. The risk for serious adverse events in this patient population is high, which could have a negative impact on the safety profile of our potential product candidates if we were to provide them to these patients, which could cause significant delays or an inability to successfully commercialize our potential product candidates, which could materially harm our business. If we were to provide patients with our potential product candidates under an expanded access program, we may in the future need to restructure or pause any compassionate use and/or expanded access programs in order to perform the controlled clinical trials required for regulatory approval and successful commercialization of our potential product candidates, which could prompt adverse publicity or other disruptions related to current or potential participants in such programs.

Risks Related To Our Relationships with Third Parties

We may enter into collaborations with collaborators and strategic partners such as Beam Therapeutics or other third parties for the research, development, delivery, manufacturing and commercialization of Prime Editing technology and certain of the product candidates we may develop. If any such collaborations are not successful, we may not be able to capitalize on the market potential of our Prime Editing platform or product candidates.

We may seek third-party collaborators and strategic partners for the research, development, delivery, manufacturing and commercialization of certain of the product candidates we may develop. If we enter into any such arrangements with any third parties, we will likely have limited control over the amount and timing of resources that our collaborators dedicate to collaboration, including the development, delivery, manufacturing or commercialization of any product candidates we may seek to develop with them. Our ability to generate revenues from these arrangements will depend on our collaborators’ and strategic partners’ abilities to successfully perform the functions assigned to them in these arrangements. We cannot predict the success of any collaboration that we enter into.

Collaborations involving our research, development, expansion of our technology or for any product candidates we may develop pose numerous risks to us, including the following:

•Collaborators and strategic partners have significant discretion in determining the efforts and resources that they will apply to these collaborations, may not pursue development and commercialization of any product candidates we may develop or may elect not to continue or renew development or commercialization programs based on clinical trial results, changes in the collaborator’s strategic focus or available funding or external factors such as an acquisition that diverts resources or creates competing priorities.

•Collaborators and strategic partners may have significant overlap in their areas of interest and capabilities, research and development activities and product candidates with us, which may result in potential conflicts of interest.

•The transfer of key technology between our collaborators and strategic partners and us may be incomplete, delayed or not meet our standards of quality.

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•Collaborators and strategic partners may delay clinical trials, provide insufficient funding for a clinical trial program, stop a clinical trial or abandon a product candidate, repeat or conduct new clinical trials or require a new formulation of a product candidate for clinical testing.

•Collaborators and strategic partners could independently develop or develop with third parties, products that compete directly or indirectly with our therapies or product candidates we may develop if the collaborators believe that competitive products are more likely to be successfully developed or can be commercialized under terms that are more economically attractive than ours.

•Collaborators and strategic partners with marketing and distribution rights to one or more therapies may not commit sufficient resources to the marketing and distribution of such therapy or therapies.

•Collaborators and strategic partners may have rights or may believe they have rights to sub-license our Prime Editing technology more broadly than anticipated for the collaboration.

•Collaborators and strategic partners may not properly obtain, maintain, enforce or defend our intellectual property or proprietary rights or may use our intellectual property or proprietary information in such a way as to invite litigation that could jeopardize or invalidate our intellectual property or proprietary information or expose us to potential litigation.

•Collaborators and strategic partners may not properly use our technology, perform activities below quality standards or wrongly interpret results, any of which may result in adverse public perception of Prime Editing or negatively impact the regulatory approval of, and/or demand for, our potential product candidates.

•There may be areas of ambiguity in the interpretation of obligations and deliverables under any collaboration agreements we have entered or may enter into, including disputes that may arise between the collaborators and strategic partners and us that result in the delay or termination of the research, development or commercialization of our therapies or product candidates or that result in costly litigation or arbitration that diverts management attention and resources.

•We may lose certain valuable rights under circumstances identified in our collaborations, including if we undergo a change of control.

•Collaborations may be terminated and, if terminated, may leave incomplete some or all of the goals that were set for such collaboration or result in a need for additional capital to pursue further development or commercialization of the applicable product candidates we may develop.

•Collaboration agreements may not lead to development or commercialization of product candidates in the most efficient manner or at all. If a present or future collaborator of ours were to be involved in a business combination, the continued pursuit and emphasis on our product development or commercialization program under such collaboration could be delayed, diminished or terminated.

If our collaborations do not result in successful research or delivery approaches or successful development and commercialization of product candidates, or if one of our collaborators or strategic partners terminates its agreement with us, there may be adverse consequences. For example, we may not receive any future research funding or milestone or royalty payments under the collaboration. If we do not receive the funding we expect under these agreements, our development of product candidates could be delayed, and we may need additional resources to develop product candidates. In addition, if one of our collaborators or strategic partners terminates its agreement with us, we may find it more difficult to find a suitable replacement or attract a new collaboration, lose access to key technology or our development programs may be delayed or the perception of us in the business and financial communities could be adversely affected. All of the risks relating to product development, regulatory approval and commercialization described in this prospectus apply to the activities of our collaborators and strategic partners.

These relationships, or those like them, may require us to incur non-recurring and other charges, increase our near- and long-term expenditures, issue securities that dilute our existing stockholders, result in a loss of value to our

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stock or disrupt our management and business. In addition, we could face significant competition in seeking appropriate collaborators and strategic partners and the negotiation process is time-consuming and complex. Our ability to reach a definitive collaboration agreement will depend, among other things, upon our assessment of the collaborator’s and strategic partner’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator’s evaluation of several factors. If we license rights to any product candidates we may develop we or our collaborators and strategic partners may develop, we may not be able to realize the benefit of such transactions if we are unable to successfully integrate them with our existing operations and company culture.

If conflicts arise between us and our collaborators or strategic partners, these parties may act in a manner adverse to us and could limit our ability to implement our strategies.

If conflicts arise between our corporate or academic collaborators or strategic partners and us, the other party may act in a manner adverse to us and could limit our ability to implement our strategies. Some of our academic collaborators and strategic partners are conducting multiple product development efforts within each area that is the subject of the collaboration with us. Our collaborators or strategic partners, however, may develop, either alone or with others, products in related fields that are competitive with the product candidates we may develop that are the subject of these collaborations with us. Competing products, either developed by the collaborators or strategic partners or to which the collaborators or strategic partners have rights, may result in the withdrawal of partner support for any product candidates we may develop.

Some of our collaborators or strategic partners could also become our competitors in the future. For example, Beam Therapeutics, currently one of our strategic partners, may develop product candidates in areas where both companies have freedom to pursue development. For more information regarding our agreement with Beam Therapeutics, see “Business—Our License and Collaboration Agreements” and the risk factor entitled “The gene editing field is relatively new and is evolving rapidly. We are focusing our research and development efforts on gene editing using Prime Editing technology, but other gene editing technologies may be discovered that provide significant advantages over Prime Editing, which could materially harm our business.”

Our collaborators or strategic partners could develop competing products, preclude us from entering into collaborations with their competitors, fail to obtain timely regulatory approvals, prevent us from obtaining timely regulatory approvals, terminate their agreements with us prematurely or fail to devote sufficient resources to the collaboration efforts, including development, delivery, manufacturing and commercialization of products. Any of these developments could harm our company and product development efforts.

We expect to rely on third parties to conduct our clinical trials and some aspects of our research, as well as some aspects of our delivery methods, and those third parties may not perform satisfactorily, including failing to meet deadlines for the completion of such trials, research or testing.

We currently, and expect to continue to, rely on third parties, such as CROs, clinical data management organizations, medical institutions, preclinical laboratories and clinical investigators, to conduct some aspects of our research. For example, we may rely on a third party to conduct electroporation, to supply LNPs or AAVs, or to conduct some of our preclinical animal experiments. Any of these third parties may terminate their engagements with us at any time under certain criteria. If we need to enter into alternative arrangements, it may delay our product development activities.

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, the EMA and other regulatory authorities require us and the study sites and investigators we work with to comply with standards, commonly referred to as GLPs and GCPs for conducting, recording and reporting the results of preclinical studies and clinical trials to assure, amongst other things, that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. In the United States, we also are required to register certain clinical trials and post the results of completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within certain timeframes. Failure to do so can result in fines, adverse publicity and civil and criminal sanctions.

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Although we intend to design the clinical trials for our potential product candidates, CROs will conduct some or all of the clinical trials. As a result, many important aspects of our development programs, including their conduct and timing, will be outside of our direct control. Our reliance on third parties to conduct preclinical studies and future clinical trials will also result in less direct control over the management of data developed through preclinical studies and clinical trials than would be the case if we were relying entirely upon our own staff. Communicating with outside parties can also be challenging, potentially leading to mistakes as well as difficulties in coordinating activities. Among other reasons that may delay or impact the development of our potential product candidates, outside parties may:

•have staffing difficulties;

•fail to comply with contractual obligations;

•experience regulatory compliance issues;

•undergo changes in priorities or become financially distressed; or

•form relationships with other entities, some of which may be our competitors.

These factors may materially adversely affect the willingness or ability of third parties to conduct our preclinical studies and clinical trials and may subject us to unexpected cost increases that are beyond our control. If the CROs and other third parties do not perform such preclinical studies and future clinical trials in a satisfactory manner, breach their obligations to us or fail to comply with regulatory requirements, the development, regulatory approval and commercialization of our potential product candidates may be delayed, we may not be able to obtain regulatory approval and commercialize our potential product candidates or our development programs may be materially and irreversibly harmed. If we are unable to rely on preclinical and clinical data collected by our CROs and other third parties, we could be required to repeat, extend the duration of or increase the size of any preclinical studies or clinical trials we conduct and this could significantly delay commercialization and require greater expenditures.

We may also expect to rely on other third parties to store and distribute drug supplies for our future clinical trials. Any performance failure on the part of our distributors could delay clinical development or marketing approval of any product candidates we may develop or commercialization of our therapies, producing additional losses and depriving us of potential product revenue.

We contract with third parties for the manufacture of materials for our research programs and expect to continue to do so for clinical trials and for any commercialization of product candidates that we may develop. This reliance on third parties increases the risk that we will not have sufficient quantities of such materials, product candidates or any therapies that we may develop and commercialize, or that such supply will not be available to us on time or at an acceptable cost.

We do not have any manufacturing facilities at the present time. We currently rely on third-party manufacturers to manufacture many of our materials for research and may continue to do so for preclinical studies and possibly even clinical trials. We have not yet formulated our plans for commercial supply of any product candidates that we may develop or for which we or our collaborators may in the future obtain marketing approval, but our future decisions may be subject to similar risks to the ones discussed below.

We may be unable to establish any agreements with third-party manufacturers or to do so on acceptable terms. Even if we are able to establish agreements with third-party manufacturers, reliance on third-party manufacturers entails additional risks, some of which may include:

•the possible breach of the manufacturing agreement by the third party;

•the possible termination or nonrenewal of the agreement by the third party at a time that is costly or inconvenient for us; and

•reliance on the third party for regulatory compliance, quality assurance, safety and pharmacovigilance and related reporting.

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Third-party manufacturers may not be able to comply with cGMP regulations or similar regulatory requirements outside the United States. Our failure, or the failure of our third-party manufacturers, to comply with applicable regulations could result in sanctions being imposed on us, including fines, injunctions, civil penalties, delays, suspension or withdrawal of approvals, license revocations, seizures or recalls of product candidates or therapies, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of our therapies and harm our business, financial condition, results of operations and prospects.

Any therapies that we may develop may compete with other product candidates and products for access to manufacturing facilities. There are a limited number of manufacturers that operate under cGMP regulations and that might be capable of manufacturing for us.

Any performance failure on the part of our existing or future manufacturers could delay clinical development or marketing approval. We do not currently have arrangements in place for redundant supply for bulk drug substances. If any third party-manufacturer with whom we contract fails to perform its obligations, we may be forced to manufacture the materials ourselves, for which we may not have the facilities or resources, or enter into an agreement with a different third party-manufacturer, which we may not be able to do on reasonable terms, if at all. In either scenario, our clinical trials supply could be delayed significantly as we establish alternative supply sources. In some cases, the technical skills required to manufacture our products or product candidates may be unique or proprietary to the original third party-manufacturer and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. In addition, if we are required to change third party-manufacturers for any reason, we will be required to verify that the new third party-manufacturer maintains facilities and procedures that comply with quality standards and with all applicable regulations. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturing process will produce our potential product candidates according to the specifications previously submitted to the FDA or another regulatory authority. The delays associated with the verification of a new third party-manufacturer could negatively affect our ability to develop product candidates or commercialize our products in a timely manner or within budget. Furthermore, a third party-manufacturer may possess technology related to the manufacture of our product candidate that such third party-manufacturer owns independently. This would increase our reliance on such third party-manufacturer or require us to obtain a license from such third party-manufacturer in order to have another third party-manufacturer manufacture our product candidates, which may not be available on commercially reasonable terms, or at all. In addition, changes in manufacturers often involve changes in manufacturing procedures and processes, which could require that we conduct bridging studies between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials.

Our current and anticipated future dependence upon others for the manufacture of any product candidates or therapies we may develop may adversely affect our future profit margins and our ability to commercialize any therapies that receive marketing approval on a timely and competitive basis.

If we are not able to establish collaborations on a timely basis, on commercially reasonable terms, or at all, we may have to alter, reduce or delay our development and commercialization plans or increase our expenditures to fund development or commercialization activities at our own expense.

For some of the product candidates we may develop, we may decide to collaborate with other pharmaceutical and biotechnology companies for the development and potential commercialization of those product candidates, which is a complex and time-consuming process to negotiate and document. Whether we reach a definitive agreement for a collaboration will depend, among other things, upon our assessment of the collaborator or strategic partner’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator or strategic partner’s evaluation of a number of factors. Those factors may include the design or results of clinical trials, the likelihood of approval by the FDA, the EMA or similar regulatory authorities outside the United States, the potential market for the subject product candidate, the costs and complexities of manufacturing and delivering such product candidate to patients, the potential of competing products, the existence of uncertainty with respect to our ownership of technology, which can exist if there is a challenge to such ownership without regard to the merits of the challenge and industry and market conditions generally. The collaborator or strategic partner may

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also consider alternative product candidates or technologies for similar indications that may be available to collaborate on and whether such a collaboration could be more attractive than the one with us. In addition, we and the collaborator or strategic partner may have differences in risk tolerance, which may affect the development and execution of such collaborations with respect to timing and other considerations.

We may also be restricted under existing collaboration agreements from entering into future collaboration agreements on certain terms with potential collaborators. In addition, there have been a significant number of recent business combinations among large pharmaceutical companies that have resulted in a reduced number of potential future collaborators, which further increases competition we face in seeking potential collaborations.

We may not be able to negotiate collaborations on a timely basis, on acceptable terms, or at all. If we are unable to do so, we may have to curtail the development of the product candidate for which we are seeking to collaborate, reduce or delay its development program or one or more of our other development programs, delay its potential commercialization or reduce the scope of any sales or marketing activities or increase our expenditures and undertake development or commercialization activities at our own expense. If we elect to increase our expenditures to fund development or commercialization activities on our own, we may need to obtain additional capital, which may not be available to us on acceptable terms or at all. If we do not have sufficient funds, we may not be able to develop product candidates or bring them to market and generate product revenue.

Risks Related To Our Intellectual Property

If we are unable to obtain and maintain patent and other intellectual property protection for any product candidates we develop and for our Prime Editing technology, or if the scope of the patent and other intellectual property protection obtained is not sufficiently broad, third parties could develop and commercialize products and technology similar or identical to ours and our ability to successfully commercialize any product candidates we may develop and our Prime Editing technology may be adversely affected.

Our commercial success will depend in large part on our ability to obtain and maintain patent, trademark, trade secret and other intellectual property protection of our Prime Editing technology, product candidates and other technology, methods used to manufacture them and methods of treatment, as well as to successfully defend our patent and other intellectual property rights against third-party challenges. It is difficult and costly to protect our Prime Editing technology and product candidates, and we may not be able to ensure their protection. The development of our product candidates and technology is at an early stage and consequently, our patent portfolio is also at an early stage. For example, while we in-license one issued patent, we do not currently own any, or in-license any other, issued patents relating to our technology and product candidates and many of our and our licensors’ patent applications are either at the provisional stage or at an early stage in prosecution. Our ability to stop unauthorized third parties from making, using, selling, offering to sell, importing or otherwise commercializing our product candidates we may develop is dependent upon the extent to which we have established rights under valid and enforceable patents or trade secrets that cover these activities.

We seek to protect our proprietary position by in-licensing intellectual property relating to our platform technology and filing patent applications in the United States and abroad related to our Prime Editing technology and product candidates that are important to our business. If we or our licensors are unable to obtain or maintain patent protection with respect to our Prime Editing technology and product candidates we may develop, or if the scope of the patent protection secured is not sufficiently broad, third parties could develop and commercialize products and technology similar or identical to ours and our ability to commercialize any product candidates we may develop may be adversely affected.

The patent prosecution process is expensive, time-consuming and complex, and we may not be able to file, prosecute, maintain, enforce, defend or license all necessary or desirable patent applications at a reasonable cost or in a timely manner. In addition, we may not pursue or obtain patent protection in all relevant markets. It is also possible that we will fail to identify patentable aspects of our research and development output in time to obtain patent protection. Although we enter into non-disclosure and confidentiality agreements with parties who have access to confidential or patentable aspects of our research and development output, such as our employees, corporate collaborators, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and

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other third parties, any of these parties may breach the agreements and disclose such output before a patent application is filed, thereby jeopardizing our ability to seek patent protection. In addition, our ability to obtain and maintain valid and enforceable patents depends on whether the differences between our inventions and the prior art allow our inventions to be patentable over the prior art. Furthermore, 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 owned or licensed pending patent applications or in-licensed issued patent, or that we or our licensors were the first to file for patent protection of such inventions. If a third party can establish that we or our licensors were not the first to make or the first to file for patent protection of such inventions, our owned or licensed patent applications may not issue as patents and even if issued, may be challenged and invalidated or rendered unenforceable.

The patent position of biotechnology and pharmaceutical companies generally is highly uncertain, involves complex legal and factual questions and has been the subject of much litigation in recent years. The field of genome editing has been the subject of extensive patenting activity and litigation. As a result, the issuance, scope, validity, enforceability and commercial value of our patent rights are highly uncertain and we may become involved in complex and costly litigation. Our pending and future patent applications may not result in patents being issued which protect our Prime Editing technology and product candidates we may develop or which effectively prevent others from commercializing competitive technologies and product candidates. For example, our provisional applications may never result in issued patents. A provisional patent application is not eligible to become an issued patent until, among other things, we file a non-provisional patent application within 12 months of filing the related provisional patent application. If we do not timely file non-provisional patent applications, we may lose our priority dates with respect to our provisional patent applications and any patent protection on the inventions disclosed in our provisional patent applications. While we intend to timely file non-provisional patent applications relating to our provisional patent applications, we cannot predict whether any of our patent applications for our technology and product candidates will result in the issuance of patents that effectively protect our technology and product candidates.Any failure to obtain or maintain patent protection with respect to our technology and product candidates would have a material adverse effect on our business, financial condition, results of operations and prospects.

No consistent policy regarding the scope of claims allowable in the field of genome editing, including for Prime Editing technologies such as our Prime Editing technology, has emerged in the United States. The scope of patent protection outside of the United States is also uncertain. Changes in either the patent laws or their interpretation in the United States and other countries may diminish our ability to protect our inventions, obtain, maintain, enforce and defend our intellectual property rights and, more generally, could affect the value of our intellectual property or narrow the scope of our owned and licensed patent rights. With respect to both in-licensed and owned intellectual property, we cannot predict whether the patent applications we and our licensors are currently pursuing will issue as patents in any particular jurisdiction or whether the claims of any issued patents will be valid and enforceable and provide sufficient protection from third parties.

Moreover, the coverage claimed in a patent application can be significantly reduced before the patent is issued, and its scope can be reinterpreted after issuance. Even if patent applications we license or own currently or in the future issue as patents, they may not issue in a form that will provide us with any meaningful protection, prevent competitors or other third parties from competing with us, or otherwise provide us with any competitive advantage. Any patent applications that we own or in-license may, if issued as patents, be challenged, narrowed, circumvented, or invalidated by third parties. Consequently, we do not know whether any of our platform advances and product candidates we may develop will be protectable or remain protected by valid and enforceable patents. Our competitors or other third parties may be able to circumvent our patents that may be issued from our patent applications by developing similar or alternative technologies or products in a non-infringing manner. In addition, given the amount of time required for the development, testing and regulatory review of new product candidates, patents that may be issued protecting such candidates might expire before or shortly after such candidates are commercialized. As a result, our intellectual property may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

Some of our owned and in-licensed patent applications are, and may in the future be, co-owned with third parties. With respect to any patent applications co-owned by third parties, we may require exclusive licenses to such

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co-owners' interest to such patents. If we are unable to obtain an exclusive license to any such third-party co-owners' interest in such patent applications, we may be unable to prevent such co-owner from licensing their rights under the patent applications to other third parties, including our competitors, and our competitors may be able to market competing products and technology. In addition, we may need the cooperation of any such co-owners of our future patents in order to enforce such future patents against third parties, and such cooperation may not be provided to us.

Our rights to develop and commercialize our Prime Editing platform technology and product candidates are subject to the terms and conditions of licenses granted to us by others. If we fail to comply with our obligations in the agreements under which we license intellectual property rights from third parties or otherwise experience disruptions to our business relationships with our licensors, we could lose license rights that are important to our business.

We do not currently own any issued patents and are heavily reliant upon certain patent rights and proprietary technology we have licensed from third parties that are important or necessary to the development of our Prime Editing technology and product candidates. For example, we are a party to a license agreement with Broad Institute. In September 2019, we entered into a license agreement with Broad Institute, and in May 2020 and February 2021, we entered into amendments to such license agreement. Under the amended license agreement, or the Broad License Agreement, Broad Institute grants us certain rights and licenses under certain patent rights it owns or controls relating to our Prime Editing technology and product candidates. The Broad License Agreement imposes various diligence, milestone payment, royalty, insurance and other obligations on us. Our licenses are subject to Broad Institute’s inclusive innovation model, pursuant to which Broad Institute retains the right, in certain circumstances, to grant to third parties (other than specified competitors of ours) licenses under the licensed patent rights that would otherwise fall within the scope of the exclusive license granted to us. All gene targets, which are any human genes to which a program is directed, are subject to Broad Institute's march-in license, which means Broad Institute has the right to terminate our license to gene targets under certain conditions and could make one or more gene targets unavailable to us. However, once we initiate a program for a gene target, in accordance with the terms of the Broad License Agreement, Broad Institute loses the right to use its march-in license for such gene target, provided we continue to use commercially reasonable efforts to continue to progress such development. As such, we believe Broad Institute cannot exercise its march-in license with respect to any of our current programs for gene targets because such programs have been initiated in accordance with the terms and requirements of the Broad License Agreement. Internally, we determine when a program for a gene target has been initiated by considering factors such as whether a gene target has been identified as the subject of a program, how much time or resources have been dedicated to researching, developing, and/or designing and using reagents for a program, and the amount of preclinical testing in process for such program. For more information regarding the scope of our rights and obligations under the Broad License Agreement, see the section titled “Business—Our License and Collaboration Agreements—License Agreement with Broad Institute.” If we fail to comply with these or other obligations in our current or future license agreements, our licensors may have the right to terminate our license, in which event we would not be able to develop or market our Prime Editing technology or any other technology or product candidates covered by the intellectual property licensed under this agreement. Our business would be seriously harmed if any current or future licenses terminate, if our licensors fail to abide by the terms of the license, if our licensors fail to enforce licensed patents against infringing third parties, if the licensed patents or other rights are found to be invalid or unenforceable, or if we are unable to enter into necessary licenses on acceptable terms. If our license agreements terminate, or we experience a reduction or elimination of licensed rights under these agreements, we may have to negotiate new or reinstated licenses with less favorable terms or we may not have sufficient intellectual property rights to operate our business. Moreover, if certain of our license agreements terminate, we may be required to continue to license or assign certain of our intellectual property to the applicable counterparty.

Certain of the patent rights that we license from Broad Institute are co-owned by Broad Institute with Harvard and certain of the licensed patent rights are co-owned by Broad Institute, Harvard, and Massachusetts Institute of Technology, or MIT. In addition, some of the inventors of the licensed patent and patent applications are or were employees of HHMI, which retains certain rights to patents and patent applications invented by their employees. Our rights to our in-licensed patent and patent applications from Broad Institute are dependent, in part, on inter-institutional or other operating agreements between Broad Institute, Harvard, MIT and HHMI. If Broad Institute, Harvard, MIT or HHMI breaches or terminates such inter-institutional or operating agreements, our rights to such

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in-licensed patent and patent applications may be adversely affected. We have also licensed certain improvements to Prime Editing from Dr. Liu’s laboratory at Broad Institute. For example, Dr. Liu’s laboratory at Broad Institute recently developed engineered pegRNAs, or epegRNAs, which we have exclusively in-licensed. Dr. Liu has entered into an agreement with us pursuant to which he is obligated to assign to us any inventions with respect to the services he performs for us. However, such obligations are subject to limitations and do not extend to his work in other fields or to the intellectual property arising from his employment with Harvard, HHMI and Broad Institute. To obtain such intellectual property rights, we would need to enter into license agreements with such institutions, including negotiations under the Broad Option Agreement, which may expire in November 2022, and such license agreements may not be available on commercially reasonable terms or at all.

Additionally, in September 2019, we established a strategic relationship with Beam Therapeutics, a biotechnology company developing gene editing products using its proprietary base editing technology. Under our license and collaboration agreement with Beam Therapeutics, or the Beam Collaboration Agreement, each party grants to the other certain exclusive and non-exclusive licenses and rights to certain Prime Editing, CRISPR and delivery technologies for use in certain specified fields. Activities performed by Prime and Beam Therapeutics under the Beam Collaboration Agreement may lead to co-owned patents and patent applications. For more information regarding the Broad License Agreement and the Beam Collaboration Agreement and our other material agreements related to our technology, see the section titled “Business—Our License and Collaboration Agreements.”

These and other licenses may not provide exclusive rights to use such intellectual property and technology in all relevant fields of use and in all territories in which we may wish to develop or commercialize our Prime Editing technology and product candidates in the future. Some licenses granted to us are expressly subject to certain preexisting rights held by the licensors or certain third parties. As a result, we may not be able to prevent third parties from developing and commercializing competitive products in certain territories or fields. For example, the rights granted to us under the Broad License Agreement are subject to certain retained rights of Broad Institute, MIT, Harvard, HHMI and the U.S. federal government, and the rights granted to us under the Beam Collaboration Agreement are subject to certain third party agreements and certain rights retained by third parties. Additionally, the Broad License Agreement provides that our field of use is limited to the field of prevention or treatment of human disease, and most licenses granted to us under the Broad License are further limited to the prevention or treatment of human disease by editing (including modifying or converting) or targeting DNA ex vivo, in vivo, or through xeno-transplantation methods and includes other specified exclusions. If we determine that rights to additional fields, including the specifically excluded fields, are necessary to commercialize our product candidates or maintain our competitive advantage, we may need to obtain a license from Broad Institute and/or other third parties in order to continue developing, manufacturing or marketing our product candidates. We may not be able to obtain such a license on an exclusive basis, on commercially reasonable terms, or at all, which could prevent us from commercializing our product candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

We do not control the preparation, filing, prosecution and maintenance of the patents and patent applications covering the technology that we license from Broad Institute or Beam Therapeutics. For example, pursuant to our licenses with Broad Institute and Beam Therapeutics, our licensors retain control of preparation, filing, prosecution and maintenance of their wholly-owned patents and patent applications. We rely on such licensors to determine inventorship and perfect priority of their patent applications. We cannot be certain that these patents and patent applications will be prepared, filed, prosecuted, maintained and defended in a manner consistent with the best interests of our business. If Broad Institute or Beam Therapeutics fails to prosecute or maintain such patents and patent applications or loses rights to such patents and patent applications, the rights we have licensed may be reduced or eliminated, our right to develop and commercialize any of our product candidates we may develop that are the subject of such licensed rights could be adversely affected and we may not be able to prevent third parties from making, using and selling competing products. In addition, we do not control all enforcement of the patents and patent applications we license from Broad Institute. It is possible that our licensors’ enforcement of patents against infringers or defense of such patents against challenges of validity or claims of enforceability may be less vigorous than if we had conducted them ourselves, or may not be conducted in accordance with our best interests.

Our licensors have also relied on third-party collaborators or on funds from third parties such that our licensors are not the sole and exclusive owners of the patent rights we have in-licensed. For example, our optioned patent

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applications directed to the use of MMR inhibition for prime editing is jointly owned by Broad Institute, Harvard, The Trustees of Princeton University, or Princeton, and The Regents of the University of California, or University of California. The exclusivity of such option is solely with respect to Broad Institute and Harvard, and if we are unable to secure licenses to the rights of all co-owners of such patent applications, including Princeton and University of California, the license granted to us in jurisdictions where the consent of a co-owner is necessary to grant such a license may not be valid, and such co-owners for which we do not secure exclusive licenses may be able to license such patent rights to third parties, including our competitors, and such third parties may be able to market competing products and technology.

Furthermore, inventions contained within some of our in-licensed issued patent and patent applications were made using U.S. government funding. We rely on our licensors to ensure compliance with applicable obligations arising from such funding, such as timely reporting, an obligation associated with our in-licensed patent and patent applications. The failure of our licensors to meet their obligations may lead to a loss of rights or the unenforceability of relevant patents that may issue from such applications. For example, the U.S. government could have certain rights in such in-licensed issued patent and patent applications, including a non-exclusive license authorizing the U.S. government to use the invention or to have others use the invention on its behalf. If the U.S. government decides to exercise these rights, it is not required to engage us as its contractor in connection with doing so. The U.S. government’s rights may also permit it to disclose the funded inventions and technology to third parties and to exercise march-in rights to use or allow third parties to use the technology we have licensed that was developed using U.S. government funding. The U.S. government may also exercise its march-in rights if it determines that action is necessary because we or our licensors failed to achieve practical application of the U.S. government-funded technology, because action is necessary to alleviate health or safety needs, to meet requirements of federal regulations, or to give preference to U.S. industry. For example, if the U.S. government determines it is necessary, the U.S. government may exercise its march-in rights and license to third-party manufacturers any or all of our future products or current or future product candidates covered by in-licensed patents and patent applications made using U.S. government funding. In addition, our rights in such in-licensed U.S. government-funded inventions may be subject to certain requirements to manufacture product candidates embodying such inventions in the United States. Any of the foregoing could harm our business, financial condition, results of operations and prospects significantly.

In the event that any of our third-party licensors determines that, in spite of our efforts, we have materially breached a license agreement or have failed to meet certain obligations thereunder, it may elect to terminate the license agreement or, in some cases, one or more license(s) under the applicable license agreement and such termination would result in us no longer having the ability to develop and commercialize product candidates and technology covered by that license agreement or license. In the event of such termination of a third-party in-license, or if the underlying patent rights under a third-party in-license fail to provide the intended exclusivity, third parties may be able to seek regulatory approval of, and to market, products identical to ours. Moreover, our licensors may own or control intellectual property that has not been licensed to us and, as a result, we may be subject to claims, regardless of their merit, that we are infringing or otherwise violating the licensor’s rights. Any of these events could have a material adverse effect on our competitive position, business, financial conditions, results of operations and prospects.

Pursuant to our license agreements with Beam Therapeutics and Broad Institute, we are generally responsible for bringing any actions against any third party for infringing on certain of the patent rights we have licensed from such counterparty, subject to certain conditions.Certain provisions of the Broad License Agreement also require us to meet development thresholds within specified timeframes to maintain the license, including establishing a set timeline for developing and commercializing products, while some provisions of the Beam Collaboration Agreement require us to use commercially reasonable efforts to conduct development activities for collaboration products. For more information regarding the scope of our rights and obligations under the Broad License Agreement and the Beam Collaboration Agreement, see the section titled “Business—Our License and Collaboration Agreements.”In spite of our efforts, Broad Institute, Beam Therapeutics, or any future licensor from whom we may seek to license intellectual property rights might conclude that we have materially breached our obligations under such license agreements and might therefore terminate the license agreements, thereby removing or limiting our ability to develop and commercialize products and technology covered by these license agreements. If these in-licenses are

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terminated, or if the underlying patent rights fail to provide the intended exclusivity, competitors or other third parties may be able to seek regulatory approval of, and to market, products identical to ours and we may be required to cease our development and commercialization of our Prime Editing technology or product candidates. Any of the foregoing could have a material adverse effect on our competitive position, business, financial condition, results of operations and growth prospects. Disputes may arise regarding intellectual property subject to a licensing agreement, including:

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

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

•the sublicensing of patent rights to third parties under our collaborative development relationships;

•our diligence obligations under the license agreement 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;

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

•the priority of invention of patented technology.

In addition, the agreements under which we currently license intellectual property rights from Beam Therapeutics and Broad Institute are complex, and certain provisions in such agreements may be susceptible to multiple interpretations. The resolution of any contract interpretation disagreement that may arise under our existing license agreements or future license agreements into which we may enter could narrow what we believe to be the scope of our rights to the relevant intellectual property or technology or broaden what we believe to be the scope of the licensor’s rights to our intellectual property and technology, or increase what we believe to be our financial or other obligations under the relevant agreement, any of which could have a material adverse effect on our business, financial condition, results of operations and prospects. For example, we have exclusively licensed and sublicensed certain of our owned and licensed intellectual property rights to Beam Therapeutics under the Beam Collaboration Agreement in certain fields. Such agreement may be susceptible to multiple interpretations and the resolution of any contract interpretation disagreement could expand the field of exclusivity or other rights we have granted to Beam Therapeutics and therefore, narrow our field of exclusivity or rights with respect to such licensed intellectual property rights. Moreover, if disputes over intellectual property that we have licensed prevent or impair our ability to maintain our current licensing arrangements on commercially acceptable terms, we may be unable to successfully develop and commercialize the affected product candidates. As a result, any termination of or disputes over our intellectual property licenses could result in the loss of our ability to develop and commercialize our Prime Editing technology or other product candidates or we could lose other significant rights, any of which could have a material adverse effect on our business, financial conditions, results of operations and prospects. It is also possible that a third party could be granted limited licenses to some of the same technology, in certain circumstances.

Our in-licensed issued patent and owned and in-licensed patent applications may not provide sufficient protection of our Prime Editing technologies and our future product candidates or result in any competitive advantage.

We have in-licensed an issued U.S. patent and own and have in-licensed a number of patent applications that cover Prime Editing and related technologies. We and our licensors have filed patent applications intended to specifically cover our Prime Editing technology and uses with respect to treatment of particular diseases and conditions. While we in-license one issued patent, we do not currently own any, or in-license any other, issued U.S. patents.

Our in-licensed issued U.S. patent contains claims directed to methods of using Prime Editors. Our owned and in-licensed patent applications contain claims directed to compositions of matter for our Prime Editing product candidates, as well as methods directed to the use of such product candidates for gene therapy treatment. Method-of-use patents do not prevent a competitor or other third party from developing or marketing an identical product for an

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indication that is outside the scope of the patented method. Moreover, with respect to method-of-use patents, even if competitors or other third parties do not actively promote their product for our targeted indications or uses for which we may obtain patents, providers may recommend that patients use these products off-label, or patients may do so themselves.

The strength of patents in the biotechnology and pharmaceutical field involves complex legal and scientific questions and can be uncertain. The issuance of a patent is not conclusive as to its inventorship, scope, validity, or enforceability, and our or our licensors’ current and future patents may be challenged in the courts or patent offices in the United States and abroad. The patent applications that we own or in-license may fail to result in issued patents with claims that cover our product candidates or uses thereof in the United States or in other foreign countries. For example, while our or our licensors’ patent applications are pending, such patent applications may now or in the future be subject to a third party pre-issuance submission of prior art to the USPTO, or become involved in interference or derivation proceedings or equivalent proceedings in foreign jurisdictions. For example, prior art was submitted by a third party with respect to certain of our PCT patent applications in-licensed from Broad Institute directed to Prime Editing. Third parties may challenge their inventorship, priority of invention, validity, enforceability or scope of our in-licensed patent and our or our licensors’ patent applications that successfully issue, including through opposition, revocation, reexamination, post-grant and inter partes review proceedings and litigation. Moreover, we, or one of our licensors, may have to participate in interference proceedings declared by the USPTO to determine priority of invention or in post grant challenge proceedings, such as oppositions in a foreign patent office, that challenge priority of invention or other features of patentability. An adverse determination in any such submission, proceeding or litigation may result in loss of patent rights, loss of exclusivity, or in patent claims being narrowed, invalidated, or held unenforceable, which could limit our ability to stop others from using or commercializing similar or identical technology and products, allow third parties to commercialize our technology or product candidates and compete directly with us, without payment to us, limit the duration of the patent protection of our technology and product candidates, or result in our inability to manufacture or commercialize products without infringing third-party patent rights. Furthermore, even if they are unchallenged, our patent rights may not adequately protect our intellectual property or prevent others from designing around our platform technology or product candidates. If the breadth or strength of protection provided by our in-licensed patent or patents that may issue from the patent applications we own or in-license with respect to our Prime Editing technology and product candidates is threatened, it could dissuade companies from collaborating with us to develop, and threaten our ability to commercialize, our product candidates. Further, if we encounter delays in development, testing and regulatory review of new product candidates, the period of time during which we could market our product candidates under patent protection would be reduced.

Given that patent applications in the United States and other countries are confidential for a period of time after filing, at any moment in time, we cannot be certain that we or our licensors were in the past or will be in the future the first to file any patent application related to our Prime Editing technology or product candidates. In addition, some patent applications in the United States may be maintained in secrecy until the patents are issued. As a result, there may be prior art of which we or our licensors are not aware that may affect the validity or enforceability of a patent claim, and we or our licensors may be subject to priority disputes. For our in-licensed patent portfolios, we rely on our licensors to determine inventorship and to obtain and file inventor assignments of priority applications before their conversion as PCT applications. A failure to do so in a timely fashion may give rise to a challenge to entitlement of priority for foreign applications nationalized from such PCT applications. We or our licensors may in the future become a party to proceedings or priority disputes in Europe or other foreign jurisdictions. The loss of priority for, or the loss of, any European or other foreign patent rights could have a material adverse effect on the conduct of our business.

We may be required to disclaim part or all of the term of certain patents that may issue from our owned or in-licensed patent applications. There may be prior art of which we are not aware that may affect the validity or enforceability of a patent claim. There also may be prior art of which we or our licensors are aware, but which we or our licensors do not believe affects the validity or enforceability of a claim, which may, nonetheless, ultimately be found to affect the validity or enforceability of a claim. No assurance can be given that, if challenged, our in-licensed patent and patent applications, if issued, would be declared by a court, patent office or other governmental authority to be valid or enforceable, or that even if the patent claims were found to be not invalid or unenforceable, a

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third party’s technology or product would be found by a court to infringe our patent rights. Moreover, even if our in-licensed patent and patent applications, if issued, are declared to be valid and enforceable and a third party’s technology or product found to infringe our patent rights, a court or other governmental authority may refuse to prevent a third party’s technology or product from being marketed, and the court or governmental authority would determine the royalty rate to be paid by the third party to us. We analyze patents or patent applications of third parties that we believe are relevant to our activities, but third parties may achieve issued claims, including in patents we consider to be unrelated, that block our efforts or potentially result in our product candidates or our activities infringing such claims. It is possible that third parties may have filed, and may in the future file, patent applications covering our products or gene editing technology similar to ours. Those patent applications may have priority over our in-licensed patent and owned and in-licensed patent applications, which could require us to obtain rights to issued patents covering such technologies. The possibility also exists that others will develop products that have the same effect as our product candidates on an independent basis that do not infringe our in-licensed patent or patents that may issue from our own or in-licensed patent applications, or other intellectual property rights, or will design around the claims of our in-licensed patent or our patents that may issue from our owned or in-licensed patent applications that cover our product candidates.

Likewise, our in-licensed issued patent and currently owned and in-licensed patent applications, if issued as patents, directed to our in-licensed and company-owned Prime Editing technologies and our product candidates are expected to expire between 2040 and 2043, without taking into account any possible patent term adjustments or extensions. Our in-licensed issued patent, or owned or in-licensed patent applications, if issued as patents, may expire before, or soon after, our first product candidate achieves marketing approval in the United States or foreign jurisdictions. Additionally, no assurance can be given that the USPTO or relevant foreign patent offices will grant any of the pending patent applications we own or in-license currently or in the future. Upon the expiration of such patents that may issue from our current owned or in-licensed patent applications, we may lose the right to exclude others from practicing these inventions. The expiration of these patent rights could also have a similar material adverse effect on our business, financial condition, results of operations and prospects.

Our in-licensed issued patent and owned and in-licensed patent applications and other intellectual property may be subject to priority, inventorship or ownership disputes and similar proceedings. If we or our licensors are unsuccessful in any of these proceedings, we may be required to obtain licenses from third parties, which may not be available on commercially reasonable terms or at all, or to cease the development, manufacture and commercialization of one or more of our product candidates, which could have a material adverse impact on our business.

We or our licensors may be subject to claims that former employees, collaborators, or other third parties have an interest in our in-licensed issued patent or owned or in-licensed patent applications or other intellectual property as an inventor or co-inventor. If we or our licensors are unsuccessful in any interference proceedings or other priority, validity (including any patent oppositions), inventorship or ownership disputes to which we or they are subject, we may lose valuable intellectual property rights through the loss of part or all of our owned or licensed patent rights, the loss of exclusive ownership of or the exclusive right to use our owned or in-licensed patent rights, or the narrowing, invalidation, or unenforceability of our or our licensors’ patent claims. In the event of loss of patent rights as a result of any of these disputes, we may be required to obtain and maintain licenses from third parties, including parties involved in any such interference proceeding or other priority, inventorship or ownership disputes. Such licenses may not be available on commercially reasonable terms or at all, or may be non-exclusive. If we are unable to obtain and maintain such licenses, we may need to cease the development, manufacture and commercialization of one or more of our product candidates. The loss of exclusivity or the narrowing of our patent rights could limit our ability to stop others from using or commercializing similar or identical technology and product candidates. Even if we or our licensors are successful in an inventorship or ownership dispute, it could result in substantial costs and be a distraction to management and other employees. Any of the foregoing could result in a material adverse effect on our business, financial condition, results of operations, or prospects.

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We have limited foreign intellectual property rights and may not be able to protect our intellectual property and proprietary rights throughout the world.

We have limited intellectual property rights outside the United States. Filing, prosecuting and defending patents on our Prime Editing technologies and product candidates in all countries throughout the world would be prohibitively expensive and our intellectual property rights in some countries outside the United States can be less extensive than those in the United States. The laws of foreign countries do not protect intellectual property rights to the same extent as federal and state laws of the United States, even in jurisdictions where we or our licensors do pursue patent protection. In addition, our intellectual property license agreements may not always include worldwide rights. Consequently, we or our licensors may not be able to prevent third parties from practicing our inventions in all countries outside the United States, or from selling or importing products made using our inventions in and into the United States or other jurisdictions. Third parties may use our technologies in jurisdictions where we have not obtained patent protection to develop their own products and, further, may export otherwise infringing products to territories where we have patent protection but where enforcement is not as strong as that in the United States. These products may compete with our product candidates and patents that may issue from our or our licensors’ pending patent applications 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 and pharmaceutical products, which could make it difficult for us to stop the infringement of our future patents or marketing of competing products by third parties in violation of our intellectual property and proprietary rights generally. Proceedings to enforce our future patents or our licensors’ patent or future patents and intellectual property rights in foreign jurisdictions could result in substantial costs and divert our efforts and attention from other aspects of our business, could put our future patents or our licensors’ patent or future patents at risk of being invalidated or interpreted narrowly and our or our licensors’ patent applications at risk of not issuing and could provoke third parties to assert claims against us or our licensors. We may not prevail in any lawsuits that we or our licensors initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Moreover, the initiation of proceedings by third parties to challenge the scope or validity of our or our licensors’ patent rights in foreign jurisdictions could result in substantial cost and divert our efforts and attention from other aspects of our business. Accordingly, our or our licensors’ efforts to enforce our or our licensors’ intellectual property and proprietary rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that we develop or license.

Many countries have compulsory licensing laws under which a patent owner may be compelled to grant licenses to third parties. In addition, many countries limit the enforceability of patents against government agencies or government contractors. In these countries, the patent owner may have limited remedies, which could materially diminish the value of such patent. If we or our licensors are forced to grant one or more licenses to third parties with respect to any patent or future patents relevant to our business, our competitive position may be impaired, and our business, financial condition, results of operations and prospects may be adversely affected.

We may not be successful in acquiring or in-licensing necessary rights to key technologies or any product candidates we may develop.

We currently have rights to intellectual property, through licenses from third parties, to identify and develop product candidates, and we expect to seek to expand our product candidate pipeline in part by in-licensing additional rights to key technologies. The future growth of our business will depend in part on our ability to in-license or otherwise acquire the rights to additional product candidates and technologies. Although we have succeeded in licensing technologies from Beam Therapeutics and Broad Institute in the past, we cannot guarantee that we will be able to in-license or acquire additional rights to any product candidates or technologies from Beam Therapeutics, Broad Institute, or other third parties on acceptable terms or at all. For example, Broad Institute is developing improvements to the Prime Editing technology for which we may find it necessary or useful to obtain a license. In addition, our agreements with Beam Therapeutics and Broad Institute provide that our fields of use excludes particular fields. If we determine that rights to such fields are necessary to commercialize our technology or product

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candidates or maintain our competitive advantage, we may need to obtain a license from Beam Therapeutics or Broad Institute in order to continue developing, manufacturing or marketing our technology or product candidates. In addition, we may seek to obtain additional licenses from our licensors and, in connection with obtaining such licenses, we may agree to amend our existing licenses in a manner that may be more favorable to the licensors, including by agreeing to terms that could enable third parties (potentially including our competitors) to receive licenses to a portion of the intellectual property that is subject to our existing licenses. Additionally, upon our finalization of our product candidates, we may determine that there are third parties who possess technologies related to gene editing or other technologies which we may need to in-license, including intellectual property covering the use of Cas proteins and reverse transcriptases. We may not be able to obtain such a license on an exclusive basis, on commercially reasonable terms, or at all, which could prevent us from commercializing our product candidates or allow our competitors or other third parties the chance to access technology that is important to our business.

Furthermore, there has been extensive patenting activity in the field of gene editing. Pharmaceutical companies, biotechnology companies and academic institutions are competing with us or are expected to compete with us in the in the field of gene editing technology and filing patent applications potentially relevant to our business and we are aware of certain third-party patent applications that, if issued, may allow the third party to circumvent our patent rights. For example, we are aware of several third-party patents and patent applications, that if issued, may be construed to cover or be relevant to our Prime Editing technology and product candidates. In order to market our product candidates, we may find it necessary or prudent to obtain licenses from such third-party intellectual property holders. However, we may be unable to secure such licenses or otherwise acquire or in-license any compositions, methods of use, processes, or other intellectual property rights from third parties that we identify as necessary for product candidates we may develop and our Prime Editing technology. We may also require licenses from third parties for certain additional technologies, including technologies relating to Prime Editing, such as guide RNA modification, target sequences, Cas proteins such as Cas9, reverse transcriptases, as well as delivery technologies for product candidates we may develop.

Additionally, we may collaborate with academic institutions to accelerate our research or development under written agreements with these institutions. In certain cases, these institutions may provide us with an option to negotiate a license to any of the institution’s rights in technology resulting from the collaboration. Even if we hold such an option, we may be unable to negotiate a license from the institution within the specified timeframe or under terms that are acceptable to us. If we are unable to do so, such institution may offer the intellectual property rights to others, potentially blocking our ability to pursue our program.

The licensing or acquisition of third-party intellectual property rights is a highly competitive area, and a number of more established companies are also pursuing strategies to license or acquire third-party intellectual property rights that we may consider attractive or necessary. These established companies may have a competitive advantage over us due to their size, capital resources and greater clinical development and commercialization capabilities. In addition, companies that perceive us to be a competitor may be unwilling to assign or license rights to us. We also may be unable to license or acquire third-party intellectual property rights on terms that would allow us to make an appropriate return on our investment or at all. If we are unable to successfully obtain rights to required third party intellectual property rights or maintain the existing intellectual property rights we have, we may have to abandon development of the relevant program or product candidate, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

The intellectual property landscape around the technologies we use or plan to use, including gene editing technology, is highly dynamic, and third parties may initiate legal proceedings alleging that we are infringing, misappropriating, or otherwise violating their intellectual property rights, the outcome of which would be uncertain and may prevent, delay or otherwise interfere with our product discovery and development efforts.

The field of gene editing is still in its infancy, and no such therapeutic product candidates have reached the market. Due to the intense research and development that is taking place by several companies, including us and our competitors, in this field, the intellectual property landscape is evolving and in flux, and it may remain uncertain for the coming years. There may be significant intellectual property related litigation and proceedings relating to our owned and in-licensed, and other third-party, intellectual property and proprietary rights in the future.

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Our commercial success depends upon our ability and the ability of our collaborators and present and future licensees to develop, manufacture, market and sell any product candidates that we may develop and use our proprietary technologies without infringing, misappropriating, or otherwise violating the intellectual property and proprietary rights of third parties. The biotechnology and pharmaceutical industries are characterized by extensive litigation regarding patents and other intellectual property rights as well as administrative proceedings for challenging patents, including interference, derivation, inter partes review, post grant review and reexamination proceedings before the USPTO or oppositions and other comparable proceedings in foreign jurisdictions. We may be subject to and may in the future become party to, or threatened with, adversarial proceedings or litigation regarding intellectual property rights with respect to our Prime Editing technology and product candidates we may develop, including interference proceedings, post-grant review, inter partes review and derivation proceedings before the USPTO and similar proceedings in foreign jurisdictions such as oppositions before the European Patent Office, or EPO. Numerous U.S. and foreign issued patents and pending patent applications that are owned by third parties exist in the fields in which we are developing our product candidates and they may assert infringement claims against us based on existing patents or patents that may be granted in the future, regardless of their merit.

As the biotechnology and pharmaceutical industries expand and more patents are issued, the risk increases that our Prime Editing technology and product candidates may give rise to claims of infringement of the patent rights of others. Moreover, it is not always clear to industry participants, including us, which patents cover various types of therapies, products or their methods of use or manufacture. There may be third-party patents of which we are currently unaware with claims to technologies, methods of manufacture or methods for treatment related to the use or manufacture of our product candidates. Because patent applications can take many years to issue, there may be currently pending patent applications that may later result in issued patents that our product candidates may infringe. In addition, third parties may obtain patents in the future and claim that use of our technologies infringes upon these patents.

Numerous third-party U.S. and foreign issued patents and pending patent applications exist in the fields in which we are developing product candidates. Our product candidates make use of CRISPR-based technology, which is a field that is highly active for patent filings. As of June 2019, it was reported that approximately 2072 patent families worldwide related to CRISPR gene editing inventions and their uses.The extensive patent filings related to CRISPR make it difficult for us to assess the full extent of relevant patents and pending applications that may cover our Prime Editing technology and product candidates and their use or manufacture. There may be third-party patents or patent applications with claims to materials, formulations, methods of manufacture or methods for treatment related to the use or manufacture of our Prime Editing platform technology and product candidates. We are aware of multiple patents and patent applications directed to CRISPR technologies, Cas molecules, including Cas9, and their uses in gene editing. For example, we are aware of a patent portfolio that is co-owned by the University of California, University of Vienna and Emmanuelle Charpentier, which we refer to together as CVC, which contains multiple patents and pending applications directed to gene editing. We are also aware of patents and patent applications directed to gene editing owned or co-owned by Broad Institute, MIT, Rockefeller University and Harvard, which we refer to together as the Boston Licensing Parties, Toolgen Inc. and Sigma-Aldrich. Additional patents and patent applications that we are aware of and directed to gene-editing are owned or co-owned by The General Hospital Corporation, BASF, SNIPR Technologies Ltd., Novartis, Columbia University, Agilent Technologies, Thermo Fisher Scientific, Life Technologies Corporation and Intellia.

Our ability to commercialize our product candidates may be adversely affected if we require but cannot obtain a license to these patents. 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 nonexclusive, thereby giving our competitors and other third parties access to the same technologies licensed to us, and it could require us to make substantial licensing and royalty payments. If we are unable to obtain a necessary license to a third-party patent on commercially reasonable terms, we may be unable to commercialize our Prime Editing technology or product candidates or such commercialization efforts may be significantly delayed, which could in turn significantly harm our business.

Several patents and pending applications with claims directed to foundational aspects of gene editing are currently involved in interference proceedings at the USPTO. The Patent Trial and Appeal Board, or PTAB, of the USPTO declared a second interference between 10 pending applications co-owned by the CVC and 13 patents and one pending application co-owned by the Boston Licensing Parties on June 24, 2019, after the first interference

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between the two parties was terminated in 2018. Toolgen subsequently joined the patent dispute and two more interferences were declared in December 2020, between a pending application owned by Toolgen and several pending applications co-owned by the CVC or patents and pending applications co-owned by the Boston Licensing Parties. In June 2021, two additional interferences were declared between patents and applications co-owned by the Boston Licensing Parties or pending applications co-owned by the CVC and pending applications owned by Sigma-Aldrich. It is presently unclear who will prevail in these proceedings and own or partially own the patents subject to such interferences. If it is necessary for us to obtain a license to one or more of the patents currently involved in such interference proceedings, such patents may not be available to license on commercially reasonable termsor at all. For example, we are aware that the Boston Licensing Parties and CVC have previously licensed certain of such patents to third parties. Our ability to commercialize our product candidates in the United States and abroad may be adversely affected if we cannot obtain a license on commercially reasonable terms to relevant third-party patents that cover our product candidates or Prime Editing technology.

Because of the large number of patents issued and patent applications filed in our field, third parties may allege they have patent rights encompassing our product candidates, technologies or methods. Third parties may assert that we are employing their proprietary technology without authorization and may file patent infringement claims or lawsuits against us, and if we are found to infringe such third-party patents, we may be required to pay damages, cease commercialization of the infringing technology, or obtain a license from such third parties, which may not be available on commercially reasonable terms or at all. In addition, we have in the past, and may in the future, receive an offer for license from third parties regarding their proprietary intellectual property for which they may believe encompass our product candidates and technologies. We will evaluate such offers for relevance to our business.

Even if we believe third-party claims that we or our technology or product candidates are infringing, misappropriating or otherwise violating such third party's intellectual property are without merit, there is no assurance that a court would find in our favor on questions of infringement, validity, enforceability, or priority. A court of competent jurisdiction could hold that these third-party patents are valid, enforceable and infringed, which could materially and adversely affect our ability to commercialize our product candidates and any other product candidates or technologies covered by the asserted third-party patents. In order to successfully challenge the validity of any such U.S. patent in federal court, we would need to overcome a presumption of validity. As this burden is a high one requiring us to present clear and convincing evidence as to the invalidity of any such U.S. patent claim, there is no assurance that a court of competent jurisdiction would invalidate the claims of any such U.S. patent. Further, even if we were successful in defending against any such claims, such claims could require us to divert substantial financial and management resources that we would otherwise be able to devote to our business. If we are found to infringe a third party’s intellectual property rights, and we are unsuccessful in demonstrating that such patents are invalid or unenforceable, we could be forced, including by court order, to cease developing, manufacturing and commercializing the infringing technology or product candidates. In addition, we could be found liable for significant monetary damages, including treble damages and attorneys’ fees, if we are found to have willfully infringed a patent or other intellectual property right. We also could be required to obtain a license from such third party to continue developing, manufacturing and marketing product candidates we may develop and our technology. 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 and other third parties access to the same technologies licensed to us, and it could require us to make substantial licensing and royalty payments. If we are unable to obtain a necessary license to a third-party patent on commercially reasonable terms, we may be unable to commercialize our Prime Editing technology or product candidates or such commercialization efforts may be significantly delayed, which could in turn significantly harm our business. Claims that we have misappropriated the confidential information or trade secrets of third parties could have a similar material adverse effect on our business, financial condition, results of operations and prospects.

In addition, our agreements with certain suppliers with whom we do business require us to defend or indemnify such parties to the extent they become involved in patent infringement claims.We could also voluntarily agree to defend or indemnify third parties in instances where we are not obligated to do so if we determine it would be important to our business relationships. If we are required or agree to defend or indemnify third parties in connection with any infringement claims, we could incur significant costs and expenses that could adversely affect our business, operating results or financial condition.

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Defense of third-party claims of infringement of misappropriation, or violation of intellectual property rights involves substantial litigation expense and would be a substantial diversion of management and employee time and resources from our business. Some third parties may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. In addition, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on our ability to raise the funds necessary to continue our operations or could otherwise have a material adverse effect on our business, financial condition, results of operations and prospects. There could also 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 common stock. Any of the foregoing events could have a material adverse effect on our business, financial condition, results of operations and prospects.

We may become involved in lawsuits to protect or enforce our future patents, or the issued patents or future patents of our licensors, which could be expensive, time consuming and unsuccessful and could result in a finding that such patents are unenforceable or invalid.

Competitors and other third parties may infringe, misappropriate or otherwise violate our future patents or the patent or future patents of our licensors, or we may be required to defend against claims of infringement, misappropriation or other violation. In addition, our future patents, or the issued or future patents of our licensors also may become involved in inventorship, priority, validity or enforceability disputes. Countering or defending against such claims can be expensive and time consuming. In an infringement proceeding, a court may decide that a patent owned or in-licensed by us is invalid or unenforceable, or may refuse to stop the other party from using the technology at issue on the grounds that our future owned patents and in-licensed patent and future patents do not cover the technology in question. An adverse result in any litigation proceeding could put one or more of our future owned patents or in-licensed patent or future patents at risk of being invalidated or interpreted narrowly.

In patent litigation in the United States, defendant counterclaims alleging invalidity and/or unenforceability are commonplace, and there are numerous grounds upon which a third party can assert invalidity or unenforceability of a patent. Grounds for a validity challenge could be an alleged failure to meet any of several statutory requirements, including lack of novelty, obviousness, or non-enablement. Grounds for an unenforceability assertion could be an allegation that someone connected with prosecution of the patent withheld relevant information from the USPTO, or made a misleading statement, during prosecution. Third parties may also raise similar claims before administrative bodies in the United States or abroad, even outside the context of litigation. These types of mechanisms include re-examination, post-grant review, inter partes review, interference proceedings, derivation proceedings and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings). These types of proceedings could result in revocation or amendment to our in-licensed patent or future patents such that they no longer cover our product candidates. The outcome for any particular patent following legal assertions of invalidity and unenforceability is unpredictable. With respect to the validity question, for example, we cannot be certain that there is no invalidating prior art, of which we, our licensor, our patent counsel and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity and/or unenforceability, or if we are otherwise unable to adequately protect our rights, we would lose at least part, and perhaps all, of the patent protection on our technology and/or product candidates. Defense of these types of claims, regardless of their merit, would involve substantial litigation expense and would be a substantial diversion of employee resources from our business.

Conversely, we may choose to challenge the patentability of claims in a third party’s U.S. patent by requesting that the USPTO review the patent claims in re-examination, post-grant review, inter partes review, interference proceedings, derivation proceedings and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings). We may choose to challenge third-party patents in patent opposition proceedings in the EPO or another foreign patent office. Even if successful, the costs of these opposition proceedings could be substantial and may consume our time or other resources. If we fail to obtain a favorable result at the USPTO, EPO or other patent office then we may be exposed to litigation by a third party alleging that their patent may be infringed by our product candidates, Prime Editing technology or other proprietary technologies.

Even if resolved in our favor, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our personnel from their normal responsibilities.

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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 this type of 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 common stock. Such litigation or proceedings could substantially increase our operating losses and reduce the resources available for development activities or any future sales, marketing, or distribution activities. We may not have sufficient financial or other resources to conduct such litigation or proceedings adequately. Certain third parties, including 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. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could have a material adverse effect on our ability to compete in the marketplace.

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

Periodic maintenance fees, renewal fees, annuity fees and various other government fees on patents and applications are due to be paid to the USPTO and foreign patent agencies outside of the United States over the lifetime of our in-licensed patent, owned or licensed patent applications and patents that may issue from such applications. In certain circumstances, we rely on our licensors to pay these fees due to U.S. and non-U.S. patent agencies. The USPTO and foreign patent agencies require compliance with several procedural, documentary, fee payment and other similar provisions during the patent application process. We are also dependent on our licensors to take the necessary action to comply with these requirements with respect to our licensed intellectual property. While an inadvertent lapse or non-compliance with such requirements can sometimes be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which non-compliance can result a partial or complete loss of patent rights in the relevant jurisdiction. Were a noncompliance event to occur, third parties might be able to enter the market with similar or identical products or technology, which could have a material adverse effect on our business, financial condition, results of operations and prospects.

Changes in patent law in the United States and in non-U.S. jurisdictions could diminish the value of patents in general, thereby impairing our ability to protect our Prime Editing platform technology and product candidates.

As is the case with other biotech and pharmaceutical companies, our success is heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biopharmaceutical industry involve both technological and legal complexity, and is therefore costly, time-consuming and inherently uncertain.

Changes in either the patent laws or interpretation of the patent laws could increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of our issued in-licensed patent and future issued patents. For example, in March 2013, under the Leahy-Smith America Invents Act, or the America Invents Act, the United States transitioned from a “first to invent” to a “first-to-file” patent system. Under a “first-to-file” system, assuming that other requirements for patentability are met, the first inventor to file a patent application generally will be entitled to a patent on an invention regardless of whether another inventor had made the invention earlier. A third party that files a patent application in the USPTO after March 2013, but before us could therefore be awarded a patent covering an invention of ours even if we had made the invention before it was made by such third party. This will require us to be cognizant going forward of the time from invention to filing of a patent application. Since patent applications in the United States and most other countries are confidential for a period of time after filing or until issuance, we cannot be certain that we or our licensors were the first to either file any patent application related to our technology or product candidates or invent any of the inventions claimed in our or our licensors’ patent applications. The America Invents Act also includes a number of other significant changes to U.S. patent law, including provisions that affect the way patent applications will be prosecuted, allowing third party submission of prior art and establishing a new post-grant review system including post-grant review, inter partes review and derivation proceedings. Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in U.S. federal courts necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though

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the same evidence would be insufficient to invalidate the claim if first presented in a district court action. Accordingly, a third party may attempt to use the USPTO procedures to invalidate our patent claims that would not have been invalidated if first challenged by the third party as a defendant in a district court action. The effects of these changes are currently unclear as the USPTO continues to promulgate new regulations and procedures in connection with the America Invents Act and many of the substantive changes to patent law, including the “first-to-file” provisions, only became effective in March 2013. In addition, the courts have yet to address many of these provisions and the applicability of the act and new regulations on the specific patents discussed in this filing have not been determined and would need to be reviewed. However, the America Invents Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our patent applications and the enforcement or defense of our issued in-licensed patent and future issued patents.

In addition, recent U.S. Supreme Court rulings have narrowed the scope of patent protection available in certain circumstances and weakened 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 validity and enforceability of patents, once obtained. Depending on future actions 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 new patents or to enforce patents that we or our licensors have obtained or might obtain in the future. For example, in the case, Assoc. for Molecular Pathology v. Myriad Genetics, Inc., the U.S. Supreme Court held that certain claims to DNA molecules are not patentable. We cannot predict how this and future decisions by the courts, the U.S. Congress or the USPTO may impact the value of our or our licensors’ patent or patent applications. Similarly, foreign courts have made, and will likely continue to make, changes in how the patent laws in their respective jurisdictions are interpreted. We cannot predict future changes in the interpretation of patent laws or changes to patent laws that might be enacted into law by U.S. and foreign legislative bodies. Any similar adverse changes in the patent laws of other jurisdictions could also have a material adverse effect on our business, financial condition, results of operations and prospects.

Patent terms may be inadequate to protect our competitive position on our product candidates for an adequate amount of time.

Patents have a limited lifespan. The terms of individual patents depend upon the legal term for patents in the countries in which they are granted. In most countries, including the United States, if all maintenance fees are timely paid, the natural expiration of a patent is generally 20 years from its earliest non-provisional filing date in the applicable country. However, the actual protection afforded by a patent varies from country to country and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions, the availability of legal remedies in a particular country and the validity and enforceability of the patent. Various extensions including patent term extensions, or PTEs, and patent term adjustments, or PTAs, may be available, but the life of a patent and the protection it affords is limited. For more information regarding PTA and PTE, see the section titled“Business—Intellectual Property.” Even if patents covering our product candidates are obtained, once the patent life has expired, we may be open to competition from competitive products, including generics or biosimilars. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting our product candidates might expire before or shortly after we or our partners commercialize those candidates. As a result, our owned and licensed patent portfolio may not provide us with sufficient rights to exclude others from commercializing products similar or identical to ours.

If we do not obtain PTE and data exclusivity for any product candidates we may develop, our business may be materially harmed.

Depending upon the timing, duration and specifics of any FDA marketing approval of product candidates we may develop, one or more of our U.S. patents may be eligible for limited PTE under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Amendments. The Hatch-Waxman Amendments provides a PTE term of up to five years as compensation for patent term lost during the FDA regulatory review process. A PTE cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, only one patent per product may be extended and only those claims covering the approved product, a method for using it, or a method for manufacturing it may be extended. However, even if we were to seek a PTE, it may not be granted because of, for example, the failure to exercise due diligence during the testing phase or

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regulatory review process, the failure to apply within applicable deadlines, the failure to apply prior to expiration of relevant patents, or any other failure to satisfy applicable requirements. Moreover, the applicable time period or the scope of patent protection afforded could be less than we request. In addition, to the extent we wish to pursue a PTE based on a patent that we in-license from a third party, we would need the cooperation of that third party, which may not be available. If we are unable to obtain PTE or term of any such extension is less than we request, third parties may obtain approval of competing products following our patent expiration, and our business, financial condition, results of operations and prospects could be materially harmed.

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 protection for our technology and product candidates, we also rely on know-how and trade secret protection, as well as confidentiality agreements, non-disclosure agreements and invention assignment agreements with our employees, consultants and third-parties, to protect our confidential and proprietary information, especially where we do not believe patent protection is appropriate or obtainable.

It is our policy to require our employees, corporate collaborators, outside scientific collaborators, CROs, contract manufacturers, consultants, advisors and other third parties to execute confidentiality agreements upon the commencement of employment or consulting relationships with us. These agreements generally provide that all confidential information concerning our business or financial affairs developed by or made known to the individual or entity during the course of the party’s relationship with us is to be kept confidential and not disclosed to third parties, except in certain specified circumstances. In the case of employees, the agreements generally provide that all inventions conceived by the individual, and that are related to our current or planned business or research and development or made during normal working hours, on our premises or using our equipment or proprietary information, are our exclusive property. In the case of consultants and other third parties, the agreements generally provide that all inventions conceived in connection with the services provided are our exclusive property. However, we cannot guarantee that we have entered into such agreements with each party that may have or have had access to our trade secrets or proprietary technology and processes or who were involved in the development of intellectual property. Additionally, the assignment of intellectual property rights may not be self-executing, or the assignment agreements may be breached, and we may be forced to bring claims against third parties, or defend claims that they may bring against us, to determine the ownership of what we regard as our intellectual property. Any of these parties may breach the agreements and disclose our proprietary information, including our trade secrets, and we may not be able to obtain adequate remedies for such breaches. We may not be able to prevent the unauthorized disclosure or use of our technical know-how or other trade secrets by the parties to these agreements. Monitoring unauthorized uses and disclosures is difficult and we do not know whether the steps we have taken to protect our proprietary technology will be effective. 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 to contractual measures, we try to protect the confidential nature of our proprietary information through other appropriate precautions, such as physical and technological security measures. However, trade secrets and know-how can be difficult to protect and we do not have a formal trade secret policy at this time. These measures may not, for example, in the case of misappropriation of a trade secret by an employee or third party with authorized access, provide adequate protection for our proprietary information. Our security measures may not prevent an employee or consultant from misappropriating our trade secrets and providing them to a third party, and any recourse we might take against this type of misconduct may not provide an adequate remedy to protect our interests fully. In addition, trade secrets may be independently developed by others in a manner that could prevent us from receiving legal recourse. If any of our confidential or proprietary information, such as our trade secrets, were to be disclosed or misappropriated, or if any of that information was independently developed by a third party, our competitive position could be harmed.

In addition, some courts inside and outside the United States are sometimes less willing or unwilling to protect trade secrets. If we choose to go to court to stop a third party from using any of our trade secrets, we may incur substantial costs. Even if we are successful, these types of lawsuits may consume our time and other resources. Any of the foregoing could have a material adverse effect on our business, financial condition, results of operations and prospects.

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Third parties may assert that our employees, consultants, or advisors have wrongfully used or disclosed confidential information or misappropriated trade secrets.

As is common in the biotechnology and biopharmaceutical industries, we employ individuals who were previously employed at universities or other biotechnology or biopharmaceutical companies, including our competitors or potential competitors. Although no claims against us are currently pending, and although we try to ensure that our employees, consultants, independent contractors or other third parties do not use the proprietary information or know-how of others in their work for us, we may be subject to claims that we or our employees, consultants, independent contractors or other third parties have inadvertently or otherwise used or disclosed intellectual property, including trade secrets or other proprietary information, of a former employer or other third parties. Litigation may be necessary to defend against these claims. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. Even if we are successful in defending against such claims, litigation or other legal proceedings relating to intellectual property claims may cause us to incur significant expenses and could distract our technical and management personnel from their normal responsibilities. 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 common stock. This type of litigation or proceeding could substantially increase our operating losses and reduce our resources available for development activities. We may not have sufficient financial or other resources to adequately conduct such litigation or proceedings. Certain third parties, including our competitors, may be able to sustain the costs of such litigation or proceedings more effectively than we can because of their substantially greater financial resources. Uncertainties resulting from the initiation and continuation of patent litigation or other intellectual property related proceedings could adversely affect our ability to compete in the marketplace.

If our trademarks and trade names are not adequately protected, then we may not be able to build name recognition in our markets of interest and our business may be adversely affected.

We do not currently own any registered trademarks.Our unregistered trademarks or trade names may be challenged, infringed, circumvented or declared generic or determined to be infringing on other marks. We may not be able to protect our rights to these trademarks and trade names, which we need to build name recognition among potential partners or customers in our markets of interest. At times, competitors or other third parties may adopt trade names or trademarks similar to ours, thereby impeding our ability to build brand identity and possibly leading to market confusion. In addition, there could be potential trade name or trademark infringement claims brought by owners of other registered trademarks or trademarks that incorporate variations of our unregistered trademarks or trade names. Over the long term, if we are unable to establish name recognition based on our trademarks and trade names, then we may not be able to compete effectively and our business may be adversely affected. Our efforts to enforce or protect our proprietary rights related to trademarks, trade secrets, domain names, copyrights or other intellectual property may be ineffective and could result in substantial costs and diversion of resources and could adversely affect our business, financial condition, results of operations and growth prospects.

Intellectual property rights do not necessarily address all potential threats.

The degree of future protection afforded by our intellectual property rights is uncertain because intellectual property rights have limitations and may not adequately protect our business or permit us to maintain our competitive advantage. For example:

•our product candidates, if approved, will eventually become commercially available in generic or biosimilar product forms;

•others may be able to make gene therapy products that are similar to our product candidates or utilize similar gene editing technology but that are not covered by the claims of the issued patent or patent applications that we own or license or the patents that we may own or license in the future;

•we, our licensors, or our current or future collaborators, might not have been the first to make the inventions covered by the issued patent or pending patent applications that we license or may own in the future;

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•we, our licensors, or our current or future collaborators, might not have been the first to file patent applications covering certain of our or their inventions;

•we, our licensors, or our current or future collaborators, may fail to meet our obligations to the U.S. government regarding any in-licensed patent or patent applications funded by U.S. government grants, leading to the loss or unenforceability of patent rights;

•others may independently develop similar or alternative technologies or duplicate any of our technologies without infringing our owned or licensed intellectual property rights;

•it is possible that our pending, owned or licensed patent applications or those that we may own in the future will not lead to issued patents;

•it is possible that there are prior public disclosures that could invalidate our owned or in-licensed patent rights, or parts of our owned or in-licensed patent rights;

•it is possible that there are unpublished patent applications or patent applications maintained in secrecy that may later issue with claims covering our product candidates or technology similar to ours;

•it is possible that our owned or in-licensed patent or patent applications omit individual(s) that should be listed as inventor(s) or include individual(s) that should not be listed as inventor(s), which may cause the patent or patents issuing from these patent applications to be held invalid or unenforceable;

•patents, if and when issued, that we obtain in the future may be held invalid, unenforceable, or narrowed in scope, including as a result of legal challenges by third parties, including our competitors;

•the claims of our owned or in-licensed patents, if and when issued, may not cover our product candidates;

•the laws of foreign countries may not protect our proprietary rights or the proprietary rights of license partners or current or future collaborators to the same extent as the laws of the United States;

•the inventors of our owned or in-licensed patent or patent applications may become involved with competitors, develop products or processes that design around our patent or patent applications, or become hostile to us or the patent, patent applications or patents that may issue from such patent applications on which they are named as inventors;

•third parties might conduct research and development activities in countries where we do not have patent rights and then use the information learned from such activities to develop competitive products for sale in our major commercial markets;

•we have engaged in scientific collaborations in the past and will continue to do so in the future and our collaborators may develop adjacent or competing products that are outside the scope of our patent or patent applications;

•we may not develop additional proprietary technologies that are patentable;

•any product candidates we develop may be covered by third-parties’ patents or other exclusive rights;

•the patents of others may harm our business; or

•we may choose not to file a patent in order to maintain certain trade secrets or know-how and a third party may subsequently file a patent covering such intellectual property.

Should any of these events occur, they could have a material adverse effect on our business, financial condition, results of operations and prospects.

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Risks Related To Regulatory and Other Legal Compliance Matters

The FDA, the EMA and the National Institutes of Health, or NIH, have demonstrated caution in their regulation of gene therapy treatments, and ethical and legal concerns about gene therapy and genetic testing may result in additional regulations or restrictions on the development and commercialization of any product candidates we may develop, which may be difficult to predict.

The FDA, the EMA and the NIH have each expressed interest in further regulating biotechnology, including gene therapy and genetic testing. For example, the EMA advocates a risk-based approach to the development of a gene therapy product. Agencies at both the federal and state level in the United States, as well as the U.S. congressional committees and other governments or governing agencies, have also expressed interest in further regulating the biotechnology industry. Such action may delay or prevent commercialization of any product candidates we may develop. Additionally, gene therapies may be associated with undesirable or unacceptable side effects, unexpected characteristics or other serious adverse events, including death, off-target cuts of DNA, or the introduction of cuts in DNA at locations other than the target sequence. These off-target cuts could lead to disruption of a gene or a genetic regulatory sequence at an unintended site in the DNA, or, in those instances where we also provide a segment of DNA to serve as a repair template, it is possible that following off-target cut events, DNA from such repair template could be integrated into the genome at an unintended site, potentially disrupting another important gene or genomic element. There also is the potential risk of delayed adverse events following exposure to gene therapies due to persistent biologic activity of the genetic material or other components of products used to carry the genetic material. Due to concerns from regulatory agencies on the development of gene therapies and their potential for unknown long-term effects, participants in gene-therapy clinical trials may also require long-term follow-up for as long as 15 years.

Regulatory requirements in the United States and in other jurisdictions governing gene therapy products have changed frequently and may continue to change in the future. In January 2020, the FDA issued several new guidance documents on gene therapy products, and in March 2022, the FDA published a draft guidance document providing recommendations for human genome editing gene therapy products. The FDA established the Office of Tissues and Advanced Therapies within its Center for Biologics Evaluation and Research to consolidate the review of gene therapy and related products and established the Cellular, Tissue and Gene Therapies Advisory Committee to advise this review. In addition to the government regulators, the IBC and IRB of each institution at which we will conduct clinical trials of our potential product candidates, or a central IRB if appropriate, would need to review the proposed clinical trial to assess the safety of the trial. In addition, adverse developments in clinical trials of gene therapy product candidates conducted by others may cause the FDA or other oversight bodies to change the requirements for approval of any of our potential product candidates. Similarly, the EMA governs the development of gene therapies in the European Union and may issue new guidelines concerning the development and marketing authorization for gene therapy products and require that we comply with these new guidelines. These regulatory review agencies and committees and the new requirements or guidelines they promulgate may lengthen the regulatory review process, require us to perform additional studies or trials, increase our development costs, lead to changes in regulatory positions and interpretations, delay or prevent approval and commercialization of any product candidates we may develop or lead to significant post-approval limitations or restrictions. As we advance our potential product candidates, we will be required to consult with these regulatory agencies and committees and comply with applicable requirements and guidelines. If we fail to do so, we may be required to delay or discontinue development of such product candidates. These additional processes may result in a review and approval process that is longer than we otherwise would have expected. Delays as a result of an increased or lengthier regulatory approval process or further restrictions on the development of our potential product candidates can be costly and could negatively impact our or our collaborators’ ability to complete clinical trials and commercialize our current and future product candidates in a timely manner, if at all.

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Even if we, or any of our collaborators or strategic partners, obtain marketing approvals for any product candidates we may develop, the terms of approvals and ongoing regulation of such product candidates could require the substantial expenditure of resources and may limit how we, or they, manufacture and market such product candidates, which could materially impair our ability to generate revenue.

Any product candidate for which we obtain marketing approval, along with the manufacturing processes, post-approval clinical data, labeling, advertising and promotional activities for such product, will be subject to continual requirements of and review by the FDA, the EMA and other regulatory authorities. These requirements include submissions of safety and other post-marketing information and reports, facility registration and drug listing requirements, cGMP requirements relating to quality control, quality assurance and corresponding maintenance of records and documents, applicable product tracking and tracing requirements and requirements regarding the distribution of samples to physicians and recordkeeping. In addition, our manufacturing and testing facilities will be required to undergo pre-license inspections and pre-approval inspections. Even if marketing approval of a product candidate is granted, the approval may be subject to limitations on the indicated uses for which the products may be marketed or to the conditions of approval, or contain requirements for costly post-marketing testing and surveillance to monitor the safety or efficacy of the products.

Accordingly, assuming we, or any collaborators we may have, receive marketing approval for one or more product candidates we develop, we, and such collaborators, and our and their contract manufacturers will continue to expend time, money and effort in all areas of regulatory compliance, including manufacturing, production, product surveillance and quality control. If we and such collaborators are not able to comply with post-approval regulatory requirements, we and such collaborators could have the marketing approvals for our products withdrawn by regulatory authorities and our, or such collaborators’, ability to market any future products could be limited, which could adversely affect our ability to achieve or sustain profitability. Furthermore, the cost of compliance with post-approval regulations may have a negative effect on our business, operating results, financial condition and prospects.

Reductions in government operations may delay necessary manufacturing facility inspections by regulators and adversely affect the supply of any product candidates we may develop. Since March 2020 when foreign and domestic inspections of facilities were largely placed on hold, the FDA has been working to resume pre-pandemic levels of inspection activities, including routine surveillance, bioresearch monitoring and pre-approval inspections. Should the FDA determine that an inspection is necessary for approval and an inspection cannot be completed during the review cycle due to restrictions on travel, and the FDA does not determine a remote interactive evaluation to be adequate, the agency has stated that it generally intends to issue, depending on the circumstances, a complete response letter or defer action on the application until an inspection can be completed. During the COVID-19 public health emergency, a number of companies announced receipt of complete response letters due to the FDA’s inability to complete required inspections for their applications. Regulatory authorities outside the U.S. may adopt similar restrictions or other policy measures in response to the ongoing COVID-19 pandemic and may experience delays in their regulatory activities.

Disruptions at the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved, or commercialized in a timely manner or at all, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory, and policy changes, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of other government agencies that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA and other agencies may also slow the time necessary for biologics or modifications to approved biologics to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, over the last several years, including for 35 days beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities.

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Healthcare and other reform legislation may increase the difficulty and cost for us and any collaborators we may have to obtain marketing approval of and commercialize any product candidates we may develop and affect the prices we, or they, may obtain.

In the United States and some foreign jurisdictions, there have been and continue to be ongoing efforts to implement legislative and regulatory changes regarding the healthcare system. Such changes could prevent or delay marketing approval of any product candidates that we may develop, restrict or regulate post-approval activities and affect our ability to profitably sell any product candidates for which we obtain marketing approval. Although we cannot predict what healthcare or other reform efforts will be successful, such efforts may result in more rigorous coverage criteria, in additional downward pressure on the price that we, or our future collaborators, may receive for any approved products or in other consequences that may adversely affect our ability to achieve or maintain profitability.

Within the United States, the federal government and individual states have aggressively pursued healthcare reform, as evidenced by the passing of the Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively the ACA, and the ongoing efforts to modify or repeal that legislation. The ACA substantially changed the way healthcare is financed by both governmental and private insurers and contains a number of provisions that affect coverage and reimbursement of drug products and/or that could potentially reduce the demand for pharmaceutical products such as increasing drug rebates under state Medicaid programs for brand name prescription drugs and extending those rebates to Medicaid managed care and assessing a fee on manufacturers and importers of brand name prescription drugs reimbursed under certain government programs, including Medicare and Medicaid. Other aspects of healthcare reform, such as expanded government enforcement authority and heightened standards that could increase compliance-related costs, could also affect our business. Modifications have been implemented under the former Trump administration and additional modifications or repeal may occur.

There have been executive, judicial and congressional challenges to certain aspects of the ACA. On February 10, 2021, the Biden administration withdrew the federal government’s support for overturning the ACA. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. Prior to the Supreme Court’s decision, President Biden issued an executive order that initiated a special enrollment period for purposes of obtaining health insurance coverage through the ACA marketplace, from February 15, 2021 through August 15, 2021. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. It is unclear how other healthcare reform measures of the Biden administration or other efforts, if any, to challenge, repeal or replace the ACA will impact our business. There is no assurance that federal or state health care reform will not adversely affect our future business and financial results, and we cannot predict how future federal or state legislative, judicial or administrative changes relating to healthcare reform will affect our business.

In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted. For example, on March 22, 2021, President Biden signed the American Rescue Plan Act of 2021 into law, which eliminates the statutory Medicaid drug rebate cap, currently set at 100 percent of a drug’s average manufacturer price, for single source and innovator multiple source drugs, beginning January 1, 2024. On August 2, 2011, the U.S. Budget Control Act of 2011, among other things, included aggregate reductions of Medicare payments to providers of 2% per fiscal year. These reductions went into effect on April 1, 2013 and, due to subsequent legislative amendments to the statute, will remain in effect through 2030, with the exception of a temporary suspension that lasted from May 1, 2020 through March 31, 2022 due to the COVID-19 pandemic. Following the suspension, a 1% payment reduction began April 1, 2022, lasting through June 30, 2022. The 2% payment reduction resumed on July 1, 2022. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments to several providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. The Bipartisan Budget Act, or BBA, also amended the ACA, effective January 1, 2019, by increasing the point-of-sale discount that is owed by

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pharmaceutical manufacturers who participate in Medicare Part D and closing the coverage gap in most Medicare drug plans, commonly referred to as the “donut hole.”

Furthermore, the prices of prescription pharmaceuticals in the United States and foreign jurisdictions is subject to considerable legislative and executive actions and could impact the prices we obtain for our products, if and when licensed. At the U.S. federal level, the former Trump administration used several means to propose or implement drug pricing reform, including through federal budget proposals, executive orders and policy initiatives. For example, on July 24, 2020 and September 13, 2020, the Trump administration announced several executive orders related to prescription drug pricing that seek to implement several of the administration’s proposals. As a result, the FDA released a final rule on September 24, 2020, effective November 30, 2020, providing guidance for states to build and submit importation plans for drugs from Canada. Furthermore, on November 20, 2020, the U.S. Department of Health and Human Services, or HHS, finalized a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Medicare Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The implementation of the rule has been delayed by the Biden administration from January 1, 2022 to January 1, 2023 in response to ongoing litigation. The rule also creates a new safe harbor for price reductions reflected at the point-of-sale, as well as a new safe harbor for certain fixed fee arrangements between pharmacy benefit managers and manufacturers, the implementation of which have also been delayed until January 1, 2023. On November 20, 2020, CMS, issued an interim final rule implementing the Trump administration’s Most Favored Nation executive order, which would tie Medicare Part B payments for certain physician-administered drugs to the lowest price paid in other economically advanced countries, effective January 1, 2021. On December 28, 2020, the U.S. District Court in Northern California issued a nationwide preliminary injunction against implementation of the interim final rule. It is unclear whether the Biden administration will work to reverse these measures or pursue similar policy initiatives.

In addition to pricing regulations, reforms of regulatory approval frameworks may adversely affect our pricing strategy. For example, on July 9, 2021, President Biden issued an executive order directing the FDA to, among other things, continue to clarify and improve the approval framework for biosimilars, including the standards for interchangeability of biological products, facilitate the development and approval of biosimilar and interchangeable products, clarify existing requirements and procedures related to the review and submission of BLAs, and identify and address any efforts to impede biosimilar competition. Individual states in the United States have also become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical 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. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. It is difficult to predict the future legislative landscape in healthcare and the effect on our business, results of operations, financial condition and prospects. However, we expect that additional state and federal healthcare reform measures will be adopted in the future, particularly in light of the new presidential administration. Furthermore, it is possible that additional governmental action is taken in response to the ongoing COVID-19 pandemic. At the state level, legislatures have also been increasingly passing legislation and implementing 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.

In the European Union, similar political, economic and regulatory developments may affect our ability to profitably commercialize our potential product candidates. In markets outside of the United States and the European Union, reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on specific products and therapies. In some countries, particularly the countries of 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 reimbursement or pricing approval in some countries, we may be required to conduct a clinical trial that compares the cost-effectiveness of any product candidates we may develop to other available

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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, possibly materially.

While we intend to seek designations for our potential product candidates with the FDA and comparable foreign regulatory authorities that are intended to confer benefits such as a faster development process or an accelerated regulatory pathway, there can be no assurance that we will successfully obtain such designations. In addition, even if one or more of our potential product candidates are granted such designations, we may not be able to realize the intended benefits of such designations.

The FDA and comparable foreign regulatory authorities offer certain designations for product candidates that are designed to encourage the research and development of product candidates that are intended to address conditions with significant unmet medical need. These designations may confer benefits such as additional interaction with regulatory authorities, a potentially accelerated regulatory pathway and priority review. However, there can be no assurance that we will successfully obtain such designations for any product candidates. In addition, while such designations could expedite the development or approval process, they generally do not change the standards for approval. Even if we obtain such designations for one or more of our potential product candidates, there can be no assurance that we will realize their intended benefits. For example, we may seek fast track designation for some of our potential product candidates. If a therapy is intended for the treatment of a serious or life threatening condition and the therapy nonclinical or clinical data demonstrates the potential to address unmet medical needs for this condition, the therapy sponsor may apply for fast track designation. The FDA has broad discretion whether or not to grant this designation, so even if we believe a particular product candidate is eligible for this designation, there can be no assurance that the FDA would decide to grant it. Even if we do receive fast track designation, we may not experience a faster development process, review or approval compared to conventional FDA procedures, and receiving a fast track designation does not provide assurance of ultimate FDA approval. In addition, the FDA may withdraw fast track designation if it believes that the designation is no longer supported by data from our clinical development program. Additionally, we may seek a breakthrough therapy designation for some of our potential product candidates. A breakthrough therapy is defined as a therapy that is intended, alone or in combination with one or more other therapies, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence indicates that the therapy may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For therapies that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patients placed in ineffective control regimens. Therapies designated as breakthrough therapies by the FDA may also be eligible for accelerated approval. Designation as a breakthrough therapy is within the discretion of the FDA. Accordingly, even if we believe one of our potential product candidates meets the criteria for designation as a breakthrough therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of a breakthrough therapy designation for a product candidate may not result in a faster development process, review or approval compared to therapies considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our potential product candidates qualify as breakthrough therapies, the FDA may later decide that such product candidates no longer meet the conditions for qualification. In addition, we may seek a regenerative medicine advanced therapy, or RMAT, designation for some of our potential product candidates. An RMAT is defined as cell therapies, therapeutic tissue engineering products, human cell and tissue products and combination products using any such therapies or products. Gene therapies, including genetically modified cells that lead to a durable modification of cells or tissues may meet the definition of a regenerative medicine therapy. The RMAT program is intended to facilitate efficient development and expedite review of RMATs, which are intended to treat, modify, reverse or cure a serious or life-threatening disease or condition. A new drug application or a biologics license application, or BLA, for an RMAT may be eligible for priority review or accelerated approval through (1) surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit or (2) reliance upon data obtained from a meaningful number of sites. Benefits of such designation also include early interactions with FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A regenerative medicine therapy that is granted accelerated approval and is subject to post-approval requirements may fulfill such requirements through the submission of clinical evidence, clinical trials, patient registries or other sources of real world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval

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monitoring of all patients treated with such therapy prior to its approval. RMAT designation is within the discretion of the FDA. Accordingly, even if we believe one of our potential product candidates meets the criteria for designation as a regenerative medicine advanced therapy, the FDA may disagree and instead determine not to make such designation. In any event, the receipt of RMAT designation for a product candidate may not result in a faster development process, review or approval compared to drugs considered for approval under conventional FDA procedures and does not assure ultimate approval by the FDA. In addition, even if one or more of our potential product candidates qualify as for RMAT designation, the FDA may later decide that the biological products no longer meet the conditions for qualification.

In the future, we may also seek approval of product candidates under the FDA’s accelerated approval pathway. A product may be eligible for accelerated approval if it is designed to treat a serious or life-threatening disease or condition and generally provides a meaningful advantage over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, or IMM, that is reasonably likely to predict an effect on IMM or other clinical benefit. The FDA considers a clinical benefit to be a positive therapeutic effect that is clinically meaningful in the context of a given disease, such as IMM. For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign or other measure that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. An intermediate clinical endpoint is a clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. The accelerated approval pathway may be used in cases in which the advantage of a new drug over available therapy may not be a direct therapeutic advantage, but is a clinically important improvement from a patient and public health perspective. If granted, accelerated approval is usually contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verity and describe the drug’s clinical benefit. If the sponsor fails to conduct such studies in a timely manner or if such post-approval studies fail to verify the drug’s predicted clinical benefit, the FDA may withdraw its approval of the drug on an expedited basis. In addition, for products being considered for accelerated approval, the FDA generally requires, unless otherwise informed by the Agency, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to the Agency for review during the pre-approval review period. There can be no assurance that FDA would allow any of the product candidates we may develop to proceed on an accelerated approval pathway, and even if FDA did allow such pathway, there can be no assurance that such submission or application will be accepted or that any expedited development, review or approval will be granted on a timely basis, or at all. Moreover, even if we received accelerated approval, any post-approval studies required to confirm and verify clinical benefit may not show such benefit, which could lead to withdrawal of any approvals we have obtained. Receiving accelerated approval does not assure that the product’s accelerated approval will eventually be converted to a traditional approval.

If the FDA determines that a product candidate offers a treatment for a serious condition and, if approved, the product would provide a significant improvement in safety or effectiveness, the FDA may designate the product candidate for priority review. A priority review designation means that the goal for the FDA to review an application is six months, rather than the standard review period of ten months. We may request priority review for the product candidates that we may develop. The FDA has broad discretion with respect to whether or not to grant priority review status to a product candidate, so even if we believe a particular product candidate is eligible for such designation or status, the FDA may decide not to grant it. Moreover, a priority review designation does not necessarily result in an expedited regulatory review or approval process or necessarily confer any advantage with respect to approval compared to conventional FDA procedures. Receiving priority review from the FDA does not guarantee approval within the six-month review cycle or at all.

In addition, in the European Union, we may seek to participate in the PRIME scheme for our product candidates. The PRIority MEdicines, or PRIME, scheme is intended to encourage drug development in areas of unmet medical need and provides accelerated assessment of products representing substantial innovation, where the marketing authorization application will be made through the centralized procedure in the European Union. Eligible products must target conditions for which where is an unmet medical need (there is no satisfactory method of diagnosis, prevention or treatment in the European Union or, if there is, the new medicine will bring a major

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therapeutic advantage) and they must demonstrate the potential to address the unmet medical need by introducing new methods of therapy or improving existing ones. Many benefits accrue to sponsors of product candidates with PRIME designation, including but not limited to, early and proactive regulatory dialogue with the EMA, frequent discussions on clinical trial designs and other development program elements, and accelerated marketing authorization application assessment once a dossier has been submitted. There is no guarantee, however, that our product candidates would be deemed eligible for the PRIME scheme and even if we do participate in the PRIME scheme, where during the course of development a medicine no longer meets the eligibility criteria, support under the PRIME scheme may be withdrawn.

We may not be able to obtain orphan drug designation or exclusivity for our potential product candidates, and even if we do, that designation may not provide an expedited development or regulatory review or approval process and any orphan drug exclusivity we may receive for approved products may not prevent the FDA or the EMA from approving other competing products.

Under the Orphan Drug Act, the FDA may designate a product candidate as an orphan drug if it is a drug or biologic intended to treat a rare disease or condition. A similar regulatory scheme governs approval of orphan product candidates by the EMA in the European Union. Generally, if a product with an orphan drug designation subsequently receives the first marketing approval for the indication for which it has such designation, the product is entitled to a period of marketing exclusivity, which precludes the FDA or the EMA (as applicable) from approving another marketing application for another similar product candidate for the same orphan therapeutic indication for that time period. The applicable period is seven years in the United States and ten years in the European Union. The exclusivity period in the European Union can be reduced to six years if at the end of the fifth year it is determined that a product no longer meets the criteria for orphan drug designation, including if the product is sufficiently profitable so that market exclusivity is no longer justified.

In order for the FDA to grant orphan drug exclusivity to one of our potential product candidates, the agency must find that the product candidate is indicated for the treatment of a condition or disease that affects fewer than 200,000 individuals in the United States or that affects 200,000 or more individuals in the United States and for which there is no reasonable expectation that the cost of developing and making the product candidate available for the disease or condition will be recovered from sales of the product in the United States. The FDA may conclude that the condition or disease for which we seek orphan drug exclusivity does not meet this standard. Even if we obtain orphan drug exclusivity for a product candidate, that exclusivity may not effectively protect the product candidate from competition because different product candidates can be approved for the same condition. In addition, even after an orphan drug is approved, the FDA can subsequently approve the same product candidate for the same condition if the FDA concludes that the later product candidate is clinically superior in that it is shown to be safer, more effective or makes a major contribution to patient care compared with the product that has orphan exclusivity. Orphan drug exclusivity may also be lost if the FDA or EMA determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantity of the product to meet the needs of the patients with the rare disease or condition.

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

We are exposed to the risk of fraud or other misconduct by our employees, consultants and commercial partners, and, if we commence clinical trials, our principal investigators. Misconduct by these parties could include intentional failures to comply with FDA regulations or the regulations applicable in the European Union and other jurisdictions, provide accurate information to the FDA, the EMA and other regulatory authorities, comply with healthcare fraud and abuse laws and regulations in the United States and abroad, report financial information or data accurately or disclose unauthorized activities to us. In particular, sales, marketing and 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 restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Such misconduct also could involve the improper use of information obtained in the course of clinical trials or interactions with the FDA, the EMA or other regulatory authorities, which could result in regulatory sanctions and cause serious harm to our reputation. We are also exposed to risks in connection with any insider

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trading violations by employees or others affiliated with us. Upon the effectiveness of this registration statement, we will adopt a code of conduct and an insider trading policy applicable to all of our employees, but it is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from government investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, financial condition, results of operations and prospects, including the imposition of significant fines or other sanctions.

Laws and regulations governing any international operations we may have in the future may preclude us from developing, manufacturing and selling certain product candidates outside of the United States and require us to develop and implement costly compliance programs.

We are subject to numerous laws and regulations in each jurisdiction outside the United States in which we operate. The creation, implementation and maintenance of international business practices compliance programs is costly and such programs are difficult to enforce, particularly where reliance on third parties is required.

The Foreign Corrupt Practices Act, or FCPA, prohibits any U.S. individual or business from paying, offering, authorizing payment or offering of anything of value, directly or indirectly, to any foreign official, political party or candidate for the purpose of influencing any act or decision of the foreign entity in order to assist the individual or business in obtaining or retaining business. The FCPA also obligates companies whose securities are listed in the United States to comply with certain accounting provisions requiring the company to maintain books and records that accurately and fairly reflect all transactions of the corporation, including international subsidiaries, and to devise and maintain an adequate system of internal accounting controls for international operations. The anti-bribery provisions of the FCPA are enforced primarily by the Department of Justice. The SEC is involved with enforcement of the books and records provisions of the FCPA.

Similarly, the U.K. Bribery Act 2010 has extra-territorial effect for companies and individuals having a connection with the United Kingdom. The U.K. Bribery Act prohibits inducements both to public officials and private individuals and organizations. Compliance with the FCPA and the U.K. Bribery Act is expensive and difficult, particularly in countries in which corruption is a recognized problem. In addition, the FCPA presents 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 FCPA enforcement actions.

Various laws, regulations and executive orders also restrict the use and dissemination outside of the United States, or the sharing with certain non-U.S. nationals, of information classified for national security purposes, as well as certain products and technical data relating to those products. Our expansion outside of the United States has required, and will continue to require, us to dedicate additional resources to comply with these laws, and these laws may preclude us from developing, manufacturing or selling certain drugs and drug candidates outside of the United States, which could limit our growth potential and increase our development costs. The failure to comply with laws governing international business practices may result in substantial penalties, including suspension or debarment from government contracting. Violation of the FCPA can result in significant civil and criminal penalties. Indictment alone under the FCPA can lead to suspension of the right to do business with the U.S. government until the pending claims are resolved. Conviction of a violation of the FCPA can result in long-term disqualification as a government contractor. The termination of a government contract or relationship as a result of our failure to satisfy any of our obligations under laws governing international business practices would have a negative impact on our operations and harm our reputation and ability to procure government contracts. The SEC also may suspend or bar issuers from trading securities on U.S. exchanges for violations of the FCPA’s accounting provisions.

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We are subject to stringent laws, rules, regulations, policies, standards and contractual obligations related to data privacy and security and changes in such laws, rules, regulations, policies, standards and contractual obligations could adversely affect our business.

We are subject to data privacy and protection laws, rules, regulations, policies, standards and contractual obligations that apply to the collection, transmission, storage, use, disclosure, transfer, maintenance and other processing of sensitive, personal and personally-identifying information, which, among other things, impose certain requirements relating to the privacy, security, transmission and other processing of personal information, including comprehensive regulatory systems in the United States and European Union. The legislative and regulatory landscape for privacy and data protection continues to evolve in jurisdictions worldwide, and there has been an increasing focus on privacy and data protection issues with the potential to affect our business. However, our data privacy program is in its early stages and we have not yet assessed the applicability of and our compliance with data privacy-related laws, rules and regulations. As a result, we cannot guarantee that we are and have been in compliance with all applicable data privacy and protection laws, rules regulations, policies and standards, and we may need to expend significant resources to implement privacy compliance measures. Additionally, we rely on certain third-party vendors to process certain confidential, sensitive or personal information on our behalf. Failure by us or our third-party vendors to comply with any of these laws, rules, regulations, contractual obligations or standards could result in notification obligations, enforcement actions, regulatory investigations or inquiries, significant fines, imprisonment of company officials and public censure, litigation and claims for damages by affected individuals, customers or business partners, damage to our reputation and loss of goodwill, any of which could have a material adverse effect on our business, financial condition, results of operations or prospects.

There are numerous U.S. federal and state laws, rules and regulations related to the privacy and security of personal information. In particular, regulations promulgated pursuant to the Health Insurance Portability and Accountability Act of 1996, or HIPAA, establish privacy and security standards that limit the use and disclosure of individually identifiable health information, or protected health information, and require the implementation of administrative, physical and technological safeguards to protect the privacy of protected health information and ensure the confidentiality, integrity and availability of electronic protected health information. Additionally, laws in all 50 states require businesses to provide notice to customers whose personally identifiable information has been disclosed as a result of a data breach. Determining whether personal information has been handled in compliance with applicable privacy standards and our contractual obligations can be complex and may be subject to changing interpretation.

If we are unable to properly protect the privacy and security of personal information, we could be alleged or actually found to have breached our contracts. Furthermore, if we fail to comply with applicable privacy laws, including applicable HIPAA privacy and security standards, we could face significant civil and criminal penalties. HHS has the discretion to impose penalties without attempting to resolve violations through informal means, and such enforcement activity can result in financial liability and reputational harm, and responses to such enforcement activity can consume significant internal resources. In addition, state attorneys general are authorized to bring civil actions seeking either injunctions or damages in response to violations that threaten the privacy of state residents. We cannot be sure how these laws, rules and regulations will be interpreted, enforced or applied to our operations. In addition to the risks associated with enforcement activities and potential contractual liabilities, our ongoing efforts to comply with evolving laws, rules and regulations at the international, federal and state level may be costly and require ongoing modifications to our policies, procedures and systems.

We make public statements about our use, collection, disclosure and other processing of personal information through our privacy policies, information provided on our website and press statements. Although we endeavor to comply with our public statements and documentation, we may at times fail to do so or be alleged to have failed to do so. The publication of our privacy policies and other statements that provide promises and assurances about data privacy and security can subject us to potential government or legal action if they are found to be deceptive, unfair or misrepresentative of our actual practices.

Data privacy remains an evolving landscape at both the domestic and international level, with new laws, rules and regulations coming into effect and continued legal challenges, and our efforts to comply with the evolving data protection laws, rules and regulations may be unsuccessful. It is possible that these laws, rules and regulations may

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be interpreted and applied in a manner that is inconsistent with our practices. The laws are not consistent, and compliance in the event of a widespread data breach is costly and time-consuming. States are also frequently amending existing laws, requiring attention to frequently changing regulatory requirements. We must devote significant resources to understanding and complying with this changing landscape. Failure by us or our third-party vendors to comply with laws, rules and regulations regarding data privacy and protection would expose us to risk of enforcement actions taken by data protection authorities and carries with it the potential for significant penalties if we are found to be non-compliant. Similarly, failure to comply with federal and state laws, rules and regulations in the United States regarding privacy and security of personal information could expose us to penalties under such laws, rules and regulations. Any such failure to comply with data protection and privacy laws, rules and regulations could result in significant government-imposed fines or orders requiring that we change our practices, claims for damages or other liabilities, regulatory investigations and enforcement action, litigation and significant costs for remediation, any of which could adversely affect our business. Even if we are not determined to have violated these laws, rules or regulations, government investigations into these issues typically require the expenditure of significant resources and generate negative publicity, which could harm our business, financial condition, results of operations or prospects.

Risks Related To Employee Matters, Managing Growth and Information Technology

Our future success depends on our ability to retain our President and Chief Executive Officer, our Co-Founders, our Chief Scientific Officer, our Chief Technical Officer and other key executives and to attract, retain and motivate qualified personnel.

We are highly dependent on Keith Gottesdiener, our President and Chief Executive Officer, David R. Liu and Andrew Anzalone, our Co-Founders, Jeremy Duffield, our Chief Scientific Officer, Ann Lee, our Chief Technical Officer, as well as the other principal members of our management and scientific teams. Dr. Gottesdiener, Dr. Liu, Dr. Anzalone and Dr. Lee and such other principal members are engaged “at will,” meaning we or they may terminate the relationship at any time. We do not maintain “key person” insurance for any of our executives or other employees. The loss of the services of any of these persons could impede the achievement of our research, development and commercialization objectives.

Following this offering, Dr. Liu will continue to serve on our Scientific Advisory Board and as our paid consultant and will retain his position and affiliation with Harvard, HHMI and Broad Institute. Furthermore, Dr. Liu is one of our principal stockholders. Dr. Liu’s positions at Harvard, HHMI and Broad Institute could result in, or may create the appearance of, conflicts of interest related to our license of intellectual property rights from Harvard , HHMI and Broad Institute and other contractual relationships we may enter into from time to time with Harvard, HHMI and Broad Institute. For more information, see “Business—Team— Relationship with David Liu, Ph.D.”

Recruiting and retaining qualified scientific, clinical, manufacturing and sales and marketing personnel will also be critical to our success. In addition, our company-building efforts and establishment of a company culture will also be important to developing an innovative company in a high-evolving area. We may not be able to succeed in these efforts to build Prime Medicine as an attractive and exciting place to build a career or to attract and retain these types of 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, including our scientific co-founders, may be employed by employers other than us and may have commitments under consulting or advisory contracts with other entities that may limit their availability to us. The inability to recruit, or loss of services of, certain executives, key employees, consultants or advisors, may impede the progress of our research, development and commercialization objectives and have a material adverse effect on our business, financial condition, results of operations and prospects.

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We expect to expand our research, development, delivery, manufacturing, commercialization, regulatory and future sales and marketing capabilities over time, and as a result, we may encounter difficulties in managing our growth, which could disrupt our operations.

As of September 30, 2022, we had more than 150 full-time employees, of which 77 have M.D. or Ph.D. degrees. Within our workforce, 134 employees are engaged in research and development and 24 are engaged in business development, finance, legal, and general management and administration. In connection with the growth and advancement of our pipeline and becoming a public company, we expect to increase the number of our employees and the scope of our operations, particularly in the areas of drug development, regulatory affairs and sales and marketing. To manage our anticipated future growth, we must continue to implement and improve our managerial, operational and financial systems, expand our facilities, and continue to recruit and train additional qualified personnel. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expected expansion of our operations or recruit and train additional qualified personnel. Moreover, our current physical laboratory space may be insufficient for our near-term research and development hiring plans, and the expected physical expansion of our operations may lead to significant costs and may divert our management and business development resources. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.

As a growing biotechnology company, we are actively pursuing new platforms and product candidates in many therapeutic areas and across a wide range of diseases. Successfully developing product candidates for and fully understanding the regulatory and manufacturing pathways to all of these therapeutic areas and disease states requires a significant depth of talent, resources and corporate processes in order to allow simultaneous execution across multiple areas. Due to our limited resources, we may not be able to effectively manage this simultaneous execution and the expansion of our operations or recruit and train additional qualified personnel. This may result in weaknesses in our infrastructure, give rise to operational mistakes, legal or regulatory compliance failures, loss of business opportunities, loss of employees and reduced productivity among remaining employees. The physical expansion of our operations may lead to significant costs and may divert financial resources from other projects, such as the development of our potential product candidates. If our management is unable to effectively manage our expected development and expansion, our expenses may increase more than expected, our ability to generate or increase our revenue could be reduced and we may not be able to implement our business strategy. Our future financial performance and our ability to compete effectively and commercialize any product candidates we may develop will depend in part on our ability to effectively manage the future development and expansion of our company.

The administrator of the 2019 Plan is authorized to exercise its discretion to effect the repricing of stock options and stock appreciation rights and there may be adverse consequences to our business if the administrator of the 2019 Plan exercises such discretion.

Pursuant to our 2019 Stock Option and Grant Plan, or the 2019 Plan, we are authorized to grant equity awards, including stock options and stock appreciation rights, to our employees, directors and consultants. The administrator of the 2019 Plan (which we expect will be, as is customary, our compensation committee) is authorized to exercise its discretion to reduce the exercise price of stock options or stock appreciation rights or effect the repricing of such awards. Although we do not anticipate needing to exercise this discretion in the near term, or at all, if the administrator of the 2019 Plan were to exercise such discretion without seeking prior stockholder approval, certain proxy advisory firms or institutional investors may be unsupportive of such actions and publicly criticize our compensation practices, and proxy advisory firms may recommend an “against” or “withhold” vote for members of our compensation committee. In addition, if we are required to hold an advisory vote on named executive officer compensation (known as the “say-on-pay” vote) at the time of, or subsequent to, any such repricing, it is likely that proxy advisory firms would issue an “against” recommendation on our say on pay vote and institutional investors may not be supportive of our say-on-pay vote. If proxy advisory firms or institutional investors are successful in aligning their views with our broader stockholder base and we are required to make changes to the composition of our board and its committees, or if we need to make material changes to our compensation and corporate governance practices, our business might be disrupted and our stock price might be negatively impacted. Even if we are able to successfully rationalize the exercise of such discretionary power, defending against any “against” or “withhold”

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recommendation for members of our compensation committee, any “against” recommendation on our say on pay vote or public criticism could be distracting to management, and responding to such positions from such firms or investors, even if remedied, can be costly and time-consuming.

In addition, if the administrator of the 2019 Plan does determine to reprice stock options or stock appreciation rights, even absent negative reactions from proxy advisory firms and institutional investors, management attention may be diverted and we could incur significant costs, including accounting and administrative costs and attorneys’ fees. We may also be required to recognize incremental compensation expense as a result of such repricing. These actions could cause our stock price to decrease and experience periods of increased volatility, which could result in material adverse consequences to our business.

Our board of directors has determined not to make any further awards under the 2019 Plan following the closing of this offering.

Our internal computer and information technology systems, or those of our third-party vendors, collaborators, contractors, consultants or other third parties, may fail or suffer security incidents or data breaches, which could result in a material disruption of our product development programs, compromise confidential, sensitive or personal information related to our business or prevent us from accessing critical information, potentially exposing us to liability or otherwise adversely affecting our business.

Our internal computer and information technology systems and those of our current and any future third-party vendors, collaborators, contractors, consultants or other third parties, are vulnerable to damage or interruption from, among other things, computer viruses, computer hackers, phishing attacks, ransomware, malware, social engineering, malicious code, employee theft, fraud, misconduct or misuse, denial-of-service attacks, sophisticated nation-state and nation-state-supported actors, unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failures. While we seek to protect our information technology systems from system failure, accident and security breach, we have in the past and may in the future experience phishing and other security incidents which 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, personal or confidential information or other disruptions. For example, the loss of clinical trial data from future clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data.

Controls employed by our information technology department and other third parties could prove inadequate, and our ability to monitor such third parties’ data security practices is limited. Due to applicable laws, rules, regulations and standards or contractual obligations, we may be held responsible for any information security failure or cybersecurity attack attributed to our third-party vendors as they relate to the information we share with them.

If we were to experience a cybersecurity breach or other security incident relating to our information systems or data, the costs, time and effort associated with the investigation, remediation and potential notification of the breach to counterparties, regulators and data subjects could be material. We may incur significant costs in an effort to detect and prevent security incidents, and we may face increased costs and requirements to expend substantial resources in the event of an actual or perceived security incident. In addition, techniques used to sabotage or to obtain unauthorized access to networks in which data is stored or through which data is transmitted change frequently, become more complex over time and generally are not recognized until launched against a target. As a result, we and our third-party vendors may be unable to anticipate these techniques or implement adequate preventative measures quickly enough to prevent either an electronic intrusion into our systems or services or a compromise of critical information. We cannot guarantee that we will be able to detect or prevent any such incidents, and, our remediation efforts may not be successful or timely. Our efforts to improve security and protect data from compromise may also identify previously undiscovered instances of data breaches or other cybersecurity incidents. If we do not allocate and effectively manage the resources necessary to build and sustain the proper technology and cybersecurity infrastructure, we could suffer significant business disruption, including transaction errors, supply chain or manufacturing interruptions, processing inefficiencies, data loss or the loss of or damage to intellectual property or other proprietary, personal or confidential information. Additionally, we do not currently maintain cybersecurity insurance, and any insurance we may maintain in the future against the risk of this type of loss in the future may not be sufficient to cover actual losses, or may not apply to the circumstances relating to any particular loss.

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To the extent that any disruption or security breach were to result in a loss of, or damage to, our or our third-party vendors’, collaborators’, contractors’, consultants’ or other third parties’ data, including personal data, or applications or inappropriate disclosure, loss, destruction or alteration of, or access to, confidential, personal or proprietary information, we could incur significant liability including litigation exposure, substantial penalties and fines, we could become the subject of regulatory action, inquiry or investigation, our competitive position could be harmed, we could incur significant reputational damage and the further development and commercialization of any product candidates we may develop could be delayed. Any of the above could have a material adverse effect on our business, financial condition, results of operations or prospects.

Risks Related To This Offering and Ownership of Our Common Stock

We do not know whether a market will develop for our common stock or what the market price of our common stock will be, and, as a result, it may be difficult for you to sell your shares of our common stock.

Before this offering, there was no public trading market for our common stock. If a market for our common stock does not develop or is not sustained, it may be difficult for you to sell your shares of common stock at an attractive price or at all. We cannot predict the prices at which our common stock will trade. It is possible that in one or more future periods our results of operations may be below the expectations of public market analysts and investors, and, as a result of these and other factors, the price of our common stock may fall.

You will incur immediate and substantial dilution as a result of this offering.

If you purchase common stock in this offering, you will incur immediate and substantial dilution of $12.91 per share, representing the difference between the assumed initial public offering price of $17.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, and our pro forma as adjusted net tangible book value per share as of June 30, 2022 after giving effect to this offering. Moreover, we issued options in the past that allow the holders to acquire common stock at prices significantly below the assumed initial public offering price. As of June 30, 2022, there were 3,593,533 shares subject to outstanding options with a weighted-average exercise price of $4.82 per share. To the extent that these outstanding options are ultimately exercised, the underwriters exercise their option to purchase additional shares or further vesting of restricted stock occurs, you will incur further dilution. For a further description of the dilution you will experience immediately after this offering, see “Dilution.”

If securities analysts do not publish research or reports about our business or if they publish negative evaluations of our stock, the price of our stock could decline.

The trading market for our common stock will rely in part on the research and reports that industry or financial analysts publish about us or our business. We do not currently have and may never obtain research coverage by industry or financial analysts. If no or few analysts commence coverage of us, the trading price of our stock would likely decrease. Even if we do obtain analyst coverage, if one or more of the analysts covering our business downgrade their evaluations of our stock, the price of our stock could decline. If one or more of these analysts cease to cover our stock, we could lose visibility in the market for our stock, which in turn could cause our stock price to decline.

Future sales of our common stock in the public market could cause our stock price to fall.

Our stock price could decline as a result of sales of a large number of shares of our common stock after this offering or the perception that these sales could occur. These sales, or the possibility that these sales may occur, also might make it more difficult for us to sell equity securities in the future at a time and at a price that we deem appropriate.

Upon completion of this offering, 94,336,033 shares of our common stock will be outstanding (or 95,671,033 shares of common stock will be outstanding assuming exercise in full of the underwriters’ option to purchase additional shares), based on our shares outstanding as of June 30, 2022. All shares of common stock expected to be sold in this offering will be freely tradable without restriction or further registration under the Securities Act of 1933, as amended, or Securities Act, unless held by our “affiliates,” as that term is defined in Rule 144 under the Securities Act. The resale of the remaining 84,937,964 shares, or approximately 99 percent of our outstanding shares

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after this offering, is currently prohibited or otherwise restricted as a result of securities law provisions, market standoff agreements entered into by our stockholders with us or lock-up agreements entered into by our stockholders with the underwriters. However, subject to applicable securities law restrictions and excluding shares of restricted stock that will remain unvested, these shares will be able to be sold in the public market beginning 180 days after the date of this prospectus. Shares of unvested restricted stock that were issued and outstanding as of the date of this prospectus will become available for sale immediately upon the vesting of such shares, as applicable, and the expiration of any applicable market stand-off or lock-up agreements. Shares issued upon the exercise of stock options pursuant to future awards that may be granted under our equity incentive plans or pursuant to future awards granted under those plans will become available for sale in the public market to the extent permitted by the provisions of applicable vesting schedules, any applicable market stand-off and lock-up agreements and Rule 144 and Rule 701 under the Securities Act. For more information see the section entitled “Shares Eligible for Future Sale” included elsewhere in this prospectus.

Upon completion of this offering, the holders of approximately 62,728,599 shares, or approximately 73 percent, of our common stock, will have rights, subject to some conditions, to require us to file registration statements covering the sale of their shares or to include their shares in registration statements that we may file for ourselves or other stockholders. We also intend to register the offer and sale of all shares of common stock that we may issue under our equity compensation plans. Once we register the offer and sale of shares for the holders of registration rights and shares to be issued under our equity incentive plans, they can be freely sold in the public market upon issuance, subject to the lock-up agreements described in the section entitled “Underwriting” included elsewhere in this prospectus.

In addition, in the future, we may issue additional shares of common stock or other equity or debt securities convertible into common stock in connection with a financing, acquisition, litigation settlement, employee arrangements or otherwise. Any such issuance could result in substantial dilution to our existing stockholders and could cause our stock price to decline.

Insiders will continue to have substantial influence over us after this offering, which could limit your ability to affect the outcome of key transactions, including a change of control.

After this offering, our directors and executive officers and their affiliates will beneficially own shares representing approximately 67% percent of our outstanding common stock. As a result, these stockholders, if they act together, will be able to influence our management and affairs and all matters requiring stockholder approval, including the election of directors and approval of significant corporate transactions. This concentration of ownership may have the effect of delaying or preventing a change in control of our company and might affect the market price of our common stock.

The market price of our common stock may be volatile, which could result in substantial losses for investors purchasing shares in this offering.

The initial public offering price for our common stock was determined through negotiations with the underwriters. This initial public offering price may vary from the market price of our common stock after the offering. As a result, you may not be able to sell your common stock at or above the initial public offering price. The market price for our common stock may be influenced by those factors discussed in this “Risk Factors” section and many others, some of which may include:

•the success of existing or new competitive product candidates or technologies;

•the timing and results of preclinical studies and clinical trials for any product candidates we may develop;

•failure or discontinuation of any of our development and research programs;

•results of any preclinical studies, clinical trials or regulatory approvals of product candidates of our competitors, or announcements about new research programs or product candidates of our competitors;

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•developments or changing views regarding the use of genetic therapies, including those that involve gene editing;

•commencement or termination of collaborations for our product development and research programs;

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

•developments or disputes concerning patent applications, issued patents or other intellectual property or proprietary rights;

•the recruitment or departure of key personnel;

•the level of expenses related to any of our research programs, clinical development programs or product candidates that we may develop;

•the results of our efforts to develop product candidates;

•actual or anticipated changes in estimates as to financial results, development timelines or recommendations by securities analysts, if any, that cover our stock;

•announcement or expectation of additional financing efforts;

•sales of our common stock by us, our insiders or other stockholders;

•expiration of market stand-off or lock-up agreements;

•variations in our financial results or those of companies that are perceived to be similar to us;

•changes in the structure of healthcare payment systems;

•market conditions in the pharmaceutical and biotechnology sectors;

•the ongoing COVID-19 pandemic, natural disasters or major catastrophic events;

•general economic, industry and market conditions, including rising interest rates and inflation; and

•the other factors described in this “Risk Factors” section.

In recent years, the stock market in general and the market for pharmaceutical and biotechnology companies in particular, has experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to changes in the operating performance of the companies whose stock is experiencing those price and volume fluctuations. In particular, in relation to uncertainty around inflation and the U.S. Federal Reserve’s measures to slow inflation, the stock market has been exceptionally volatile. Market and industry factors may seriously affect the market price of our common stock, regardless of our actual operating performance. These fluctuations may be even more pronounced in the trading market for our stock shortly following this offering. Following periods of such volatility in the market price of a company’s securities, securities class action litigation has often been brought against that company. Because of the potential volatility of our stock price, we may become the target of securities litigation in the future.

Securities litigation could result in substantial costs and divert management’s attention and resources from our business.

We are an “emerging growth company” and a “smaller reporting company,” and the reduced disclosure requirements applicable to emerging growth companies and smaller reporting companies may make our common stock 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, and may remain an emerging growth company for up to five years. For so long as we remain an emerging growth company, we are permitted and plan to rely on exemptions from certain disclosure requirements

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that are applicable to other public companies that are not emerging growth companies. These exemptions include not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act of 2002, or SOX Section 404, not being required to comply with any requirement for a supplement to the auditor’s report providing additional information about the audit and the financial statements, reduced disclosure obligations regarding executive compensation and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and stockholder approval of any golden parachute payments not previously approved. As a result, the information we provide stockholders will be different than the information that is available with respect to other public companies. In this prospectus, we have not included all of the executive compensation related information that would be required if we were not an emerging growth company.

In addition, the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. This allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to avail ourselves of this exemption, and, therefore, while we are an emerging growth company we will not be subject to the new or revised accounting standards at the same time that they become applicable to other public companies that are not emerging growth companies. As a result of this election, our financial statements may not be comparable to those of other public companies that comply with new or revised accounting pronouncements as of public company effective dates. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.

We are also a “smaller reporting company,” meaning that the market value of our stock held by non-affiliates plus the proposed aggregate amount of gross proceeds to us as a result of this offering is less than $700 million and our annual revenue is less than $100 million during the most recently completed fiscal year. We may continue to be a smaller reporting company after this offering if either (i) the market value of our stock held by non-affiliates is less than $250 million or (ii) our annual revenue is less than $100 million during the most recently completed fiscal year and the market value of our stock held by non-affiliates is less than $700 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company we may choose to present only the two most recent fiscal years of audited financial statements in our Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.

We cannot predict whether investors will find our common stock less attractive if we rely on these exemptions. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile.

We will incur increased costs as a result of operating as a public company, and our management will be required to devote substantial time to new compliance initiatives and corporate governance practices.

As a public company, and particularly after we are no longer an “emerging growth company,” we will incur significant legal, accounting and other expenses that we did not incur as a private company. The Sarbanes-Oxley Act of 2002, the Dodd-Frank Wall Street Reform and Consumer Protection Act, the listing requirements of The Nasdaq Global Market and other applicable securities rules and regulations impose various requirements on public companies, including establishment and maintenance of effective disclosure and financial controls and corporate governance practices. We expect that we will need to hire additional accounting, finance and other personnel in connection with our becoming, and our efforts to comply with the requirements of being, a public company. Our management and other personnel will need to devote a substantial amount of time towards maintaining compliance with these requirements. These requirements will increase our legal and financial compliance costs and will make some activities more time-consuming and costly. For example, we expect that the rules and regulations applicable to us as a public company may make it more difficult and more expensive for us to obtain director and officer liability insurance, which could make it more difficult for us to attract and retain qualified members of our board of directors. We are currently evaluating these rules and regulations and cannot predict or estimate the amount of additional costs we may incur or the timing of such costs. 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

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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 SOX Section 404, we will be required to furnish a report by our management on our internal control over financial reporting beginning with our second filing of an Annual Report on Form 10-K with the SEC after we become a public company. 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 achieve compliance with SOX Section 404 within the prescribed period, 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, 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 SOX Section 404. This could result in an adverse reaction in the financial markets due to a loss of confidence in the reliability of our financial statements.

We do not expect to pay any dividends for the foreseeable future. Investors in this offering may never obtain a return on their investment.

You should not rely on an investment in our common stock to provide dividend income. We do not anticipate that we will pay any dividends to holders of our common stock in the foreseeable future. Instead, we plan to retain any earnings to maintain and expand our existing operations. In addition, any future credit facility may contain terms prohibiting or limiting the amount of dividends that may be declared or paid on our common stock. Accordingly, investors must rely on sales of their common stock after price appreciation, which may never occur, as the only way to realize any return on their investment. As a result, investors seeking cash dividends should not purchase our common stock.

General Risks Factors

Changes in tax laws or in their implementation or interpretation may adversely affect our business and financial condition.

The rules dealing with U.S. federal, state and local income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect our business and our financial condition. In recent years, many such changes have been made and changes are likely to continue to occur in the future. We cannot predict whether, when, in what form or with what effective dates, tax laws, regulations and rulings may be enacted, promulgated or decided or whether they could increase our tax liability or require changes in the manner in which we operate in order to minimize increases in our tax liability.

If we fail to establish and maintain proper and effective internal control over financial reporting, our operating results and our ability to operate our business could be harmed.

Ensuring that we have adequate internal financial and accounting controls and procedures in place so that we can produce accurate financial statements on a timely basis is a costly and time-consuming effort that needs to be re-evaluated frequently. Our internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements in accordance with generally accepted accounting principles. In connection with this offering, we intend to begin the process of documenting, reviewing and improving our internal controls and procedures for compliance with Section 404 of the Sarbanes-Oxley Act of 2002, or SOX, which will require annual management assessment of the effectiveness of our internal control over financial reporting.

Implementing any appropriate changes to our internal controls may distract our officers and employees, entail substantial costs to modify our existing processes and take significant time to complete. These changes may not,

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however, be effective in maintaining the adequacy of our internal controls, and any failure to maintain that adequacy or consequent inability to produce accurate financial statements on a timely basis could increase our operating costs and harm our business. In addition, investors’ perceptions that our internal controls are inadequate or that we are unable to produce accurate financial statements on a timely basis may harm our common share price and make it more difficult for us to effectively market and sell our service to new and existing customers.

We have identified a material weakness in our internal control over financial reporting. If we fail to remediate this material weakness or identify additional material weaknesses in the future or otherwise fail to maintain effective internal control over financial reporting in the future, we may not be able to accurately report our financial condition or results of operations which may adversely affect investor confidence in us and, as a result, the value of our common stock.

In preparing our financial statements as of and for the years ended December 31, 2019 and 2020, we identified a material weakness in our internal control over financial reporting that existed as of the end of those periods, and which remains unremediated as of June 30, 2022. A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of our annual or interim financial statements will not be prevented or detected on a timely basis.

Specifically, we did not design and maintain effective controls over segregation of duties commensurate with our financial reporting requirements, as certain personnel have access to edit financial information without an independent review. This material weakness did not result in a misstatement to the consolidated financial statements. However, this material weakness could result in a misstatement of substantially all of the financial statement accounts and disclosures that would result in a material misstatement to the annual or interim consolidated financial statements that would not be prevented or detected. 

We cannot assure you that we will be successful in fully remediating this material weakness, or that additional material weaknesses in our internal control over financial reporting will not be identified in the future. Our failure to design, implement and maintain effective internal control over financial reporting could result in misstatements in our financial statements that could result in a restatement of our financial statements, and could cause us to fail to meet our reporting obligations.

The process of designing and implementing effective internal control over financial reporting is a continuous effort that requires us to anticipate and react to changes in our business and the economic and regulatory environments and to expend significant resources that are adequate to satisfy our reporting obligations. We have not performed a formal evaluation of our internal control over financial reporting, as required by the rules and regulations of the SEC, nor are we required to have an independent registered public accounting firm perform an audit of our internal control over financial reporting as of any balance sheet date or for any period reported in our financial statements. Presently, we are not an accelerated filer, as such term is defined by Rule 12b-2 of the Exchange Act, and therefore, our management is not presently required to perform an annual assessment of the effectiveness of our internal control over financial reporting. Our independent registered public accounting firm will first be required to attest to the effectiveness of our internal control over financial reporting for our Annual Report on Form 10-K for the first year we are no longer an "emerging growth company” or a “smaller reporting company.” Failure to comply with the rules and regulations of the SEC could potentially subject us to sanctions or investigations by the SEC, the applicable stock exchange or other regulatory authorities, which would require additional financial and management resources. We have begun the process of compiling the system and processing documentation necessary to perform the evaluation needed to comply with the rules and regulations of the SEC in the future, but we may not be able to complete our evaluation, testing and any required remediation in a timely fashion. An independent assessment of the effectiveness of our internal control over financial reporting could detect deficiencies in our internal control over financial reporting that our management’s assessment might not. Undetected material weaknesses in our internal control over financial reporting could lead to financial statement restatements and require us to incur the expense of remediation.

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Provisions in our third amended and restated certificate of incorporation, our amended and restated by-laws and Delaware law may have anti-takeover effects that could discourage an acquisition of us by others, even if an acquisition would be beneficial to our stockholders, and may prevent attempts by our stockholders to replace or remove our current management.

Our third amended and restated certificate of incorporation, amended and restated by-laws and Delaware law contain provisions that may have the effect of discouraging, delaying or preventing a change in control of us or changes in our management that stockholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares. Our third amended and restated certificate of incorporation, which will become effective immediately prior to the closing of this offering, and by-laws, which will become effective upon the effectiveness of the registration statement of which this prospectus is a part, include provisions that:

•authorize “blank check” preferred stock, which could be issued by our board of directors without stockholder approval and may contain voting, liquidation, dividend and other rights superior to our common stock;

•create a classified board of directors whose members serve staggered three-year terms;

•specify that special meetings of our stockholders can be called only by our board of directors;

•prohibit stockholder action by written consent;

•establish an advance notice procedure for stockholder approvals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to our board of directors;

•provide that vacancies on our board of directors may be filled only by a majority of directors then in office, even though less than a quorum;

•provide that our directors may be removed only for cause;

•specify that no stockholder is permitted to cumulate votes at any election of directors;

•expressly authorized our board of directors to make, alter, amend or repeal our amended and restated by-laws; and

•require supermajority votes of the holders of our common stock to amend specified provisions of our third amended and restated certificate of incorporation and amended and restated by-laws.

These provisions, alone or together, could delay or prevent hostile takeovers and changes in control or changes in our management. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, thereby depressing the market price of our common stock.

In addition, because we are incorporated in the State of Delaware, we are governed by the provisions of Section 203 of the General Corporation Law of the State of Delaware, or the DGCL, which prohibits a person who owns in excess of 15 percent of our outstanding voting stock from merging or combining with us for a period of three years after the date of the transaction in which the person acquired in excess of 15 percent of our outstanding voting stock, unless the merger or combination is approved in a prescribed manner.

Any provision of our third amended and restated certificate of incorporation, amended and restated by-laws or Delaware law that has the effect of delaying or deterring a change in control could limit the opportunity for our stockholders to receive a premium for their shares of our common stock and could also affect the price that some investors are willing to pay for our common stock.

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Our amended and restated bylaws that will become effective upon the effectiveness of our registration statement designate specific courts as the exclusive forum for certain litigation that may be initiated by our stockholders, which could limit stockholders’ ability to obtain a favorable judicial forum for disputes with us.

Pursuant to our amended and restated bylaws that will become effective upon the effectiveness of our registration statement, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware is the sole and exclusive forum for any state law claims for (i) any derivative action or proceeding brought on our behalf; (ii) any action asserting a claim of or based on a breach of a fiduciary duty owed by any director, officer or other employee of ours to us or our stockholders; (iii) any action asserting a claim pursuant to any provision of the DGCL, our third amended and restated certificate of incorporation or our amended and restated bylaws or as to which the DGCL confers jurisdiction on the Court of Chancery of the State of Delaware; or (iv) any action asserting a claim governed by the internal affairs doctrine, or the Delaware Forum Provision. The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act or the Securities Exchange Act of 1934, as amended, or the Exchange Act. Our amended and restated bylaws further provide that unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States shall be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, the Exchange Act, the respective rules and regulations promulgated thereunder or the Federal Forum Provision. In addition, our amended and restated bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision; provided, however, that stockholders cannot and will not be deemed to have waived our compliance with the federal securities laws and the rules and regulations thereunder.

We recognize that the Delaware Forum Provision and the Federal Forum Provision in our amended and restated bylaws may impose additional litigation costs on stockholders in pursuing any such claims, particularly if the stockholders do not reside in or near the State of Delaware. Additionally, the forum selection clauses in our amended and restated bylaws may limit our stockholders’ ability to bring a claim in a judicial forum that they find favorable for disputes with us or our directors, officers or employees, which may discourage the filing of lawsuits against us and our directors, officers and employees, even though an action, if successful, might benefit our stockholders. In addition, while the Delaware Supreme Court ruled in March 2020 that federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court are “facially valid” under Delaware law, there is uncertainty as to whether other courts will enforce our Federal Forum Provision. If the Federal Forum Provision is found to be unenforceable, we may incur additional costs associated with resolving such matters. The Federal Forum Provision may also impose additional litigation costs on stockholders who assert that the provision is not enforceable or invalid. The Court of Chancery of the State of Delaware and the federal district courts of the United States may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments may be more or less favorable to us than our stockholders.

We have wide discretion in the use of the net proceeds from this offering and may not use them effectively.

We cannot specify with certainty the particular uses of the net proceeds we will receive from this offering. Our management will have wide discretion in the application of the net proceeds, including for any of the purposes described in “Use of Proceeds.” Accordingly, you will have to rely upon the judgment of our management with respect to the use of the proceeds, with only limited information concerning management’s specific intentions. Our management may spend a portion or all of the net proceeds from this offering in ways that our stockholders may not desire or that may not yield a favorable return. The failure by our management to apply these funds effectively could harm our business, financial condition, results of operations and prospects. Pending their use, we may invest the net proceeds from this offering in a manner that does not produce income or that loses value.

Unfavorable global economic conditions could adversely affect our business, financial condition or results of operations.

Our results of operations could be adversely affected by general conditions in the global economy and in the global financial markets. A severe or prolonged economic downturn or additional global financial crises could result

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in a variety of risks to our business, including weakened demand for any product candidates we develop or our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could also strain our suppliers, possibly resulting in supply disruption. Any of the foregoing could harm our business and we cannot anticipate all of the ways in which the current economic climate and financial market conditions could adversely impact our business.

Our operations are vulnerable to interruption by disasters, terrorist activity, pandemics and other events beyond our control, which could harm our business.

Our facilities are located in Massachusetts. We have not undertaken a systematic analysis of the potential consequences to our business and financial results from a major flood, power loss, terrorist activity, pandemics or other disasters and do not have a recovery plan for such events. In addition, we do not carry sufficient insurance to compensate us for actual losses from interruption of our business that may occur, and any losses or damages incurred by us could harm our business. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the sections entitled “Prospectus Summary,” “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and “Business,” contains express or implied forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. Although we believe that the expectations reflected in these forward-looking statements are reasonable, these statements relate to future events or our future operational or financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements in this prospectus include, but are not limited to, statements about:

•the initiation, timing, progress and results of our research and development programs, preclinical studies and future clinical trials;

•our ability to demonstrate, and the timing of, preclinical proof-of-concept in vivo for multiple programs;

•our ability to advance any product candidates that we may identify and successfully complete any clinical studies, including the manufacture of any such product candidates;

•our ability to pursue our four strategic indication categories: immediate target indications, differentiation target indications, “blue sky” indications and “march up the chromosome” approaches;

•our ability to quickly leverage programs within our initial target indications and to progress additional programs to further develop our pipeline;

•the timing of our investigational new drug applications submissions;

•the implementation of our strategic plans for our business, programs and technology;

•the scope of protection we are able to establish and maintain for intellectual property rights covering our Prime Editing technology;

•developments related to our competitors and our industry;

•our ability to leverage the clinical, regulatory, and manufacturing advancements made by gene therapy and gene editing programs to accelerate our clinical trials and approval of product candidates;

•our ability to identify and enter into future license agreements and collaborations;

•developments related to our Prime Editing technology;

•regulatory developments in the United States and foreign countries;

•our ability to attract and retain key scientific and management personnel;

•our use of proceeds from this offering, estimates of our expenses, capital requirements, and needs for additional financing; and

•general economic, industry and market conditions, including rising interest rates and inflation.

In some cases, you can identify forward-looking statements by terminology such as “may,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “potential,” “continue” or the negative of these terms or other comparable terminology. These statements are only predictions. You should not place undue reliance on forward-looking statements because they involve known and unknown risks, uncertainties, and other factors, which are, in some cases, beyond our control and which could materially affect results. Factors that may cause actual results to differ materially from current expectations include, among other things, those listed under the

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section entitled “Risk Factors” and elsewhere in this prospectus. If one or more of these risks or uncertainties occur, or if our underlying assumptions prove to be incorrect, actual events or results may vary significantly from those implied or projected by the forward-looking statements. No forward-looking statement is a guarantee of future performance. You should read this prospectus and the documents that we reference in this prospectus and have filed with the SEC as exhibits to the registration statement, of which this prospectus forms a part, completely and with the understanding that our actual future results may be materially different from any future results expressed or implied by these forward-looking statements.

The forward-looking statements in this prospectus represent our views as of the date of this prospectus. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should therefore not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus.

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. While we are not aware of any misstatements regarding any third-party information presented in this prospectus, their estimates, in particular, as they relate to projections, involve numerous assumptions, are subject to risks and uncertainties and are subject to change based on various factors, including those discussed under the section entitled “Risk factors” and elsewhere in this prospectus.

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USE OF PROCEEDS

We estimate that the net proceeds to us from the sale of 8,900,000 shares of our common stock in this offering will be approximately $136.2 million, or approximately $157.3 million if the underwriters exercise in full their option to purchase additional shares, assuming an initial public offering price of $17.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, and after deducting 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 $17.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, would increase (decrease) the net proceeds to us from this offering by $8.3 million, assuming the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. An increase (decrease) of 1.0 million shares in the number of shares offered by us, as set forth on the cover page of this prospectus, would increase (decrease) net proceeds to us from this offering by $15.8 million, assuming no change in the assumed initial public offering price per share, the midpoint of the price range set forth on the cover page of this prospectus, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. We do not expect that a change in the offering price or the number of shares by these amounts would have a material effect on our intended uses of the net proceeds from this offering, although it may impact the amount of time prior to which we may need to seek additional capital.

As of June 30, 2022, we had cash and cash equivalents and short-term investments of $180.6 million, excluding restricted cash, or $194.1 million, including restricted cash. We currently intend to use the net proceeds from this offering, together with our existing cash and cash equivalents, as follows:

•approximately $90.0 million for continued research and development of our Prime Editing portfolio, including preclinical studies and advancement through potential preclinical proof-of-concept;

•approximately $65.0 million for IND-enabling studies and the potential initiation of clinical studies for certain of our current therapeutic programs;

•approximately $65.0 million for continued advancement of our Prime Editing platform and discovery-stage research for other potential programs;

•approximately $50.0 million to develop our early-stage manufacturing processes and build out our dedicated chemistry facility; and

•the remainder for general corporate purposes.

Based on our current plans, we believe our existing cash and cash equivalents and short-term investments, together with the net proceeds from this offering, will be sufficient to fund our operating expenses and capital expenditure requirements into 2025.

All of our programs are currently in preclinical stage of development. At our current stage of preclinical development, a large proportion of our activities are cross-program (e.g. development of manufacturing, animal experiments) and generally are not allocated to specific programs or product candidates, unlike a company in the clinical development stage. The expected use of the net proceeds from this offering represents our intentions based upon our current plans and business conditions, which could change in the future as our plans and business conditions evolve. 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 closing of this offering or the amounts that we will actually spend on the uses set forth above. The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the progress of our research and development, the status of and results from preclinical studies or clinical trials we may commence in the future, as well as any collaborations that we may enter into with third parties for our product candidates or strategic opportunities that become available to us, and any unforeseen cash needs. As a result, our management will retain broad discretion over the allocation of the net proceeds from this offering. We expect the net proceeds from this offering, together with our existing cash and cash equivalents, and short-term investments, will not be sufficient for us to advance any of our programs through regulatory approval, and we will

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need to raise additional capital to complete the development and potential commercialization of any of our programs.

Pending our use of proceeds from this offering, we intend to invest the net proceeds in a variety of capital preservation instruments, including short-term, investment-grade, interest-bearing instruments and U.S. government securities.

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DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock. We currently intend to retain any future earnings to fund the development and expansion of our business, and therefore we do not anticipate paying cash dividends on our common stock in the foreseeable future. Any future determination to pay dividends will be at the discretion of our board of directors and will depend on our results of operations, financial condition, capital requirements and other factors deemed relevant by our board of directors.

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CAPITALIZATION

The following table sets forth our cash and cash equivalents and our capitalization as of June 30, 2022:

•on an actual basis;

•on a pro forma basis to give effect to (i) the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of common stock upon the completion of this offering and (ii) the filing and effectiveness of our third amended and restated certificate of incorporation immediately prior to the closing of this offering, in each case as if such events had occurred on June 30, 2022; and

•on a pro forma as adjusted basis to give further effect to our issuance and sale of 8,900,000 shares of our common stock in this offering at an assumed initial public offering price of $17.00 per share, which is the midpoint of the price range set forth on the cover page of this prospectus, after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

The pro forma as adjusted information below is illustrative only, and our capitalization following the completion of this offering will be adjusted based on the actual initial public offering price and other terms of this offering determined at pricing. You should read the information in this table together with our consolidated financial statements and the related notes included elsewhere in this prospectus and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” section of this prospectus.

	As of June 30, 2022
	Actual		Pro forma		Pro forma as adjusted(1)
	(in thousands, except share and per share data)
Cash and cash equivalents	$	92,239	$	92,239	$	231,430
Convertible preferred stock (Series A and B), $0.00001 par value; 161,420,799 shares authorized; 161,420,799 shares issued and outstanding, actual; no shares authorized, issued or outstanding, pro forma and pro forma as adjusted	395,800		—		—
Stockholders’ equity (deficit):
Preferred stock, $0.00001 par value; no shares authorized, issued or outstanding, actual; 10,000,000 shares authorized and no shares issued or outstanding, pro forma and pro forma as adjusted	—		—		—
Common stock, $0.00001 par value; 293,258,790 shares authorized, 33,512,269 shares issued and outstanding, actual;  775,000,000 shares authorized, 85,436,033 shares issued and outstanding, pro forma; 775,000,000 shares authorized, 94,336,033 shares issued and outstanding, pro forma as adjusted	—		1		1
Additional paid-in capital	29,651		425,450		561,659
Accumulated other comprehensive loss	(150)		(150)		(150)
Accumulated deficit	(224,564)		(224,564)		(224,564)
Total stockholders' equity (deficit)	(195,063)		200,737		336,946
Total capitalization	$	200,737	$	200,737	$	336,946

___________________

(1) Each $1.00 increase (decrease) in the assumed initial public offering price of $17.00 per share, 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 and cash equivalents, total stockholders’ equity and total capitalization by $8.3 million, assuming that the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Each increase (decrease) of 1,000,000 shares in the number of shares 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 and cash equivalents, total stockholders’

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equity and total capitalization by $15.8 million, assuming no change in the assumed initial public offering price per share and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

The number of shares of our common stock outstanding after this offering is based on 85,436,033 shares (which includes 11,995,985 shares of unvested restricted common stock) of our common stock outstanding as of June 30, 2022, after giving effect to the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of our common stock upon the completion of this offering, and excludes:

•58,903 shares of common stock issued after June 30, 2022 upon the exercise of stock options under our 2019 Stock Option and Grant Plan;

•3,593,533 shares of common stock issuable upon the exercise of stock options outstanding as of June 30, 2022, with a weighted-average exercise price of $4.82 per share under our 2019 Stock Option and Grant Plan;

•516,269 shares of common stock issuable upon the exercise of stock options granted after June 30, 2022, with a weighted-average exercise price of $7.96 per share under our 2019 Stock Option and Grant Plan;

•1,818,210 shares of common stock reserved for issuance under our 2019 Stock Option and Grant Plan as of June 30, 2022, which shares will cease to be available for issuance at the time our 2022 Stock Option and Incentive Plan becomes effective;

•8,041,688 shares of common stock reserved for future issuance under our 2022 Stock Option and Incentive Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective and which includes an aggregate of 511,500 shares of common stock issuable upon the exercise of stock options which will be granted to certain of our executive officers, directors, and other employees at the time of effectiveness of the 2022 Stock Option and Incentive Plan with an exercise price equal to the initial public offering price per share; and

•971,350 shares of common stock reserved for future issuance under our 2022 Employee Stock Purchase Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective.

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DILUTION

If you invest in our common stock in this offering, your ownership interest will be diluted immediately to the extent of the difference between the initial public offering price per share of our common stock and the pro forma as adjusted net tangible book value per share of our common stock immediately after this offering.

Our historical net tangible book (deficit) as of June 30, 2022 was $(198.3) million, or $(9.22) per share of our common stock. Our historical net tangible book deficit per share is the amount of our total tangible assets less our total liabilities and the carrying values of our convertible preferred stock, which is not included within stockholders’ deficit. Our historical net tangible book deficit per share represents historical net tangible book deficit divided by the 21,516,284 shares of our common stock outstanding (which excludes 11,995,985 shares of unvested restricted common stock) as of June 30, 2022.

Our pro forma net tangible book value as of June 30, 2022 was $197.5 million, or $2.69 per share of our common stock. Pro forma net tangible book value represents the amount of our total tangible assets less our total liabilities, after giving effect to the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of common stock upon the completion of this offering. Pro forma net tangible book value per share represents pro forma net tangible book value divided by the total number of shares outstanding (which excludes 11,995,985 shares of unvested restricted common stock) as of June 30, 2022, after giving effect to the pro forma adjustment described above.

After giving further effect to our issuance and sale of shares of our common stock in this offering at an assumed initial public offering price of $17.00 per share, the midpoint of the price range set forth on the cover page of this prospectus, and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value as of June 30, 2022 would have been $336.9 million, or $4.09 per share. This amount represents an immediate increase in pro forma as adjusted net tangible book value per share of $1.40 to our existing stockholders and immediate dilution of $12.91 in pro forma as adjusted net tangible book value per share to new investors purchasing common stock in this offering.

Dilution per share to new investors is determined by subtracting pro forma as adjusted net tangible book value per share after this offering from the initial public offering price per share paid by new investors. The following table illustrates this dilution on a per share basis (without giving effect to any exercise by the underwriters of their option to purchase additional shares):

Assumed initial public offering price per share			$	17.00
Historical net tangible book value (deficit) per share as of June 30, 2022	$	(9.22)
Increase per share attributable to the pro forma adjustments described above	$	11.91
Pro forma net tangible book value per share as of June 30, 2022	$	2.69
Increase in pro forma as adjusted net tangible book value per share attributable to new investors participating in this offering	$	1.40
Pro forma as adjusted net tangible book value per share immediately after this offering			$	4.09
Dilution per share to new investors participating in this offering			$	12.91

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. Each $1.00 increase (decrease) in the assumed initial public offering price of $17.00 per share, 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 per share after this offering by $0.10 and dilution per share to new investors purchasing common stock in this offering by $0.90, assuming that the number of shares offered by us, as set forth on the cover page of this prospectus, remains the same and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Each increase of 1,000,000 shares in the number of shares offered by us, as set forth on the cover page of this prospectus, would increase our pro forma as adjusted net tangible book value per share after this offering by $0.14 and decrease dilution per share to new investors purchasing common stock in this offering by $0.14, assuming no

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change in the assumed initial public offering price per share and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. Each decrease of 1,000,000 shares in the number of shares offered by us, as set forth on the cover page of this prospectus, would decrease our pro forma as adjusted net tangible book value per share after this offering by $0.14 and increase dilution per share to new investors purchasing common stock in this offering by $0.14, assuming no change in the assumed initial public offering price and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

If the underwriters exercise their option to purchase additional shares in full, our pro forma as adjusted net tangible book value per share after this offering would be $4.28, representing an immediate increase in pro forma as adjusted net tangible book value per share of $1.59 to existing stockholders and immediate dilution in pro forma as adjusted net tangible book value per share of $12.72 to new investors purchasing common stock in this offering, based on the assumed initial public offering price of $17.00 per share and after deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us.

The following table summarizes on the pro forma as adjusted basis described above, the total number of shares of common stock purchased from us, including shares of unvested restricted stock, on an as converted to common stock basis, the total consideration paid or to be paid, and the average price per share paid or to be paid by existing stockholders and by new investors in this offering at an assumed initial public offering price of $17.00 per share, which is the midpoint of the estimated price range set forth on the cover of this prospectus, before deducting estimated underwriting discounts and commissions and estimated offering expenses payable by us. As the table shows, new investors purchasing common stock in this offering will pay an average price per share substantially higher than our existing stockholders paid.

	Shares Purchased			Total Consideration				Average Price Per Share
	Number	Percent		Amount		Percent
Existing stockholders	85,436,033	90.6	%	$	315,762,666	67.6	%	$	3.70
Investors participating in this offering	8,900,000	9.4	%	$	151,300,000	32.4	%	$	17.00
Total	94,336,033	100	%	$	467,062,666	100	%

The table above assumes no exercise of the underwriters’ option to purchase additional shares in this offering. If the underwriters’ option to purchase additional shares is exercised in full, the number of shares of our common stock held by existing stockholders would be reduced to 89.3 percent of the total number of shares of our common stock outstanding after this offering, and the number of shares of common stock held by new investors purchasing common stock in this offering would be increased to 10.7 percent of the total number of shares of our common stock outstanding after this offering.

The number of shares of our common stock outstanding after this offering is based on 85,436,033 shares (which includes 11,995,985 shares of unvested restricted common stock) of our common stock outstanding as of June 30, 2022, after giving effect to the automatic conversion of all outstanding shares of our Series A and Series B convertible preferred stock into an aggregate of 51,923,764 shares of our common stock upon the completion of this offering, and excludes:

•58,903 shares of common stock issued after June 30, 2022 upon the exercise of stock options under our 2019 Stock Option and Grant Plan;

•3,593,533 shares of common stock issuable upon the exercise of stock options outstanding as of June 30, 2022, with a weighted-average exercise price of $4.82 per share under our 2019 Stock Option and Grant Plan;

•516,269 shares of common stock issuable upon the exercise of stock options granted after June 30, 2022, with a weighted-average exercise price of $7.96 per share under our 2019 Stock Option and Grant Plan;

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•1,818,210 shares of common stock reserved for issuance under our 2019 Stock Option and Grant Plan as of June 30, 2022, which shares will cease to be available for issuance at the time our 2022 Stock Option and Incentive Plan becomes effective;

•8,041,688 shares of common stock reserved for future issuance under our 2022 Stock Option and Incentive Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective and which includes an aggregate of 511,500 shares of common stock issuable upon the exercise of stock options which will be granted to certain of our executive officers, directors, and other employees at the time of effectiveness of the 2022 Stock Option and Incentive Plan with an exercise price equal to the initial public offering price per share; and

•971,350 shares of common stock reserved for future issuance under our 2022 Employee Stock Purchase Plan, which will become effective upon the date immediately preceding the date on which the registration statement of which this prospectus is a part is declared effective.

To the extent that new stock options are issued or any outstanding options are exercised, or we issue additional shares of common stock in the future, there will be further dilution to new investors. In addition, we may choose to raise additional capital because of market conditions or strategic considerations, even if we believe that we have sufficient funds for our current or future operating plans. If we raise additional capital through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

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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 our consolidated financial statements and the related notes appearing at the end of this prospectus. This discussion and other parts of this prospectus contain forward-looking statements that involve risks and uncertainties, such as statements regarding our plans, objectives, expectations, intentions and projections. Our actual results could differ materially from those discussed in these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the “Risk Factors” section of this prospectus. Our historical results are not necessarily indicative of the results that may be expected for any period in the future.

Overview

We are a biotechnology company committed to delivering a new class of differentiated one-time curative genetic therapies to address the widest spectrum of diseases by deploying our Prime Editing technology, which we believe is a versatile, precise, efficient and broad gene editing technology.

Genetic mutations implicated in disease are diverse and can range from errors of a single base, known as point mutations, to errors that extend beyond a single base, such as insertions, deletions, duplications, or combinations thereof. Other mutations can affect regulatory sequences that control the function of genes and can affect the function of larger biochemical and genetic pathways. Furthermore, natural genetic variations, revealed by population-level genomic studies, are known to protect against or to increase risk of disease. To maximize the impact of these genetic insights, we believe the ability to alter the human genome at the foundational level may confer the greatest therapeutic impact on human disease.

Since our inception in September 2019, we have devoted substantially all of our efforts on organizing and staffing our company, business planning, raising capital, research and development activities, developing our Prime Editing platform, building our intellectual property portfolio and providing general and administrative support for these operations. To date, we have financed our operations primarily with proceeds from sales of preferred stock. Through June 30, 2022, we had received gross proceeds of $315.8 million from sales of preferred stock.

We have incurred significant operating losses since inception. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of any product candidates we may develop. We generated net losses of $2.5 million, $3.4 million, $165.4 million, $86.0 million, and $53.2 million for the period from September 13, 2019 (inception) to December 31, 2019, the years ended December 31, 2020 and 2021, and the six months ended June 30, 2021 and 2022, respectively. As of June 30, 2022, we had an accumulated deficit of $224.6 million. We expect to continue to incur significant expenses for at least the next several years if and as we:

•continue our current research programs and preclinical development of any product candidates we identify;

•seek to identify additional research programs and product candidates;

•initiate preclinical studies and clinical trials for any product candidates we may identify;

•experience any delays or interruptions due to the ongoing COVID-19 pandemic, including delays in preclinical testing and clinical trials or interruptions in the supply chain for any future product candidates;

•further develop our in-licensed and company-owned gene editing platform, which we call our Prime Editing platform;

•maintain, expand, enforce, defend and protect our intellectual property portfolio and provide reimbursement of third-party expenses related to our patent portfolio;

•seek marketing approvals for any product candidates for which we successfully complete clinical trials;

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•develop, maintain and enhance a sustainable, scalable, reproducible and transferable manufacturing process for the product candidates we may develop;

•ultimately establish a sales, marketing and distribution infrastructure to commercialize any therapies for which we may obtain marketing approval;

•hire additional research and development personnel;

•hire clinical and commercial personnel;

•add operational, financial and management information systems and personnel, including personnel to support our product development;

•acquire or in-license product candidates, intellectual property and technologies;

•establish and maintain collaborations;

•should we decide to do so, build and maintain a commercial-scale current Good Manufacturing Practices, or cGMP, manufacturing facility; and

•operate as a public company.

We will not generate revenue from product sales unless and until we successfully initiate and complete clinical development and obtain regulatory approval for any product candidates. If we obtain regulatory approval for any of our product candidates and do not enter into a commercialization partnership, we expect to incur significant expenses related to developing our commercialization capability to support product sales, manufacturing, marketing, and distribution. Further, following the completion of this offering, we expect to incur additional costs associated with operating as a public company, including increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses associated with being a public 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 a combination of private and public equity offerings, debt financings, or other capital sources, which may include additional collaborations with other companies, marketing, distribution or licensing arrangements with third parties, 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, reduce or eliminate the development and commercialization of any product candidates that we may identify or delay our pursuit of potential in-licenses or acquisitions.

Because of the numerous risks and uncertainties associated with product development, we are unable to accurately predict the timing or amount of increased expenses or when or if we will be able to achieve or maintain profitability. Even if we are able to generate product sales, we may not become profitable. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations at planned levels and be forced to reduce or terminate our operations.

We believe our existing cash and cash equivalents and short-term investments, together with the net proceeds from this offering, will be sufficient to fund our operating expenses and capital expenditure requirements into 2025. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. See “—Liquidity and Capital Resources.” and “Risk Factors—Risks Related To Our Financial Position and Need for Additional Capital.”

Impact of COVID-19 on Our Operations

We are subject to a number of risks associated with the COVID-19 global pandemic, including potential delays associated with our ongoing preclinical studies and anticipated clinical trials. COVID-19 may have an adverse

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impact on our operations, supply chains and distribution systems or those of our third-party vendors and collaborators, and increase expenses, including as a result of impacts associated with preventive and precautionary measures that are being taken, such as restrictions on travel and border crossings, quarantine policies and social distancing. For example, our laboratory-based personnel have been unable to maximize use of our existing laboratory space due to restrictions on density of people and other aspects of our work have been limited by the need for our staff to isolate. We and our third-party vendors and collaborators may experience disruptions in supply of items that are essential for our research and development activities. We cannot predict the scope and severity of any economic recovery after the COVID-19 pandemic abates, including following any additional “waves” or other intensifying of the pandemic will have on our financial condition, operations and business plans.

License Agreement with Broad Institute

In September 2019, we entered into a license agreement with Broad Institute, and in May 2020 and February 2021, we entered into amendments to the license agreement, for certain patents related to delivery or targeting of DNA, or the Broad License Agreement. Under the Broad License Agreement, Broad Institute grants to us (i) an exclusive, worldwide license under the licensed patent rights solely to offer for sale, sell, have sold and import products covered by such licensed patent rights, or licensed products, solely for use within the Prime Broad Field, as defined below (subject to certain specified limitations and exclusions with respect to certain applications), (ii) a non-exclusive, worldwide license under the licensed patent rights solely to make, have made, offer for sale, sell, have sold, and import licensed products solely for use in the Prime Broad Field, (iii) a non-exclusive, worldwide license under the licensed patent rights solely to make, have made, offer for sale, sell, have sold and import other products that are enabled by (a) the licensed patent rights or (b) the use of certain materials transferred to us by Broad Institute, solely for the prevention or treatment of human diseases and (iv) a non-exclusive, worldwide license solely for internal research. Further, with respect to DNA delivery or targeting applications covered by the licensed patent rights, the exclusive license granted to us by Broad Institute is limited only to “prime editor” products and specifically excludes applications relating to the production or processing of small or large molecules, including for the prevention or treatment of human disease. Under the Broad License Agreement, we also have the right to grant sublicenses to our affiliates and third parties, subject to certain requirements. We are obligated to use commercially reasonable efforts to develop, seek marketing approval for, and commercialize licensed products in the field. As partial consideration for the license, we made an upfront payment of $0.5 million to Broad Institute.

Concurrently with the Broad License Agreement, we entered into a subscription agreement with Broad Institute, or the Broad Subscription Agreement. Under the Broad Subscription Agreement, as additional consideration for the license, we issued 623,529 shares of common stock, with a fair value of $39,000, to Broad Institute, representing 5.0 percent of our then outstanding capital stock on a fully diluted basis. The Broad Subscription Agreement also obligated us to issue additional shares of common stock to Broad Institute without additional consideration to maintain Broad Institute’s ownership of us at 5.0 percent on a fully-diluted basis, if at any time prior to the achievement of an equity financing up to $100.0 million, we issue additional securities that would cause Broad Institute shares of common stock to be less than 5.0 percent of our outstanding capital stock on a fully-diluted basis, or the Anti-Dilution Obligation. Upon the achievement of the $100.0 million of equity financing in connection with the closing of the fourth tranche of our Series A preferred stock, we fully settled the Anti-Dilution Obligation, which resulted in the issuance of 2,498,850 shares of common stock to Broad Institute with a fair value of $7.5 million.

We also granted certain preemptive rights to Broad Institute, under which if after we reach the financing threshold of $100.0 million, we propose to offer or sell any new securities, then Broad Institute shall have the right to purchase from us the portion of such new securities that would allow Broad Institute to maintain its 5.0 percent ownership in us. In April 2021, we exceeded the financing threshold with the fourth issuance of the Series A preferred stock. In connection with the fourth closing of Series A preferred stock, Broad Institute purchased an additional 761,844 shares of Series A preferred stock, at a price of $1.00 per share for gross proceeds of $0.8 million, to maintain its 5.0 percent ownership in us.

Under the Broad License Agreement, we are required to use commercially reasonable efforts to develop licensed products in the Prime Broad Field in accordance with a development plan that we prepared and submitted to Broad Institute. We are also obligated to pay Broad Institute an annual license maintenance fee ranging from the low to mid five-figures to the low six-figures, depending on the particular calendar year, for the term of the agreement.

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Broad Institute is also entitled to receive clinical and regulatory milestone payments up to a total of $20.0 million per licensed product, depending on the patient population to be treated by the licensed product achieving the applicable milestone. If we undergo a change of control at any time during the term of the Broad License Agreement, certain of the clinical and regulatory milestone payments will increase by a specified percentage. Broad Institute is also entitled to sales-based milestone payments up to a total of $54.0 million per licensed product, depending on the patient population to be treated by the licensed product achieving the applicable milestone. Broad Institute is entitled to lower payments to the extent the clinical and regulatory milestones or sales-based milestones are achieved by enabled products, rather than licensed products.

Broad Institute is entitled to receive mid-single digit percentage royalties on net sales of licensed products, and low single-digit percentage royalties of enabled products. Royalties payable to Broad Institute are subject to customary offsets and reductions with respect to a product in a given country, to a floor. On a country-by-country and product-by-product basis, the royalty term for a product in a country will terminate on the latest of (i) the expiration of the last to expire valid claim of an issued patent or pending patent application within the licensed patent rights covering such product in such country, (ii) the period of regulatory exclusivity for such product in such country or (iii) 10 years after the first commercial sale of such product in such country.

Unless earlier terminated, the Broad License Agreement will remain in effect until the later of (i) the last to expire valid claim of an issued patent or pending patent application within the licensed patent rights covering our licensed products or (ii) the expiration of the last royalty term for a licensed product in a country. We can terminate the Broad License Agreement for our convenience following prior written notice to Broad Institute. Each party may terminate the Broad License Agreement for the other party’s uncured material breach. Broad Institute may also immediately terminate the Broad License Agreement (i) to the extent we (or our affiliates or sublicensees) challenge a licensed patent right, (ii) upon our bankruptcy or insolvency or (iii) if we fail to procure and maintain insurance.

Exclusive Option Agreement with Broad Institute

In May 2021, we executed an exclusive option agreement with Broad Institute, or the Broad Option Agreement, pursuant to which, Broad Institute granted to us an exclusive option to negotiate an amendment to the Broad License Agreement to include certain additional patent rights relating to Prime Editing improvements to our license thereunder (subject to certain specific limitations and exclusions with respect to certain applications), or the Exclusive Option.

In connection with the Broad Option Agreement, Broad Institute also granted to us, during the option period, a limited, non-exclusive license under the new patent rights solely for research purposes to evaluate whether to exercise our option (subject to certain specified exceptions). We paid a upfront fee of $0.1 million to Broad Institute under the agreement upon execution of the agreement.

We may terminate the Broad Option Agreement for convenience by giving advance written notice of termination to Broad Institute. Broad Institute has the right to terminate the agreement if we (i) fail to make a payment to Broad Institute under the option agreement and fail to cure such non-payment within a certain time period, (ii) are otherwise in material breach of the option agreement and fail to cure within a certain time period, or (iii) become insolvent.

Our option expires in November 2022, unless we mutually agree in writing with Broad Institute to extend such expiration date. Through June 30, 2022, we have not exercised our Exclusive Option.

Pledge to Broad Institute and Harvard

In February 2021, we committed to donate $5.0 million to Broad Institute and Harvard annually for 14 years, commencing in 2021, or the Pledge. The Pledge is intended to be used for research and development related to new genome editing technologies, for example Prime Editing, improve on existing genome-editing technologies, identify delivery mechanisms for these technologies and apply these technologies to the understanding and treatment of rare genetic diseases. We can terminate the Pledge at our discretion, subject to providing one year of funding from the date of termination. In August 2022, we amended and restated the Pledge to clarify that the funds may be used by the laboratory of David Liu, who is a member of Broad Institute and a faculty member at Harvard.

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Related Party Beam Collaboration Agreement

In September 2019, we entered into a collaboration and license agreement, or the Beam Collaboration Agreement, with Beam Therapeutics Inc., or Beam, to collaborate on the research, development, manufacture and commercialization of certain Prime Editing products within a specified field and provide each other with access and licenses to certain proprietary technology to advance the other’s progress. Under the Beam Collaboration Agreement, each party agreed to provide each other with access to, and licenses under, certain technology, know-how and patent rights controlled by each party for a limited number of years after the effective date, known as the initial term, and certain improvements thereto. Under the Beam Collaboration Agreement, we grant to Beam an exclusive (even as to us and our affiliates), worldwide license under (i) certain prime editing technology, know-how and patent rights that we control during the initial term, and improvements thereto that we control for a specified number of years following the initial term, and (ii) our interest in certain jointly-owned collaboration technology, in each case, solely to develop, make, have made, use, offer for sale, sell, import and commercialize licensed products only in the Beam field. Beam also grants to us certain non-exclusive, worldwide licenses under certain technology, know-how and patent rights, including under certain CRISPR or delivery-related technology, know-how and patent rights, that it controls during the initial term, and improvements thereto that Beam controls for a specified number of years following the initial term, solely to develop, make, have made, use, offer for sale, sell, import and commercialize products only in the Prime field. As partial consideration for the Beam Collaboration Agreement, Beam agreed to pay us, upon its election to continue its collaboration with us on the first anniversary of the Beam Collaboration Agreement, $5.0 million worth of its own shares of common stock which such shares were issued to us on October 6, 2020.

Before and within a short period of time after the filing of an IND for a development candidate being developed under the Beam Collaboration Agreement, Beam has the option to designate up to a mid-single digit number of licensed products for which we are not permitted to exercise our profit share right, or the Beam Option (described below). Under the Beam Collaboration Agreement, a licensed product for which we have not exercised our profit share option or for which Beam has exercised the Beam Option is referred to as a protected product. Beam must exercise its option within 30 days following the filing of an IND for such product. Unless we exercise our profit sharing option for a licensed product, Beam is solely responsible for the development and commercialization of licensed products in the Beam field under the Beam Collaboration Agreement. If Beam exercises its option for a protected product, Beam will owe us a payment of $5.0 million if the product is developed for non-sickle cell disease or $10.0 million if the product is developed for sickle cell disease.

On a licensed product-by-licensed product basis, we have the right to elect to share equally with Beam in the profits and losses in the United States for Beam’s licensed products. We may exercise such right for each licensed product within a specified period of time. Any such licensed product for which we exercise our right we refer to as a collaboration product. If we exercise such right, we agree to share equally in the costs, profits and losses of each such collaboration product in the United States, rather than receiving milestones and royalties based on development and sales thereof by Beam in the United States. For clarity, we are still entitled to receive milestones and royalties on the development and sale of each such collaboration product outside the United States. We also have the right to elect, within a specified time period, at least one year prior to the expected filing of an NDA, to co-promote with Beam each collaboration product in the United States, in addition to sharing in the profits and losses. To the extent we exercise our co-promote option with respect to a given collaboration product, we and Beam must use commercially reasonable efforts to commercialize such collaboration product, in each case, in the Beam field in the major markets in which marketing authorization has been obtained. After we have exercised our right to profit share on a collaboration product, we are able to, at any time during the term of the Beam Collaboration Agreement, on a collaboration product-by-collaboration product basis, opt-out of the profit and loss share and co-promotion activities with respect to any collaboration product with prior written notice to Beam within a certain time period.

We are entitled to receive development milestone payments from Beam on Beam’s development of protected products (which, for clarity, includes any licensed product for which we have not exercised our profit share option) and collaboration products. For protected products, we are entitled to receive up to a total of $35.5 million on a protected product-by-protected product basis based on Beam’s development of such protected product and, for collaboration products, up to a total of $17.8 million on a collaboration product-by-collaboration product basis based on Beam’s development of such collaboration product outside of the United States, in each case, with such amounts

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lowered if such licensed product achieves a given milestone for use in treating an orphan disease. We are also entitled to receive sales-based milestone payments from Beam based on net sales of licensed products. For protected products, we are entitled to receive up to a total of $84.5 million on a protected product-by-protected product basis based on net sales of such protected product worldwide, and, for collaboration products, up to a total of $42.3 million on a collaboration product-by-collaboration product basis based on net sales of collaboration products outside of the United States.

The sickle cell disease product partnered with Beam is a licensed product under the Beam Collaboration Agreement. Beam has not designated this product as a protected product and we have not received any development or sales-based milestones with respect to Beam’s exploitation thereof.

Beam is obligated to pay to us tiered royalties ranging from a high-single digit percentage to a low double-digit percentage, but less than teens on net sales of protected products worldwide on a protected product-by-protected product basis and net sales of collaboration products outside of the United States on a collaboration product-by-collaboration product basis. Our royalties are subject to customary offsets and reductions, to a floor that takes into account any royalties we are obligated to pay to our third party licensors, including Broad Institute. In addition, certain of the rights licensed under the Beam Collaboration Agreement are sublicensed from third parties, and Beam agrees to reimburse us for certain payments we are required to make to our third party licensors attributable to Beam’s exercise of any sublicense we grant to Beam, including payments we make to Broad Institute under the Broad License Agreement.

If we develop a product that is covered by the technology, know-how or patent rights that Beam licenses to us under the Beam Collaboration Agreement, which we refer to as a Prime product, we are obligated to pay to Beam a low single digit percentage royalty on our worldwide net sales of such any product on a Prime product-by-Prime product and country-by-country basis, subject to certain customary reductions, to a floor.

Unless earlier terminated in accordance with its terms, the Beam Collaboration Agreement will expire on the later of (a) expiration of the last royalty term for a product on which a party is obligated to pay royalties to the other party or (b) with respect to any collaboration product, the date on which neither party is developing or commercializing any such collaboration product in the United States. See “Business—Our License and Collaboration Agreements.”

In connection with the Beam Collaboration Agreement, concurrently in September 2019, we also entered into a mutual subscription agreement, or the Beam Mutual Subscription Agreement. Under the Beam Mutual Subscription Agreement, if Beam elected to continue its collaboration with us, on the first anniversary of the collaboration agreement, we were obligated to grant Beam 1,608,337 shares of our common stock that represented an amount equal to 5.0 percent of the 100 million shares of Series A preferred stock that we had issued or committed to issue as of the effective date, as part of our first preferred stock offering. In connection with the Beam Mutual Subscription Agreement, on October 6, 2020, we issued to Beam an aggregate of 1,608,337 shares of our common stock with a fair value of $0.2 million.

Research Collaboration, Option and License Agreement with Myeloid Therapeutics, Inc.

In December 2021, we entered into a research collaboration and exclusive option agreement with Myeloid Therapeutics Inc., or Myeloid, and such agreement, the Myeloid Agreement. Under the Myeloid Agreement, we collaborate with Myeloid, a related party, on the research and development of LINE-1 retrotransposon technology. This retrotransposon-based approach is complementary to Prime Editing and, if successfully deployed alongside Prime Editing, could expand the applicability of our technologies towards our goal of more broadly addressing human diseases. In connection with the Myeloid Agreement, we also entered into a subscription agreement with Myeloid under which we were obligated to issue an aggregate of 1,101,525 shares of our common stock as additional consideration for the license.

Myeloid grants to us an exclusive option, exercisable during the research term and for 60 days thereafter, to obtain ownership of certain patent rights and know-how owned by Myeloid that relate to LINE-1 retrotransposon technology. If we exercise our option, in addition to assigning us ownership of the applicable patent rights and

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know-how, Myeloid also agrees to grant us certain exclusive and non-exclusive licenses, including to certain improvements and other enabling technology.

Through June 30, 2022, we have not exercised our option. Following the exercise of our option, we agree to grant Myeloid, in addition to certain other licenses, an exclusive, worldwide license under the assigned patent rights and know-how to develop and commercialize products in the field of myeloid cells and myeloid cell engineering, or the Myeloid Field.

Upon entering into the Myeloid Agreement, Myeloid was entitled to receive an upfront payment of $30.0 million in cash and an aggregate of 1,101,525 shares of our common stock, with a then fair value of $12.0 million, both of which Myeloid received in January 2022. If the research agreement meets its goals, then (i) during the research term, Myeloid is entitled to cash payments of up to $35.0 million in the aggregate upon the achievement of certain milestones reflecting the technology’s development; and (ii) if we exercise our option, we agree to pay to Myeloid an option exercise fee of $80.0 million in cash, and shares of our common stock with a then fair value of $30.0 million. Additionally, if the research collaboration meets its goal and we exercise our option, and we are able to proceed with the development and commercialization of a product that is covered by (a) the patent rights or know-how subject to our option or (b) the patent rights or know-how developed by one or both of the parties during the research term related to LINE-1 retrotransposon technology, or, collectively, a Prime Product, Myeloid would be eligible to receive, for the first five Prime Products, development and regulatory milestone payments of up to $120.0 million on a Prime Product-by-Prime Product basis and sales-based milestone payments of up to $210.0 million on a Prime Product-by-Prime Product basis.

Myeloid is also eligible to receive tiered low to mid single-digit percentage royalties on our annual aggregate global net sales of Prime Products on a Prime Product-by-Prime Product and country-by-country basis, subject to customary offsets and reductions to a floor. On a country-by-country and Prime Product-by-Prime Product basis, the period during which royalties will be paid will continue until the latest of (i) the expiration date of the last to expire valid claim of an issued patent or pending patent application within the patent rights subject to our option or the patent rights developed by one or both of the parties during the research term related to LINE-1 retrotransposon technology, in each case, covering the applicable Prime Product, (ii) loss of regulatory exclusivity for such Prime Product in such country, or (iii) ten (10) years after the first commercial sale of such Prime Product in such country.

Following the exercise of our option and for a period of two years thereafter, Myeloid will have the right to select up to three targets, subject to certain exclusions, for the development and commercialization of products directed at such targets in all fields and we will be eligible to receive the development, regulatory and sales-based milestone payments and royalty payments as set forth above from Myeloid with respect to such products.

Unless earlier terminated based on customary termination rights, the Myeloid Agreement will continue on a Prime Product-by-Prime Product and country-by-country basis until the expiration of the royalty term for such Prime Product in such country. If we exercise our option, neither party will have the right to terminate the Myeloid Agreement for any reason.

Components of Our Results of Operations

Related Party Collaboration Revenue

We have not generated any revenue from product sales and do not expect to generate any revenue from the sale of products for the foreseeable future. Our revenues to date have been generated through the Beam Collaboration Agreement, as set forth above. In the future, we may generate additional revenue from collaboration, grant or license agreements we have entered into, or may enter into, with respect to our product candidates, as well as product sales from any approved product. Our ability to generate product revenues will depend on the successful development and eventual commercialization of any product candidates that we identify. If we fail to complete the development of any future product candidates in a timely manner or to obtain regulatory approval for such product candidates, our ability to generate future revenue and our results of operations and financial position would be materially adversely affected.

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We concluded that the Beam Collaboration Agreement and the Beam Mutual Subscription Agreement should be combined and treated as a single arrangement for accounting purposes as the agreements were entered into contemporaneously and in contemplation of one another. We determined that the combined agreements are accounted for under Topic 606, Revenue recognition, or ASC 606. We identified the following performance obligations: (i) exclusive, worldwide license to certain Prime patents (ii) non-exclusive, worldwide license to CRISPR technology and (iii) joint research committee participation.

We also evaluated whether the Beam Option and our right to elect collaboration products in the Beam Collaboration Agreement represented material rights that would give rise to a performance obligation and concluded that neither the Beam Option nor our right to elect collaboration products convey a material right to Beam and therefore are not considered separate performance obligations within the Beam Collaboration Agreement. There have been no protected products or collaborations products to date. Under the Beam Collaboration Agreement, we are eligible to receive certain milestones and royalties regardless of whether any options are exercised, which are considered variable consideration. At each reporting period, we evaluate whether milestones are considered probable of being reached and, to the extent that a significant reversal would not occur in future periods, estimate the amount to be included in the transaction price. During the years ended December 31, 2020 and 2021, and the six months ended June 30, 2021 and 2022, we did not receive any milestone payments and all variable consideration related to the Beam Collaboration Agreement remained fully constrained.

We recognized revenue for the license performance obligations at a point in time, that is upon the first anniversary of the effective date when Beam elected to continue its collaboration with us. We determined that the joint research committee performance promise is immaterial in the context of the contract.

Operating Expenses

Research and Development Expenses

Research and development expenses consist primarily of costs incurred in connection with the development and research of our immediate target indications and our differentiation target indications. These expenses include:

•the cost allocated to acquire in-process research and development, or IPR&D, with no alternative future use associated with asset acquisitions or transactions to license intellectual property, such as our Myeloid Agreement and Broad License Agreement;

•expenses incurred in connection with our Pledge to Broad Institute;

•personnel-related expenses, including salaries, bonuses, benefits and stock-based compensation for employees engaged in manufacturing, research and development functions;

•expenses incurred in connection with continuing our current research programs and preclinical development of any product candidates we may identify, including under agreements with third parties, such as consultants and contractors;

•the cost of developing and validating our manufacturing process for use in our preclinical studies and future clinical trials;

•laboratory supplies and research materials; and

•facilities, depreciation and other expenses related to research and development activities, which include direct or allocated expenses for rent and maintenance of facilities, and utilities.

We measure and recognize asset acquisitions or licenses to intellectual property that are not deemed to be business combinations based on the cost to acquire or license the asset or group of assets, which includes transaction costs. Goodwill is not recognized in asset acquisitions or transaction to license intellectual property. In an asset acquisition or license to intellectual property, the cost allocated to acquire in-process research and development, or IPR&D, with no alternative future use is recognized as research and development expense on the acquisition date. For the period from September 13, 2019 (inception) to December 31, 2019, we recorded $0.7 million of research and

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development expense related to the acquired IPR&D from Broad Institute, which consisted of the initial upfront payment of $0.5 million, the $39,000 fair value of common stock issued to Broad Institute and the initial fair value of the Anti-Dilution Obligation of $0.2 million. For the year ended December 31, 2021, we recorded $42.0 million of research and development expense related to the acquired IPR&D from Myeloid, which consisted of the accrued initial upfront payment of $30.0 million and the $12.0 million fair value of common stock to be issued to Myeloid.

Upfront and milestone payments made are accrued for and expensed when the achievement of the milestone is probable up to the point of regulatory approval. Milestone payments made upon regulatory approval will be capitalized and amortized over the remaining useful life of the related product.

We expense all research and development costs in the periods in which they are incurred. Most of our research and development expenses have been related to early stage development activities. We have not reported program costs because we have not historically tracked or recorded our research and development expenses on a program-by-program basis, as we do not currently have any product candidates. In the future, external research and development costs for any individual product candidate will be tracked commencing upon product candidate nomination. We do not allocate employee costs, costs associated with our discovery efforts, laboratory supplies, and facilities expenses, including depreciation or other indirect costs, to specific product development programs because these costs are deployed across multiple programs and our platform and, as such, are not separately classified.

We expect our research and development expenses to increase substantially for the foreseeable future as we continue to invest in research and development activities related to developing any future product candidates, including investments in manufacturing, as we advance any product candidates we may identify and begin to conduct clinical trials. The success of product candidates we may identify and develop will depend on many factors, including the following:

•timely and successful completion of preclinical studies, including toxicology studies, biodistribution studies and minimally efficacious dose studies in animals, where applicable;

•effective INDs or comparable foreign applications that allow commencement of our planned clinical trials or future clinical trials for any product candidates we may develop;

•successful enrollment and completion of clinical trials, including under the FDA’s current Good Clinical Practices, or GCPs, current Good Laboratory Practices, or GLPs, and any additional regulatory requirements from foreign regulatory authorities;

•positive results from our future clinical trials that support a finding of safety and effectiveness and an acceptable risk-benefit profile in the intended populations;

•receipt of marketing approvals from applicable regulatory authorities;

•establishment of arrangements through our own facilities or with third-party manufacturers for clinical supply and, where applicable, commercial manufacturing capabilities;

•establishment, maintenance, defense and enforcement of patent, trademark, trade secret and other intellectual property protection or regulatory exclusivity for any product candidates we may develop; and

•maintenance of a continued acceptable safety, tolerability and efficacy profile of any product candidates we may develop following approval.

Any changes in the outcome of any of these variables with respect to the development of product candidates that we may identify could mean a significant change in the costs and timing associated with the development of such candidates. For example, if the 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 to complete clinical development of that therapeutic candidate. We may never obtain regulatory approval for any of our candidates, and, even if we do, drug commercialization takes several years and millions of dollars in development costs.

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Following consummation of this offering, certain bonuses will become payable, and certain performance-based restricted stock awards and options to purchase common stock will vest and we will record approximately $0.9 million of compensation expense as research and development expenses on the closing date of the offering.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and personnel-related costs, including stock-based compensation, for our personnel in executive, legal, finance and accounting, human resources and other administrative functions. General and administrative expenses also include legal fees relating to patents and corporate matters; professional fees paid for accounting, auditing, consulting and tax service; insurance costs; office and information technology costs; and facilities, depreciation and other general and administrative expenses, which include direct or allocated expenses for rent and maintenance of facilities and utilities.

We anticipate that our general and administrative expenses will increase in the future as we increase our headcount to support development of product candidates and our continued research activities. We also anticipate that we will incur increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses associated with being a public company. We also expect to incur additional intellectual property-related expenses as we file patent applications to protect innovations arising from our research and development activities.

Following consummation of this offering, certain performance-based restricted stock awards will vest and we will record approximately $0.2 million of compensation expense as general and administrative expenses on the closing date of the offering.

Other Income (Expense)

Change in Fair Value of Preferred Stock Tranche Liability

Our Series A preferred stock purchase agreement obligated the Series A investors to participate in subsequent offerings of Series A preferred stock upon satisfaction of certain conditions, or the preferred stock tranche right. The preferred stock tranche right was classified as a liability and initially recorded at fair value upon the issuance date of the right. The liability was subsequently remeasured to fair value at each reporting date and immediately prior to being settled, and changes in fair value of the preferred stock tranche right liability were recognized as a component of other income (expense), net in our consolidated statements of operations and comprehensive loss. In 2020, we closed the second tranche Series A preferred stock financing and in April 2021, we closed the third and fourth tranche Series A preferred stock financings, resulting in full settlement of the preferred stock tranche right, upon both of which we issued additional shares of Series A preferred stock. Immediately prior to the issuance of such shares, the preferred stock tranche right liability was remeasured to fair value with the change in fair value recognized as a component of other income (expense), net.

As a result of the preferred stock tranche right settlement in April 2021, we will no longer recognize changes in the fair value of the preferred stock tranche liability in our consolidated statements of operations and comprehensive loss.

Change in Fair Value of Anti-Dilution Obligation

In connection with the Broad License Agreement, we entered into the Broad Subscription Agreement, in which we granted Broad Institute 623,529 shares of common stock, which represented a 5.0 percent of our then outstanding capital stock on a fully-diluted basis. The Broad Subscription Agreement obligated us to issue additional shares of common stock to Broad Institute without additional consideration to maintain Broad Institute’s ownership of us at 5.0 percent on a fully-diluted basis, if at any time prior to the achievement of an equity financing up to $100.0 million, we issue additional securities that would cause Broad Institute shares of common stock to be less than 5.0 percent of our outstanding capital stock on a fully-diluted basis, which we refer to collectively as the Anti-Dilution Obligation. We classified the Anti-Dilution Obligation as a liability on our consolidated balance sheet that we remeasured to fair value at each reporting date, and we recognized changes in the fair value of the liability

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associated with the Anti-Dilution Obligation as a component of other income (expense) in our consolidated statement of operations and comprehensive loss.

As a result of the achievement of $100.0 million in equity financing upon the fourth Series A preferred stock closing, we fully settled the Anti-Dilution Obligation and will no longer recognize changes in the fair value of the Anti-Dilution Obligation in our consolidated statements of operations and comprehensive loss.

Change in Fair Value of Related Party Short-Term Investment

In connection with the Beam Collaboration Agreement, Beam issued 200,307 shares of Beam common stock to us on October 6, 2020. Our related party short-term investment is recorded at fair value based upon quoted market prices at each reporting date. Unrealized and realized gains and losses on this investment subsequent to its initial recognition are recognized as a component of other income (expense) in the consolidated statements of operations and comprehensive loss.

Other Income (Expense), Net

Other income (expense), net consists of the change in the fair value of the shares we were entitled to receive from our related party Beam from the first anniversary of the Beam Collaboration Agreement through the date we received the shares from Beam, October 6, 2020. In connection with the Beam Collaboration Agreement, Beam granted 200,307 shares of Beam common stock to us. We were entitled to receive the shares of Beam upon the first anniversary of the Beam Collaboration Agreement in September 2020. We received the shares of Beam on October 6, 2020. The change in the fair value of the shares from September through our receipt on October 6, 2020 is included as other income (expense), net in the consolidated statements of operations and comprehensive loss. As the shares were received on October 6, 2020, we no longer recognize changes in the fair value of the Beam shares we were entitled to receive.

Income Taxes

For the period from September 13, 2019 (inception) to December 31, 2019 and the years ended December 31, 2020 and 2021, we recorded an income tax provision (benefit) of $4,000, $1.9 million and $(0.5) million, respectively. For the six months ended June 30, 2021, we recorded an income tax provision of $0.5 million and for the six months ended June 30, 2022 we recorded an income tax benefit of $1.0 million. The income tax benefits for the year ended December 31, 2021 and the six months ended June 30, 2022, and the income tax provision for the six months ended June 30, 2021 are a result of changes associated with the unrealized gains on investments. We recorded a full valuation allowance of our net deferred tax assets as of December 31, 2021 and June 30, 2022, respectively, as we believed it was more likely than not we would not be able to utilize our deferred tax assets prior to their expiration.

As of December 31, 2021, we had U.S. federal NOL carryforwards of $41.8 million, which may be available to reduce future taxable income which do not expire. In addition, as of December 31, 2021, we had state NOL carryforwards of $40.9 million, which may be available to reduce future taxable income, and expire at various times beginning in 2039. As of December 31, 2021, we also had U.S. federal and state research and development tax credit carryforwards of $1.3 million and $0.4 million, respectively, which may be available to reduce future tax liabilities and expire at various dates beginning in 2040 and 2035, respectively.

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Results of Operations

Comparison of the six months ended June 30, 2021 and 2022

The following table summarizes our results of operations for the six months ended June 30, 2021 and 2022:

	Six Months Ended June 30,
	2021		2022		Change
	(in thousands)
Operating expenses:
Research and development	$	10,261	$	32,617	$	22,356
General and administrative	3,710		13,586		9,876
Total operating expenses	13,971		46,203		32,232
Income (loss) from operations	(13,971)		(46,203)		(32,232)
Other income (expense):
Change in fair value of preferred stock tranche right liability	(74,319)		—		74,319
Change in fair value of anti-dilution obligation	(6,681)		—		6,681
Change in fair value of related party short-term investment	9,429		(8,208)		(17,637)
Other income (expense), net	1		249		248
Total other expense, net	(71,570)		(7,959)		63,611
Net loss before income taxes	(85,541)		(54,162)		31,379
Provision for (benefit) from income taxes	503		(974)		(1,477)
Net loss	$	(86,044)	$	(53,188)	$	32,856

Related Party Collaboration Revenue

No collaboration revenue was recognized for the six months ended June 30, 2021 and 2022.

Operating Expenses

Research and Development Expenses

	Six Months Ended June 30,
	2021		2022		Change
	(in thousands)
License, intellectual property fees and other	$	2,726	$	2,630	$	(96)
Personnel related (including stock-based compensation)	3,206		13,034		9,828
Lab supplies and services	1,913		9,932		8,019
Professional and consultant fees	152		720		568
Facility related and other	2,264		6,301		4,037
Total research and development expenses	$	10,261	$	32,617	$	22,356

Research and development expenses were $10.3 million for the six months ended June 30, 2021, compared to $32.6 million for the six months ended June 30, 2022. The increase of $22.4 million was primarily due to an increase of $9.8 million in personnel-related expense driven by new hires in research and development, an increase of $8.0 million in lab supplies and services expense due to continued discovery efforts and expansion of our research and development activities, an increase of $4.0 million facility related expense primarily due to the expansion of our office and laboratory space through new facilities being leased, and an increase of $0.6 million in professional and consultant fees as we prepare to become and operate as a public company.

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General and Administrative Expenses

	Six Months Ended June 30,
	2021		2022		Change
	(in thousands)
Personnel related (including stock-based compensation)	$	1,197	$	5,456	$	4,259
Professional and consultant fees	2,028		5,701		3,673
Facility related and other	485		2,429		1,944
Total general and administrative expenses	$	3,710	$	13,586	$	9,876

General and administrative expenses were $3.7 million for the six months ended June 30, 2021, compared to $13.6 million for the six months ended June 30, 2022. The increase of $9.9 million was primarily due to an increase of $4.3 million of personnel-related expense primarily due to compensation related costs related to new hires to support our expanding operations, $3.7 million in professional and consultant fees as we prepare to become and operate as a public company, and an increase of $1.9 million of facility and IT related expenses primarily due to newly signed office leases to support our expanded general and administrative staff.

Other Income (Expense)

	Six Months Ended June 30,
	2021		2022		Change
	(in thousands)
Change in fair value of preferred stock tranche right liability	$	(74,319)	$	—	$	74,319
Change in fair value of anti-dilution obligation	(6,681)		—		6,681
Change in fair value of related party short-term investment	9,429		(8,208)		(17,637)
Other income (expense), net	1		249		248
Total other expense, net	$	(71,570)	$	(7,959)	$	63,611

Change in Fair Value of Preferred Stock Tranche Right Liability

The change in fair value of the preferred stock tranche right liability decreased by $74.3 million from the six months ended June 30, 2021 compared to the six months ended June 30, 2022. The decrease was primarily due to a $1.55 increase in the per share fair value of the underlying preferred stock used to determine the fair value of the preferred stock tranche right from December 31, 2020 to June 30, 2021, with no corresponding change in the six months ended June 30, 2022 due to the preferred stock tranche right being settled in full upon the satisfaction of certain conditions in April 2021.

Change in Fair Value of Anti-Dilution Obligation

The change in fair value of the Anti-Dilution Obligation decreased by $6.7 million from the six months ended June 30, 2021 compared to the six months ended June 30, 2022. The decrease was primarily due to a $2.68 increase in the per share fair value of our common stock used to determine the fair value of the Anti-Dilution Obligation from December 31, 2020 through the settlement date in connection with the fourth Series A preferred stock closing in 2021, with no corresponding change in the six months ended June 30, 2022.

Change in Fair Value of Related Party Short-Term Investment

The change in fair value of related party short-term investment decreased by $17.6 million from the six months ended June 30, 2021 compared to the six months ended June 30, 2022. The decrease was due to a $40.98 decrease in the stock price from December 31, 2021 to June 30, 2022, as compared to the $47.07 increase in the stock price of the Beam stock from December 31, 2020 to June 30, 2021 .

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Other Income (Expense), Net

The amount of other income (expense), net for the six months ended June 30, 2022 was insignificant.

Income Taxes

We recorded an income tax provision of $0.5 million for the six months ended June 30, 2021 and an income tax benefit of $1.0 million for the six months ended June 30, 2022.

Comparison of Years Ended December 31, 2020 and 2021

The following table summarizes our results of operations for the years ended December 31, 2020 and 2021:

	Years Ended December 31,
	2020		2021		Change
	(in thousands)
Related party collaboration revenue	$	5,210	$	—	$	(5,210)
Operating expenses:
Research and development	2,980		70,550		67,570
General and administrative	3,162		13,924		10,762
Total operating expenses	6,142		84,474		78,332
Income (loss) from operations	(932)		(84,474)		(83,542)
Other income (expense):
Change in fair value of preferred stock tranche right liability	(10,904)		(74,319)		(63,415)
Change in fair value of anti-dilution obligation	(700)		(6,681)		(5,981)
Change in fair value of related party short-term investment	10,867		(391)		(11,258)
Other income (expense), net	126		12		(114)
Total other expense, net	(611)		(81,379)		(80,768)
Net loss before income taxes	(1,543)		(165,853)		(164,310)
Provision for (benefit from) income taxes	1,867		(486)		(2,353)
Net loss	$	(3,410)	$	(165,367)	$	(161,957)

Related Party Collaboration Revenue

Related party collaboration revenue was $5.2 million for the year ended December 31, 2020, consisting of $5.4 million of consideration received in the form of Beam shares in connection with the Beam Collaboration Agreement, offset by shares of our common stock that we issued to Beam with a then fair value of $0.2 million, and was recognized upon the first anniversary of the effective date of the agreement, when Beam elected to continue its collaboration with us. No collaboration revenue was recognized for the year ended December 31, 2021.

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Operating Expenses

Research and Development Expenses

	Years Ended December 31,
	2020		2021		Change
	(in thousands)
License, intellectual property fees and other	$	50	$	47,346	$	47,296
Personnel related (including stock-based compensation)	1,124		10,683		9,559
Lab supplies	523		6,142		5,619
Professional and consultant fees	163		650		487
Facility related and other	1,120		5,729		4,609
Total research and development expenses	$	2,980	$	70,550	$	67,570

Research and development expenses were $3.0 million for the year ended December 31, 2020, compared to $70.6 million for the year ended December 31, 2021. The increase of $67.6 million was primarily due to an increase of $47.3 million in license, intellectual property fees and other primarily due to $42.0 million of an upfront expense under the Myeloid Agreement and $5.3 million under the Broad License Agreement (including amounts associated with the Pledge, as described above), an increase of $9.6 million in personnel-related expense driven by approximately 50 new hires in research and development, an increase of $5.6 million lab supplies expense due to continued discovery efforts and expansion of our research and development activities and an increase of $4.6 million facility related expense primarily due to the expansion of our office and laboratory space through new facilities being leased.

General and Administrative Expenses

	Years Ended December 31,
	2020		2021		Change
	(in thousands)
Personnel related (including stock-based compensation)	$	1,030	$	3,622	$	2,592
Professional and consultant fees	1,951		8,088		6,137
Facility related and other	181		2,214		2,033
Total general and administrative expenses	$	3,162	$	13,924	$	10,762

General and administrative expenses were $3.2 million for the year ended December 31, 2020, compared to $13.9 million for the year ended December 31, 2021. The increase of $10.8 million was primarily due to an increase of $6.1 million in professional and consultant fees as we prepare to become and operate as a public company, an increase of $2.6 million of personnel-related expense primarily due to compensation related costs related to eight new hires to expand upon our administrative staff functions and an increase of $2.0 million of facility related expenses primarily due to newly signed office leases to support our expanded general and administrative staff.

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Other Income (Expense)

	Years Ended December 31,
	2020		2021		Change
	(in thousands)
Change in fair value of preferred stock tranche right liability	$	(10,904)	$	(74,319)	$	(63,415)
Change in fair value of anti-dilution obligation	(700)		(6,681)		(5,981)
Change in fair value of related party short-term investment	10,867		(391)		(11,258)
Other income (expense), net	126		12		(114)
Total other expense, net	$	(611)	$	(81,379)	$	(80,768)

Change in Fair Value of Preferred Stock Tranche Right Liability

The change in fair value of the preferred stock tranche right liability increased by $63.4 million from the year ended December 31, 2020 compared to the year ended December 31, 2021. The increase was primarily due to a $1.55 increase in the per share fair value of the underlying preferred stock used to determine the fair value of the preferred stock tranche right from December 31, 2020 through the settlement date in April 2021, as compared to the $0.33 increase in per share fair value of the underlying preferred stock used to determine the fair value of the preferred stock tranche right from December 31, 2019 to December 31, 2020.

Change in Fair Value of Anti-Dilution Obligation

The change in fair value of the Anti-Dilution Obligation increased by $6.0 million from the year ended December 31, 2020 compared to the year ended December 31, 2021. The increase was primarily due to a $2.68 increase in the per share fair value of our common stock used to determine the fair value of the Anti-Dilution Obligation from December 31, 2020 through the settlement date in connection with the fourth Series A preferred stock closing, as compared to the $0.28 increase in the per share fair value of our common stock used to determine the fair value of the Anti-Dilution Obligation from December 31, 2019 to December 31, 2020.

Change in Fair Value of Related Party Short-Term Investment

The change in fair value of related party short-term investment decreased by $11.3 million from the year ended December 31, 2020 compared to the year ended December 31, 2021. The decrease was primarily due to a $1.95 decrease in the stock price of the Beam stock from December 31, 2020 to December 31, 2021 as compared to the $54.25 increase in the per share value of Beam common stock used to determine the fair value of related party short-term investments from October 6, 2020, the date on which we received the Beam shares, to December 31, 2020.

Other Income (Expense), Net

The change in other income (expense), is due to the unrealized loss of $0.1 million recognized in the year ended December 31, 2020 related to the change in the fair value of the Beam shares we were entitled to receive for the period from the first anniversary date of the Beam Collaboration agreement, or September 26, 2020, through October 6, 2020, when we received the Beam shares due to a decrease in the stock price of the Beam stock. There is no similar unrealized loss in the year ended December 31, 2021 as any change in the fair value of the shares received subsequent to October 6, 2020 is included in the change in fair value of related party short-term investment.

Income Taxes

For the years ended December 31, 2020 and 2021, we recorded an income tax provision (benefit) of $1.9 million and $(0.5) million, respectively. The deferred income tax provision for the year ended December 31, 2020 was attributable to releasing our valuation allowance on our deferred tax assets as we were in a net deferred tax liability position, primarily due to our recognition of an unrealized gain on our related party short term investment. The deferred income tax benefit for the year ended December 31, 2021 was attributable to recording a valuation allowance on our deferred tax assets and liabilities due to being in a net deferred tax asset position.

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Comparison of Period from September 13, 2019 (Inception) to December 31, 2019 and the Year Ended December 31, 2020

The following table summarizes our results of operations for the period from September 13, 2019 (inception) to December 31, 2019 and the year ended December 31, 2020:

	Period from September 13, 2019 (Inception) to December 31,		Year Ended December 31,		Change
	2019		2020
	(in thousands)
Related party collaboration revenue	$	—	$	5,210	$	5,210
Operating expenses:
Research and development	920		2,980		2,060
General and administrative	1,252		3,162		1,910
Total operating expenses	2,172