The accompanying consolidated financial statements include those of the Company, Autolus Limited, and its U.S. subsidiary, Autolus Inc., and have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany accounts and transactions have been eliminated upon consolidation.

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of income and expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses, the fair value of ordinary shares, share-based compensation and income taxes. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ materially from those estimates.

The Company entered into a lease that requires a letter of credit supported by $0.6 million deposit held by the Company's bank for the duration of the lease and a credit card arrangement that requires a security deposit of $0.2 million. The Company includes the restricted cash balance in cash and cash equivalents when reconciling beginning-of-period and end-of-period total amounts shown on the Company's consolidated statements of cash flows.

Financial instruments that subject the Company to credit risk consist primarily of cash and cash equivalents. The Company places cash and cash equivalents in established financial institutions. The Company has no significant off-balance-sheet risk or concentration of credit risk, such as foreign exchange contracts, options contracts, or other foreign hedging arrangements.

The Company’s cloud computing arrangements primarily comprise hosting arrangements which are service contracts, whereby the Company gains remote access to use enterprise software hosted by the vendor or another third party on an as-needed basis for a period of time in exchange for a subscription fee. Implementation costs for cloud computing arrangements are capitalized if certain criteria are met and consist of internal and external costs directly attributable to developing and configuring cloud computing software for its intended use. These capitalized implementation costs are presented in the condensed consolidated balance sheet in prepaid expenses and other assets, current and non-current, and are generally amortized over the fixed, non-cancellable term of the associated hosting arrangement on a straight-line basis.

Property and equipment are recorded at cost and depreciated or amortized using the straight-line method over the estimated useful lives of the respective assets. As of December 31, 2020 and 2019, the Company’s property and equipment consisted of office equipment, lab equipment, furniture and fixtures, and leasehold improvements. The office equipment has an estimated useful life of three years, lab equipment has an estimated useful life of five or ten years, and furniture and fixtures have an estimated useful life of five years. Leasehold improvements are depreciated over the shorter of the lease term or the estimated useful life of the asset. Assets under construction consist of costs incurred with leasehold improvements and, once placed into service, will be depreciated over the

shorter of the lease term or the estimated useful life of the asset. Upon retirement or sale, the cost of assets disposed of, and the related accumulated depreciation, are removed from the accounts and any resulting gain or loss is included in the statement of operations and other comprehensive loss. Repairs and maintenance expenditures, which are not considered improvements and do not extend the useful life of property and equipment, are expensed as incurred.

The Company evaluates an asset for potential impairment when events or changes in circumstances indicate the carrying value of the asset may not be recoverable. Recoverability is measured by comparing the book value of the asset to the expected future net undiscounted cash flows that the asset is expected to generate. If such asset is considered to be impaired, the impairment to be recognized is measured by the amount by which the book value of the asset exceeds the fair value. The Company did not recognize an impairment nor a disposal for the year ended December 31, 2020, but did recognize a loss on impairment of $4.1 million for the year ended December 31, 2019 related to leasehold improvements, as the Company chose to discontinue the fit-out of the Company's manufacturing capacity at the Enfield, U.K. facility. There were no impairments or disposals for the three months ended December 31, 2018, and an asset disposal of less than $10,000 for the year ended September 30, 2018.

The Company routinely evaluates the useful life attributed to its assets. During the second quarter ended June 30, 2019, the Company determined that the useful lives of certain lab equipment should be increased from five-years to ten-years based on expectation of future usability. The Company accounted for this as a change in estimate that was applied prospectively, effective April 1, 2019. This change in useful life resulted in a reduction of depreciation expense of $0.3 million, and an increase in basic and diluted earnings per share of $0.01, for the year ended December 31, 2019.

Effective January 1, 2019, the Company adopted Accounting Standards Codification (“ASC”), Topic 842, Leases (“ASC 842”), using the required modified retrospective approach and utilizing the effective date as its date of initial application, for which prior periods are presented in accordance with the previous guidance in ASC 840, Leases.

At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the unique facts and circumstances present. Most leases with a term greater than one year are recognized on the balance sheet as right-of-use assets, lease liabilities and, if applicable, long-term lease liabilities. The Company has elected not to recognize on the balance sheet leases with terms of one year or less. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected remaining lease term. However, certain adjustments to the right-of-use asset may be required for items such as incentives received, initial direct costs, or prepayments. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rates, which are the rates incurred to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment.

In accordance with the guidance in ASC 842, components of a lease should be split into three categories: lease components (e.g., land, building, etc.), non-lease components (e.g., common area maintenance, consumables, etc.), and non-components (e.g., property taxes, insurance, etc.). Then the fixed and in-substance fixed contract consideration (including any related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components.

Although separation of lease and non-lease components is required, certain practical expedients are available. Entities may elect the practical expedient to not separate lease and non-lease components. Rather, they would account for each lease component and the related non-lease component together as a single component. For new and amended leases beginning in 2019, the Company elected the practical expedients to account for the lease and non-lease components for leases for classes of all underlying assets and allocate all of the contract consideration to the lease component only. The Company determined the underlying lease to be the predominant component, and therefore, the entire agreement was accounted for under ASC 842.

The Company’s intangible assets have been related to acquired software licenses with finite lives are amortized over their useful lives and reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. If any indicators were present, the Company would test for recoverability by comparing the carrying amount of the asset to the net undiscounted cash flows expected to be generated from the asset. If those net undiscounted cash flows do not exceed the carrying amount (i.e., the asset is not recoverable), the Company would perform the next step, which is to determine the fair value of the asset and record an impairment loss, if any. The Company evaluates the useful lives for these intangible assets each reporting period to determine whether events and circumstances warrant a revision in their remaining useful lives. The Company did not recognize an impairment loss in the years ended December 31, 2020 and 2019. The Company recognized an impairment loss of $0.4 million for the three months ended December 31, 2018 related to software which the Company elected to discontinue. The Company did not recognize an impairment loss in the year ended September 30, 2018.

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker in deciding how to allocate resources and assess performance. The Company and the Company’s chief operating decision maker, the Company’s Chief Executive Officer, view the Company’s operations and manages its business as a single operating segment, which is the business of developing and commercializing gene therapies. The Company operates in two geographic regions: the United Kingdom and the United States. A majority of the Company’s assets are held in the United Kingdom.

Prior to the adoption of ASC 842, rent expense and lease incentives from operating leases were recognized on a straight-line basis over the lease term. The Company has operating leases that include rent escalation payment terms and a rent-free period. Deferred rent represents the difference between actual operating lease payments and straight-line rent expense over the term of the lease. Upon adoption of ASC 842, the Company no longer records or presents deferred rent.

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, share-based compensation and benefits, depreciation expense, third-party license fees, external costs of outside vendors engaged to conduct clinical development activities, clinical trials, costs to manufacture clinical trial materials and certain tax credits associated with research and development activities. The Company recorded the U.K.'s research and development expenditure credit ("RDEC") of $0.1 million and $0.2 million for the years ended December 31, 2020 and 2019, $37,000 for the three months ended December 31, 2018, and $0.2 million for the year ended September 30, 2018, respectively, as reductions of research and development expenses within the Company’s statement of operations and comprehensive loss.

As part of the process of preparing consolidated financial statements, the Company is required to estimate accruals for research and development expenses. This process involves reviewing and identifying services which have been performed by third parties on the Company’s behalf and determining the value of these services. In addition, the Company makes estimates of costs incurred to date but not yet invoiced, in relation to external clinical research organizations and clinical site costs. The Company analyzes the progress of clinical trials, including levels of patient enrollment; invoices received and contracted costs, when evaluating the adequacy of the accrued liabilities for research and development. The Company makes judgments and estimates in determining the accrued balance in any accounting period.

The Company recognizes compensation expense for equity awards based on the grant date fair value of the award. The Company recognizes share-based compensation expense for awards granted to employees that have a graded vesting schedule based on a service condition only on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards (the “graded-vesting attribution method”), based on the estimated grant date fair value for each separately vesting tranche. For equity awards with a graded vesting schedule and a combination of service and performance conditions, the Company recognizes share-based compensation expense using a graded-vesting attribution method over the requisite service period when the achievement of a performance-based milestone is probable, based on the relative satisfaction of the performance condition as of the reporting date. The Company accounts for forfeitures as they occur.

For share-based awards granted to consultants and non-employees, compensation expense is recognized using the graded-vesting attribution method over the period during which services are rendered by such consultants and non-employees until completed. The measurement date for employee awards is the date of grant, and share-based compensation costs are recognized as expense over the employees’ requisite service period, which is the vesting period, on an accelerated basis. In the year ended December 31, 2019 the Company adopted Accounting Standards Update (“ASU”) No. 2018-07, “Compensation —Stock Compensation (Topic 718): Improvements to Non-employee Share-Based Payment Accounting” (“ASU No. 2018-07”), prior to which the measurement date for non-employee awards was generally the date the services were completed, resulting in financial reporting period adjustments to share-based compensation during the vesting terms for changes in the fair value of the awards. After the adoption of

The fair value of each share option grant is estimated on the date of grant using the Black-Scholes option pricing model. See Note 8 for the Company’s assumptions used in connection with option grants made during the periods covered by these consolidated financial statements. Assumptions used in the option pricing model include the following:

Expected volatility. We lack company-specific historical and implied volatility information for our ADSs for expected terms greater than 2.5 years. Therefore, we use a combination of the historical volatility of our ADSs and also the expected share volatility based on the historical volatility of publicly traded peer companies and expect to continue to do so until such time as we have adequate historical data regarding the volatility of our own traded security price

Prior to the IPO, the Company calculated the fair value of its ordinary shares in accordance with the guidelines in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. The Company’s valuations of ordinary shares were prepared using a market approach, based on precedent transactions in the shares, to estimate the Company’s total equity value using the option-pricing method (“OPM”), which used a combination of market approaches and an income approach to estimate the Company’s enterprise value.

The OPM derives an equity value such that the value indicated is consistent with the investment price, and it provides an allocation of this equity value to each class of the Company’s securities. The OPM treats the various classes of shares as call options on the total equity value of a company, with exercise prices based on the value thresholds at which the allocation among the various holders of a company’s securities changes. Under this method, each class of shares has value only if the funds available for distribution to shareholders exceed the value of the share liquidation preferences of the class or classes of shares with senior preferences at the time of the liquidity event. Key inputs and assumptions used in the OPM calculation include the following:

When considering the fair value of options granted in the period prior to the IPO, the Company considered probability-weighted scenarios based on the relative likelihoods of completing the IPO and remaining a privately-held company. In the IPO scenarios, the fair value was calculated by dividing the total estimated equity value by the number of fully diluted ordinary shares outstanding, and then discounting the implied per-share value at a rate intended to approximate the Company's cost of equity between share option grant date and the expected IPO date. The stay-private scenario utilized an OPM "Backsolve" calculation to estimate its equity value implied by the purchase price of the series A preference shares in September 2017. In March and May 2018, the Company issued share option grants to employees that applied a 50% and 80% probability weighting of an IPO, respectively, to the fair value of the underlying ordinary share utilized in the Black-Scholes option pricing model.

The Company maintains its financial statements in its functional currency, which is the pounds sterling. Monetary assets and liabilities denominated in currencies other than the functional currency are translated into the functional currency at rates of exchange prevailing at the balance sheet dates. Non-monetary assets and liabilities denominated in foreign currencies are translated into the functional currency at the exchange rates prevailing at the date of the transaction. Exchange gains or losses arising from foreign currency transactions are included in the determination of net income (loss) for the respective periods. The Company recorded foreign

exchange loss of $0.2 million for the year ended December 31, 2020, foreign exchange gains of $4.6 million, $1.1 million, and $4.0 million for the year ended December 31, 2019, the three months ended December 31, 2018, and the year ended September 30, 2018, respectively, which are included in other income in the statements of operations and comprehensive loss.

For financial reporting purposes, the financial statements of the Company have been translated into U.S. dollars. Assets and liabilities have been translated at the exchange rates at the balance sheet dates, while revenue and expenses are translated at the average exchange rates over the reporting period and shareholders’ equity amounts are translated based on historical exchange rates as of the date of each transaction. Translation adjustments are not included in determining net income (loss) but are included in foreign exchange adjustment to other comprehensive loss, a component of shareholders’ equity.

The Company expenses patent prosecution and related legal costs as they are incurred and classifies such costs as general and administrative expenses in the accompanying statements of operations and comprehensive loss. The Company recorded patent expenses of $2.1 million and $2.0 million for the years ended December 31, 2020 and 2019, $0.2 million for the three months ended December 31, 2018, and $1.0 million for the year ended September 30, 2018, respectively.

The Company has received research grants under which it is reimbursed for specific research and development activities. Payments received are recognized as income in the statements of operations and comprehensive loss over the period in which the Company recognizes the related costs. At the time the Company recognizes grant income, it has complied with the conditions attached to it and the receipt of the reimbursement is reasonably assured. The Company has received grants from the U.K. government, which are repayable under certain circumstances, including breach or noncompliance. For grants with refund provisions, the Company reviews the grant to determine the likelihood of repayment. If the likelihood of repayment of the grant is determined to be remote, then the grant is recognized as grant income. The Company has determined that the likelihood of any repayment events included in its current grants is remote.

The Company has no products approved for commercial sale and has not generated any revenue from commercial product sales. The total revenue to date has been generated from a license agreement with an investee company of one our affiliates. The terms of the agreement include a non-refundable license fee, payments based upon achievement of clinical development and regulatory objectives, and royalties on product sales.

In determining the appropriate amount of revenue to be recognized as the Company fulfills its obligations under its agreements, the Company performs the following steps: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations, including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation.

If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, upfront fees allocated to the license at such time as the license is transferred to the licensee and the licensee is able to use, and benefit from, the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligations to determine whether the combined performance obligations are satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, upfront fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition.

Appropriate methods of measuring progress include output methods and input methods. In determining the appropriate method for measuring progress, the Company considers the nature of service that the Company promises to transfer to the customer. When the Company decides on a method of measurement, the Company will apply that single method of measuring progress for each performance obligation satisfied over time and will apply that method consistently to similar performance obligations and in similar circumstances.

ASC Topic 606 constrains the amount of variable consideration included in the transaction price in that either all, or a portion, of an amount of variable consideration should be included in the transaction price. The variable consideration amount should be included only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The assessment of whether variable consideration should be constrained is largely a qualitative one that has two elements: the likelihood of a change in estimate, and the magnitude thereof. Variable consideration is not constrained if the potential reversal of cumulative revenue recognized is not significant, for example.

If the consideration in a contract includes a variable amount, the Company will estimate the amount of consideration in exchange for transfer of promised goods or services. The consideration also can vary if the Company’s entitlement to the consideration is contingent on the occurrence or non-occurrence of a future event. The Company considers contingent research milestone payments to fall under the scope of variable consideration, which should be estimated for revenue recognition purposes at the inception of the contract and reassessed ongoing at the end of each reporting period.

The Company assesses whether contingent research milestones should be considered variable consideration that should be constrained and thus not part of the transaction price. This includes an assessment of the probability that all or some of the milestone revenue could be reversed when the uncertainty around whether or not the achievement of each milestone is resolved, and the amount of reversal could be significant.

For the year ended December 31, 2020, the Company has not recognized any variable consideration with regards to the development milestones which are included in the license agreement that was executed in the third quarter of the year. This is due to the fact that those development milestones have not yet been met and the recognition of the related revenue is not yet probable.

The Company accounts for income taxes under the asset and liability method which includes the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the Company’s financial statements. Under this approach, deferred taxes are recorded for the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. The provision for income taxes represents income taxes paid or payable for the current year plus deferred taxes. Deferred taxes result from differences between the financial statements and tax bases of the Company’s assets and liabilities, and are adjusted for changes in tax rates and tax law when changes are enacted. The effects of future changes in income tax laws or rates are not anticipated.

The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income of the same character and in the same jurisdiction. The Company considers all available positive and negative evidence in making this assessment, including, but not limited to, the scheduled reversal of deferred tax liabilities, projected future taxable income, and tax planning strategies. In circumstances where there is sufficient negative evidence indicating that the Company’s deferred tax assets are not more likely than not realizable, the Company establishes a valuation allowance.

The Company uses a two-step approach for recognizing and measuring uncertain tax positions. The first step is to evaluate tax positions taken or expected to be taken in a tax return by assessing whether they are more likely than not sustainable, based solely on their technical merits, upon examination, and including resolution of any related appeals or litigation process. The second step is to measure the associated tax benefit or each position as the largest amount that the Company believes is more likely than not realizable. Differences between the amount of tax benefits taken or expected to be taken in the Company’s income tax returns and the amount of tax benefits recognized in the its financial statements represent the Company’s unrecognized income tax benefits, which it either records as a liability or reduction of deferred tax assets.

The Company benefits from the U.K. research and development tax credit regime under both the small and medium sized enterprise, or SME, scheme and by claiming an RDEC in respect of grant funded projects. Under the SME regime, a portion of the Company’s losses can be surrendered for a cash rebate of up to 33.35% of eligible expenditures. Such credits are accounted for within the tax provision in the year in which the expenditures were incurred.

The Company follows the provisions of the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 220, Comprehensive Income, which establishes standards for the reporting and display of comprehensive income and its components. Comprehensive gain or loss is defined to include all changes in equity during a period except those resulting from investments by owners and distributions to owners. The Company recorded a gain of $2.8 million and $6.8 million for the years ended December 31, 2020 and 2019, a loss of $5.6 million for the three months ended December 31, 2018, and a loss $6.1 million for the year ended September 30, 2018, respectively to foreign currency translation.

Basic and diluted net loss per ordinary share is determined by dividing net loss by the weighted average number of ordinary shares outstanding during the period. For all periods presented, the preferred shares and outstanding but unvested restricted shares and share options have been excluded from the calculation, because their effects would be anti-dilutive. Therefore, the weighted average shares outstanding used to calculate both basic and diluted loss per share are the same for all periods presented.

The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act (“JOBS Act”) and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an emerging growth company. Section 107 of the JOBS Act provides that an emerging growth company can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.

These exemptions provided by the JOBS Act will apply up until the last day of the fiscal year following the fifth anniversary of the IPO or such earlier time that the Company is no longer meets the requirements of being an emerging growth company. The Company would cease to be an emerging growth company if it has more than $1.07 billion in annual revenue, has more than $700 million in market value of its securities held by non-affiliates (and it has been a public company for at least 12 months, and has filed one annual report on Form 20-F), or it issues more than $1 billion of non-convertible debt securities over a three-year period.

On April 5, 2012, the Jumpstart Our Business Startups Act, or the JOBS Act, was enacted. The JOBS Act provides that, among other things, an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. As an emerging growth company, the Company has irrevocably elected not to take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards and, as a result, the Company will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth public companies.

In addition, the Company intends to rely on the other exemptions and reduced reporting requirements provided by the JOBS Act. Subject to certain conditions set forth in the JOBS Act, the Company is entitled to rely on certain exemptions as an “emerging growth company.” As an emerging growth company, the Company is not required to, among other things, (i) provide an auditor’s attestation report on the Company’s system of internal controls over financial reporting pursuant to Section 404(b), (ii) provide all of the compensation disclosure that may be required of non-emerging growth public companies under the Dodd-Frank Wall Street Reform and Consumer Protection Act, (iii) comply with any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation or a supplement to the auditor’s report providing additional information about the audit and the financial statements (auditor discussion and analysis), and (iv) disclose certain executive compensation-related items such as the correlation between executive compensation and performance and comparisons of the chief executive officer’s compensation to median employee compensation. These exemptions will apply for a period of five years following the completion of the IPO or until the Company no longer meets the requirements of being an emerging growth company, whichever is earlier.

In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, a new standard on a customer's accounting for implementation, set-up, and other upfront costs incurred in a cloud computing arrangement ("CCA") that aligns the requirements for capitalizing implementation costs in a CCA service contract with existing internal-use software guidance. The standard is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted, and can be adopted prospectively or retrospectively. The Company adopted the new standard on January 1, 2020 on a prospective basis. The Company’s CCAs are service contracts for the hosting of software primarily related to recording and tracking information related to its clinical trials, including but not limited to patient data and clinical manufacturing. The capitalized implementation costs are presented in the condensed consolidated balance sheet in prepaid expenses and other assets, current and non-current. The deferred implementation costs will be expensed over the term of the hosting arrangement, which is the non-cancelable term of the arrangement plus any reasonably certain renewal periods. As of December 31, 2020, $1.0 million was recorded in prepaid expenses and other assets, current and $1.1 million was recorded to prepaid expenses and other assets, non-current as deferred implementation costs. During the year ended December 31, 2020, $0.3 million of deferred implementation costs were expensed.