The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, and include the accounts of the Company and its direct and indirect wholly owned subsidiaries, Replimune UK, Replimune US, Replimune Securities Corporation and Replimune (Ireland) Limited after elimination of all intercompany accounts and transactions.

The preparation of consolidated financial statements in conformity with 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 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 and the valuation of stock-based awards. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances.

The functional currency for the Company’s wholly owned foreign subsidiary, Replimune UK, is the British pound. Assets and liabilities of Replimune UK are translated into United States dollars at the exchange rate in effect on the balance sheet date. Revenues and expenses are translated at the average exchange rate in effect during the period. Unrealized translation gains and losses are recorded as a cumulative translation adjustment, which is included in the consolidated statements of stockholders’ equity as a component of accumulated other comprehensive income (loss). Adjustments that arise from exchange rate changes on transactions denominated in a currency other than the local currency are included in other income (expense), net in the consolidated statements of operations as incurred.

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents as well as short-term investments. The Company deposits its cash in financial institutions in amounts that may exceed federally insured limits. We limit our exposure to credit risk by placing investments with high credit quality financial institutions, diversifying our investment portfolio and placing investments with maturities that maintain safety and liquidity. To date, the Company has not experienced any losses on such accounts.

The Company relies, and expects to continue to rely, on a small number of vendors to manufacture and supply raw materials and supply services for its development programs. These programs could be adversely affected by a significant interruption in these services or the availability of raw materials.

The Company considers all highly liquid investments with original maturities of three months or less at date of purchase to be cash equivalents. Cash equivalents consisted of money market funds as of March 31, 2026 and 2025, respectively. As of March 31, 2026 and 2025, the amount of cash equivalents included in cash and cash equivalents totaled $120.3 million and $89.9 million, respectively.

The Company holds restricted cash in segregated bank accounts in connection with a letter of credit. As of March 31, 2026 and 2025, restricted cash consisted of $1.7 million, respectively, held for the benefit of the landlords in connection with our leases and for the Company's credit card program in the United Kingdom. These amounts have been classified as non-current assets on the Company’s consolidated balance sheets.

The Company’s short-term debt security investments are classified as available-for-sale and are carried at fair value, with the unrealized gains and non-credit related losses reported as a component of accumulated other comprehensive income (loss) and included in stockholders’ equity. Realized gains and losses and declines in value determined to be other than temporary are based on the specific identification method and are included as a component of other income (expense), net in the consolidated statements of operations.

For available-for-sale debt securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through a charge to investment income. For available-for-sale debt securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, the Company considers such

factors as, among other things, the severity of the impairment, any changes in interest rates, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the short-term debt security investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in investment income through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive loss on the statements of comprehensive loss.

The Company’s short-term investments as of March 31, 2026 and 2025 had maturities of less than one year. The Company has classified its investments with maturities beyond one year as short term, based on their highly liquid nature and because they represent the investment of cash that is available for current operations.

Costs for capital assets not yet placed into service are capitalized as construction-in-progress and depreciated in accordance with the above guidelines once placed into service. 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 loss from operations. Expenditures for repairs and maintenance are charged to expense as incurred.

Capitalized software as a service costs represent implementation costs incurred during the application development stage and are included in "property, plant and equipment, net" on the Company's consolidated balance sheet. Such costs are amortized on a straight-line basis over the term of the associated arrangement plus any reasonably certain renewal period. Costs incurred during the preliminary project stage and the post-implementation-operation stage are expensed as incurred.

Prior to the regulatory approval of the Company’s product candidates, the Company incurs expenses for the manufacture of drug product that could potentially be available to support the commercial launch of those products. Until the date at which regulatory approval has been received or is otherwise considered probable, the Company records all such costs as research and development expenses. There were no capitalized inventory costs recorded as of March 31, 2026 and 2025.

Long-lived assets consist of property, plant and equipment, right-of-use-asset - operating leases, and right-of-use-asset - finance leases. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset group for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the

Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable:

•Level 2 — Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data.

The Company’s short-term investments and cash equivalents are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of research and development incentives receivable, prepaid expenses and other current assets, accounts payable and accrued expenses and other current liabilities approximate their fair values due to the short-term nature of these assets and liabilities. Furthermore, the carrying value of the Company’s long-term debt approximates its fair value at each balance sheet date due to its variable interest rate, which approximates a market interest rate.

Debt issuance costs consist of payments made to secure commitments under certain debt financing arrangements. These amounts are recognized as interest expense over the period of the financing arrangement using the effective interest method. If the financing arrangement is canceled or forfeited, or if the utility of the arrangement to the Company is otherwise compromised, these costs are recognized as interest expense immediately. The Company’s consolidated financial statements present debt issuance costs related to a recognized debt liability as a direct reduction from the carrying amount of that debt liability.

Research and development costs are expensed as incurred. Research and development expenses consist of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs and laboratory supplies, depreciation and external costs of outside vendors engaged to conduct preclinical development, clinical development activities and clinical trials as well as to manufacture clinical trial materials. Non-refundable prepayments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. Such amounts are recognized as an expense as the goods are delivered or the related services are performed, or until it is no longer expected that the goods will be delivered or the services rendered. Upfront payments for materials and supplies acquired for particular research and development activities that have no alternative future use in other research and development projects or otherwise, and therefore have no separate economic value, are expensed as research and development costs at the time the costs are incurred.

The Company has entered into various research and development-related contracts with companies both inside and outside of the United States. These agreements are generally cancellable, and related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research costs. Accrual estimates are based on a number of factors, including management’s assessment of progress towards completion of the research and development activities, invoicing to date under the contracts, communication from the research organization or other companies of any actual costs incurred during the period that have not yet been invoiced, and the costs included in the contracts. When billing terms under these contracts do not coincide with the timing of when the work is performed, management is required to make estimates of outstanding obligations to those third parties as of the end of the reporting period. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs.

The Company accounts for share-based payment awards granted to employees, consultants, and non-employees and directors using the fair value of the award on the grant date and compensation expense is recognized for those awards over the requisite service period, which is generally the vesting period of the respective award. To date, the Company has issued stock-based awards in the form of restricted stock units, or RSUs, performance stock units, or PSUs, and stock option grants. Forfeitures for all awards are accounted for as they occur.

The grant date fair value for RSUs and PSUs is based on the closing price of the Company's common stock on the date of grant. The Company’s RSUs have service-based vesting conditions and the related expense for these awards is recorded using the straight-line method. The Company's PSUs have performance-based vesting conditions and expense is recognized when the achievement of the performance condition is probable.

The grant date fair value of each stock option grant is estimated using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield (see Note 10). Expense for these awards is recorded using the straight-line method over the vesting period of the respective award.

The Company, through its subsidiary in the United Kingdom, receives reimbursements of certain research and development expenditures as part of a United Kingdom government’s research and development tax reliefs program. Under the program, a percentage of qualifying research and development expenses incurred by the Company’s subsidiary in the United Kingdom are reimbursed up to 16.2%.

Management has assessed the Company’s research and development activities and expenditures to determine which activities and expenditures are likely to be eligible under the research and development incentive program described above. At each period end, management estimates the reimbursement available to the Company based on available information at the time.

The Company recognizes income from the research and development incentives when the relevant expenditure has been incurred, the associated conditions have been satisfied and there is reasonable assurance that the reimbursement will be received. The Company records these research and development incentives as other income. The research and development incentives receivable represents an amount due in connection with the above program. The Company recorded other income

from research and development incentives of $1.6 million and $1.8 million during the years ended March 31, 2026 and 2025, respectively, in the consolidated statements of operations and a research and development incentives receivable of $1.6 million and $3.7 million as of March 31, 2026 and 2025, respectively, on the consolidated balance sheets.

Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. For the year ended March 31, 2026, comprehensive loss included $0.3 million of unrealized losses on short-term investments, as well as $0.3 million of foreign currency translation gains. For the year ended March 31, 2025, comprehensive loss included $0.4 million of unrealized gains on short-term investments and $0.2 million of foreign currency translation gains.

The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax provision. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies.

The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the consolidated financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties.

Basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per common share is computed by dividing the diluted net income (loss) by the weighted average number of shares of common stock outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents.

In December 2023, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU primarily focuses on the rate reconciliation and income taxes paid. ASU No. 2023-09 requires a public business entity (PBE) to disclose, on an annual basis, a tabular rate reconciliation using both percentages and currency amounts, broken out into specified categories with certain reconciling items further broken out by nature and jurisdiction to the extent those items exceed a specified threshold. In addition, all entities are required to disclose income taxes paid, net of refunds received disaggregated by federal, state/local, and foreign and by jurisdiction if the amount is at least 5% of total income tax payments, net of refunds received. For PBEs, the new standard is effective for annual periods beginning after December 15, 2024, with early adoption permitted. An entity may apply the amendments in this ASU prospectively by providing the revised disclosures for the first period ending December 31, 2025 or later, and continuing to provide the pre-ASU disclosures for the prior periods, or may apply the amendments retrospectively by providing the revised disclosures for all period presented. For the year ended March 31, 2026, the Company adopted this

In November 2024, the FASB issued ASU-2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Topic 220): Disaggregation of Income Statement Expenses. The ASU requires more detailed information about specified categories of expenses (purchases of inventory, employee compensation, depreciation, amortization, and depletion) included in certain expense captions presented on the face of the income statement. This ASU is effective for fiscal years beginning after December 15, 2026, and for interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The amendments may be applied either (1) prospectively to financial statements issued for reporting periods after the effective date of this ASU or (2) retrospectively to all prior periods presented in the financial statements. The Company is currently evaluating the impact of adopting this ASU on its consolidated financial statements and related disclosures.

In September 2025, the FASB issued ASU 2025-06, "Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06)", which is intended to simplify the capitalization guidance for internal-use software by removing references to project stages and clarifying when the capitalizing of eligible costs is required. The new guidance is effective for annual periods beginning after December 15, 2027, and interim periods within those fiscal years, with early adoption permitted. ASU 2025-06 may be applied retrospectively or prospectively. The Company is in the process of evaluating the impact of this new guidance on its consolidated financial statements and related disclosures.