ARVINAS, INC.

1. Nature of Business and Basis of Presentation

Nature of Business

Arvinas, Inc. is a clinical-stage biotechnology company dedicated to improving the lives of patients suffering from debilitating and life-threatening diseases through the discovery, development and commercialization of therapies that degrade disease-causing proteins. Arvinas, Inc. hasfour wholly owned subsidiaries; Arvinas Operations, Inc. formed in 2013, Arvinas Androgen Receptor, Inc. formed in 2015, Arvinas Estrogen Receptor, Inc. formed in 2016, and Arvinas Winchester, Inc. formed in 2018 (collectively, "Arvinas" or the "Company").

Basis of Presentation

The Company's consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States of America ("U.S. GAAP") and include the accounts of Arvinas, Inc. and its wholly owned subsidiaries. All intercompany transactions have been eliminated upon consolidation. The accounting policies used to prepare the Company's consolidated financial statements are the same as those used to prepare the consolidated financial statements in prior years.

The preparation of the Company’s consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts and disclosures in the consolidated financial statements and notes. While management believes that estimates and assumptions used in the preparation of the consolidated financial statements and notes are appropriate, actual results could differ from those estimates. The most significant estimates are those used in the determination of the Company’s revenue recognition, uncertain tax positions and research and development expenses.

2. Summary of Significant Accounting Policies

Cash and Cash Equivalents

The Company classifies as cash and cash equivalents amounts on deposit in banks and cash invested temporarily in various instruments, primarily money market accounts, with original maturities of three months or less at time of purchase. The carrying amounts reported in the consolidated balance sheets represent the fair values of cash and cash equivalents and are considered Level 1 financial instruments.

Restricted Cash

Restricted cash represents a letter of credit collateralized by a certificate of deposit in the same amount which was canceled in connection with a lease termination agreement the Company entered into with 101 College Street LLC in August 2024.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets to the total amounts shown on the consolidated statements of cash flows for the years ended December 31, 2025, 2024 and 2023:

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Concentration of Credit Risk and Other Risks and Uncertainties

The Company is subject to a number of risks similar to other biotechnology companies in a similar stage, including, but not limited to, the need to obtain adequate additional funding, possible failure of preclinical testing or clinical trials, the need to obtain marketing approval for its product candidates, competitors developing new technological innovations, and the need to successfully commercialize and gain market acceptance of the Company’s products and protect its proprietary technology. If the Company does not successfully obtain regulatory approval for its product candidates, it will be unable to generate revenue from product sales or achieve profitability.

To date, the Company has not generated any revenue from product sales and expects to incur additional operating losses and negative operating cash flows for the foreseeable future. The Company has financed its operations primarily through sales of assets and equity, proceeds from collaborations and a licensing arrangement, grant funding and debt financing. The Company had cash, cash equivalents and marketable securities of approximately $685.4 million as of December 31, 2025.

The Company maintains its cash in financial institution accounts that may at times exceed federally insured limits. The cash balances in the financial institutions are insured by the Federal Deposit Insurance Corporation ("FDIC") up to $250,000. Cash may also be maintained at commercial institutions that are not insured by the FDIC.

For the years ended December 31, 2025, 2024 and 2023, one collaborator represented 92.0%,62.0% and 97% of the Company's revenue, respectively.

Marketable Securities

The Company's marketable securities are classified as available-for-sale securities and are carried at their fair value based on the quoted market prices of the securities, with unrealized gains and losses reported as accumulated other comprehensive income (loss), a separate component of stockholders' equity. Realized gains and losses on available-for-sale securities are included in other income in the period earned or incurred.

Property, Equipment, and Leasehold Improvements

Property and equipment are recorded at cost. Depreciation is calculated using the straight-line method over the estimated useful lives, which range from three years for office equipment tofive years for laboratory equipment. Maintenance and repairs which do not extend the lives of the assets are charged directly to expense as incurred. Upon retirement or disposal, cost and related accumulated depreciation is removed from the related accounts, and any resulting gain or loss is recognized as a component of income or loss for the period. Leasehold improvements are recorded at cost and amortized using the straight-line method over the shorter of the lease term or the useful life of the asset.

Lease and Rent Expense

The Company accounts for leases under Accounting Standards Codification (“ASC”) 842, 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 in the arrangement. Leases with a term greater than one year are recognized on the balance sheet as right-of-use ("ROU") assets and short-term and long-term lease liabilities, as applicable. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. The Company has elected not to recognize leases with an original term of one year or less on the balance sheet. The Company typically only includes an initial lease term in its assessment of the term of the lease arrangement. It also considers termination options and factors those into the determination of lease payments. Options to renew a lease are not included in the lease term unless there is reasonable certainty of renewal.

Operating lease liabilities and their corresponding ROU assets are recorded based on the present value of lease payments over the expected remaining lease term. Certain adjustments to the ROU asset may be required for items such as incentives received. The interest rate implicit in lease contracts is typically not readily determinable. As a result, the Company utilizes its incremental borrowing rate, which reflects the fixed rate at which it could borrow on a collateralized basis the amount of the lease payments in the same currency, for a

F - 9 similar term, in a similar economic environment. The Company's weighted average incremental borrowing rate at December 31, 2025 totaled 7.0%.

Variable lease payments are not included within the lease right-of-use asset and lease liability on the consolidated balance sheet, and instead are reflected as expense in the period they are incurred.

Impairment of Long-Lived Assets

The Company monitors its long-lived assets for indicators of impairment. If such indicators are present, the Company assesses the recoverability of affected assets by determining whether the carrying value of such assets is less than the sum of the undiscounted future cash flows of the assets. If such assets are found not to be recoverable, the Company measures the amount of such impairment by comparing the carrying value of the assets to the fair value of the assets, with the fair value generally determined based on the present value of the expected future cash flows associated with the assets. No such impairments were recorded during 2025, 2024 or 2023.

Revenue Recognition and Deferred Revenue

Revenues from Contracts

The Company recognizes revenue under ASC 606, Revenue from Contracts with Customers. The Company’s revenue is primarily generated through research collaborations and licensing arrangements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones and royalty payments based on product sales derived from the collaboration. Under ASC 606, the Company evaluates whether the license agreement, research and development services and participation in research and development steering committees represent separate or combined performance obligations. The Company has determined that these services within its existing contracts represent combined single performance obligations. The Company also generated revenue through the sale of assets based on fair value.

The research collaboration and license agreements may include contingent milestone payments related to specified preclinical and clinical development milestones and regulatory milestones. These milestone payments represent variable consideration to be included within the transaction price using the most likely amount method. The Company continually assesses the probability of significant reversals for any amounts that become likely to be realized prior to recognizing the variable consideration associated with these payments within the transaction price.

Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. Management makes its best estimate of the period over which the Company expects to fulfill its performance obligations, which includes access to technology through the license agreement and research activities. Given the uncertainties of these collaboration arrangements, significant judgment is required to determine the duration of the performance period. Management evaluates changes in the duration of the performance period at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate.

For the years ended December 31, 2025, 2024 and 2023, the transaction price allocated to the combined performance obligation identified under the individual research collaboration and license agreements was recognized as revenue on either a straight-line basis over the estimated performance period under the arrangement or over the estimated performance period based on the Company’s best estimate of costs to be incurred. Straight-line basis was considered the best measure of progress for certain agreements in which control of the combined obligation transfers to the customers, due to the contract containing license rights to technology, research and development services, and joint committee participation, which in totality are expected to occur ratably over the performance period. For agreements accounted for under the costs to be incurred method, revenue is recognized as program costs are incurred by measuring actual costs incurred to date compared to the total expected costs to satisfy the performance obligations. Management evaluates estimates of expected costs to satisfy the performance obligations at each reporting period and adjusts revenue as necessary. Changes are accounted for prospectively as a change in accounting estimate.

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The Company’s contracts may also call for certain sales-based milestone and royalty payments upon successful commercialization of a target. The Company recognizes revenues from sales-based milestone and royalty payments at the later of a) the occurrence of the subsequent sale, or b) the performance obligation to which some or all of the sales-based milestone or royalty payments has been allocated has been satisfied (or partially satisfied). The Company anticipates recognizing these milestones and royalty payments if and when subsequent sales are generated by customers from the use of the technology. To date, no revenue from these sales-based milestone and royalty payments has been recognized for any periods.

Amounts received prior to satisfying the above revenue recognition criteria are recorded as contract liabilities in the Company’s accompanying consolidated balance sheets.

The Company expenses direct and incremental costs to obtaining and fulfilling a contract as and when incurred if the expected amortization period of the asset that would be recognized is one year or less, or if the amount of the asset is immaterial. Otherwise, such costs are capitalized as collaboration contract assets and amortized as general and administrative expenses over the total estimated period of performance of each underlying contract.

Equity Method Investments

The Company accounts for investments for which it does not have a controlling interest in accordance with ASC 323, Investments – Equity Method and Joint Ventures. The Company recognizes its pro-rata share of income and losses in the investment in “Loss from equity method investment” on the consolidated statement of operations and comprehensive loss, with a corresponding change to the investment in equity method investment in the consolidated balance sheet until such investment is reduced tozero.

Income Taxes

Arvinas, Inc. and its wholly owned subsidiaries use the asset and liability method of accounting for income taxes, as set forth in ASC 740, Accounting for Income Taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequence of temporary differences between the carrying amounts and the tax basis of assets and liabilities and net operating loss carry forwards, all calculated using presently enacted tax rates. A valuation allowance is established to reduce deferred tax assets to their estimated realizable value. The Company provides a valuation allowance to the extent that it is more likely than not that all or a portion of the deferred tax assets will not be realized.

The Company follows the authoritative guidance under ASC 740 for recognizing and measuring uncertainty in income tax positions taken or expected to be taken in a tax return. The Company recognizes interest accrued related to unrecognized tax benefits and penalties in tax expense.

Equity-based Compensation

The Company measures employee and board of director equity-based compensation for stock option and restricted stock grants based on the grant date fair value of the equity awards. Equity-based compensation expense is recognized over the requisite service period of the awards, net of estimated forfeitures. Estimated forfeitures are updated on a periodic basis based on actual experience. For equity awards that have a performance condition, the Company recognizes compensation expense based on its assessment of the probability that the performance condition will be achieved.

The Company classifies equity-based compensation expense in its consolidated statements of operations in the same manner in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified.

401(k) Savings Plan

The Company has a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pretax basis. Under the 401(k) Plan, the Company made discretionary matching contributions on behalf of eligible employees

F - 11 totaling $2.6 million, $3.4 million and $3.1 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Research and development expenses include (i) employee-related expenses, including salaries, benefits, stock-based compensation expense and travel; (ii) external research and development expenses incurred under arrangements with third parties, such as contract research organization agreements, investigational sites and consultants; (iii) the cost of acquiring, developing and manufacturing clinical study materials; (iv) costs associated with preclinical and clinical activities and regulatory operations; and (v) costs incurred in development of intellectual property. Costs incurred in connection with research and development activities are expensed as incurred.

The Company enters into consulting, research and other agreements with commercial entities, researchers, universities and others for the provision of goods and services. Such arrangements are generally cancellable upon reasonable notice and payment of costs incurred. Costs are considered incurred based on an evaluation of the progress to completion of specific tasks under each contract using information and data provided by the respective vendors, including the Company’s clinical sites. These costs consist of direct and indirect costs associated with specific projects, as well as fees paid to various entities that perform certain research on behalf of the Company. Depending upon the timing of payments to the service providers, the Company recognizes prepaid expenses or accrued expenses related to these costs. These accrued or prepaid expenses are based on management’s estimates of the work performed under service agreements, milestones achieved and experience with similar contracts. The Company monitors each of these factors and adjusts estimates accordingly.

Fair Value Measurements

The Company determines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Inputs used in the valuation techniques to determine fair values are classified based on a three-level hierarchy. The basis for fair value measurements for each level within the hierarchy is described below, with Level 1 having the highest priority and Level 3 having the lowest. The three levels of the fair value hierarchy are as follows:

Level 1— Inputs are based upon observable or quoted prices (unadjusted) for identical instruments traded in active markets. The Company’s Level 1 financial instruments consist of cash equivalents.

Level 2— Inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 investments consist primarily of corporate notes and bonds and U.S. government and agency securities.

Level 3— Inputs are generally unobservable and typically reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are therefore determined using model-based techniques that include option pricing models, discounted cash flow models and similar techniques.

In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value.

Net Loss per Common Share

Basic net loss per common share is computed by dividing net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted-average number of potential shares of common shares.

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The weighted-average number of common shares included in the computation of basic and diluted net loss per common share gives effect to pre-funded warrants. See Note 9, Equity, and Note 13, Net Loss Per Share.

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements

Income Taxes (Topic 740) - In December 2023, the FASB issued ASU No. 2023-09, "Improvements to Income Tax Disclosures," which requires enhanced income tax disclosures, including specific categories and disaggregation of information in the effective tax rate reconciliation, disaggregated information related to income taxes paid, income or loss from continuing operations before income tax expense or benefit and income tax expense or benefit from continuing operations. The requirements of the ASU are effective for annual periods beginning after December 15, 2024, with early adoption permitted. The Company adopted the new standard on January 1, 2025 and presented disclosures on a retrospective basis. The adoption of the standard did not have a material impact on the Company's consolidated financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40) - In November 2024, the FASB issued ASU No. 2024-03, "Disaggregation of Income Statement Expenses," which requires disaggregation and disclosure of specified information about certain costs and expenses in the notes to the financial statements. The requirements of the ASU are effective for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the impact ASU No. 2024-03 will have on its consolidated financial statements.

3. Research Collaboration and License Agreements

Vepdegestrant (ARV-471) Collaboration Agreement

In July 2021, the Company entered into a collaboration agreement with Pfizer (the “Vepdegestrant (ARV-471) Collaboration Agreement”) pursuant to which the Company granted Pfizer worldwide co-exclusive rights to develop and commercialize products containing the Company’s proprietary compound vepdegestrant (the “Licensed Products”). Under the Vepdegestrant (ARV-471) Collaboration Agreement, the Company received an upfront, non-refundable payment of $650.0 million. In addition, the Company will be eligible to receive up to an additional $1.4 billion in contingent payments based on specific regulatory and sales-based milestones for the Licensed Products. Of the total contingent payments, $400.0 million in regulatory milestones are related to marketing approvals and $1.0 billion are related to sales-based milestones. There were no regulatory or sales-based milestone payments received through December 31, 2025.

The Company and Pfizer share equally all development costs, including costs of conducting clinical trials, for the Licensed Products, subject to certain exceptions. Except for certain regions described below, the parties will also share equally all profits and losses in commercialization and medical affairs activities for the Licensed Products in all other countries, subject to certain exceptions.

The Company will be the marketing authorization applicant in the United States and, subject to approval, can book sales in the United States, while Pfizer will hold marketing authorizations outside the United States. The parties will determine which, if any, regions within the world will be solely commercialized by one party, and in such region the parties will adjust their share of profits and losses for the Licensed Products based on the role each party will be performing.

In addition, in connection with the execution of the Vepdegestrant (ARV-471) Collaboration Agreement, the Company and Pfizer entered into a Stock Purchase Agreement (the "Pfizer Stock Purchase Agreement") for the sale and issuance of 3,457,815 shares of the Company’s common stock (the “Shares”) to Pfizer at a price of $101.22 per share, for an aggregate purchase price of $350.0 million (the “Pfizer Equity Transaction”), less financial advisor fees of $4.6 million, which was consummated in September 2021. Pursuant to terms of the Pfizer Stock Purchase Agreement, Pfizer has agreed not to sell or transfer the Shares without prior written approval of the Company for a specified time period, subject to specified exceptions.

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The Company determined that the Vepdegestrant (ARV-471)Collaboration Agreement and the Pfizer Equity Transaction entered into with Pfizer concurrently should be evaluated as a combined contract in accordance with Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers. The Company determined the fair value of the shares sold under the Pfizer Equity Transaction to be $85.4 million less than the contractual purchase price stipulated in the agreement. In accordance with the applicable accounting guidance in ASC 815-40, Contracts in Entity’s Own Equity, the Company determined that the sale of stock should be recorded at fair value and therefore allocated the excess consideration received under the Pfizer Equity Transaction to the Vepdegestrant (ARV-471)Collaboration Agreement, which, along with the non-refundable payment of $650.0 million, is being recognized as revenue over the total estimated period of performance based on the Company’s best estimate of costs to be incurred.

As a direct result of the Company’s entry into the Vepdegestrant (ARV-471)Collaboration Agreement, the Company incurred direct and incremental costs to obtain the contract, paid to a financial advisor, totaling $12.9 million. In accordance with ASC 340, Other Assets and Deferred Costs, the Company recognized an asset of $12.9 million in collaboration contract asset and other assets in the consolidated balance sheet, which is being amortized as general and administrative expense over the total estimated period of performance under the Vepdegestrant (ARV-471)Collaboration Agreement.

In September 2025, the Company announced that the Company and Pfizer have agreed to jointly select a third party for the commercialization and potential further development of vepdegestrant. The announcement did not have an effect on revenue recognition for the year ended December 31, 2025.

In December 2017, the Company entered into a Research Collaboration and License Agreement with Pfizer (the "Pfizer Research Collaboration Agreement"). Under the terms of the Pfizer Research Collaboration Agreement, the Company received an upfront, non-refundable payment and certain additional payments totaling $28.0 million in 2018 in exchange for use of the Company’s technology license and to fund Pfizer-related research as defined within the Pfizer Research Collaboration Agreement. These payments are being recognized over the total estimated period of performance. As of December 31, 2025, there remains a single target under the Pfizer Research Collaboration Agreement, and, in accordance with the terms of such Agreement, the Company is eligible to receive up to an additional $3.8 million in non-refundable option payments if Pfizer exercises its option for such target protein under the Pfizer Research Collaboration Agreement.

The Company is also entitled to receive up to $225.0 million in development milestone payments and up to $550.0 million in sales-based milestone payments for all designated targets under the Pfizer Research Collaboration Agreement, as well as tiered royalties based on sales. There were no sales-based milestone payments or royalties received through December 31, 2025.

Novartis License and Asset Agreements

In April 2024, the Company entered into a transaction (the "Novartis Transaction"), including both a license agreement (the "Novartis License Agreement") and an asset purchase agreement (the "Novartis Asset Agreement") with Novartis Pharma AG ("Novartis") for the worldwide development, manufacture and commercialization of luxdegalutamide (ARV-766), the Company's second generation PROTAC androgen receptor (AR) degrader for patients with prostate cancer and for the sale of the Company's preclinical AR-V7 program. Under the terms of the agreements, Novartis is responsible for worldwide clinical development and commercialization of luxdegalutamide (ARV-766) and has all research, development, manufacturing, and commercialization rights with respect to the Company’s PROTAC protein degrader targeting AR-V7, a splice variant of the AR.

In May 2024, Novartis paid to the Company a one-time, upfront payment in the aggregate amount of $150.0 million in accordance with the terms of the Novartis License Agreement and the Novartis Asset Agreement. Under the terms of the Novartis License Agreement, the Company is eligible to receive up to an additional $1.01 billion as contingent payments based on specified development, regulatory and commercial milestones for luxdegalutamide (ARV-766) being met, as well as tiered royalties based on worldwide net sales of luxdegalutamide (ARV-766), subject to reduction under certain circumstances as provided in the Novartis License Agreement. During the year ended December 31, 2025, the Company recognized as revenue $20.0 million upon the achievement of a development milestone pursuant to the terms of the Novartis License

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Agreement. There were no development, regulatory or commercial milestone payments, or sales-based royalties received during the year ended December 31, 2024.

The Novartis License Agreement will continue on a country-by-country basis (or, in certain cases, a region-by-region basis) until the expiration of the applicable royalty term for such country (or region, as applicable). The Novartis License Agreement contains customary termination provisions, including that either party may terminate the Novartis License Agreement (a) upon the material breach of the other party or (b) in the event the other party experiences an insolvency event. Additionally, Novartis may terminate the Novartis License Agreement for convenience or upon a safety or regulatory issue.

The Company determined that the Novartis License Agreement and the Novartis Asset Agreement entered into with Novartis concurrently should be accounted for as a combined contract in accordance with ASC 606, Revenue from Contracts with Customers. The Company determined the fair value of the assets sold under the Novartis Asset Agreement to be $20.0 million, which was recognized at the time of sale as revenue, and the fair value of the Novartis License Agreement to be $130.0 million, which was recognized as revenue over the total estimated period of performance during the technology transfer period, as defined in the agreement, based on the cost incurred input method. Under the Novartis License Agreement, Novartis will also reimburse the Company for development costs incurred during the technology transfer period, which will be recognized as revenue as costs are incurred. As of December 31, 2024, the technology transfer period ended as the Company completed the transition of its ongoing and planned clinical trials of luxdegalutamide (ARV-766) to Novartis.

As a direct result of the Company’s entry into the Novartis Transaction, the Company incurred direct and incremental costs to obtain the contract, paid to a financial advisor, totaling $3.0 million. In accordance with ASC 340, Other Assets and Deferred Costs, the Company recognized an asset of $3.0 million in collaboration contract asset and other assets in the consolidated balance sheet at inception of the Novartis License Agreement and the Novartis Asset Agreement, which was amortized as general and administrative expense over the total estimated period of performance under the Novartis License Agreement and the Novartis Asset Agreement.

Genentech Modification

In November 2017, the Company entered into an Amended and Restated Option, License, and Collaboration Agreement (the "Genentech Modification") with Genentech, Inc. and F. Hoffman-La Roche Ltd (together "Genentech"), amending a previous Genentech agreement entered into in September 2015. Under the Genentech Modification, the Company received upfront, non-refundable payments of $34.5 million (in addition to $11.0 million received under the previous agreement in 2015) to fund Genentech-related research. Upfront non-refundable payments were recognized as revenue over the total estimated period of performance, which concluded during the first quarter of 2023.

The Company is eligible to receive up to $44.0 million per target in development milestone payments, $52.5 million in regulatory milestone payments and $60.0 million in commercial milestone payments based on sales as well as tiered royalties based on sales. There were no development, regulatory or commercial milestone payments or royalties received through December 31, 2025.

Bayer Collaboration Agreement

In June 2019, the Company and Bayer AG entered into a Collaboration and License Agreement (the "Bayer Collaboration Agreement") setting forth the Company’s collaboration with Bayer AG to identify or optimize proteolysis targeting chimeras, or PROTAC targeted protein degraders, that mediate for degradation of target proteins ("Targets"), using the Company’s proprietary platform technology, which Targets were selected by Bayer AG, subject to certain exclusions and limitations. Under the terms of the Bayer Collaboration Agreement, the Company received an upfront, non-refundable payment of $17.5 million in exchange for the use of the Company’s technology license. The Company also received an additional $12.0 million from Bayer AG from inception through 2023, including $1.5 million received during the year ended December 31, 2023. These payments were recognized over the total estimated period of performance.

Pursuant to notice from Bayer AG in accordance with the terms of the Bayer Collaboration Agreement, the Bayer Collaboration Agreement was terminated effective August 12, 2024.

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The Company was also eligible to receive up to $197.5 million in development milestone payments and up to $490.0 million in sales-based milestone payments for all designated Targets. In addition, the Company was eligible to receive, on net sales of PROTAC targeted protein degrader-related products, mid-single digit to low-double digit tiered royalties, which were subject to reductions. There were no development or sales-based milestone payments or royalties received through August 12, 2024, the termination date of the agreement.

Changes in the Company's contract balances were as follows:

During the year ended December 31, 2025, the Company updated its estimate to satisfy the performance obligations under the Vepdegestrant (ARV-471) Collaboration Agreement due to the removal of the first-line Phase 3 combination trial with Pfizer’s novel investigational CDK4 inhibitor, atirmociclib, and the removal of the second-line Phase 3 combination trial with a CDK4/6 inhibitor from the development plan. The change in accounting estimate resulted in an increase in revenue of $150.2 million, an increase in operating expenses of $2.6 million, a decrease in net loss of $147.6 million, and a decrease in basic and diluted loss per share of $2.08 for the year ended December 31, 2025.

During the year ended December 31, 2025, the Company also changed its estimate of the duration of the performance period under the Pfizer Research Collaboration Agreement as a result of updated research timelines. The change in accounting estimate resulted in a decrease of $6.6 million in revenue, an increase in net loss, and an increase in basic and diluted loss per share of $0.09 for the year ended December 31, 2025. The reversed revenue will continue to be recognized in future periods as the Company continues to advance on the performance obligation under the updated collaboration timeline.

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During the year ended December 31, 2024, the Company changed its estimate of the duration of the performance period under the Pfizer Research Collaboration Agreement as a result of updated research timelines. The changes in accounting estimate resulted in a decrease in revenue and an increase in net loss of $2.4 million, respectively, and an increase in net loss per share of $0.03 for the year ended December 31, 2024. The reversed revenue will be recognized in subsequent periods as the Company continues to advance on the performance obligation under the updated collaboration timeline.

During the fourth quarter of 2023, the Company had a change to its estimate to satisfy the performance obligations under the Vepdegestrant (ARV-471) Collaboration Agreement due to the expansion of the development programs. The changes in accounting estimate resulted in a decrease in revenue and increase in net loss of $35.0 million, respectively, and an increase in net loss per share of $0.63 for the year ended December 31, 2023. The reversed revenue will continue to be recognized in future periods as the Company continues to advance on the performance obligation under the collaboration.

During the year ended December 31, 2023, the Company also changed its estimate of the duration of the performance period under the Bayer Collaboration Agreement and Pfizer Research Collaboration Agreement as a result of updated research timelines. The changes in accounting estimate resulted in a decrease in revenue and an increase in net loss of $10.6 million, respectively, and an increase in net loss per share of $0.19 for the year ended December 31, 2023. The reversed revenue was recognized in subsequent periods as the Company continued to advance on the performance obligation under the updated collaboration timelines.

The aggregate amount of the transaction price allocated to performance obligations that were unsatisfied as of December 31, 2025 totaled $205.6 million, which is expected to be recognized in the following periods:

4. Marketable Securities and Fair Value Measurements

The following is a summary of the Company’s available for sale marketable securities measured at fair value on a recurring basis.

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The Company generally does not intend to sell any investments prior to recovery of their amortized cost basis for any investment in an unrealized loss position. As such, the Company has classified these losses as temporary in nature.

The carrying value of cash and cash equivalents, accounts receivable and accounts payable and accrued liabilities approximate their fair values due to the short-term nature of these assets and liabilities.

5. Property, Equipment and Leasehold Improvements

Property, equipment and leasehold improvements consist of the following:

Depreciation and amortization expense totaled $3.0 million, $4.6 million, and $4.8 million for the years ended December 31, 2025, 2024 and 2023, respectively.

During the year ended December 31, 2024, the Company wrote-off leasehold improvements totaling $2.4 million resulting from the termination of the Terminated Lease, as discussed below in Note 6, Right-of-Use Assets and Liabilities.

6. Right-of-Use Assets and Liabilities

In August 2024, the Company entered into a Lease Termination Agreement with 101 College Street LLC (the "Landlord"). Under the terms of the Lease Termination Agreement, the lease, by and between the Company and the Landlord, dated May 4, 2021 (as amended, the "Terminated Lease"), for certain leased premises of approximately 160,000 square feet of laboratory and office space, was terminated in full, effective August 15, 2024. The leased premises were expected to be occupied by the Company in 2025. In connection with the Lease Termination Agreement and as consideration for the Landlord’s agreement to terminate the lease for its laboratory and office space at 101 College Street in full, the Company agreed to pay to the Landlord a one-time cash termination fee in the amount of $41.5 million and wrote-off $1.9 million of prepaid rent, both of which were recognized in general and administrative operating expenses on the consolidated statements of operations. The Company also cancelled its previously issued letter of credit in the amount of $5.5 million.

The Company has operating leases for its corporate office, laboratories and certain equipment, which expire no later than December 2029. The leases have a weighted-average remaining term of 4.0 years.

The components of lease expense were as follows:

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Supplemental cash flow information related to leases was as follows:

In December 2024, the Company, entered into a Seventh Amendment and an Eighth Amendment to its lease (collectively the “Seventh and Eighth Building 5 Lease Amendments") with Science Park Development Corporation for certain premises in New Haven, Connecticut (the “Building 5 Premises”). The Seventh and Eighth Building 5 Lease Amendments extend the term of the original lease to December 31, 2029, resulting in an increase in the Company's ROU assets of $8.5 million, and, effective on January 1 2025, expand the Building 5 Premises to include approximately 11,200 square feet of additional laboratory and office space resulting in an increase in the Company's ROU assets of $1.5 million. The annual base rent during the extended term will range from $2.2 million to $2.6 million.

Maturities of operating lease liabilities as of December 31, 2025 were as follows:

7. Accounts Payable and Accrued Liabilities

Accounts payable and accrued liabilities consisted of the following:

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8. Long-Term Debt

Debt obligations consisted of the following:

In June 2018, the Company entered into an Assistance Agreement with the State of Connecticut (the "2018 Assistance Agreement") to provide funding for the expansion and renovation of laboratory and office space. In September 2018, the Company borrowed $2.0 million under the 2018 Assistance Agreement, of which $1.0 million was forgiven by the State of Connecticut in April 2021 as the Company met certain employment conditions, as defined in the agreement. Borrowings under the 2018 Assistance Agreement bear an interest rate of 3.25% per annum, with interest-only payments required for the first 60 months, and mature in September 2028. The 2018 Assistance Agreement requires that the Company be located in the State of Connecticut through September 2028 with a default penalty of repayment of the full original funding amount of $2.0 million plus liquidated damages of 7.5% of the total amount of funding received.

Minimum future principal payments on long-term debt as of December 31, 2025 are as follows:

During the years ended December 31, 2025, 2024 and 2023, interest expense was immaterial.

9. Equity

Preferred Stock

As of December 31, 2025 and 2024, the Company had authorized 5,000,000 shares of preferred stock, at a $0.001 par value per share. Preferred stock may be issued in one or more series upon authorization of the Company's board of directors. The board of directors is authorized to fix the designations, powers, preferences and the relative, participating, optional or other special rights and any qualifications, limitations and restrictions of the shares of each series of preferred stock. The authorized shares of the Company's preferred stock are available for issuance without further action by the Company's stockholders, unless such action is required by applicable law or the rules of any stock exchange on which our securities may be listed.

Common Stock

As of December 31, 2025 and 2024, the Company had authorized 200,000,000 shares of common stock, at a $0.001 par value per share. The holders of shares of common stock are entitled toone vote for each share of common stock held at all meetings of stockholders and written actions in lieu of meetings. The holders of shares of common stock are entitled to receive dividends, if and when declared by the board of directors. No dividends have been declared or paid by the Company since its inception.

In November 2023, the Company completed a private placement offering with certain institutional investors in which the Company issued and sold 12,963,542 shares of common stock at a price of $21.36 per share and, to one investor, in lieu of common stock, pre-funded warrants to purchase up to 3,422,380 shares of common stock at a price of $21.359 per pre-funded warrant. Each pre-funded warrant has an exercise price of $0.001 per share, is exercisable immediately and is exercisable until exercised in full. The aggregate gross

F - 20 proceeds from the issuance of common stock and pre-funded warrants totaled approximately $350.0 million, before deducting placement agent fees and offering costs of approximately$15.9 million. As of December 31, 2025, all outstanding pre-funded warrants had been cashless exercised for no consideration and the Company issued 3,422,186 shares of common stock to the holders.

Share Repurchase Program

On September 17, 2025, the Company announced that its board of directors authorized and approved a share repurchase program for the repurchase of up to $100.0 million of the then-currently outstanding shares of the Company’s common stock. Share repurchases under the share repurchase program may be made from time to time through a variety of methods, which may include open market purchases, privately negotiated block trades, accelerated share repurchases, other privately negotiated transactions or any combination of these methods. Repurchases may also be made under a Rule 10b5-1 plan, which would permit shares to be repurchased when the Company might otherwise be precluded from doing so under insider trading laws. The share repurchase program is funded using the Company's working capital. The share repurchase program has no time limit and can be modified, suspended or discontinued at any time without prior notice. Repurchased shares are recorded as treasury stock, at cost, and are eligible to be reissued under the Company's stock plans and for other corporate purposes.

During the year ended December 31, 2025, the Company repurchased 10,009,758 shares of its common stock, at an average price of $9.09 per share, for an aggregate purchase price of $91.0 million, plus commissions and excise tax of $0.9 million. As of December 31, 2025, the Company hassuspended the program and has no further plans to repurchase additional shares.

Equity Distribution Agreements

In August 2021, the Company entered into an Equity Distribution Agreement with Piper Sandler & Company (“Piper Sandler”) and Cantor Fitzgerald & Co. (“Cantor”), as agents, pursuant to which the Company may offer and sell from time to time, through the agents, up to $300.0 million of the common stock registered under a universal shelf registration statement pursuant to one or more “at-the-market" offerings. During the year ended December 31, 2023, the Company issued 1,449,275 shares of common stock under this agreement resulting in gross proceeds of approximately $37.2 million, less offering costs of approximately $1.1 million.

In November 2023, the Company amended and restated the Equity Distribution Agreement with Piper Sandler and Cantor, pursuant to which the Company may offer and sell from time to time, through the agents, up to approximately$262.8 million of the common stock registered under a universal shelf registration statement pursuant to one or more “at-the-market” offerings. During the years ended December 31, 2025 and 2024, no shares were issued under this amended and restated agreement.

Stock-based Compensation

2018 Employee Stock Purchase Plan

In September 2018, the Company adopted the 2018 Employee Stock Purchase Plan (the "2018 ESPP"), with the first offering period under the 2018 ESPP commencing on January 1, 2020, by initially providing participating employees with the opportunity to purchase an aggregate of 311,850 shares of the Company's common stock. The number of shares of the Company's common stock reserved for issuance under the 2018 ESPP increased, pursuant to the terms of the 2018 ESPP, by additional shares equal to 1% of the Company’s then-outstanding common stock, effective as of January 1 of each year. As of December 31, 2025,3,577,025 shares remained available for purchase. During the years ended December 31, 2025, 2024 and 2023, the Company issued 110,412,120,834 and 78,528 shares, respectively, of common stock under the 2018 ESPP.

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2018 Stock Incentive Plan

In September 2018, the Company’s board of directors adopted, and the Company’s stockholders approved, the 2018 Stock Incentive Plan (the "2018 Plan"), which became effective upon the effectiveness of the registration statement on Form S-1 for the Company’s initial public offering. The number of common shares initially available for issuance under the 2018 Plan equaled the sum of (1)4,067,007 shares of common stock; plus (2) the number of shares of common stock (up to 1,277,181 shares) issued in respect of incentive units granted under the Incentive Plan that were subject to vesting immediately prior to the effectiveness of the registration statement that expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus (3) an annual increase on the first day of each year beginning with the year ended December 31, 2019 and continuing to, and including, the year ending December 31, 2028, equal to the lesser of 4,989,593 shares of the Company’s common stock,4% of the number of shares of the Company’s common stock outstanding on the first day of the year or an amount determined by the Company’s board of directors. As of December 31, 2025,2,966,406 shares are available for issuance under the 2018 Plan. Common shares subject to outstanding equity awards that expire or are terminated, surrendered, or cancelled without having been fully exercised or are forfeited in whole or in part are available for future grants of awards.

Compensation Expense

In connection with the strategic restructuring actions initiated by the Company in the second and third quarters of 2025, as further discussed below in Note 14, Restructuring Activity, the Company modified the vesting terms of certain restricted stock units previously granted to employees. The incremental impact of the modification for the year ended December 31, 2025 totaled $5.3 million, as a decrease to compensation expense.

For the years ended December 31, 2025, 2024 and 2023, the Company recognized compensation expense of $44.0 million, $88.2 million and $71.6 million, respectively, related to the issuance of incentive awards, including $0.5 million, $0.7 million and $0.8 million, respectively, related to the 2018 ESPP.

As of December 31, 2025, there was $30.4 million of compensation expense that is expected to be recognized over a weighted-average period of approximately 1.5 years.

Stock Options

The fair value of the stock options granted during each of the years ended December 31, 2025, 2024 and 2023 was determined using the Black-Scholes option pricing model at the grant date with the following range of assumptions:

(1) Expected volatility is calculated by utilizing the Company's historical volatility of its stock price over a period equal to the expected term.

(2) Expected term is calculated based on the Company's historical experience.

(3) Risk free interest rate is based on an interpolation of U.S. Treasury rates to reflect the expected term at the date of grant.

During the year ended December 31, 2023, the Company calculated volatility of its common stock by utilizing a weighted-average of a collection of peer company volatilities and its own common stock volatility as the Company’s common stock had not been trading for a sufficient period of time. The expected term was calculated utilizing the simplified method.

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A summary of the stock option activity under the 2018 Plan as of December 31, 2025 is presented below. Included in the table are stock options granted to employees, directors and consultants under the 2018 Plan, as well as options to purchase 255,611 shares of common stock granted to certain employees pursuant to the Nasdaq inducement grant exception in accordance with Nasdaq Listing Rule 5635(c)(4).

The weighted-average grant date fair value of options granted during the years ended December 31, 2025, 2024 and 2023 was $8.15, $27.35 and $21.99, respectively. The total intrinsic value of options exercised during the years ended December 31, 2024 and 2023 was $3.6 million and $1.4 million, respectively. There wereno options exercised during the year ended December 31, 2025.

Restricted Stock Units

A summary of restricted stock unit ("RSU") activity under the 2018 Plan for the year ended December 31, 2025 is presented below. Included in the table are RSUs granted to employees and directors under the 2018 Plan, as well as RSUs representing 170,365 shares of common stock granted to certain employees pursuant to the Nasdaq inducement grant exception in accordance with Nasdaq Listing Rule 5635(c)(4).

The weighted-average grant date fair value of RSUs granted during the years ended December 31, 2025, 2024 and 2023 was $12.34, $44.43 and $32.27, respectively. The total intrinsic value of RSUs released during the years ended December 31, 2025, 2024 and 2023 was $17.7 million, $13.2 million and $4.3 million, respectively. The total fair value of RSUs vested during the years ended December 31, 2025, 2024 and 2023 was $44.3 million, $13.1 million and $6.9 million, respectively.

10. Equity Method Investments

In July 2019, the Company and Bayer CropScience LP ("Bayer LP") formed Oerth Bio, a joint venture to research, develop and commercialize PROTAC targeted protein degraders for applications in the field of agriculture. Pursuant to the terms of the joint venture agreement, the Company made an in-kind intellectual property contribution to Oerth Bio in the form of a license to certain of the Company’s proprietary technology and Bayer LP committed and subsequently made cash contributions to Oerth Bio totaling $56.0 million, as well as an in-kind intellectual property contribution. The Company and Bayer LP each held an initial ownership interest in Oerth Bio representing 50% of the ownership interests. A 15% ownership interest of Oerth Bio was

F - 23 reserved for the future grants of incentive units to employees and service providers and, as a result, the Company's ownership interest totaled 42.9%,43.6% and 45.0% as of December 31, 2025, 2024 and 2023, respectively, as a result of vested incentive units.

Under the joint venture agreement, the Company has no obligation to provide additional funding and the Company’s ownership interest will not be diluted from future contributions from Bayer LP. The activities of Oerth Bio are controlled by a management board under the joint control of the Company and Bayer LP. As Oerth Bio is jointly controlled by the Company and Bayer LP, the Company accounts for its interest using the equity method of accounting. The Company determined that Oerth Bio is a variable interest entity and, accordingly, the Company has evaluated the significant activities of Oerth Bio under the variable interest entity model and concluded that the significant activities consist primarily of research and development activities and, as the Company does not have the sole power to direct such activities, the Company is not the primary beneficiary.

Operating expenses and net loss of Oerth Bio for the years ended December 31, 2025, 2024 and 2023 totaled$1.1 million, $3.7 million and $8.3 million, respectively. The Company recognizedno equity method losses for the years ended December 31, 2025 and 2024. The Company recognized equity method losses of $2.5 million for the year ended December 31, 2023. As of December 31, 2025, and 2024, the Company’s carrying value of the investment waszero.

The Company also provides Oerth Bio with compensated research and development and administrative services through a separate agreement. The services rendered by the Company during the years ended December 31, 2025, 2024 and 2023 were immaterial.

11. Income Taxes

For the years ended December 31, 2025, 2024 and 2023, income tax expense totaled$0.3 million, $0.6 million and $0.9 million, respectively, and consisted of the following:

The Company generated a taxable loss for the year ended December 31, 2025 primarily due to losses from operations. The Company has not recorded any income tax benefits for the net operating losses incurred in the period due to its uncertainty of realizing a benefit from those items.

The Company generated a taxable income for the year ended December 31, 2024 primarily due to the Novartis License Agreement, the Novartis Asset Agreement and the required capitalization of research and development expenses. The taxable income for federal purposes has been partially offset by losses from operations.

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The Company generated a taxable loss for the year ended December 31, 2023 primarily due to losses from operations. The Company has not recorded any income tax benefits for the net operating losses incurred in the period due to its uncertainty of realizing a benefit from those items.

On July 4, 2025, H.R.1, commonly referred to as the One Big Beautiful Bill Act, was signed into law in the U.S., which includes a broad range of tax reform provisions, including extending and modifying certain key Tax Cuts and Jobs Act provisions, and provisions allowing accelerated tax deductions for qualified property and research expenditures. The tax impacts of this legislation do not have a material impact on the Company's consolidated financial statements.

All of the Company’s losses before income taxes were generated in the United States.

A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate for the years ended December 31, 2025, 2024 and 2023 were as follows:

For the year ended December 31, 2025, state and local income taxes in Connecticut, Massachusetts, and New York comprised the majority of the state and local income taxes, net of federal effect. For the year ended December 31, 2024, state and local income taxes in Connecticut comprised the majority of the state and local income taxes, net of federal effect. For the year ended December 31, 2023, state and local income taxes in New York comprised the majority of the state and local income taxes, net of federal effect.

The following table summarizes income taxes paid, net of refunds received for the years ended December 31, 2025, 2024 and 2023:

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•The amount of income taxes paid during the year does not meet the 5% disaggregation threshold.

Deferred income taxes represent the tax effect of transactions that are reported in different periods for financial and tax reporting purposes. Temporary differences and carryforwards that give rise to a significant portion of the deferred income tax benefits and liabilities were as follows as of December 31, 2025 and 2024:

A valuation allowance is established when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company has provided a valuation allowance against the full amount of the deferred tax assets since it is more likely than not that the benefits will not be realized. This assessment is based on the Company's historical cumulative losses, which provide strong objective evidence that cannot be overcome with projections of income, as well as the fact the Company expects continuing losses in the future.

All, or a portion of, the remaining valuation allowance may be reduced in future years based on an assessment of earnings sufficient to utilize these potential tax benefits. The valuation allowance increased by $10.0 million and $63.5 million in 2025 and 2024, respectively, due to increases in net operating loss carryforwards, revenue recognition for tax purposes from the Vepdegestrant (ARV-471) Collaboration Agreement and the mandatory capitalization of qualified research and development costs in 2024.

The Company had $533.6 million and $111.0 million of federal net operating loss carryforwards as of December 31, 2025 and 2024, respectively. Federal net operating losses incurred in 2018 and in future years may be carried forward indefinitely, but the deductibility of such carryforwards is limited to 80% of the Company’s taxable income in the year in which carryforwards are used. The Company had $563.2 million and $129.0 million of state and local net operating loss carryforwards as of December 31, 2025 and 2024, respectively, which expire at various dates beginning in 2035. The Company had $44.7 million and $37.7 million of federal tax credit carryforwards as of December 31, 2025 and 2024, respectively. The Company had $22.3 million and $22.4 million of state tax credit carryforwards as of December 31, 2025 and 2024, respectively, which expire at various dates beginning in 2035.

The Company has performed a Section 382 analysis through December 31, 2024 to determine whether an ownership change occurred for tax purposes. Based on this analysis, the Company determined that ownership changes occurred on July 31, 2018 and December 31, 2020 due to various equity offerings, vesting of restricted stock awards and stock option exercises. These ownership changes resulted in Section 382 limitations on the Company’s net operating loss and tax credit carryforwards generated before these dates. However, because the amount of the Section 382 limitations (including carryover of the unused Section 382 limitations and realized built-in gains) exceeds the amount of the Company’s carryforwards generated before these dates, the limitations will not affect the Company's ability to fully utilize these carryforwards.

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The Company complies with the provisions of ASC 740, Accounting for Income Taxes, in accounting for its uncertain tax positions. ASC 740 addresses the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the financial statements. Under ASC 740, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. As of December 31, 2025 and 2024, the Company recorded net uncertain tax positions of $5.9 million and $5.4 million, respectively, relating primarily to state income tax filing positions in various jurisdictions.

Changes in the Company's gross unrecognized tax benefits were as follows:

The Company recognizes interest accrued related to unrecognized tax benefits and penalties in tax expense. The Company's accrual for interest and penalties as of December 31, 2025 and 2024 totaled $1.6 million and $1.0 million, respectively.

The Company is required to file income tax returns in the U.S. Federal and various state jurisdictions. As a result of the Company’s net operating loss carryforwards, the Company’s federal and state statutes of limitations generally remain open for all tax years until its net operating loss and tax credit carryforwards are utilized or expire prior to utilization. The Company is currently under federal income tax examination for the year ended December 31, 2023, and state income tax examination with the state of New York for the years ended December 31, 2021 through December 31, 2023.

12. Commitments and Contingencies

From time to time, the Company may be subject to legal proceedings, claims and disputes that arise in the ordinary course of business. The Company accrues a liability for such matters when it is probable that future expenditures will be made and that such expenditures can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount, which could differ materially. Legal fees and other costs associated with such actions are expensed as incurred. As of December 31, 2025, 2024 and 2023, the Company accrued zero, $5.0 million and $15.2 million, respectively, for such matters, related to the Amended License Agreement with Yale University ("Yale"), as further described below.

Clinical and Preclinical Development and Licensing Arrangements

From time to time, the Company enters into contracts in the normal course of business with various third parties who support its clinical trials, preclinical research studies and other services related to its development activities. The scope of the services under these agreements can generally be modified at any time, and the agreement can be terminated by either party after a period of notice and receipt of written notice.

In addition, under licensing and related arrangements to which the Company is a party, the Company may be obligated to make milestone payments to third parties. The payment obligations under these arrangements are contingent upon future events, such as achievement of specified milestones or generation of product sales, and the amount, timing and likelihood of such payments are not known.

Yale University License Agreement

In June 2024, the Company entered into an Amended and Restated License Agreement (the “Amended License Agreement”) with Yale pursuant to which the parties amended and restated the license agreement dated July 5, 2013, as amended to date (the "Original Agreement"). In connection with the signing of the Amended License Agreement, the Company made a payment of $14.95 million to Yale, comprising both an upfront payment connected to the Amended License Agreement and an amount related to the collaboration income under the Novartis License Agreement and Novartis Asset Agreement (see Note 3, Research

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Collaboration and License Agreements, for a description of the agreements). The Company made another $5.0 million payment in June 2025 on the first anniversary of signing. Thereafter, the Company will also pay to Yale (1) up to $15.0 million if it secures approval of the first and second royalty products (as defined in the Amended License Agreement), (2) a low single digit percentage royalty on certain, more narrowly defined “collaboration products,” and (3) a lower single digit royalty on its aggregate worldwide net sales of certain newly defined “meaningfully involved products.”

The Company’s obligations under the Original Agreement to pay Yale minimum annual royalties and certain other annual fees have been eliminated and Yale has agreed to release all claims arising previously under the Original Agreement. Other provisions of the Original Agreement remain materially unchanged under the Amended License Agreement, including therequirement to pay to Yale a minimum license maintenance royalty totaling $0.1 million per year until the first sale to a third party of any licensed product, followed by success-based milestones for the firsttwo licensed products for the development of the protein degradation technologies totaling approximately $3.0 million for the first licensed product and approximately $1.5 million for the second licensed product, certain of which milestones have already been satisfied, and low single-digit royalties on aggregate worldwide net sales of certain licensed products, which may be subject to reductions, and subject to minimum royalty payments that range from $0.2 million to $0.5 million.

During each of the years ended December 31, 2025, 2024 and 2023, the Company recognized expenses under the license agreement totaling $0.7 million, zero and $0.3 million, respectively, under the license agreement. The payment made in the year ended December 31, 2024 included the payment made in connection with signing the Amended License Agreement, as summarized above.

13. Net Loss Per Share

Basic and diluted loss per common share was calculated as follows:

Treasury shares are not considered outstanding and are excluded from the calculation of basic and diluted loss per common share.

The weighted-average number of common shares included in the computation of basic and diluted net loss per common share for the years ended December 31, 2024 and 2023 gave effect to pre-funded warrants which allowed holders to acquire a specified number of common shares at a nominal exercise price of$0.001 per share and were classified as equity. The shares underlying the pre-funded warrants were exercisable for little or no consideration and therefore the underlying shares were considered outstanding at the issuance of the pre-funded warrants for purposes of calculating the weighted-average number of common shares outstanding in basic and diluted net loss per share for common share. As of December 31, 2025, all outstanding pre-funded warrants had been cashless exercised for no consideration. See Note 9, Equity.

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The Company reported net losses for each of the years ended December 31, 2025, 2024 and 2023, and therefore excluded all stock options and RSUs from the computation of diluted net loss per common share as their inclusion would have had an anti-dilutive effect, as summarized below:

14. Restructuring Activity

In the second quarter of 2025, the Company committed to and approved a reduction of the Company’s workforce by approximately 33% across all areas of the Company, as part of the Company’s decision to streamline operations across the organization and enable the efficient progression of the Company’s portfolio. This decision was made following a strategic review aimed at reducing internal costs while minimally impacting the Company's targeted clinical stage programs to drive value over the next several years by aligning the Company's operations with long-term program development objectives. As of June 30, 2025, these restructuring activities were substantially completed.

In September 2025, the Company announced an update on its collaboration with Pfizer and further actions to support value creation by optimizing organizational and cost structures and streamlining operations in advance of multiple anticipated upcoming value inflection points, including: further limiting additional expenditures on the vepdegestrant program supporting activities required for commercialization readiness and identification, with Pfizer, of a third party for the commercialization and potential further development of vepdegestrant; reducing the Company's workforce by an additional 15% to streamline operations, with the most significant reductions being roles related to vepdegestrant commercialization; and proactively managing pipeline cost by seeking strategic business development opportunities and by identifying further efficiencies across the business. The September 2025 workforce reduction was substantially completed in the first quarter of 2026.

Components of Restructuring Charges

During the year ended December 31, 2025, the Company recognized net restructuring charges of $3.7 million, including $15.3 million of cash severance and other one-time employee related termination benefit related to the workforce reduction, partially offset by a reversal of $11.6 million of non-cash stock compensation and bonus expenses, of which $2.3 million of charges are reflected inresearch and development expenses and $1.3 million of a reversal of previously recognized expense reflected ingeneral and administrative expenses in the accompanying consolidated statement of operations. The Company recognizedno restructuring charges during the years ended December 31, 2024 and 2023.

The Company's restructuring accrual totaled $4.4 million andzero as of December 31, 2025 and 2024, respectively.

15. Segment Information

The Company's operations are organized intoone operating and reportable segment focused onthe discovery, development and commercialization of therapies that degrade disease-causing proteins. The segment develops protein degradation therapies designed to harness the body's natural protein disposal system to selectively and efficiently degrade and remove disease-causing protein through the Company's PROTAC (PROteolysis TArgeting Chimera) protein degrader platform. The Company is progressing multiple product candidates through clinical development programs, including ARV-102, targeting the leucine-rich repeat kinase 2 protein for the treatment of neurodegenerative diseases; ARV-806, targeting Kirsten rat sarcoma G12D protein for cancers with the G12D mutation, including pancreatic, colorectal and non-small cell lung cancers; ARV-393, targeting the B-cell lymphoma 6 protein for the treatment of relapsed/refractory non-Hodgkin Lymphoma; ARV-027, targeting the polyQ-AR in skeletal muscle and specifically selected for potentin vitro

F - 29 reduction of cytosolic and nuclear polyQ-AR and for favorable skeletal muscle exposure following oral administration; and vepdegestrant, targeting the estrogen receptor for the treatment of locally advanced or metastatic ER positive / human epidermal growth factor receptor 2 negative breast cancer. The Company's tangible assets are held in the United States and all of the Company's revenue has been generated in the United States. The Company manages all business activities on a consolidated basis. The Company's chief operating decision maker is the Chief Executive Officer.

The operating segment's revenue is primarily generated through research collaborations and licensing arrangements with pharmaceutical partners. The terms of these agreements contain multiple goods and services which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include non-refundable, upfront license or option fees, payments for research and development activities, payments upon the achievement of certain milestones and royalty payments based on product sales derived from the collaboration. Revenue is recognized ratably over the Company’s expected performance period under each respective arrangement. The Company also generated revenue through the sale of assets based on fair value. The Company does not have intra-entity sales or transfers.

The accounting policies of the operating segment are the same as those described in Note 2, Summary of Significant Accounting Policies. The chief operating decision maker evaluates the performance of the operating segment and allocates resources based on net income/ loss that also is reported on the consolidated income statement as net loss. The measure of the operating segment assets is reported on the consolidated balance sheet as total assets.

The chief operating decision maker uses net loss to monitor budget versus actual results and to analyze cash flows in assessing performance of the segment and allocating resources.

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The following table summarizes the reportable segment's financial information:

(*) Includes net reimbursement to and from Pfizer pursuant to the Vepdegestrant (ARV-471) Collaboration Agreement which are accounted for pursuant to ASC 808 and are recorded as an offset or an increase to research and development expenses.

(**) Includes loss on disposal of fixed assets, realized gains/ losses on sale of marketable securities and refundable research and development credits from the State of Connecticut.

Depreciation and amortization expense totaled $3.0 million, $4.6 million, and $4.8 million for the years ended December 31, 2025, 2024 and 2023, respectively.

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