ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Overview

We are a global commercial-stage biopharmaceutical company that discovers, develops, manufactures and commercializes novel therapeutics based on RNAi. Our commercial products and broad pipeline of investigational RNAi therapeutics are targeting a broad range of disease areas and indications.

As described in Part I, Item 1. “Business” of this Annual Report on Form 10-K, we currently have six products that have received marketing approval, including two products marketed by our collaborators, and multiple late-stage investigational programs advancing towards potential commercialization.

We achieved profitability for the first time in 2025, with full-year net product revenues of approximately $3.0 billion, driven primarily by strong growth in our TTR franchise. Nevertheless, we have incurred significant losses since inception and, as of December 31, 2025, we had an accumulated deficit of $6.70 billion. Historically, we generated losses primarily from costs associated with research and development activities; acquiring, filing and protecting our intellectual property rights; and selling, general and administrative activities. With the achievement of profitability in 2025, going forward we expect to be able to fund our operations primarily from product revenues, which we expect will be supplemented by collaboration revenue and royalty revenue from products commercialized by our collaborators.

We expect to continue investing significantly in research and development to advance our RNAi platform and clinical pipeline. These planned expenditures include costs associated with our activities as we (i) progress our late-stage programs, including the Phase 3 TRITON-PN and TRITON-CM clinical trials of nucresiran (our next generation TTR silencer) in patients with hATTR-PN and ATTR-CM, respectively, and the Phase 3 ZENITH cardiovascular outcomes trial of zilebesiran in patients with uncontrolled hypertension, all three of which we initiated in 2025; (ii) progress our early stage clinical pipeline, including CNS and metabolic programs; (iii) continue our efforts to deliver RNAi therapeutics to additional tissues and to treat new disease areas; and (iv) selectively pursue complementary modalities through business development.

Through these investments, we plan to expand our efforts to discover, develop and commercialize the next wave of RNAi therapeutics and aim to achieve the goals associated with our Alnylam 2030 strategy. These goals include expanding to 10 tissue types and more than 40 clinical programs, delivering at least two new transformative medicines beyond TTR with blockbuster potential, investing approximately 30% of our revenues in non-GAAP R&D (including select external innovation), achieving 25%+ total revenue compound annual growth rate, and delivering approximately 30% non-GAAP operating margin through year-end 2030.

As of December 31, 2025, we generate worldwide product revenues from our four commercialized products, AMVUTTRA, ONPATTRO, GIVLAARI and OXLUMO, primarily in the U.S. and Europe. Collaboration revenues, in particular from our collaborations with Roche, Regeneron and Novartis, have also represented a meaningful portion of our total revenues in recent years. We expect our sources of potential funding for the next several years to be derived primarily from sales of our commercialized products, with contributions from our existing collaborations, including royalties on sales of Leqvio by Novartis and on sales of Qfitlia by Sanofi, and any new strategic collaborations that we may enter in the future. However, we and our collaborators may not be able to successfully market and sell our existing commercialized products or any approved products in the future. Moreover, our ongoing development and regulatory efforts may not be successful, and we and our collaborators may not be able to commence sales of any other products in the future. We anticipate that our operating results will continue to fluctuate for the foreseeable future and, therefore, period-to-period comparisons should not be relied upon as predictive of the results in future periods.

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Given the significant and growing contribution of AMVUTTRA to our total product revenues following regulatory approvals of AMVUTTRA for the treatment of ATTR-CM, our cost of goods sold, operating income and operating margin in 2025 were significantly impacted by the royalties we pay to Sanofi on global sales of AMVUTTRA under our TTR license agreements, and we expect this will continue in future years. Sanofi is eligible to receive tiered royalties on global annual net sales of AMVUTTRA across all indications in the following tiers: 15% of global annual net sales of $0 to $150.0 million; 17.5% of global annual net sales greater than $150.0 million to $300.0 million; 20% of global annual net sales greater than $300.0 million to $500.0 million; 25% of global annual net sales greater than $500.0 million to $1.50 billion; and 30% of global annual net sales in excess of $1.50 billion. There are no royalties owed on nucresiran, our next-generation investigational RNAi therapeutic, which is currently in development for the treatment of ATTR amyloidosis. Assuming successful development and regulatory approval, we believe that with its anticipated product profile, nucresiran has the potential to become a leading therapy for ATTR amyloidosis and to significantly improve our gross margins on product sales and our non-GAAP operating income margin.

Results of Operations

The following table summarizes the results of our operations:

* Not meaningful

For a discussion of our 2024 results and a comparison with 2023 results please refer to “Management’s Discussion and Analysis of Financial Conditions and Results of Operations” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, which was filed with the SEC on February 13, 2025.

Discussion of Results of Operations

Revenues

Total revenues consisted of the following:

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Net Product Revenues

Net product revenues, classified based on the geographic region in which the product is sold and by franchise (“TTR,” which includes AMVUTTRA and ONPATTRO, and “Rare,” which includes GIVLAARI and OXLUMO) consisted of the following:

AMVUTTRA

ONPATTRO

GIVLAARI

OXLUMO

Net product revenues increased during the year ended December 31, 2025, compared to the year ended December 31, 2024, primarily due to growth from AMVUTTRA revenues driven by increased patient demand, mainly in patients with ATTR-CM in the U.S., which was partially offset by a decreased number of patients on ONPATTRO, and due to growth from an increased number of patients on GIVLAARI and OXLUMO.

Please see Note 3, Net Product Revenues, to our consolidated financial statements included in Part II, Item 8, “Financial Statements and Supplementary Data” of this Annual Report on Form 10-K for balances and activity in each product revenue allowance and reserve category for the years ended December 31, 2025 and 2024.

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Net Revenues from Collaborations and Royalty Revenue

Net revenues from collaborations and royalty revenue consisted of the following:

Net revenues from collaborations increased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, primarily driven by:

•recognition of $300.0 million of milestone revenue under our collaboration with Roche in September 2025 associated with the dosing of the first patient in the ZENITH Phase 3 clinical trial of zilebesiran; and

•recognition of a $30.0 million payment in connection with the amendment to our agreement with Vir Biotechnology in March 2025.

Partially offset by:

•recognition of $185.0 million of revenue under our collaboration with Regeneron during the year ended December 31, 2024, as we modified the collaboration agreement in June 2024 and provided Regeneron with an exclusive license to develop, manufacture and commercialize cemdisiran as a monotherapy;

•recognition of $65.0 million of milestone revenue under our collaboration with Roche during the year ended December 31, 2024 associated with the dosing of the first patient in the KARDIA-3 Phase 2 clinical trial of zilebesiran; and

•revenue recognized under our license agreement with Novartis associated with the achievement of a specified Leqvio commercialization milestone during the year ended December 31, 2024.

Royalty revenue increased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, due to increased volume and rate of royalties earned from global net sales of Leqvio by Novartis.

Recognition of our combined net revenues from collaborations and royalty revenue is dependent on a variety of factors, including the level of work reimbursed by collaborators, achievement of milestones under our collaboration agreements, and royalties associated with sales of Leqvio. We expect net revenues from collaborations will decrease in 2026, as compared to 2025, due to the $300.0 million of milestone revenue that we recognized under our Roche Collaboration and License Agreement in the year ended December 31, 2025. We expect our royalty revenue will increase in 2026, as compared to 2025, primarily due to the continued growth of royalties earned from global net sales of Leqvio by Novartis.

The amount of revenue from collaborations that we recognize is based, in part, on estimates of total costs to be incurred. These estimates reflect our historical experiences, current contractual requirements, and forecasted plans of development or manufacturing activities. We adjust these estimates for changes in actual costs incurred, contractual terms, and further forecasts. Such changes in estimates could have a significant impact on revenue and earnings in the period of the adjustment.

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Operating Costs and Expenses

Operating costs and expenses consisted of the following:

Cost of goods sold as a percentage of net product revenues 22.7 % 18.6 % 21.6 %

Cost of Goods Sold

Cost of goods sold as a percentage of net product revenues increased to 22.7% for the year ended December 31, 2025, as compared to 18.6% for the year ended December 31, 2024, primarily as a result of increased sales of AMVUTTRA and an associated increase in the blended royalty rate payable on net sales of AMVUTTRA.

We expect our cost of goods sold, including cost of goods sold as a percentage of net product revenues, will increase during 2026, as compared to 2025, primarily as a result of an expected increase in sales of AMVUTTRA and an associated increase in the royalty rate payable on net sales of AMVUTTRA.

Cost of Collaborations and Royalties

Cost of collaborations and royalties decreased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, primarily due to decreased demand for GalNAc material supplied to our collaborators in support of certain product manufacturing as our collaborators transition to producing the material independently.

We expect our cost of collaborations and royalties will decrease during 2026, as compared to 2025, primarily as a result of our collaborators having transitioned to producing GalNAc material independently.

Research and Development

Research and development expenses consisted of the following:

(1) Occupancy and all other costs includes facilities, information technology, depreciation and certain departmental expenses.

Research and development expenses increased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, primarily due to the following:

•increased clinical trial expenses for the ZENITH Phase 3 clinical trial of zilebesiran, the TRITON-CM Phase 3 clinical trial of nucresiran in patients with ATTR-CM and the TRITON-PN Phase 3 clinical trial of nucresiran in patients with hATTR-PN;

•increased employee compensation and related expenses to support our research and development pipeline and development expenses; and

•increased stock-based compensation expense.

Partially offset by:

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•decreased expenses within other clinical programs, in particular for the KARDIA-1 and KARDIA-2 Phase 2 clinical trials of zilebesiran and the HELIOS-B Phase 3 clinical trial of vutrisiran in patients with ATTR-CM due to the wind-down of clinical activities.

Selling, General and Administrative

Selling, general and administrative expenses consisted of the following:

(1) Occupancy and all other costs includes facilities, information technology, depreciation and certain departmental expenses.

Selling, general and administrative expenses increased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, primarily due to higher employee compensation costs, including stock-based compensation, mainly driven by higher headcount, and increased marketing investment associated with the commercial launch of AMVUTTRA in ATTR-CM.

We expect that research and development expenses combined with selling, general and administrative expenses will increase during 2026, as compared to 2025, as we continue to launch our current commercial products into new markets, prepare for future commercial product launches, including the continued launch of AMVUTTRA for the treatment of ATTR-CM, advance our product candidates, including collaborated programs, into later-stage development, advance and develop our platform and preclinical pipeline, and prepare regulatory submissions. However, we expect that certain expenses will be variable depending on the timing of manufacturing batches, clinical trial enrollment and results, regulatory review of our product candidates and programs, and stock-based compensation expenses based on our determinations regarding the probability of vesting for performance-based awards.

Other (Expense) Income

Other (expense) income consisted of the following:

Loss related to convertible debt (42,473) — — (42,473) N/A — N/A

Other income (expense), net

* Not meaningful

Total other expense, net decreased during the year ended December 31, 2025, as compared to the year ended December 31, 2024, primarily due to:

•decreased loss associated with the change in fair value of the development derivative liability as a result of the adoption of Accounting Standards Update 2025-07, or ASU 2025-07, as discussed in Note 2, Summary of Significant Accounting Policies and Note 9, Liabilities Related To The Sale Of Future Royalties And Development Funding, to our consolidated financial statements included in Part II, Item 8, “Financial Statements and Supplementary Data” of this Annual Report on Form 10-K.

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Partially offset by:

•increased interest expense associated with the vutrisiran and zilebesiran development funding liabilities as a result of the adoption of ASU 2025-07; and

•loss related to convertible debt representing an inducement expense in connection with the partial repurchases of our 1.00% Convertible Senior Notes due 2027, or the 2027 Notes, in September and December 2025.

(Provision for) Benefit from Income Taxes

(Provision for) benefit from income taxes was as follows:

* Not meaningful

We recorded a provision for income taxes of $9.4 million for the year ended December 31, 2025 and a benefit from income taxes of $99.2 million for the year ended December 31, 2024. The provision for income taxes for the year ended December 31, 2025 primarily related to U.S. state income taxes, utilization of Switzerland net deferred tax assets, as well as taxable income from jurisdictions in which we are subject to tax. For the year ended December 31, 2025, we maintained a full valuation allowance against our net deferred tax assets in the U.S. Based on our recent financial performance and our future projections, we could record a reversal of all or a portion of the U.S. valuation allowance within the foreseeable future. However, any such change is subject to actual performance and other considerations that may present positive or negative evidence at the time of the assessment.

Liquidity and Capital Resources

The following table summarizes our cash flow activities:

Years Ended December 31, $ Change

Net cash provided by (used in):

Operating Activities

During the year ended December 31, 2025, net cash provided by operating activities was $524.1 million, whereas during the year ended December 31, 2024 net cash used in operating activities was $8.3 million. This was primarily driven by stronger cash receipts from increased product sales during the year ended December 31, 2025, as compared to the year ended December 31, 2024, partially offset by increased employee compensation costs and higher interest payments.

Investing Activities

During the year ended December 31, 2025, net cash provided by investing activities was $436.3 million, whereas during the year ended December 31, 2024 net cash used in investing activities was $116.8 million. This was primarily attributed to the timing of sales, maturities, and purchases of our marketable securities during the year ended December 31, 2025, as compared to the year ended December 31, 2024.

Financing Activities

During the year ended December 31, 2025, net cash used in financing activities was $305.2 million, whereas during the year ended December 31, 2024 net cash provided by financing activities was $294.2 million. This was primarily due to $1.15 billion paid for the repurchase of $672.2 million aggregate principal amount of our 2027 Notes during the year ended December 31, 2025, partially offset by $645.7 million of net proceeds from our offering of the 0.00% Convertible Senior Notes due 2028 in the aggregate principal amount of $661.3 million, $35.3 million of which was used to pay the cost of the related capped call transactions. Additionally, we collected lower net proceeds from the issuance of common stock in connection with stock option exercises during the year ended December 31, 2025, as compared to the year ended December 31, 2024.

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Additional Capital Requirements

We currently have programs focused in many therapeutic areas and, as of December 31, 2025, have six marketed products, including two products commercialized by collaborators. However, our ongoing development efforts may not be successful and we may not be able to commence sales of any other products in the future. In addition, we may incur additional operating losses as a result of planned expenditures for research and development activities relating to our research platform, our drug development programs, including clinical trial and manufacturing costs, the continued build-out of late-stage clinical, manufacturing, commercial and compliance capabilities, including global operations, continued management and growth of our intellectual property, including our patent portfolio, collaborations and general corporate activities.

Based on our current operating plan, we believe that our cash, cash equivalents, marketable securities, as well as the revenue we expect to generate from product sales and under our existing collaborations, including royalties on sales of Leqvio and Qfitlia, and available borrowing capacity under the revolving credit agreement as of December 31, 2025 will be sufficient to satisfy our near-term capital and operating needs for at least 12 months from the filing of this Annual Report on Form 10-K. Recent and expected working and other capital requirements, in addition to the above matters, also include the items described below:

•Amounts related to future lease payments for operating lease obligations as of December 31, 2025 totaled $366.3 million, with $48.1 million expected to be paid within the next 12 months.

•Cash outflows for capital expenditures were $58.7 million in 2025 and $34.3 million in 2024. We expect capital expenditures to increase in 2026 to support the increase in our manufacturing and production capacity needs.

•As of December 31, 2025, the carrying value of our convertible debt was $1.01 billion, of which we do not expect to make payments on principal within the next 12 months.

•Payments to Blackstone associated with the liability related to the sale of future Leqvio royalties were $118.0 million in 2025, with an estimated $126.7 million to be paid within the next 12 months.

•Payments associated with an achieved development milestone for the zilebesiran development funding liability due to Blackstone were $21.1 million in 2025, with the same amount expected to be paid within the next 12 months. Payments associated with an achieved development milestone for the vutrisiran development funding liability due to Blackstone were $65.6 million in 2025, and we expect to pay $87.5 million within the next 12 months.

Since we commenced operations in 2002, we have generated significant losses and as of December 31, 2025, we had an accumulated deficit of $6.70 billion. As of December 31, 2025, we had cash, cash equivalents and marketable securities of $2.91 billion, compared to $2.69 billion as of December 31, 2024.

Due to numerous factors described in more detail under the caption Part I, Item 1A, “Risk Factors” of this Annual Report on Form 10-K, we may require significant additional funds earlier than we currently expect in order to continue to commercialize AMVUTTRA, ONPATTRO, GIVLAARI and OXLUMO, and to develop, conduct clinical trials for, manufacture and, if approved, commercialize additional product candidates.

Critical Accounting Policies and Estimates

Our discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with GAAP. The preparation of our consolidated financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and disclosure of contingent assets and liabilities in our consolidated financial statements. Actual results may differ from these estimates under different assumptions or conditions and could have a material impact on our reported results. While our significant accounting policies are more fully described in the Notes to our consolidated financial statements included elsewhere in this Annual Report on Form 10-K, we believe the following accounting policies to be the most critical in understanding the judgments and estimates we use in preparing our consolidated financial statements:

Net Product Revenues

Our net product revenues are recognized, net of variable consideration related to certain allowances and accruals, at the time the customer obtains control of our product. We record reserves, based on contractual terms, for components related to product sold during the reporting period, as well as our estimate of product that remains in the distribution channel inventory at the end of the reporting period that we expect will be sold to qualified healthcare providers. On a quarterly basis, we update our estimates and record any needed adjustments in the period we identify the adjustments.

The estimates for our product revenue allowances and accruals are most significantly affected by chargebacks, which are contractual commitments with the government and other entities to sell products to qualified healthcare providers at prices lower than the list prices charged to the customer who directly purchases from us, and rebates that represent discount obligations under government programs, including Medicare and Medicaid in the U.S. and similar programs in certain other countries, including countries in which we are accruing for estimated rebates because final pricing has not yet been negotiated.

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We are also subject to potential rebates in connection with our value-based agreements, or VBAs, with certain commercial payors.

We use the expected value method, which is the sum of probability-weighted amounts in a range of possible consideration amounts, or the most likely amount method, which is the single most likely amount in a range of possible considerations, to estimate variable consideration related to our product revenues. We use the expected value method to estimate variable consideration for chargebacks, certain rebates, and other incentives and we use the most likely amount method for certain rebates and trade discounts and allowances.

Net Revenues from Collaborations

We earn revenue in connection with collaboration agreements which allow our collaborators to utilize our technology platforms and develop product candidates.

For elements of collaboration arrangements that are accounted for pursuant to Accounting Standards Codification Topic 606, Revenue from Contracts with Customers, or ASC 606, we identify the performance obligations and allocate the total consideration we expect to receive on a relative standalone selling price basis to each performance obligation. Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, the expected number of targets or indications expected to be pursued under each license, discount rates and probabilities of technical and regulatory success. We recognize revenue associated with each performance obligation as the control over the promised goods or services transfer to our collaborator which occurs either at a point in time or over time. If control transfers over time, revenue is recognized by using a method of measuring progress that best depicts the transfer of goods or services, for example based on actual costs incurred relative to total forecasted costs to be incurred over the period the transfer of goods or services occurs. We evaluate the measure of progress and related inputs each reporting period and any resulting adjustments to revenue are recorded on a cumulative catch-up basis. Revenue to be recognized is equal to the total transaction price multiplied by the ratio of actual expense incurred divided by total forecasted expense.

Liabilities Related to the Sale of Future Royalties and Development Funding

We account for the liabilities related to the sale of future royalties and development funding as debt financings. Interest on these liabilities is recognized using the effective interest rate method over the life of the related repayment period.

The liabilities related to the sale of future royalties and development funding and the related interest expense are based on our current estimates of future royalties and milestones expected to be paid and received over the life of the arrangement, which we determine by using third-party data to estimate Leqvio’s and AMVUTTRA’s global net revenues. We periodically assess the expected payments and to the extent the amount or timing of our future estimated payments is materially different than our previous estimates, we account for any such change by prospectively adjusting the effective interest rate and related non-cash interest expense.

An increase or decrease of 10% to the interest rate would result in an increase or decrease to our liability related to the sale of future royalties and development funding of approximately $42.1 million as of December 31, 2025. If realized, the change in value would affect interest expense over the remaining life of the agreements.

Recent Accounting Pronouncements

Please read Note 2, Summary of Significant Accounting Policies, to our consolidated financial statements included in Part II, Item 8, “Financial Statements and Supplementary Data” of this Annual Report on Form 10-K for a description of recent accounting pronouncements.

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Interest Rate Risk - Investment Portfolio. We invest a portion of our cash in a number of diversified fixed- and floating-rate securities consisting of cash equivalents and marketable debt securities related to our investment portfolio that are subject to interest rate risk. Changes in the general level of interest rates can affect the fair value of our investment portfolio. If interest rates in the general economy were to rise, our holdings could lose value. As of December 31, 2025 and 2024, a hypothetical increase in interest rates of 100 basis points across the entire yield curve on our holdings would have resulted in an immaterial decrease to the fair value of our holdings.

Foreign Currency Exchange Risk. As a result of our foreign operations, we face exposure to movements in foreign currency exchange rates, primarily the Japanese yen, Euro and British pound against the U.S. Dollar. Fluctuations in the global markets may have a positive or negative effect on our foreign exchange rate exposure. The current exposures arise primarily from net product revenue, operating costs and expenses and balance sheet amounts. Therefore, significant changes in foreign exchange rates of the countries outside the United States where our products are sold, where development expenses are incurred by us or our collaborators, or where we incur operating expenses can impact our operating results and financial condition. As sales outside the United States continue to grow, and as we expand our international operations, we will continue to assess potential steps, including foreign currency hedging and other strategies, to mitigate our foreign exchange risk.

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ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID 238) 91

Consolidated Balance Sheets as of December 31, 2025 and 2024 93

Notes to Consolidated Financial Statements 97

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Stockholders of Alnylam Pharmaceuticals, Inc.

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of Alnylam Pharmaceuticals, Inc. and its subsidiaries (the "Company") as of December 31, 2025 and 2024, and the related consolidated statements of operations and comprehensive income (loss), of stockholders' equity (deficit) and of cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as the "consolidated financial statements"). We also have audited the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Changein AccountingPrinciple

As discussed in Note 2 to the consolidated financial statements, the Company changed the manner in which it accounts for liabilities related to development funding in 2025.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in Management’s Annual Report on Internal Control over Financial Reporting appearing under Item 9A. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matters

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that (i) relates to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Liability Related to Sale of Future Royalties – Leqvio

As described in Notes 2 and 9 to the consolidated financial statements, the Company accounts for the liability related to the sale of future royalties as debt financing. Interest on the liability is recognized using the effective interest rate method over the repayment period. The liability related to the sale of future royalties and the related interest expense for Leqvio are based on management’s current estimates of future royalties expected to be paid over the life of the arrangement, which management determines by using third-party data to estimate Leqvio’s global net revenue. At each balance sheet date, management assesses the expected payments and prospectively adjusts the effective interest rate and the related interest expense. As of and for the year ended December 31, 2025, respectively, the Company’s liability related to the sale of future royalties for Leqvio was $1.48 billion and the related interest expense was $149.8 million.

The principal consideration for our determination that performing procedures relating to the liability related to sale of future royalties for Leqvio is a critical audit matter is a high degree of auditor effort in performing procedures related to the liability.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to the liability related to the sale of future royalties. These procedures also included, among others (i) evaluating the appropriateness of the method used by management to determine the liability; (ii) obtaining and inspecting third-party data used to estimate Leqvio’s global net revenue; (iii) testing the completeness and accuracy of underlying data used to determine the liability; (iv) recalculating the liability, effective interest rate and the related interest expense; and (v) tracing relevant information, such as key terms and royalty rate, to the purchase agreement.

/s/PricewaterhouseCoopers LLP

Boston, Massachusetts

February 12, 2026

We have served as the Company’s auditor since 2003.

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ALNYLAM PHARMACEUTICALS, INC.

CONSOLIDATED BALANCE SHEETS

(In thousands, except per share amounts)

December 31,

ASSETS

Current assets:

Marketable equity securities — 8,156

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:

Development derivative liability — 93,780

Operating lease liabilities, net of current portion 225,087 229,541

Development derivative liability, net of current portion — 393,139

Commitments and contingencies (Note 13)

Stockholders' equity:

Accumulated other comprehensive loss (20,097) (34,518)

The accompanying notes are an integral part of these consolidated financial statements.

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ALNYLAM PHARMACEUTICALS, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(In thousands, except per share amounts)

Years Ended December 31,

Statements of Operations

Revenues:

Operating costs and expenses:

Other expense:

Loss related to convertible debt (42,473) — —

Net income (loss) per common share — basic $ 2.39 $ (2.18) $ (3.52)

Net income (loss) per common share — diluted $ 2.33 $ (2.18) $ (3.52)

Statements of Comprehensive Income (Loss)

Other comprehensive income (loss):

Unrealized gains (losses) on marketable securities 1,816 (4) 11,018

Defined benefit pension plans, net of tax 981 (1,496) (1,661)

The accompanying notes are an integral part of these consolidated financial statements.

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CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (DEFICIT)

(In thousands)

Shares Amount

The accompanying notes are an integral part of these consolidated financial statements.

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CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

Years Ended December 31,

Cash flows from operating activities:

Realized and unrealized loss on marketable equity securities 2,306 3,022 16,944

Loss related to convertible debt 42,473 — —

Change in fair value of development derivative liability — 170,770 90,997

Changes in operating assets and liabilities:

Accounts payable, accrued expenses and other liabilities 75,066 91,093 80,840

Cash flows from investing activities:

Cash flows from financing activities:

Payment of issuance costs for revolving credit agreement (2,414) — —

Supplemental disclosure of cash flows:

Supplemental disclosure of noncash investing activities:

The accompanying notes are an integral part of these consolidated financial statements.

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1. NATURE OF BUSINESS

Alnylam Pharmaceuticals, Inc. (also referred to as Alnylam, the Company, we, our or us) commenced operations on June 14, 2002 as a biopharmaceutical company seeking to develop and commercialize novel therapeutics based on ribonucleic acid interference, or RNAi. We are committed to the advancement of our company strategy of building a multi-product, global, commercial biopharmaceutical company with a deep and sustainable clinical pipeline of RNAi therapeutics for future growth and a robust, organic research engine for sustainable innovation and great potential for patient impact. Since inception, we have focused on discovering, developing and commercializing RNAi therapeutics by establishing and maintaining a strong intellectual property position in the RNAi field, establishing strategic collaborations with leading pharmaceutical and life sciences companies, generating revenues through licensing agreements, and ultimately developing and commercializing RNAi therapeutics globally, either independently or with our strategic collaborators. We have devoted substantially all of our efforts to business planning, research, development, manufacturing and commercializing biopharmaceuticals products, acquiring, filing and expanding our intellectual property rights, recruiting our management and technical staff, and raising capital.

As of December 31, 2025, we have six marketed products, including two products that are commercialized by collaborators, and multiple late-stage investigational programs advancing towards potential commercialization. We currently generate worldwide product revenues from four commercialized products, AMVUTTRA, ONPATTRO, GIVLAARI and OXLUMO, primarily in the United States, or U.S., and Europe.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Principles of Consolidation

The accompanying consolidated financial statements reflect the operations of Alnylam and our wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated. Certain prior period amounts in the consolidated financial statements have been reclassified to conform to the current period presentation.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. In our consolidated financial statements, we use estimates and assumptions related to our inventory valuation and related reserves, clinical accruals, liabilities related to the sale of future royalties and development funding, income taxes, deferred tax asset valuation allowances, revenue recognition, research and development expenses, and stock-based compensation expense. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.

Liquidity

Based on our current operating plan, we believe that our cash, cash equivalents, marketable securities, as well as the revenue we expect to generate from product sales and under our existing collaborations, including royalties on sales of Leqvio and Qfitlia, and available borrowing capacity under the revolving credit agreement, or the Revolving Credit Agreement, as of December 31, 2025, will be sufficient to satisfy our near-term capital and operating needs for at least the next 12 months from the filing date of this Annual Report on Form 10-K. Please refer to Note 8, Convertible Debt and Other Financing, for further information related to the Revolving Credit Agreement.

Concentrations of Credit Risk and Significant Customers

Financial instruments that potentially expose us to concentrations of credit risk primarily consist of cash, cash equivalents and marketable securities. As of December 31, 2025 and 2024, substantially all of our cash, cash equivalents and marketable securities were invested in money market funds, certificates of deposit, commercial paper, corporate notes, U.S. government-sponsored enterprise securities and U.S. treasury securities through highly rated financial institutions. Corporate notes may also include foreign bonds denominated in U.S. dollars. Investments are restricted, in accordance with our investment policy, to a concentration limit per issuer.

During the years ended December 31, 2025, 2024 and 2023, our revenues were generated primarily from product sales to customers and collaborations with strategic partners. As of December 31, 2025 and 2024, our gross accounts receivable balance was comprised of payments primarily due from customers for product sales and our collaborators.

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The following table summarizes customers that represent 10% or greater of our consolidated total gross revenues:

Years Ended December 31,

Roche * * 15 %

Regeneron Pharmaceuticals * 11 % *

__________________________________________

*Represents less than 10% and/or not a customer in the applicable year

The following table summarizes customers with amounts due that represent 10% or greater of our consolidated gross accounts receivable balance:

As of December 31,

Distributor A 45 % 16 %

Novartis AG * 23 %

Fair Value Measurements

The fair value is 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. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are observable, such as quoted prices (adjusted), interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. The fair value hierarchy level is determined by the lowest level of significant input.

Investments in Marketable Securities and Cash Equivalents

We invest our excess cash balances in marketable debt securities and classify our investments as either trading, held-to-maturity or available-for-sale based on facts and circumstances present at the time we purchased the securities. As of December 31, 2025 and 2024, we classified all of our investments in debt securities as available-for-sale and as current assets on the consolidated balance sheets as they represent the investment of funds available for current operations. We report available-for-sale debt securities at fair value at each balance sheet date, for which fair value measurement data is obtained from independent pricing services, and include any unrealized holding gains and losses (the adjustment to fair value) in accumulated other comprehensive loss. Realized gains and losses are determined using the specific identification method and are included in other income (expense), net. If any adjustment to fair value reflects a decline in the value of the marketable debt securities, we consider all available evidence to evaluate if an impairment loss exists, and if so, mark the investment to market through a charge to our consolidated statements of operations and comprehensive income (loss). We did not record any impairment charges related to our marketable debt securities during the years ended December 31, 2025, 2024 or 2023. Our marketable debt securities are classified as cash equivalents if the original maturity, from the date of purchase, is 90 days or less, and as marketable debt securities if the original maturity, from the date of purchase, is in excess of 90 days. Our cash equivalents are generally composed of commercial paper, corporate notes, U.S. government-sponsored enterprise securities, U.S. treasury securities, money market funds and certificates of deposit.

We measure marketable equity investments (except those accounted for under the equity method of accounting or those that result in consolidation of an investee), which have readily available prices, at fair value with changes in fair value recognized in other income (expense), net on our consolidated statements of operations and comprehensive income (loss).

Accounts Receivable, Net

We record accounts receivable net of prompt payment discounts and chargebacks based on contractual terms. As of December 31, 2025 and 2024, based on our estimation of expected write-offs, we determined an allowance for doubtful accounts was not material. We have standard payment terms that generally require payment within approximately 30 to 90 days. Accounts receivable, net on our consolidated balance sheets also includes collaboration receivables and royalty receivables.

Inventory

Inventory is measured at the lower of cost or estimated net realizable value and classified based on the anticipation of when it will be consumed either within our normal operating cycle (short-term) or beyond (long-term). We use a standard cost basis, which approximates cost determined on a first-in, first-out basis. Inventory costs include all raw materials, direct conversion

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costs and overhead. Raw and intermediate materials that may be used for either research and development or commercial purposes are classified as inventory until the material is consumed or otherwise allocated for research and development. If the material is used for research and development, it is recorded as research and development expenses once that determination is made.

We capitalize inventory costs that are expected to be sold commercially once we determine it is probable that the inventory costs will be recovered through commercial sale based on the review of several factors, including (i) the likelihood that all required regulatory approvals will be received, considering any special filing status, (ii) the expected timing of validation (if not yet completed) of manufacturing processes in the associated facility, (iii) the expected expiration of the inventory, (iv) logistical or commercial constraints that may impede the timely distribution and sale of the product, including transport requirements and reimbursement status, (v) current market factors, including competitive landscape and pricing, (vi) threatened or anticipated litigation challenges, (vii) history of approvals of similar products or formulations, and (viii) U.S. Food and Drug Administration, or FDA, (or other appropriate regulatory agencies) correspondence regarding the safety and efficacy of the product. Prior to the capitalization of inventory costs, we record such costs as research and development expenses on our consolidated statements of operations and comprehensive income (loss).

We reduce our inventory to net realizable value for potentially excess, dated or obsolete inventory based on our quarterly assessment of the recoverability of our capitalized inventory. We periodically review inventory levels to identify what may expire prior to expected sale or has a cost basis in excess of its estimated realizable value and write down such inventories as appropriate.

Property, Plant and Equipment, Net

Property, plant and equipment are stated at cost, net of accumulated depreciation. Depreciation expense is recorded on a straight-line basis over the estimated useful life of the asset. Construction in progress reflects amounts incurred for construction or improvements of property, plant or equipment that have not been placed in service. Costs of construction of certain long-lived assets include capitalized interest, which is amortized over the estimated useful life of the related asset. The cost and accumulated depreciation of assets retired or sold are removed from the respective asset category, and any gain or loss is recognized in our consolidated statements of operations and comprehensive income (loss). During the years ended December 31, 2025, 2024 and 2023, we recorded $54.8 million, $55.1 million and $51.6 million, respectively, of depreciation expense related to our property, plant and equipment.

The estimated useful lives of property, plant and equipment are as follows:

Asset Category Useful Life

Laboratory equipment 5 years

Computer equipment and software 3-10 years

Furniture and fixtures 5 years

Leasehold improvements Shorter of asset life or lease term

Manufacturing equipment 7-15 years

Buildings 40 years

Leases

We determine if an arrangement is a lease at contract inception based on the facts and circumstances present in the arrangement. All of our leases are classified as operating leases. Operating lease right-of-use assets represent our right to use an underlying asset for the lease term and operating lease liabilities represent our obligation to make lease payments arising from the leasing arrangement. Operating lease liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, in determining the operating lease liabilities, we use an estimate of our incremental borrowing rate based on the information available at commencement. Operating lease right-of-use assets are measured as the lease liability plus initial direct costs and prepaid lease payments less lease incentives. Single lease cost is recognized on a straight-line basis over the lease term.

We do not separate non-lease components from lease components for all classes of underlying assets. Leases with an initial term of 12 months or less are not recorded on the consolidated balance sheets, and the respective lease cost is recognized in the consolidated statements of operations and comprehensive income (loss) on a straight-line basis over the term of the lease.

Clinical Accruals

We record accrued liabilities related to products we have received or services that we have incurred, specifically related to ongoing preclinical studies and clinical trials, for which service providers have not yet billed us, or when billing terms under these contracts do not coincide with the timing of when the work is performed, on our consolidated balance sheets. These costs

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primarily relate to third-party clinical management costs, laboratory and analysis costs, toxicology studies and investigator fees. The assessment of these costs requires judgment based on our knowledge of the research and development programs, services performed for the period, experience with related activities and the expected duration of the third-party service contract, where applicable.

Revenue Recognition

We recognize revenue when control of promised goods or services is transferred to a customer at an amount that reflects the consideration to which we expect to be entitled in exchange for those goods or services. To determine revenue recognition, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price, including variable consideration, if any; (iv) allocate the transaction price to the performance obligation(s) in the contract; and (v) recognize revenue when (or as) we satisfy the performance obligation(s). We only apply the five-step model to contracts when collectability of the consideration to which we are entitled in exchange for the goods or services we transfer to the customer is determined to be probable.

At contract inception, once the contract is determined to be within the scope of Accounting Standards Codification, or ASC, Topic 606, Revenue from Contracts with Customers, or ASC 606, we assess whether the goods or services promised within each contract are distinct and, therefore, represent a separate performance obligation. Goods and services that are determined not to be distinct are combined with other promised goods and services until a distinct bundle is identified. We then allocate the transaction price (the amount of consideration we expect to be entitled to from a customer in exchange for the promised goods or services) to each performance obligation and recognize the associated revenue when (or as) each performance obligation is satisfied. Our estimate of the transaction price for each contract includes all variable consideration to which we expect to be entitled.

Amounts are recorded as accounts receivable when our right to consideration is unconditional. We do not assess whether a contract has a significant financing component if the expectation at contract inception is that the period between payment by the customer and the transfer of the promised goods or services to the customer will be one year or less. We expense incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that we would have recognized is one year or less or the amount is immaterial. As of December 31, 2025 and 2024, we had not capitalized any costs to obtain any of our contracts.

Net Product Revenues

Our net product revenues are recognized, net of variable consideration related to certain allowances and accruals, at the time the customer obtains control of our product. We use the expected value method, which is the sum of probability-weighted amounts in a range of possible consideration amounts, or the most likely amount method, which is the single most likely amount in a range of possible considerations, to estimate variable consideration related to our product sales. We use the expected value method to estimate variable consideration for certain rebates, chargebacks, product returns, and other incentives and we use the most likely amount method for certain rebates, trade discounts and allowances.

We record reserves, based on contractual terms, for components related to product sold during the reporting period, as well as our estimate of product that remains in the distribution channel inventory at the end of the reporting period that we expect will be sold to qualified healthcare providers. On a quarterly basis, we update our estimates and record any needed adjustments in the period we identify the adjustments. The following are the components of variable consideration related to product revenues:

Chargebacks: We estimate obligations resulting from contractual commitments with the government and other entities to sell products to qualified healthcare providers at prices lower than the list prices charged to the customer who directly purchases from us. The customer charges us for the difference between what it pays to us for the product and the selling price to the qualified healthcare providers. We estimate chargebacks that we expect to pay and deduct the chargeback amount in full from gross product revenues and accounts receivable at the time we recognize the related revenues.

Rebates: We are subject to discount obligations under government programs, including Medicare and Medicaid in the U.S. and similar programs in certain other countries, including countries in which we are accruing for estimated rebates because final pricing has not yet been negotiated. We are also subject to potential rebates in connection with our value-based agreements with certain commercial payors. We record reserves for rebates in the same period the related product revenue is recognized, resulting in a reduction of product revenues and a current liability that is included in accrued expenses on our consolidated balance sheet. Our estimate for rebates is based on statutory discount rates, expected utilization or an estimated number of patients on treatment, as applicable.

Other incentives and allowances: Other incentives and allowances include trade discounts and allowances, fees, product returns, and co-payment assistance that we provide to patients with commercial insurance that have coverage and reside in states that allow co-payment assistance. We estimate discounts and fees based on contract terms and other relevant factors, and deduct these discounts and fees in full from gross product revenues and accounts receivable at the time we recognize the related revenues. We estimate the amount of product that will be returned based on our sales history for product that is damaged,

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defective or expired in accordance with the terms of each customer agreement, and we estimate the average co-payment assistance amounts for our products based on expected customer demographics. We record any such amounts within accrued expenses or product accounts receivable on our consolidated balance sheets.

Net Revenues from Collaborations

We earn revenue in connection with collaboration agreements that allow our collaborators to utilize our technology platforms and develop product candidates. Our significant collaboration agreements are detailed in Note 4, Net Revenues from Collaborations. For each collaborator, we discuss our revenue recognition, including our significant performance obligations under each agreement.

At contract inception, we assess whether the collaboration arrangements are within the scope of ASC 606 or ASC Topic 808, Collaborative Arrangements, or ASC 808, to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards dependent on the commercial success of such activities. This assessment is performed based on the responsibilities of all parties in the arrangement. For collaboration arrangements within the scope of ASC 808 that contain multiple elements, we first determine which elements of the arrangement are within the scope of ASC 808 and which elements are within the scope of ASC 606. For elements of collaboration arrangements that are accounted for pursuant to ASC 808, an appropriate recognition method is determined and applied consistently, either by analogy to authoritative accounting literature or by applying a reasonable and rational policy election.

For elements of collaboration arrangements that are accounted for pursuant to ASC 606, we identify the performance obligations and allocate the total consideration we expect to receive on a relative standalone selling price basis to each performance obligation. Variable consideration, such as performance-based milestones, will be included in the total consideration if we expect to receive such consideration and if it is probable that the inclusion of the variable consideration will not result in a significant reversal in the cumulative amount of revenue recognized under the arrangement. Our estimate of the total consideration we expect to receive under each collaboration arrangement is updated for each reporting period, and any adjustments to revenue are recorded on a cumulative catch-up basis. We exclude sales-based royalty and milestone payments from the total consideration we expect to receive until the underlying sales occur because the license to our intellectual property is deemed to be the predominant item to which the royalties or milestones relate as it is the primary driver of value in our collaboration arrangements.

Key assumptions to determine the standalone selling price may include forecasted revenues, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical and regulatory success. We recognize revenue associated with each performance obligation as the control over the promised goods or services transfer to our collaborator which occurs either at a point in time or over time. If control transfers over time, revenue is recognized by using a method of measuring progress that best depicts the transfer of goods or services. We evaluate the measure of progress and related inputs each reporting period and any resulting adjustments to revenue are recorded on a cumulative catch-up basis.

Consideration received that does not meet the requirements to satisfy ASC 808 or ASC 606 revenue recognition criteria is recorded as deferred revenue in the accompanying consolidated balance sheets, classified as either short-term (less than 12 months) or long-term (more than 12 months) deferred revenue based on our best estimate of when such revenue will be recognized.

Cost of Goods Sold

Cost of goods sold includes the cost of producing and distributing inventories that are related to product revenues during the respective period (including salaries and related costs, stock-based compensation expenses and benefits for employees involved with production and distribution, supplies, external services, freight and indirect overhead costs), third-party royalties payable on our net product revenues and amortization of intangible assets associated with the sale of our products. Cost of goods sold may also include costs related to excess or obsolete inventory adjustment charges, abnormal costs, unabsorbed manufacturing and overhead costs, and manufacturing variances.

Cost of Collaborations and Royalties

Cost of collaborations and royalties includes costs we incur in connection with providing commercial drug supplies, such as GalNAc material, to collaborators, in addition to royalties we owe to third parties on the net sales of licensed products.

Income Taxes

We account for income taxes under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted rates in effect for the year in which these temporary differences are expected to be recovered or settled. Valuation allowances are provided if, based on the weight of available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized.

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Uncertain tax positions, for which management’s assessment is that there is a more than 50% probability of sustaining the position upon challenge by a taxing authority based upon its technical merits, are subject to certain recognition and measurement criteria. The nature of the uncertain tax positions is often very complex and subject to change, and the amounts at issue can be substantial. We develop our cumulative probability assessment of the measurement of uncertain tax positions using internal experience, judgment and assistance from professional advisors. We re-evaluate these uncertain tax positions on a quarterly basis based on a number of factors including, but not limited to, changes in facts or circumstances, changes in tax law, and effectively settled issues under audit and new audit activity. Any change in these factors could result in the recognition of a tax benefit or an additional charge to the tax provision.

Research and Development Expenses

We record research and development expenses as incurred. Included in research and development expenses are salaries and related costs, stock-based compensation expenses, benefits and other operating costs, facilities, supplies, external services, clinical trial and manufacturing costs, certain costs related to our collaboration arrangements, and overhead directly related to our research and development operations, as well as costs to acquire technology licenses.

We have entered into several license agreements for rights to utilize certain technologies. The terms of the licenses may provide for upfront payments, annual maintenance payments, milestone payments based upon certain specified events being achieved and royalties on product sales. We charge costs to acquire and maintain licensed technology that has not reached technological feasibility and does not have alternative future use to research and development expenses as incurred.

Stock-Based Compensation

We recognize stock-based compensation expense for grants under our stock incentive plans and employee stock purchase plan. We account for all stock-based awards granted to employees at their fair value and recognize compensation expense over each employee’s requisite service period, which is generally the vesting period of the award. Determining the amount of stock-based compensation to be recorded requires us to develop estimates of fair values of stock awards as of the grant date. We calculate the grant date fair values of stock options using the Black-Scholes valuation model, which requires us to make assumptions, including but not limited to expected stock price volatility over the term of the awards and the expected term of stock options. The fair value of restricted stock awards granted to employees is based upon the quoted closing market price per share on the date of grant.

We have performance conditions included in certain of our restricted stock awards that are based upon the achievement of pre-specified clinical development, regulatory, commercial and/or financial performance events. As the outcome of each event has inherent risk and uncertainties, and a positive outcome may not be known until the event is achieved, we begin to recognize the grant-date fair value of the performance-based restricted stock awards when we determine the achievement of each performance condition is deemed probable, a determination which requires significant judgment by management. On the date the performance condition is deemed probable, we record a cumulative expense catch-up, with remaining expense amortized over the remaining service period. The number of shares that ultimately vests for certain performance-based restricted stock units may range from 0% to 200% of the target award, depending on the assessed level of achievement of the specified performance conditions. We reassess the probability of achievement at each reporting period and adjust cumulative expense as necessary.

Advertising Expenses

We expense the costs of advertising as incurred. Advertising expenses were $36.0 million, $29.7 million and $12.4 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Liabilities Related to the Sale of Future Royalties and Development Funding

When we enter into or modify an arrangement with a party to fund our research and development costs, we assess if the arrangement meets all of the characteristics of a derivative or contains an embedded derivative, and if so, whether any of the scope exceptions to derivative accounting are applicable. If the arrangement is not accounted for as a derivative, we assess if successful completion of the research and development is already probable at the time the funding is received, and if so we apply the guidance in ASC Topic 470-10, Debt - Overall, or ASC 470-10. If the research and development risk is substantive, such that it is not yet probable development will be successful, we apply the guidance in ASC Topic 730-20, Research and Development - Research and Development Arrangements, or ASC 730-20, to evaluate whether the research and development funding is a liability to repay the funding party or an obligation to perform contractual services. If the transfer of financial risk involved with the research and development is substantive and genuine, and we have no explicit or implicit obligation to repay any of the funds, we account for the arrangement as an obligation to perform contractual research and development services. If the transfer of financial risk is not substantive and genuine, we recognize a liability to repay the funding party. Due to the absence of specific guidance with respect to the subsequent accounting for funds recognized as repayment obligations in ASC 730-20, we apply the concepts of ASC 470-10 to account for the liability to repay the funding party when a repayment obligation has been incurred.

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The liabilities related to the sale of future royalties and development funding and the related interest expense are based on our current estimates of future royalties and milestones expected to be paid and received over the life of the arrangement, which we determine by using third-party data to estimate Leqvio’s and AMVUTTRA’s global net revenues. At each balance sheet date, we assess the expected payments and we account for any change by prospectively adjusting the effective interest rate and related interest expense.

Comprehensive Income (Loss)

Comprehensive income (loss) is comprised of net income (loss) and certain changes in stockholders’ equity (deficit) that are excluded from net income (loss). Other comprehensive income (loss) includes unrealized holding gains and losses on marketable debt securities classified as available-for-sale, foreign currency translation adjustments (if the functional currency is not the U.S. dollar), and certain changes in the fair value of the plan assets and projected benefit obligations attributed to our defined benefit pension plan.

Recently Adopted Accounting Pronouncements

In December 2023, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2023-09, Improvements to Income Tax Disclosures, or ASU 2023-09, which requires entities to disclose disaggregated information about their effective tax rate reconciliation as well as expanded information on income taxes paid by jurisdiction. We adopted ASU 2023-09 in the fourth quarter of 2025 and applied it prospectively, as disclosed in Note 14, Income Taxes. The adoption did not have an impact on our consolidated financial statements.

In November 2024, the FASB issued ASU 2024-04, Induced Conversions of Convertible Debt Instruments, or ASU 2024-04, which clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion or extinguishment of convertible debt. We adopted ASU 2024-04 in the third quarter of 2025 and applied it on a retrospective basis as of January 1, 2025. The adoption did not have a material effect on our consolidated financial statements, but we applied the guidance to the repurchase of our 1.00% Convertible Senior Notes due 2027 in the third and fourth quarters of 2025. Please refer to Note 8, Convertible Debt and Other Financing, for further information related to the repurchase.

In September 2025, the FASB issued ASU 2025-07, Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract,or ASU 2025-07. The guidance refines the scope of ASC Topic 815, Derivatives and Hedging, or ASC 815, to clarify which contracts are subject to derivative accounting. The guidance also provides clarification under ASC 606 for share-based payments from a customer in a revenue contract. We adopted the standard in the fourth quarter of 2025 on a modified retrospective basis as of January 1, 2025. As a result of the new derivative scope exception created by the standard, we now account for the previous development derivative liability similar to a debt obligation under the guidance of ASC 470-10. Refer to Note 9, Liabilities Related To The Sale Of Future Royalties And Development Funding, for additional information related to the adoption of this new standard and the related effects to the consolidated financial statements. We elected to adopt the guidance of ASU 2025-07 because we believe the accounting treatment of this guidance better reflects the economics of our existing research and development funding arrangements and provides more decision-useful information when derivative accounting is not applied. The guidance of ASU 2025-07 related to share-based noncash consideration received in exchange for the transfer of goods or services to a customer did not have any impact on our consolidated financial statements upon adoption.

As a result of the adoption, we derecognized the development derivative liability, recognized a liability related to the sale of future royalties and development funding, and recorded a cumulative effect adjustment of $271.5 million as a credit to accumulated deficit as of January 1, 2025.

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Supplementary Quarterly Financial Information (Unaudited)

The following is a summary of the unaudited prior quarterly results for the condensed consolidated statements of operations and comprehensive income (loss) reflecting the previously reported quarterly amounts and adjusted amounts after applying the new guidance of ASU 2025-07.

Recent Accounting Pronouncements

In September 2025, the FASB issued ASU 2025-06, Targeted Improvements to the Accounting for Internal-Use Software, which modernizes the guidance for internal-use software costs by increasing the operability of the recognition guidance considering different methods of software development. The standard will be effective for annual reporting periods beginning after December 15, 2027, as well as interim period reporting periods within those annual reporting periods, with early adoption permitted. The standard updates may be applied on a prospective, retrospective, or modified retrospective approach. We are currently evaluating the impact this guidance could have on our consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses, or ASU 2024-03, which is intended to improve disclosures by requiring additional information about specific expense categories in the notes to the financial statements on an annual and interim basis. The standard will be effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The standard updates may be applied on either a prospective or retrospective basis. We are currently evaluating the disclosure requirements related to ASU 2024-03.

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3. NET PRODUCT REVENUES

Years Ended December 31,

AMVUTTRA

ONPATTRO

GIVLAARI

OXLUMO

As of December 31, 2025 and 2024, net product revenue-related receivables of $669.5 million and $269.9 million, respectively, were included in accounts receivable, net on our consolidated balance sheets.

The following table summarizes balances and activity in each product revenue allowance and reserve category:

(In thousands) Chargebacks and Rebates Other Incentives and Allowances Total

Provision related to prior period sales (48,816) — (48,816)

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(In thousands) Chargebacks and Rebates Other Incentives and Allowances Total

4. NET REVENUES FROM COLLABORATIONS

Net revenues from collaborations consisted of the following:

Years Ended December 31,

The following table presents the balance of our receivables and contract liabilities related to our collaboration agreements:

As of December 31,

Receivables included in accounts receivable, net $ 48,823 $ 102,743

We recognized net revenues from collaborations of $53.8 million and $266.5 million in the years ended December 31, 2025 and 2024, respectively, each of which was included in the contract liability balance at the beginning of the applicable period.

To determine revenue recognized in the period from contract liabilities, we first allocate revenue to the individual contract liability balance outstanding at the beginning of the period until the revenue exceeds that balance. If additional consideration is received on those contracts in subsequent periods, we assume all revenue recognized in the reporting period first applies to the beginning contract liability as opposed to a portion applying to the new consideration for the period.

Product Collaborations

Roche

On July 21, 2023, or the Effective Date, we entered into a Collaboration and License Agreement, or the Roche Agreement, with F. Hoffmann-La Roche Ltd. and Genentech, Inc., or, collectively, Roche, pursuant to which we and Roche established a worldwide, strategic collaboration for the joint development of zilebesiran. Zilebesiran is our investigational small interfering RNA, or siRNA, therapeutic targeting liver-expressed angiotensinogen, which is currently in Phase 3 clinical development for the treatment of hypertension.

Under the Roche Agreement, we granted to Roche (i) co-exclusive rights to develop zilebesiran worldwide and commercialize zilebesiran in the U.S., referred to as the Co-Commercialization Territory, (ii) exclusive rights to commercialize zilebesiran outside of the U.S., referred to as the Roche Territory, and (iii) non-exclusive rights to manufacture zilebesiran for the development and commercialization of zilebesiran in the Roche Territory.

We lead the global clinical development for zilebesiran. We are responsible for forty percent (40%) and Roche is responsible for the remaining sixty percent (60%) of development costs incurred in the conduct of development activities that support regulatory approval of zilebesiran globally. We and Roche share equally (50/50) all costs incurred in connection with development activities that are conducted to support regulatory approval of zilebesiran solely in the Co-Commercialization Territory if incremental development activities are needed. Roche is solely responsible for all costs incurred in the conduct of development activities that primarily support regulatory approval in the Roche Territory. Upon regulatory approval, Roche has the exclusive right to commercialize zilebesiran in the Roche Territory and will pay us tiered, low double-digit royalties based

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on net sales of zilebesiran on a country-by-country basis during the applicable royalty term. We and Roche will co-commercialize zilebesiran in the Co-Commercialization Territory and share equally (50/50) in profits and losses (including commercialization costs).

Roche has the right to terminate the Roche Agreement for any or no reason at all upon prior written notice. In addition, either party may terminate the Roche Agreement for a material breach by, or insolvency of, the other party, subject to a cure period. Unless earlier terminated pursuant to its terms, the Roche Agreement will remain in effect until expiration on a country-by-country basis (a) in the Roche Territory, upon expiration of the applicable royalty term in the applicable country and (b) in the Co-Commercialization Territory, upon expiration of the term of the co-commercialization efforts.

As of the Effective Date, we identified the following promises in the Roche Agreement that were evaluated under the scope of ASC 606: (i) a co-exclusive license to develop zilebesiran worldwide and commercialize zilebesiran within the Co-Commercialization Territory, a non-exclusive license to manufacture zilebesiran in the Roche Territory solely for purposes of developing and commercializing zilebesiran in the Roche Territory, and an exclusive license to commercialize zilebesiran in the Roche Territory, collectively referred to as Roche License Obligation, (ii) development services, including the manufacture of clinical supply, that support regulatory approval of zilebesiran, referred to as the Roche Development Services Obligation, and (iii) a technology transfer of the existing manufacturing process for zilebesiran, referred to as the Roche Technology Transfer Obligation. The three performance obligations under the Roche Agreement are collectively referred to as the Roche Performance Obligations.

We determined that the Roche License Obligation, Roche Development Services Obligation and Roche Technology Transfer Obligation were reflective of a vendor-customer relationship and therefore represented performance obligations within the scope of ASC 606. The Roche License Obligation was considered functional intellectual property and distinct from other promises under the contract as Roche can benefit from the licenses on its own or together with other readily available resources. As the licenses were delivered at the same time, they were considered one performance obligation at contract inception. The Roche Development Services Obligation was considered distinct as Roche could benefit from the development services together with the licenses transferred by us at the inception of the agreement. The development services are not expected to significantly modify or customize the initial intellectual property as zilebesiran was in Phase 2 of clinical development at contract inception. The Roche Technology Transfer Obligation was distinct as Roche can benefit from the manufacturing license transferred by us at the inception of the agreement given the advancements of our RNAi platform and our utilization of third-party contract manufacturing organizations to manufacture zilebesiran. Therefore, each represented a separate performance obligation within the contract with a customer under the scope of ASC 606 at contract inception.

We consider the collaborative activities associated with the co-commercialization of zilebesiran in the U.S. to be a separate unit of account within the scope of ASC 808 as we and Roche are both active participants in the commercialization activities and are exposed to significant risks and rewards that are dependent on the commercial success of the activities in the arrangement.

Based on the standalone selling prices of each performance obligation as of the Effective Date, we allocated the variable consideration related to the estimated reimbursements for the Roche Development Services Obligation and the Roche Technology Transfer Obligation to each performance obligation as the terms of the variable payment relate specifically to our efforts to satisfy the performance obligation. We allocated the fixed upfront consideration entirely to the Roche License Obligation as the value of the fixed consideration together with the expected value of the remaining development and regulatory milestones, sales-based milestones, and royalties, all of which are either currently constrained at inception or subject to the sales- or usage-based royalty exception, approximates the standalone selling price of the Roche License Obligation. This allocation is consistent with the allocation objective of ASC 606 when considering all of the performance obligations and payment terms in the contract.

The Roche License Obligation was satisfied at a point in time upon transfer of the license to Roche. Control of the licenses was transferred on the Effective Date and Roche could begin to use and benefit from the licenses. Because of this, all consideration allocated to the Roche License Obligation, including the upfront payment, milestones and royalties, is recognized when these amounts are no longer considered fully constrained or when the related sales occur for amounts subject to the sales-or-usage based royalty exception of ASC 606. For the Roche Development Services Obligation, we measure proportional performance over time using an input method based on cost incurred relative to the total estimated cost of the obligation, on a quarterly basis, by determining the proportion of effort incurred as a percentage of total effort we expect to expend. This ratio is applied to the transaction price allocated to the obligation. As all costs in the proportional performance model are allowable for reimbursement from Roche, and the assumptions used to determine the total estimated cost of the obligation are consistent with the assumptions used to determine the transaction price allocated to the obligation, the revenue recognized for this obligation will approximate 60% of the actual reimbursable cost incurred. Management has applied significant judgment in the process of developing our estimates. We re-evaluate the transaction price as of the end of each reporting period and as of December 31, 2025, the total transaction price was determined to be $1.74 billion, an increase of $423.6 million from December 31, 2024 attributed to the achievement of a $300.0 million development milestone due to us upon the first patient dosing in the ZENITH Phase 3 trial in September 2025, as well as a higher probability of success associated with initiation of the Phase 3 trial offset

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by a decrease in the expected costs to perform the development services based on an updated development plan approved by the joint steering committee in September 2025. We recognized $300.0 million in net revenue from collaborations as the development milestone specifically relates to the transfer of the license to Roche which occurred on the Effective Date.

The following table provides a summary of the transaction price allocated to each performance obligation:

(In thousands) As of December 31, 2025

Roche License Obligation $ 675,000

Roche Development Services Obligation 1,061,167

Roche Technology Transfer Obligation 2,000

Net revenues from collaborations recognized under the Roche Agreement consisted of the following:

Years Ended December 31,

As of December 31, 2025, the aggregate amount of the transaction price allocated to the Roche Performance Obligations that was unsatisfied was $904.4 million, which is expected to be recognized through the term of the Roche Agreement based on our input method model as the services are performed. We incurred research and development costs related to our collaboration with Roche of $160.0 million, $92.7 million and $44.6 million during the years ended December 31, 2025, 2024 and 2023, respectively.

Regeneron Pharmaceuticals, Inc.

Overview

In 2019, we entered into a global, strategic collaboration with Regeneron Pharmaceuticals, Inc., or Regeneron, to discover, develop and commercialize RNAi therapeutics for a broad range of diseases by addressing therapeutic targets expressed in the eye and central nervous system, or CNS, in addition to a select number of targets expressed in the liver, which we refer to as the Regeneron Collaboration. The Regeneron Collaboration is governed by a Master Agreement, referred to as the Regeneron Master Agreement. In connection with the Regeneron Master Agreement, we and Regeneron entered into (i) a co-co collaboration agreement covering the continued development of cemdisiran, our C5 siRNA, currently in development for C5 complement-mediated diseases, as a monotherapy, or the C5 Co-Co Collaboration Agreement, and (ii) a license agreement to evaluate anti-C5 antibody-siRNA combinations for C5 complement-mediated diseases including evaluating the combination of Regeneron’s pozelimab and cemdisiran, or the C5 License Agreement. The Master Agreement, the C5 Co-Co Collaboration Agreement and the C5 License Agreement were accounted for as a single arrangement because the agreements were negotiated together.

In November 2022, Regeneron exercised its right under the C5 Co-Co Collaboration Agreement to opt out of the further development and commercialization of cemdisiran monotherapy. As a result of Regeneron’s decision to opt out, the licenses granted to Regeneron under the C5 Co-Co Collaboration Agreement reverted to us, we had the sole right to continue to develop and commercialize cemdisiran monotherapy, and Regeneron no longer shared in the costs on any monotherapy program. Regeneron remained eligible to receive tiered, double-digit royalties on net sales of cemdisiran as a monotherapy.

In June 2024, we entered into an amended and restated C5 License Agreement, or the Amended C5 License Agreement, which terminated the C5 Co-Co Collaboration Agreement and granted Regeneron a worldwide license to cemdisiran as a monotherapy in addition to the license to cemdisiran in combination with anti-C5 antibodies. Through the Amended C5 License Agreement, Regeneron is now solely responsible for development, manufacturing and commercialization of cemdisiran as a monotherapy and in combination with anti-C5 antibodies. As part of the Amended C5 License Agreement, we provided manufacturing technology transfer services for cemdisiran to Regeneron. Regeneron provided us with an upfront payment of $10.0 million, and we will receive certain milestone payments upon receipt of regulatory approval for cemdisiran as a monotherapy, and tiered double-digit royalties on net sales. The Amended C5 License Agreement did not change our rights to receive low double-digit royalties and commercial milestones of up to $325.0 million on any potential product sales if cemdisiran is used as part of a combination product.

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Under the terms of the Regeneron Collaboration, we continue to work exclusively with Regeneron to discover RNAi therapeutics for eye and CNS diseases for an initial research period, which we refer to as the Initial Research Term. The Regeneron Collaboration also covers a select number of RNAi therapeutic programs designed to target genes expressed in the liver. The Initial Research Term will expire in May 2026. As a result, we and Regeneron will not nominate additional targets to be added to our collaboration.

Regeneron leads development and commercialization for all programs targeting eye diseases (subject to limited exceptions), entitling us to certain potential milestone and royalty payments pursuant to the terms of a license agreement, the form of which has been agreed upon by the parties. We and Regeneron are alternating leadership on CNS and liver programs, with the lead party retaining global development and commercial responsibility. For such CNS and liver programs, both we and Regeneron have the option at lead candidate selection to enter into a co-co collaboration agreement, the form of which has been agreed upon by the parties, whereby both companies will share equally all costs of, and profits from, all development and commercialization activities under the program. If the non-lead party elects to not enter into a co-co collaboration agreement with respect to a given CNS or liver program, we and Regeneron will enter into a license agreement with respect to such program and the lead party will be the “Licensee” for the purposes of the license agreement. If the lead party for a CNS or liver program elects to not enter into the co-co collaboration agreement, then we and Regeneron will enter into a license agreement with respect to such program and leadership of the program will transfer to the other party and the former non-lead party will be the “Licensee” for the purposes of the license agreement.

In connection with the Regeneron Master Agreement, we remain eligible to receive an additional $100.0 million milestone payment upon achievement of certain criteria during early clinical development for an eye program. We and Regeneron are continuing to advance programs nominated during the Initial Research Term. For each of these programs, Regeneron will provide us with $2.5 million in funding at program initiation and an additional $2.5 million at lead candidate identification.

For any license agreement subsequently entered into, the licensee will generally be responsible for its own costs and expenses incurred in connection with the development and commercialization of the collaboration products. The licensee will pay to the licensor certain development and/or commercialization milestone payments totaling up to $150.0 million for each collaboration product. In addition, following the first commercial sale of the applicable collaboration product under a license agreement, the licensee is required to make certain tiered royalty payments, ranging from low double-digits up to 20%, to the licensor based on the aggregate annual net sales of the collaboration product, subject to customary reductions.

For any co-co collaboration agreement subsequently entered into, we and Regeneron will share equally all costs of, and profits from, development and commercialization activities. Reimbursement of our share of costs will be recognized as a reduction to research and development expense in the consolidated statements of operations and comprehensive income (loss). In the event that a party exercises its opt-out right, the lead party will be responsible for all costs and expenses incurred in connection with the development and commercialization of the collaboration products under the applicable co-co collaboration agreement, subject to continued sharing of costs through defined points. If a party exercises its opt-out right, following the first commercial sale of the applicable collaboration product under a co-co collaboration agreement, the lead party is required to make certain tiered royalty payments, ranging from low double-digits up to 20%, to the other party based on the aggregate annual net sales of the collaboration product and the timing of the exercise of the opt-out right, subject to customary reductions and a reduction for opt-out transition costs.

Contract Modification

In June 2024, we determined the Amended C5 License Agreement does not meet the requirements to account for the contract modification as a separate contract under ASC 606 because the consideration exchanged for the additional distinct goods and services does not reflect the standalone selling price. Therefore, we have accounted for the Amended C5 License Agreement and Regeneron Master Agreement as a single combined contract. The modification date was determined to be the June 2024 effective date of the Amended C5 License Agreement.

Our performance obligations subsequent to the contract modification included: (i) a research license and research services, collectively referred to as the Research Services Obligation; (ii) a worldwide license to cemdisiran for combination therapies, and manufacturing and development service obligations, collectively referred to as the C5 License Obligation; (iii) a worldwide license to cemdisiran for monotherapies, referred to as the C5 Monotherapy Obligation; and (iv) a technology transfer of the existing manufacturing process for cemdisiran, referred to as the Regeneron Technology Transfer Obligation.

The Amended C5 License Agreement did not change the Research Services Obligation or the C5 License Obligation, which were both performance obligations at the inception of our global, strategic collaboration with Regeneron prior to the contract modification. The Amended C5 License Agreement resulted in two additional performance obligations, which were the C5 Monotherapy Obligation and the Regeneron Technology Transfer Obligation. The C5 Monotherapy Obligation was considered functional intellectual property and distinct from other promises as Regeneron can benefit from the cemdisiran monotherapy license on its own or together with other readily available resources and the license is separately identifiable from the other promises in the contract. The Regeneron Technology Transfer Obligation was distinct as Regeneron can benefit from the cemdisiran monotherapy license transferred by us without the technology transfer given cemdisiran was in an advanced

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stage of clinical development and our utilization of third-party contract manufacturing organizations to manufacture cemdisiran. Therefore, the C5 Monotherapy Obligation and the Regeneron Technology Transfer Obligation each represented a separate performance obligation.

The initial transaction price of $191.5 million allocated to the C5 Monotherapy Obligation was recognized immediately as this obligation was satisfied at a point in time upon transfer of the license to Regeneron. Control of the license was transferred in June 2024 as Regeneron could begin to use and benefit from the license on its own or together with other readily available resources to generate economic benefit from the license. The remaining variable consideration allocated to the C5 Monotherapy Obligation, including milestones and royalties, will be recognized immediately when these amounts are no longer considered fully constrained or when the related sales occur for amounts subject to the sales-or-usage based royalty exception of ASC 606. In the three months ended March 31, 2025, we completed our obligations related to the C5 License Obligation and the Regeneron Technology Transfer Obligation.

We continue to perform work in satisfaction of the remaining unsatisfied performance obligation, the Research Services Obligation. For this performance obligation, we measure proportional performance over time using an input method based on cost incurred relative to the total estimated costs for each of the identified obligations by determining the proportion of effort incurred as a percentage of total effort we expect to expend. This ratio is applied to the transaction price allocated to the obligation. Management has applied significant judgment in the process of developing our estimates. Any changes to these estimates will be recognized in the period in which they change as a cumulative catch-up. We re-evaluate the transaction price as of the end of each reporting period and as of December 31, 2025, the total transaction price was determined to be $100.5 million related to this obligation. As of December 31, 2025, the aggregate amount of the transaction price that was unsatisfied was $34.1 million, which is expected to be recognized through the term of the Regeneron Collaboration based on our input method model as the services are performed.

Net revenues from collaborations recognized under the Regeneron Collaboration consisted of the following:

Years Ended December 31,

C5 Monotherapy Obligation — 191,520 —

Regeneron Technology Transfer Obligation 2,431 — —

Revenue recognized for the “Other license programs” relates to eight separate programs subject to individual agreements with Regeneron.

Deferred revenue is classified as either current or noncurrent in the consolidated balance sheets based on the period the revenue is expected to be recognized. The composition of current deferred revenue related to the Regeneron Collaboration was as follows:

As of December 31,

Regeneron Technology Transfer Obligation — 2,307

We incurred research and development costs related to the Regeneron Collaboration of $62.0 million, $71.7 million and $77.4 million during the years ended December 31, 2025, 2024 and 2023, respectively.

Novartis AG

In February 2013, we entered into a license and collaboration agreement with The Medicines Company, or MDCO, pursuant to which we granted to MDCO an exclusive, worldwide license to develop, manufacture and commercialize RNAi therapeutics targeting proprotein convertase subtilisin/kexin type 9 for the treatment of hypercholesterolemia and other human diseases, including inclisiran. We refer to this agreement, as amended through the date hereof, as the MDCO License

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Agreement. In 2020, Novartis AG, or Novartis, completed its acquisition of MDCO and assumed all of MDCO’s rights and obligations under the MDCO License Agreement.

We are entitled to royalties ranging from 10% up to 20% based on annual worldwide net sales of licensed products by Novartis, its affiliates and sublicensees, subject to reduction under specified circumstances.

Vir Biotechnology, Inc.

In March 2025, we and Vir Biotechnology, Inc., or Vir, entered into an amended and restated collaboration and license agreement, or the Amended Vir Agreement, relating to elebsiran (formerly ALN-HBV02 (VIR-2218)). Vir remains solely responsible for development, manufacturing and commercialization of elebsiran. In connection with execution of the Amended Vir Agreement, Vir made a $30.0 million payment, and we remain entitled to receive milestone payments upon the achievement of specified regulatory and commercial milestones, and royalties on the net sales of elebsiran ranging from low-to-mid teen percentages. Because the license rights have already been delivered and we have no other remaining performance obligations under the Amended Vir Agreement, the $30.0 million payment was recognized within net revenues from collaborations during the year ended December 31, 2025.

Other

In addition to the collaboration agreements discussed above, we have various other collaboration agreements that are not individually significant to our operating results or financial condition at this time. Pursuant to the terms of those agreements, we may be required to pay, or we may receive, additional amounts contingent upon the occurrence of various future events (e.g., upon the achievement of various development and commercial milestones) which in the aggregate could be significant. We may also incur, or be reimbursed for, significant research and development costs. In addition, if any products related to these collaborations are approved for sale, we may be required to pay, or we may receive, royalties on future sales. The payment or receipt of these amounts, however, is contingent upon the occurrence of various future events. Due to the uncertainty of pharmaceutical development and the high historical failure rates generally associated with drug development and commercialization, it is possible we may not receive any such payments under all of our existing collaboration and license agreements, including the agreements described within this note.

5. FAIR VALUE MEASUREMENTS

The following tables present information about our financial assets and liabilities that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques we utilized to determine such fair value:

Financial assets

Cash equivalents:

U.S. government-sponsored enterprise securities 2,690 — 2,690 —

Marketable debt securities:

U.S. government-sponsored enterprise securities 252,634 — 252,634 —

Restricted cash (money market funds) 917 917 — —

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Financial assets

Cash equivalents:

U.S. government-sponsored enterprise securities 9,952 — 9,952 —

Marketable debt securities:

U.S. government-sponsored enterprise securities 396,143 — 396,143 —

Marketable equity securities 8,156 8,156 — —

Restricted cash (money market funds) 910 910 — —

Financial liabilities

For the years ended December 31, 2025 and 2024, there were no transfers between Level 1 and Level 2 financial assets or liabilities. The carrying amounts reflected on our consolidated balance sheets for cash, accounts receivable, net, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term maturities.

6. MARKETABLE DEBT SECURITIES

The following tables summarize our marketable debt securities:

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The following table summarizes classification of our marketable debt securities in the consolidated balance sheets:

As of December 31,

7. OTHER BALANCE SHEET DETAILS

Inventory

The components of inventory are summarized as follows:

As of December 31,

As of December 31, 2025 and 2024, we had $28.9 million and $36.9 million, respectively, of long-term inventory included within other assets in our consolidated balance sheets as we anticipate it being consumed beyond our normal operating cycle.

Property, Plant and Equipment, Net

Property, plant and equipment, net consisted of the following:

As of December 31,

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Accrued Expenses

Accrued expenses consisted of the following:

As of December 31,

Preclinical, clinical trial and manufacturing 104,097 75,815

Cash, Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within our consolidated balance sheets to the totals of these amounts shown in the consolidated statements of cash flows:

As of December 31,

Total restricted cash included in other assets 1,557 2,224 2,196

Accumulated Other Comprehensive Loss

The following table summarizes the changes in accumulated other comprehensive loss, by component:

Amounts reclassified from other comprehensive (loss) income — 117 (7) — 110

Amounts reclassified from other comprehensive income — 450 (1,537) — (1,087)

Amounts reclassified out of accumulated other comprehensive loss relate to settlements of marketable debt securities and amortization of our pension obligation which are recorded as other income (expense), net in the consolidated statements of operations and comprehensive income (loss).

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8. CONVERTIBLE DEBT AND OTHER FINANCING

Convertible Senior Notes Due 2028

On September 8, 2025, we commenced a private offering of $575.0 million in aggregate principal amount of 0.00% convertible senior notes due 2028, or the Initial 2028 Notes. On September 10, 2025, the initial purchasers in such offering exercised their option to purchase an additional $86.3 million in aggregate principal amount of our 0.00% Convertible Senior Notes due 2028, or the Additional 2028 Notes, and together with the Initial 2028 Notes referred to as the 2028 Notes, bringing the total aggregate principal amount of the 2028 Notes issued and outstanding to $661.3 million. The 2028 Notes are our senior unsecured obligations. The 2028 Notes were issued pursuant to an indenture, dated September 12, 2025, or the 2025 Indenture, between us and The Bank of New York Mellon, as trustee. The 2025 Indenture includes customary covenants and sets forth certain events of default after which the 2028 Notes may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving us after which the 2028 Notes become automatically due and payable. The 2028 Notes will mature on September 15, 2028, unless earlier converted, redeemed or repurchased. The 2028 Notes will not bear regular interest.

Before June 15, 2028, noteholders will have the right to convert their 2028 Notes in certain circumstances and during specified periods: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2025 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any ten consecutive trading day period in which the trading price per $1,000 principal amount of the 2028 Notes for each trading day of that ten consecutive trading day period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on such trading day; (3) if we call any or all of the 2028 Notes for redemption; or (4) upon the occurrence of specified corporate events. From and after June 15, 2028, the 2028 Notes will be convertible at the option of the noteholders at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date.

We will settle any conversions of the 2028 Notes by paying or delivering, as applicable, cash, shares of our common stock, or a combination of cash and shares of common stock, at our election. The conversion rate for the 2028 Notes will initially be 1.4923 shares of common stock per $1,000 principal amount of 2028 Notes, which is equivalent to an initial conversion price of approximately $670.11 per share of common stock. The initial conversion price represents a premium of approximately 40% above the U.S. composite volume weighted average price of our common stock from 12:30 p.m. through 4:00 p.m. Eastern Daylight Time on September 9, 2025, which was $478.63 per share. The conversion rate is subject to adjustment under certain circumstances in accordance with the terms of the 2025 Indenture.

We may not redeem the 2028 Notes prior to September 20, 2027. We may redeem for cash all or any portion of the 2028 Notes (subject to certain limitations), at our option, on or after September 20, 2027 and on or prior to the 21st scheduled trading day immediately preceding the maturity date, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the 2028 Notes to be redeemed, plus any accrued and unpaid special interest to, but excluding, the redemption date. No sinking fund is provided for the 2028 Notes, which means that we are not required to redeem or retire the 2028 Notes periodically.

If we undergo a fundamental change, which includes certain change of control events or a termination of trading of our common stock, then subject to certain conditions, holders may require us to repurchase for cash all or any portion of their notes at a fundamental change repurchase price equal to 100% of the principal amount of the 2028 Notes to be repurchased plus accrued and unpaid special interest. In addition, if specific corporate events occur prior to the maturity date or if we issue a notice of redemption, we will increase the conversion rate by pre-defined amounts for holders who elect to convert their notes in connection with such corporate event. The conditions allowing holders of the 2028 Notes to convert were not met as of December 31, 2025.

The 2028 Notes were issued at par. As of December 31, 2025, the 2028 Notes were classified as a long-term liability on the consolidated balance sheet and had a carrying value of $647.2 million, representing the outstanding principal amount, net of unamortized issuance costs of $14.0 million. The issuance costs are amortized to interest expense over the contractual term of the 2028 Notes. As of December 31, 2025, the estimated fair value of the 2028 Notes was approximately $637.0 million, which was determined based on the last actively traded price per $100 of the 2028 Notes (Level 2) on that day. As of December 31, 2025, the effective interest rate of the 2028 Notes is 1%.

We used the net proceeds from the issuance of the 2028 Notes to pay the cost of the 2025 Capped Call Transactions, and the remainder of the net proceeds, together with cash on hand, to repay $637.8 million aggregate principal amount of the 2027 Notes, as further discussed below.

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2025 Capped Call Transactions

In September 2025, in connection with the pricing of the 2028 Notes, we entered into privately negotiated capped call transactions, or 2025 Capped Call Transactions. The 2025 Capped Call Transactions initially cover, subject to customary anti-dilution adjustments, the number of shares of common stock that underlie the 2028 Notes. The initial cap price of the 2025 Capped Call Transactions is $837.61 per share, and is subject to certain adjustments under the terms of the 2025 Capped Call Transactions.

The 2025 Capped Call Transactions are not part of the terms of the 2028 Notes and are accounted for as separate transactions. As these transactions are indexed to our own stock and are considered equity classified, they are recorded in stockholders’ equity and are not accounted for as derivatives. The cost incurred in connection with the 2025 Capped Call Transactions of $35.3 million was recorded as a reduction to additional paid-in capital on our consolidated balance sheet and the fair value of the capped call instrument is not remeasured each reporting period.

Convertible Senior Notes Due 2027

On September 12, 2022, we commenced a private offering of $900.0 million in aggregate principal amount of 1.00% Convertible Senior Notes due 2027, or the Initial 2027 Notes. On September 13, 2022, the initial purchasers in such offering exercised their option to purchase an additional $135.0 million in aggregate principal amount of our 1.00% Convertible Senior Notes due 2027, or the Additional 2027 Notes, and together with the Initial 2027 Notes collectively referred to as the 2027 Notes, bringing the total aggregate principal amount of the 2027 Notes issued and outstanding to $1.04 billion. The 2027 Notes were issued pursuant to an indenture, dated September 15, 2022, or the 2022 Indenture. The 2022 Indenture includes customary covenants and sets forth certain events of default after which the 2027 Notes may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving us after which the 2027 Notes become automatically due and payable. The 2027 Notes were issued at par.

The 2027 Notes will mature on September 15, 2027, unless earlier converted, redeemed or repurchased. The 2027 Notes bear interest at a rate of 1.00% per year payable semiannually in arrears on March 15 and September 15 of each year, beginning on March 15, 2023. The 2027 Notes are convertible at the option of the noteholder on or after June 15, 2027. Prior to June 15, 2027, the 2027 Notes are convertible only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2022 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any ten consecutive trading day period in which the trading price per $1,000 principal amount of the 2027 Notes for each trading day of that ten consecutive trading day period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate of the 2027 Notes on such trading day; (3) if we call any or all of the 2027 Notes for redemption; or (4) upon the occurrence of specific corporate events as set forth in the 2022 Indenture governing the 2027 Notes.

We will settle any conversions of the 2027 Notes by paying or delivering, as applicable, cash, shares of our common stock, or a combination of cash and shares of common stock, at our election. The initial conversion rate for the 2027 Notes is 3.4941 shares of common stock per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $286.20 per share of common stock, which represents a premium of approximately 35% over the last reported sale price of common stock of $212.00 per share on September 12, 2022. The conversion rate is subject to adjustment under certain circumstances in accordance with the terms of the 2022 Indenture. The condition allowing holders of the 2027 Notes to convert was met in the fourth quarter of 2025 due to our common stock trading for at least 20 days during a period of 30 consecutive trading days ending on, and including, the last trading day of the quarter above 130% of the conversion price, and the 2027 Notes are convertible at the option of the holders in the first quarter of 2026.

We are able to redeem the 2027 Notes after September 20, 2025. We may redeem for cash equal to 100% of the principal amount of the 2027 Notes being redeemed plus accrued and unpaid interest of all or any portion of the 2027 Notes, at our option, on or after September 20, 2025, if the last reported sales price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period. As of December 31, 2025, we have not redeemed any of the 2027 Notes under this option.

No sinking fund is provided for the 2027 Notes and therefore we are not required to redeem or retire the 2027 Notes periodically. If we undergo a fundamental change, which includes certain change of control events or a termination of trading of our common stock, then subject to certain conditions, holders may require us to repurchase for cash all or any portion of their 2027 Notes at a fundamental change repurchase price equal to 100% of the principal amount of the 2027 Notes to be repurchased plus accrued and unpaid interest. In addition, if specific corporate events occur prior to the maturity date or if we issue a notice of redemption, we will increase the conversion rate by pre-defined amounts for holders who elect to convert their notes in connection with such corporate event.

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In September 2025, concurrently with the pricing of the 2028 Notes, we entered into privately negotiated transactions with certain holders of the 2027 Notes to repurchase for cash $637.8 million aggregate principal amount of the outstanding 2027 Notes for a total repurchase cost (including accrued and unpaid interest of $3.1 million) of approximately $1.11 billion. The repurchase was accounted for as an induced conversion in accordance with ASU 2024-04. We recorded an inducement expense of $39.1 million within loss related to convertible debt in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2025 and a charge to additional paid-in capital of $430.4 million within stockholders’ equity.

In December 2025, we entered into privately negotiated transactions with certain holders of the 2027 Notes to repurchase for cash $34.4 million aggregate principal amount of the outstanding 2027 Notes for a total repurchase cost (including accrued and unpaid interest of $0.1 million) of approximately $52.3 million. The repurchase was accounted for as an induced conversion in accordance with ASU 2024-04. We recorded an inducement expense of $3.3 million within loss related to convertible debt in the consolidated statements of operations and comprehensive income (loss) for the year ended December 31, 2025 and a charge to additional paid-in capital of $14.8 million within stockholders’ equity.

As of December 31, 2025, we had $362.8 million aggregate principal amount of the 2027 Notes outstanding. As of December 31, 2025 and 2024, the 2027 Notes were classified as a long-term liability on the consolidated balance sheets and had a carrying value of $360.5 million and $1.02 billion, respectively, representing outstanding principal amount net of unamortized issuance costs of $2.3 million and $10.4 million, respectively. The issuance costs are amortized to interest expense over the contractual term of the 2027 Notes. As of December 31, 2025 and 2024, the estimated fair value of the 2027 Notes was approximately $534.1 million and $1.11 billion, respectively, which was determined based on the last actively traded price per $100 of the 2027 Notes (Level 2) on the respective dates. As of December 31, 2025 and 2024, the effective interest rate of the 2027 Notes is 1%.

2022 Capped Call Transactions

In 2022, in connection with the pricing of the 2027 Notes, we entered into privately negotiated capped call transactions, or 2022 Capped Call Transactions. The 2022 Capped Call Transactions initially cover, subject to customary anti-dilution adjustments, the number of shares of common stock that underlie the 2027 Notes. The cap price of the 2022 Capped Call Transactions is initially $424.00 per share, which represents a premium of 100% over the last reported sale price of common stock of $212.00 per share on September 12, 2022, and is subject to certain adjustments under the terms of the 2022 Capped Call Transactions. As of December 31, 2025, the 2022 Capped Call Transactions remained outstanding. Because these transactions are indexed to our own stock and are considered equity classified, they were recorded in stockholders’ equity and are not accounted for as derivatives. The cost incurred to purchase the 2022 Capped Calls was recorded as a reduction to additional paid-in capital on our consolidated balance sheets and the fair value of the capped call instrument is not remeasured each reporting period.

Revolving Credit Agreement

On September 30, 2025, we entered into the Revolving Credit Agreement, which provides for a $500.0 million revolving line of credit, including a $150.0 million sublimit for issuance of letters of credit. The Revolving Credit Agreement matures in September 2030, subject to earlier springing maturity under certain circumstances.

Borrowings, if any, will bear interest, at our option, at a base rate plus an applicable margin ranging from 0.50% to 1.50% based upon the total leverage ratio or a term Secured Overnight Financing Rate (or an alternative currency term rate) plus an applicable margin ranging from 1.50% to 2.50% based upon the total leverage ratio. We are required to pay, on a quarterly basis, a commitment fee ranging between 0.20% to 0.35% (depending on our total leverage ratio) of unused available commitments under the Revolving Credit Agreement. We are also obligated to pay the administrative agent fees customary for revolving credit facilities of this size and type.

The Revolving Credit Agreement contains customary affirmative and negative covenants and conditions to borrowing, as well as customary events of default. In addition, the Revolving Credit Agreement contains financial covenants that require us to maintain a total leverage ratio less than or equal to 3.75:1.00 and an interest coverage ratio greater than or equal to 3.00:1.00, each tested at the end of each fiscal quarter. As of December 31, 2025, we were in compliance with the financial covenants.

As of December 31, 2025, we had no borrowings and $17.5 million of letters of credit outstanding under the Revolving Credit Agreement.

9. LIABILITIES RELATED TO THE SALE OF FUTURE ROYALTIES AND DEVELOPMENT FUNDING

Development Funding Liabilities

In August 2020, we entered into a co-development agreement, referred to as the Development Funding Agreement, with BXLS V Bodyguard – PCP L.P. and BXLS Family Investment Partnership V – ESC L.P., collectively referred to as Blackstone Life Sciences, pursuant to which Blackstone Life Sciences will provide up to $150.0 million in funding for the clinical

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development of vutrisiran and zilebesiran, two of our cardiometabolic programs. As of December 31, 2025, Blackstone Life Sciences has provided $70.0 million to fund vutrisiran development costs related to the HELIOS-B Phase 3 clinical trial and $26.0 million to fund Phase 2 clinical trials of zilebesiran. Additionally, Blackstone Life Sciences is obligated to fund $18.0 million for the Phase 3 clinical trial of zilebesiran following a development milestone triggered in September 2025, of which $6.0 million has been provided as of December 31, 2025. The amount of funding ultimately provided by Blackstone Life Sciences for the Phase 3 clinical trial of zilebesiran is dependent on us achieving the remaining specified development milestones. As agreed between Blackstone Life Sciences and the Company, we retain sole responsibility for the development and commercialization of both vutrisiran and zilebesiran.

As consideration for Blackstone Life Sciences’ funding for vutrisiran clinical development costs, we agreed to pay Blackstone Life Sciences $175.0 million triggered upon obtaining regulatory approval of vutrisiran for ATTR amyloidosis with cardiomyopathy, or ATTR-CM, and a 1% royalty on net sales of vutrisiran for a 10-year term beginning upon the first commercial sale following regulatory approval of vutrisiran for ATTR-CM. In March 2025, we obtained a regulatory approval from the FDA for vutrisiran for ATTR-CM, triggering the $175.0 million payable to Blackstone Life Sciences in eight equal quarterly payments over two years.

In September 2023, we announced positive topline results from the KARDIA-1 Phase 2 clinical trial of zilebesiran, triggering the achievement of the development milestone of $84.5 million payable to Blackstone Life Sciences in 16 equal quarterly payments over four years, as consideration for Blackstone Life Sciences’ funding for Phase 2 clinical development costs of zilebesiran. As consideration for funding for Phase 3 clinical development costs of zilebesiran, we agreed to pay Blackstone Life Sciences $243.0 million in 16 equal quarterly payments over four years triggered upon regulatory approval of zilebesiran in specified countries, unless it is later withdrawn from the market following a mandatory recall.

Our payment obligations under the Development Funding Agreement are secured, subject to certain exceptions, by security interests in intellectual property owned by us relating to vutrisiran and zilebesiran, as well as in our bank account in which the funding deposits will be made.

We and Blackstone Life Sciences each have the right to terminate the Development Funding Agreement in its entirety in the event of the other party’s bankruptcy or similar proceedings. We and Blackstone Life Sciences may each terminate the Development Funding Agreement in its entirety or with respect to either product in the event of an uncured material breach by the other party, or with respect to a product for certain patient health and safety reasons, or if regulatory approval in specified major market countries is not obtained for the product following the completion of clinical trials for the product. In addition, Blackstone Life Sciences has the right to terminate the Development Funding Agreement in its entirety upon the occurrence of certain events affecting our ability to make payments under the agreement or to develop or commercialize the products, or upon a change of control of us. Blackstone Life Sciences may also terminate the Development Funding Agreement with respect to a product if the joint steering committee elects to terminate the development program for that product in its entirety, if certain clinical endpoints are not achieved for that product or, with respect to vutrisiran only, if our right to develop or commercialize vutrisiran is enjoined in a specified major market as a result of an alleged patent infringement. In certain termination circumstances, we will be obligated to pay Blackstone Life Sciences an amount that is equal to, or a multiplier of, the development funding received from Blackstone Life Sciences, and we may remain obligated under certain circumstances to make the payments to Blackstone Life Sciences described above should we obtain regulatory approval for zilebesiran following termination.

We previously accounted for the Development Funding Agreement under ASC 815 as a derivative liability measured at fair value because it did not meet any of the derivative scope exceptions. In the fourth quarter of 2025, we adopted ASU 2025-07 on a modified retrospective basis as of January 1, 2025, which codified a new scope exception to the guidance of ASC 815. Refer to Note 2, Summary of Significant Accounting Policies, for further information related to the impact of adoption. We determined the underlyings in the Development Funding Agreement now qualify for this new scope exception and, as a result, are no longer accounted for under ASC 815. Beginning on the date of adoption of ASU 2025-07, or January 1, 2025, we record the proceeds received from Blackstone Life Sciences as debt obligations, net of closing costs, on our consolidated balance sheet due to our continuing involvement and obligation to repay Blackstone Life Sciences. We recognized $271.5 million as a cumulative effect adjustment to accumulated deficit as of January 1, 2025 as a result of the removal of the development derivative liability and establishment of new debt obligations.

The debt obligations to repay Blackstone Life Sciences for the vutrisiran and zilebesiran funding are accreted from the initial carrying amount to the total payment amount using the effective interest rate method over the life of the Development Funding Agreement. The effective interest rate is determined based on the proceeds received and projections of the amounts and timing of the future cash flows. The accretion is recorded as interest expense in the consolidated statement of operations and comprehensive income (loss). We recognize the proceeds received and the principal portion of payments made to Blackstone Life Sciences as financing activities within the consolidated statement of cash flows. As of December 31, 2025, our estimate of total interest expense resulted in an effective annual interest rate of 46% related to vutrisiran and 32% related to zilebesiran.

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As payments are made to Blackstone Life Sciences, the balance of the liabilities is effectively repaid over the life of the Development Funding Agreement. The exact timing and amount of repayment is likely to change each reporting period. A significant increase or decrease in vutrisiran global net product revenues will materially impact the liability related to the vutrisiran payments and interest expense recognized. At each balance sheet date, we assess the expected payments to Blackstone Life Sciences and we prospectively adjust the amortization of the liabilities and the related interest expense.

The following table shows the activity with respect to the vutrisiran development funding liability, in thousands:

As of December 31, 2025, we recorded $94.5 million within liabilities related to the sale of future royalties and development funding and $99.7 million within liabilities related to the sale of future royalties and development funding, net of current portion on our consolidated balance sheet related to the vutrisiran development funding liability.

The following table shows the activity with respect to the zilebesiran development funding liability, in thousands:

Interest expense 6,853

Amount received 6,000

As of December 31, 2025, we recorded $6.8 million within liabilities related to the sale of future royalties and development funding and $10.3 million within liabilities related to the sale of future royalties and development funding, net of current portion on our consolidated balance sheet related to the zilebesiran development funding liability.

The fair values of the vutrisiran and zilebesiran development funding liabilities were $541.3 million and $116.2 million, respectively, as of December 31, 2025, based on our current estimates of future payments over the life of the arrangements and an estimated market participant weighted average cost of capital, which are considered Level 3 inputs.

As of December 31, 2024, the zilebesiran and vutrisiran funding obligations were accounted for as a derivative liability. We recorded $93.8 million within development derivative liability and $393.1 million within development derivative liability, net of current portion on our consolidated balance sheet. The change in fair value due to the remeasurement of the development derivative liability was recorded within other income (expense), net on our consolidated statements of operations and comprehensive income (loss) for the years ended December 31, 2024 and 2023.

As of December 31, 2024, the development derivative liability was classified as a Level 3 financial liability in the fair value hierarchy. The valuation method incorporated certain unobservable Level 3 key inputs including (i) the probability and timing of achieving stated development milestones to receive payments from Blackstone Life Sciences, (ii) the probability and timing of achieving regulatory approval and payments to Blackstone Life Sciences, (iii) an estimate of the amount and timing of the royalty payable on net sales of vutrisiran, assuming regulatory approval for ATTR-CM, (iv) our cost of borrowing (10%), and (v) Blackstone Life Sciences’ cost of borrowing (7%).

The following table presents the activity with respect to the development derivative liability, in thousands:

Amount received under the Development Funding Agreement 12,333

Amount paid under the Development Funding Agreement (21,125)

Loss recorded from change in fair value 170,770

Liability Related to the Sale of Future Royalties

In April 2020, we entered into a purchase and sale agreement, or Purchase Agreement, with BX Bodyguard Royalties L.P. (an affiliate of The Blackstone Group Inc.), or Blackstone Royalties, pursuant to which Blackstone Royalties acquired a

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percentage of royalties payable, or the Royalty Interest, initially set at 50% with respect to net sales by MDCO, its affiliates or sublicensees of inclisiran (or the branded drug product, Leqvio) and any other licensed products under the MDCO License Agreement, and 75% of the commercial milestone payments payable under the MDCO License Agreement, together with the Royalty Interest, the Purchased Interest. If Blackstone Royalties does not receive payments in respect to the Royalty Interest by December 31, 2029, equaling at least $1.00 billion, Blackstone Royalties will receive the Royalty Interest at 55% beginning on January 1, 2030. In consideration for the sale of the Purchased Interest, Blackstone Royalties paid us $1.00 billion.

Due to our continuing involvement and an obligation to repay Blackstone Royalties, we recorded the proceeds from this transaction as a debt, net of closing costs, on our consolidated balance sheets. The debt obligations to repay the Purchased Interest are accreted from the initial carrying amount to the total payment amount using the effective interest rate method over the life of the Purchase Agreement. The effective interest rate is determined based on the proceeds received and projections of the amounts and timing of the future cash flows. The accretion is recorded as interest expense in the consolidated statements of operations and comprehensive income (loss). As of December 31, 2025 and 2024, our estimate of this total interest expense resulted in an effective annual interest rate of 10% and 10%, respectively. These estimates contain assumptions that impact both the amount recorded at execution and the interest expense that will be recognized in future periods. We account for any royalties and commercial milestones due to us under the MDCO License Agreement as revenue on our consolidated statements of operations and comprehensive income (loss).

As payments are made to Blackstone Royalties, the balance of the liability is effectively repaid over the life of the Purchase Agreement. The exact timing and amount of repayment is likely to change each reporting period. A significant increase or decrease in Leqvio global net revenue will materially impact the liability, interest expense and the time period for repayment. At each balance sheet date, we assess the expected payments to Blackstone Royalties and we prospectively adjust the amortization of the liability and the related interest expense.

As of December 31, 2025 and 2024, the carrying value of the liability was $1.48 billion and $1.45 billion, net of closing costs of $8.3 million and $9.1 million, respectively. The carrying value of the liability approximates fair value as of December 31, 2025 and is based on our current estimates of future royalties expected to be paid to Blackstone Royalties over the life of the arrangement, which is considered a Level 3 input.

The following table shows the activity with respect to the liability, in thousands:

As of December 31, 2025 and 2024, we recorded $118.8 million and $112.1 million, respectively, within liabilities related to the sale of future royalties and development funding and $1.36 billion and $1.34 billion, respectively, within liabilities related to the sale of future royalties and development funding, net of current portion related to the Purchased Interest.

10. STOCKHOLDERS' EQUITY (DEFICIT)

Stock-Based Compensation

The following table summarizes stock-based compensation expenses included in operating costs and expenses:

Years Ended December 31,

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ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

ALNY US Equity☆

ALNY · 10-K · period ended 2025-12-31

ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

ITEM 7A. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

ALNY US Equity