What changed in this filing

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Item 8. Financial Statements and Supplementary Data

2026-02-12 compared with 2025-02-13 · 639 added, 442 removed, 916 unchanged (54% of the section changed)

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Consolidated Balance Sheets as of December 31, 202 5 and 202 4

Consolidated Statements of Operations and Comprehensive Loss for the Years Ended December 31, 202 4 , 202 3 and 202 2

Consolidated Statements of Operations and Comprehensive Income ( Loss ) for the Years Ended December 31, 20 25 , 202 4 and 202 3

Consolidated Statements of Stockholders’ Equity (Deficit) for the Years Ended December 31, 202 5 , 20 2 4 and 202 3

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We have audited the accompanying consolidated balance sheets of Alnylam Pharmaceuticals, Inc.

and its subsidiaries (the "Company") as of December 31, 2024 and 2023, and the related consolidated statements of operations and comprehensive loss, of stockholders’ equity (deficit) and of cash flows for each of the three years in the period ended December 31, 2024, including the related notes (collectively referred to as the "consolidated financial statements").

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).

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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.

Change in Accounting Principle

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

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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 and Commercial Milestones

As described in Notes 2 and 9 to the consolidated financial statements, the liability related to the sale of future royalties and the related interest expense are based on management’s current estimates of future royalties and commercial milestones expected to be paid over the life of the arrangement.

Interest on the liability related to the sale of future royalties will be recognized using the effective interest rate method, resulting in the recognition of interest expense.

Management periodically assesses the expected payments and to the extent the amount or timing of the future estimated payments is materially different than the previous estimates, management accounts for any such change by adjusting the liability related to the sale of future royalties and prospectively recognizing the related non-cash interest expense.

Management’s estimate of the amount of expected future payments to Blackstone over the life of the arrangement is based on the estimated global net sales of Leqvio.

The Company recorded a liability related to the sale of future royalties of $1.45 billion as of December 31, 2024 and recognized interest expense on the liability related to the sale of future royalties of $127.1 million for the year ended December 31, 2024.

The principal considerations for our determination that performing procedures relating to the liability related to the sale of future royalties and commercial milestones is a critical audit matter are the significant judgment by management when developing the estimate of the timing and amount of future royalties and commercial milestones to be paid.

This in turn led to a high degree of auditor judgment and effort in performing procedures and in evaluating audit evidence relating to management’s estimate of the expected future royalties and commercial milestones to be paid and the selection of third party data used to estimate global net sales of Leqvio.

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 for future royalties and commercial milestones, including controls over management’s process for developing the estimate of timing and amount of future royalties and commercial milestones to be paid.

These procedures also included, among others (i) testing management’s process for developing the estimate of timing and amount of future royalties and commercial milestones to be paid and (ii) evaluating the reasonableness of significant assumptions used by management when developing the estimate of expected future royalties and commercial milestones to be paid related to the selection of third party data used to estimate global net sales of Leqvio.

Evaluating management’s assumption related to the selection of third-party data used to estimate global net sales of Leqvio involved evaluating whether the assumptions used by management were reasonable considering consistency with industry data.

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

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Total assets $ 4,966,331 $ 4,239,983

LIABILITIES AND STOCKHOLDERS’ EQUITY (DEFICIT)

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:

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Deferred revenue 4,845 55,481

Liability related to the sale of future royalties 113,018 54,991

Liabilities related to the sale of future royalties and development funding

220,068 113,018

Development derivative liability

Total current liabilities 1,466,349 1,186,272

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225,087 229,541

Deferred revenue, net of current portion — 188,175

Convertible debt 1,007,784 1,024,621

Liability related to the sale of future royalties, net of current portion 1,334,353 1,322,248

Liabilities related to the sale of future royalties and development funding, net of current portion

1,470,341 1,334,353

Development derivative liability, net of current portion

Other liabilities 7,594 4,969

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Commitments and contingencies (Note 13)

Stockholders’ equity (deficit):

Stockholders' equity:

Preferred stock, $ 0.01 par value per share, 5,000 shares authorized and no shares issued and outstanding as of December 31, 2025 and December 31, 2024

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Accumulated deficit ( 6,702,524 ) ( 7,287,748 )

Total stockholders’ equity (deficit)

67,088 ( 220,644 )

Total liabilities and stockholders’ equity (deficit)

$ 4,239,983 $ 3,829,880

Total stockholders' equity 789,176 67,088

Total liabilities and stockholders' equity $ 4,966,331 $ 4,239,983

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

ALNYLAM PHARMACEUTICALS, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

(In thousands, except per share amounts)

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Total operating costs and expenses 3,212,359 2,425,128 2,110,467

Loss from operations ( 176,885 ) ( 282,175 ) ( 785,072 )

Other (expense) income:

Income (loss) from operations 501,578 ( 176,885 ) ( 282,175 )

Other expense:

Interest expense ( 252,627 ) ( 141,858 ) ( 121,221 )

Interest income 111,470 121,992 95,561

Other expense, net ( 180,624 ) ( 125,682 ) ( 134,175 )

Loss on the extinguishment of debt — — ( 76,586 )

Loss related to convertible debt

( 42,473 ) — —

Other income (expense), net 5,204 ( 180,624 ) ( 125,682 )

Total other expense, net ( 178,426 ) ( 200,490 ) ( 151,342 )

Loss before income taxes ( 377,375 ) ( 433,517 ) ( 1,126,993 )

Benefit from (provision for) income taxes 99,218 ( 6,725 ) ( 4,163 )

Net loss $ ( 278,157 ) $ ( 440,242 ) $ ( 1,131,156 )

Net loss per common share — basic and diluted $ ( 2.18 ) $ ( 3.52 ) $ ( 9.30 )

Weighted-average common shares used to compute basic and diluted net loss per common share 127,651 124,906 121,689

Statements of Comprehensive Loss

Net loss $ ( 278,157 ) $ ( 440,242 ) $ ( 1,131,156 )

Income (loss) before income taxes 323,152 ( 377,375 ) ( 433,517 )

(Provision for) benefit from income taxes ( 9,405 ) 99,218 ( 6,725 )

Net income (loss) $ 313,747 $ ( 278,157 ) $ ( 440,242 )

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 )

Weighted-average common shares — basic

131,004 127,651 124,906

Weighted-average common shares — diluted

134,684 127,651 124,906

Statements of Comprehensive Income (Loss)

Net income (loss) $ 313,747 $ ( 278,157 ) $ ( 440,242 )

Other comprehensive income (loss):

Unrealized (loss) gain on marketable securities ( 4 ) 11,018 ( 7,840 )

Foreign currency translation (loss) gain ( 9,643 ) 11,922 ( 5,274 )

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

Foreign currency translation gains (losses) 11,624 ( 9,643 ) 11,922

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

Total other comprehensive (loss) income ( 11,143 ) 21,279 ( 11,395 )

Comprehensive loss $ ( 289,300 ) $ ( 418,963 ) $ ( 1,142,551 )

Total other comprehensive income (loss) 14,421 ( 11,143 ) 21,279

Comprehensive income (loss) $ 328,168 $ ( 289,300 ) $ ( 418,963 )

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

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Common Stock Additional

Capital Accumulated

Comprehensive Loss

Deficit Total

Stockholders’

Equity (Deficit)

Capital Accumulated Other Comprehensive Loss Accumulated Deficit Total Stockholders' (Deficit) Equity

Shares Amount

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Stock-based compensation expense — — 225,865 — — 225,865

Purchase of capped calls related to convertible debt — — ( 118,611 ) — — ( 118,611 )

Other comprehensive loss — — — ( 11,395 ) — ( 11,395 )

Other comprehensive income — — — 21,279 — 21,279

Net loss — — — — ( 440,242 ) ( 440,242 )

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Stock-based compensation expense — — 275,317 — — 275,317

Other comprehensive income — — — 21,279 — 21,279

Other comprehensive loss — — — ( 11,143 ) — ( 11,143 )

Net loss — — — — ( 278,157 ) ( 278,157 )

Balance as of December 31, 2024 129,294 1,293 7,388,061 ( 34,518 ) ( 7,287,748 ) 67,088

Cumulative effect adjustment from adoption of ASU 2025-07

— — — — 271,477 271,477

Exercise of common stock options, net of tax withholdings 1,836 18 229,679 — — 229,697

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Stock-based compensation expense — — 352,745 — — 352,745

Other comprehensive loss — — — ( 11,143 ) — ( 11,143 )

Net loss — — — — ( 278,157 ) ( 278,157 )

Repurchase of 1.00 % Convertible Senior Notes due 2027

— — ( 445,185 ) — — ( 445,185 )

Purchase of capped calls related to 0.00 % Convertible Senior Notes due 2028

— — ( 35,311 ) — — ( 35,311 )

Other comprehensive income — — — 14,421 — 14,421

Net income — — — — 313,747 313,747

Balance as of December 31, 2025 132,376 $ 1,324 $ 7,510,473 $ ( 20,097 ) $ ( 6,702,524 ) $ 789,176

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Cash flows from operating activities:

Net loss $ ( 278,157 ) $ ( 440,242 ) $ ( 1,131,156 )

Non-cash adjustments to reconcile net loss to net cash (used in) provided by operating activities:

Net income (loss) $ 313,747 $ ( 278,157 ) $ ( 440,242 )

Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:

Depreciation and amortization 55,658 56,670 54,054

Non-cash interest expense on liability related to the sale of future royalties 127,133 106,554 104,200

Stock-based compensation 272,084 221,680 230,649

Realized and unrealized losses on marketable equity securities 3,022 16,944 33,312

Loss on extinguishment of debt — — 76,586

Non-cash interest expense on liabilities related to the sale of future royalties and development funding 238,399 127,133 106,554

Stock-based compensation expense 348,235 272,084 221,680

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

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Deferred revenue ( 50,635 ) ( 235,446 ) 55,022

Net cash (used in) provided by operating activities ( 8,312 ) 104,156 ( 541,274 )

Net cash provided by (used in) operating activities 524,080 ( 8,312 ) 104,156

Cash flows from investing activities:

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Other investing activities ( 2,150 ) ( 117 ) ( 4,438 )

Net cash (used in) provided by investing activities ( 116,840 ) ( 336,350 ) 169,354

Net cash provided by (used in) investing activities 436,329 ( 116,840 ) ( 336,350 )

Cash flows from financing activities:

Proceeds from issuance of 0.00 % Convertible Senior Notes due 2028, net

Purchases of capped calls related to 0.00 % Convertible Senior Notes due 2028

( 35,311 ) — —

Repayment of 1.00 % Convertible Senior Notes due 2027

( 1,154,913 ) — —

Payment of issuance costs for revolving credit agreement

( 2,414 ) — —

Proceeds from exercise of stock options and other types of equity, net 250,028 302,951 147,464

Proceeds from convertible debt, net — — 1,016,111

Purchases of capped calls related to convertible debt — — ( 118,611 )

Proceeds from liabilities related to the sale of future royalties and development funding 6,000 — —

Repayment of liabilities related to the sale of future royalties and development funding

( 14,272 ) — —

(Repayment of) proceeds from development derivative liability, net — ( 8,792 ) 24,667

Repayment of term loan facility — — ( 762,107 )

Net cash provided by financing activities 294,159 172,131 425,753

Net cash (used in) provided by financing activities ( 305,190 ) 294,159 172,131

Effect of exchange rate changes on cash, cash equivalents and restricted cash 34,936 ( 15,239 ) 6,391

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Cash paid for interest $ 218,707 $ 67,578 $ 32,118

Cash paid for income taxes $ 14,360 $ 6,021 $ 2,654

Operating lease right-of-use assets obtained in exchange for new operating lease liabilities $ 21,195 $ 9,309 $ 2,570

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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 commercial efforts, acquiring, filing and expanding intellectual property rights, recruiting management and technical staff, and raising capital.

In early 2021, we launched our Alnylam P 5 x25 strategy, which focuses on our planned transition to a top-tier biotech company by the end of 2025.

With Alnylam P 5 x25 , we aim to deliver transformative therapies across a broad range of disease areas and indications for patients around the world through sustainable innovation, while delivering exceptional financial performance.

As of December 31, 2024, we have five marketed products, including one product commercialized by a collaborator, and multiple late-stage investigational programs advancing towards potential commercialization.

We currently generate worldwide product revenues from four commercialized products, ONPATTRO, AMVUTTRA, GIVLAARI and OXLUMO, primarily in the United States, or U.S., and Europe.

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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

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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, liability related to the sale of future royalties, development derivative liability, income taxes, deferred tax asset valuation allowances, revenue recognition, research and development expenses, and stock-based compensation expense.

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.

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Changes in estimates are reflected in reported results in the period in which they become known.

Based on our current operating plan, we believe that our cash, cash equivalents and marketable securities as of December 31, 2024 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.

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

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As of December 31,

Novartis AG 23 % 18 %

Distributor A 45 % 16 %

Novartis AG * 23 %

Fair Value Measurements

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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 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 loss.

Realized gains and losses are determined using the specific identification method and are included in other income (expense), net.

We did not record any impairment charges related to our marketable debt securities during the years ended December 31, 2025, 2024 or 2023.

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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 expense, net on our consolidated statements of operations and comprehensive loss.

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

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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 billed and unbilled collaboration receivables and royalty receivables.

Accounts receivable, net on our consolidated balance sheets also includes collaboration receivables and royalty receivables.

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).

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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) 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 loss.

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.

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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 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.

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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 loss on a straight-line basis over the term of the lease.

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

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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 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.

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.

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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, 2024 and 2023, we had no t capitalized any costs to obtain any of our contracts.

As of December 31, 2025 and 2024, we had not capitalized any costs to obtain any of our contracts.

Net Product Revenues

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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 are subject to discount obligations under government programs, including Medicaid in the U.S.

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.

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.

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Our estimate for rebates is based on statutory discount rates, expected utilization or an estimated number of patients on treatment, as applicable.

Trade discounts and allowances :

We provide customary invoice discounts on product sales to our customers for prompt payment and we pay fees for distribution services, such as fees for certain data that customers provide to us.

We estimate our customers will earn these discounts and fees, and deduct these discounts and fees in full from gross product revenues and accounts receivable at the time we recognize the related revenues.

Product returns:

We offer customers product return rights if products are damaged, defective or expired, with “expired” defined within each customer agreement.

We estimate the amount of product that will be returned based on our sales history.

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,

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Other incentives:

Other incentives include customer discounts, fees, and co-payment assistance 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 we estimate the average co-payment assistance amounts for our products based on expected customer demographics.

We record any such amounts within accrued expenses on our consolidated balance sheets.

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

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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

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.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

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.

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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

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Advertising expenses were $ 36.0 million, $ 29.7 million and $ 12.4 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Liability Related to the Sale of Future Royalties

We account for the liability related to the sale of future royalties as a debt financing.

Interest on the liability related to the sale of future royalties is recognized using the effective interest rate method over the life of the related royalty stream.

The liability related to the sale of future royalties and the related interest expense are based on our current estimates of future royalties and commercial milestones expected to be paid over the life of the arrangement, which we determine by using third-party data to estimate Leqvio’s global net revenue.

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.

Development Derivative Liability

Development derivative liability is recorded at fair value based on the probability-weighted present value of the estimated cash flows pursuant to contractual terms of the funding agreement within accrued expenses or other liabilities on our consolidated balance sheets, depending on expected timing of our payments.

The liability is remeasured quarterly with any change in fair value recorded in other expense, net on the consolidated statements of operations and comprehensive loss.

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.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Comprehensive Loss

Comprehensive loss is comprised of net loss and certain changes in stockholders’ equity (deficit) that are excluded from net loss.

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 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.

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.

Net Income (Loss) per Common Share

We compute basic net income (loss) per common share by dividing net income (loss) by the weighted-average number of common shares outstanding.

Diluted net income per common share utilizing the treasury stock and if-converted methods is based upon the weighted-average number of common shares and dilutive potential common share equivalents outstanding during the period.

For periods in which we have generated a net loss, diluted net loss per common share is the same as basic net loss per common share, as the inclusion of potentially dilutive common shares would be anti-dilutive.

The following table sets forth the potential common shares (prior to consideration of the treasury stock or if-converted methods) excluded from the calculation of diluted net loss per common share because their inclusion would be anti-dilutive:

As of December 31,

(In thousands) 2024 2023 2022

Options to purchase common stock, inclusive of performance-based stock options 5,136 7,422 8,424

Unvested restricted common stock, inclusive of performance-based restricted common stock 2,679 2,058 1,487

Convertible debt 3,616 3,616 3,616

Total 11,431 13,096 13,527

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.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

(In thousands, except per share amounts)

Previously Reported Three Months Ended March 31, 2025 Adjusted Three Months Ended March 31, 2025

Previously Reported Six Months Ended June 30, 2025 Adjusted Six Months Ended June 30, 2025 Previously Reported Nine Months Ended September 30, 2025 Adjusted Nine Months Ended September 30, 2025

Interest expense

$ ( 38,646 ) $ ( 58,309 ) $ ( 78,892 ) $ ( 119,765 ) $ ( 123,290 ) $ ( 187,227 )

Other (expense) income, net

( 49,700 ) 9,191 ( 56,099 ) 18,051 ( 130,249 ) 8,564

Total other expense, net

( 59,673 ) ( 20,445 ) ( 78,832 ) ( 45,555 ) ( 207,845 ) ( 132,969 )

(Loss) income before income taxes

( 41,596 ) ( 2,368 ) ( 76,954 ) ( 43,677 ) 162,015 236,891

Net (loss) income

( 57,479 ) ( 18,251 ) ( 123,756 ) ( 90,479 ) 127,328 202,204

Net (loss) income per common share - basic

( 0.44 ) ( 0.14 ) ( 0.95 ) ( 0.70 ) 0.98 1.55

Net (loss) income per common share - diluted

( 0.44 ) ( 0.14 ) ( 0.95 ) ( 0.70 ) 0.95 1.51

Comprehensive (loss) income

$ ( 60,478 ) $ ( 21,250 ) $ ( 119,190 ) $ ( 85,913 ) $ 140,071 $ 214,947

Recent Accounting Pronouncements

In November 2024, the Financial Accounting Standards Board, or FASB, issued ASU 2024-04, Induced Conversions of Convertible Debt Instruments, 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.

The standard is effective for annual reporting periods beginning after December 15, 2025, and interim periods within those annual periods.

We are currently evaluating the impact of the standard on our consolidated financial statements and related disclosures.

In November 2024, the FASB issued ASU 2024-03, Disaggregation of Income Statement Expenses , 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.

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 this new standard.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures , which requires entities to disclose disaggregated information about their effective tax rate reconciliation as well as expanded information on income taxes paid by jurisdiction.

The disclosure requirements will be applied on a prospective basis, with the option to apply them retrospectively.

The standard is effective for fiscal years beginning after December 15, 2024, with early adoption permitted.

We are currently evaluating the disclosure requirements related to this new standard.

In November 2023, the FASB issued ASU 2023-07, Improvements to Reportable Segment Disclosures , which is intended to improve reportable segment disclosure requirements, primarily through additional disclosures about significant segment expenses.

The standard became effective for us in the fourth quarter of 2024.

Please refer to Note 16, Segment Information, for additional disclosures related to this new standard.

We are currently evaluating the disclosure requirements related to ASU 2024-03.

ALNYLAM PHARMACEUTICALS, INC.

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NET PRODUCT REVENUES

Net product revenues, classified based on the geographic region in which the product is sold, consist of the following:

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:

Years Ended December 31,

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Total 172,789 252,857 354,546

2,486,625 1,223,307 912,384

United States 205,715 165,373 141,954

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Total 191,437 167,050 109,839

499,924 422,921 329,090

Total net product revenues $ 2,986,549 $ 1,646,228 $ 1,241,474

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As of December 31, 2025

(In thousands) Chargebacks and Rebates Trade Discounts and Allowances Returns Reserve and Other Incentives Total

(In thousands) Chargebacks and Rebates

Other Incentives and Allowances

Beginning balance $ 350,908 $ 10,908 $ 361,816

Provision related to current period sales 779,332 90,435 869,767

Provision related to prior period sales

( 48,816 ) — ( 48,816 )

Credit or payments made during the period for current year sales ( 474,781 ) ( 65,454 ) ( 540,235 )

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As of December 31, 2024

(In thousands) Chargebacks and Rebates Trade Discounts and Allowances Returns Reserve and Other Incentives Total

(In thousands) Chargebacks and Rebates Other Incentives and Allowances

Beginning balance $ 325,672 $ 20,269 $ 345,941

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NET REVENUES FROM COLLABORATIONS

Net revenues from collaborations consist of the following:

Net revenues from collaborations consisted of the following:

Years Ended December 31,

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Other 44,528 8,175 21,188

Total $ 510,221 $ 546,185 $ 134,912

Total net revenues from collaborations

$ 553,366 $ 510,221 $ 546,185

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

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$ 4,845 $ 55,481

We recognized revenue of $ 266.5 million and $ 40.5 million in the years ended December 31, 2024 and 2023, respectively, that was included in the contract liability balance at the beginning of the applicable period.

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.

The following table provides research and development expenses incurred by type, for which we recognize net revenues, that are directly attributable to our collaboration agreements, by collaborator:

Years Ended December 31,

2024 2023 2022

(In thousands) Clinical Trial and Manufacturing External Services Other Clinical Trial and Manufacturing External Services Other Clinical Trial and Manufacturing External Services Other

$ 83,454 $ 7,250 $ 2,021 $ 39,320 $ 2,337 $ 2,963 $ — $ — $ —

Regeneron 41,209 14,366 16,084 38,220 5,836 33,388 12,926 2,141 27,935

Other 7,487 89 949 1,970 790 2,191 156 679 337

Total $ 132,150 $ 21,705 $ 19,054 $ 79,510 $ 8,963 $ 38,542 $ 13,082 $ 2,820 $ 28,272

The research and development expenses incurred for the agreements included in the table above consist of costs incurred for (i) clinical and manufacturing expenses, including manufacturing of clinical and preclinical product, (ii) external services, including consulting services and lab supplies and services, and (iii) other expenses, including professional services, facilities and overhead allocations, and a reasonable estimate of compensation and related costs as billed to our counterparties, for which

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

we recognize net revenues from collaborations.

For the years ended December 31, 2024, 2023 and 2022, we did not incur material selling, general and administrative expenses related to our collaboration agreements.

Product Collaborations

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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.

In connection with the Roche Agreement, Roche made an upfront, non-refundable payment to us of $ 310.0 million.

We lead the global clinical development for zilebesiran.

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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 on net sales of zilebesiran on a country-by-country basis during the applicable royalty term.

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

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

however, if the termination occurs after the achievement of the first development milestone and before the achievement of the third development milestone, Roche is required to pay us a termination fee of $ 50.0 million.

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.

We evaluated the Roche Agreement and concluded that the Roche Agreement had elements that were within the scope of ASC 606 and ASC 808.

As of the Effective Date, we identified the following promises in the Roche Agreement that were evaluated under the scope of ASC 606:

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The three performance obligations under the Roche Agreement are collectively referred to as the Roche Performance Obligations.

We also evaluated whether certain options outlined within the Roche Agreement represented material rights that would give rise to a performance obligation and concluded that none of the options convey a material right to Roche and therefore were not considered separate performance obligations within the Roche Agreement.

We assessed the above promises and 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.

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.

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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

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

platform and our utilization of third-party contract manufacturing organizations to manufacture zilebesiran.

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.

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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.

We determined the transaction price under ASC 606 at the inception of the Roche Agreement was $ 857.0 million, consisting of the $ 310.0 million upfront payment and $ 547.0 million additional variable consideration attributed to cost reimbursement from development and manufacturing services and technology transfer related to the Roche Performance Obligations.

We determined that any variable consideration related to development and regulatory milestones was deemed to be fully constrained at inception and therefore excluded from the initial transaction price due to the high degree of uncertainty and risk associated with these potential payments as we determined that we could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized would not occur.

We also determined that royalties and sales milestones relate solely to the licenses of intellectual property and were therefore excluded from the transaction price under the sales- or usage-based royalty exception of ASC 606.

We developed the estimated standalone selling price, at inception, for each of the Roche Performance Obligations with the objective of determining the price at which we would sell such an item if it were to be sold regularly on a standalone basis.

We developed the estimated standalone selling price for the Roche License Obligation primarily based on the probability-weighted present value of expected future cash flows associated with each underlying license or activity.

In developing such estimates, we applied judgment in determining the forecasted revenues, taking into consideration the applicable market conditions and relevant entity-specific factors, the probability of success, the time needed to develop zilebesiran and the discount rate.

We developed the estimated standalone selling price for the services and clinical supply included in the Roche Development Services Obligation and the Roche Technology Transfer Obligation primarily based on the level of efforts necessary to perform the service and the costs for full-time equivalent employees and expected resources to be committed plus a reasonable margin.

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 and allocating the variable amount of consideration entirely to the respective performance obligation is consistent with the allocation objective of ASC 606 when considering all of the performance obligations and payment terms in the contract.

We allocated the fixed upfront consideration of $ 310.0 million 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.

Therefore, allocating the fixed upfront consideration entirely to the Roche License Obligation is consistent with the allocation objective of ASC 606 when considering all of the performance obligations and payment terms in the contract.

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.

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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.

As of December 31, 2024, the total transaction price was determined to be $ 1.31 billion, an increase of $ 457.5 million from December 31, 2023.

The increase is due to the inclusion of the $ 65.0 million development milestone for the first patient dosed in the KARDIA-3 Phase 2 clinical trial in the transaction price as this milestone was achieved in 2024, as well as an increase in the level of effort necessary to perform the development services based on an updated development plan approved by the joint steering committee in October 2024 that expanded the size of the clinical trial for the development of zilebesiran.

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

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

The following tables provide a summary of the transaction price allocated to each performance obligation, in addition to revenue activity during the period, in thousands:

Transaction Price Allocated Revenue Recognized During

Performance Obligations As of December 31, 2024 Year Ended December 31, 2024 Year Ended December 31, 2023

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

1 unchanged sentence

Roche Technology Transfer Obligation

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

Years Ended December 31,

(In thousands)

2025 2024 2023

As of December 31, 2024, the aggregate amount of the transaction price allocated to the Roche Performance Obligations that was unsatisfied was $ 869.8 million, which is expected to be recognized through the term of the Roche Agreement as the services are performed.

Roche License Obligation $ 300,000 $ 65,000 $ 310,000

Roche Development Services Obligation 89,002 45,756 23,974

5,879 8,733 3,828

$ 394,881 $ 119,489 $ 337,802

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.

8 unchanged sentences

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 will provide manufacturing technology transfer services for cemdisiran to Regeneron.

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.

Under the terms of the Regeneron Collaboration, we are working exclusively with Regeneron to discover RNAi therapeutics for eye and CNS diseases for an initial research period of up to seven years , which we refer to as the Initial Research Term.

Regeneron has an option to extend the Initial Research Term (referred to as the Research Term Extension Period, and together with the Initial Research Term, the Research Term) for up to an additional five years , for a research term extension fee of $ 300.0 million.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

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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.

In addition, we and Regeneron are continuing to advance programs nominated during the Initial Research Term, and Regeneron has the right to nominate up to six additional targets per year during this period.

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.

If Regeneron exercises the option to extend the research term, Regeneron will retain the right to nominate up to six additional targets per year, and we will remain eligible to achieve $ 2.5 million in funding at each program initiation and an additional $ 2.5 million at each lead candidate identification during the Research Term Extension Period.

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.

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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 loss.

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.

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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 include:

Our performance obligations subsequent to the contract modification included:

(i) a research license and research services, collectively referred to as the Research Services Obligation;

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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 are the C5 Monotherapy Obligation and the Regeneron Technology Transfer Obligation.

The C5 Monotherapy Obligation is 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 is distinct as Regeneron can benefit from the cemdisiran monotherapy license transferred by us without the technology transfer given cemdisiran is in an advanced 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 represent a separate performance obligation.

As of the modification date, we established a new transaction price of $ 329.7 million, which represents the remaining deferred revenue as of the modification date of $ 260.3 million, variable consideration of $ 59.4 million, which relates to estimated reimbursements and milestones for the Research Services Obligation, C5 License Obligation and Regeneron Technology Transfer Obligation, and the $ 10.0 million upfront payment related to the Amended C5 License Agreement.

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

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

allocated the $ 59.4 million of variable consideration to the respective performance obligation as the terms of the variable payments relate specifically to our efforts to satisfy the performance obligations and allocating the variable amount of consideration entirely to the respective performance obligations is consistent with the allocation objective of ASC 606 when considering all of the performance obligations and payment terms in the contract.

We determined that any variable consideration related to regulatory milestones was deemed to be fully constrained and therefore excluded from the transaction price due to the high degree of uncertainty and risk associated with these potential payments and we determined that we could not assert that it was probable that a significant reversal in the amount of cumulative revenue recognized would not occur.

We determined that royalties and sales-based milestones relate solely to the license of intellectual property and were therefore excluded from the transaction price under the sales-or usage-based royalty exception of ASC 606.

As of the modification date, the transaction price for each performance obligation is as follows, in thousands:

Performance Obligations Standalone Selling Price Fixed Consideration

Variable Consideration Allocated

Transaction Price Allocated

Research Services Obligation $ 78,820 $ 45,469 $ 30,000 $ 75,469

C5 License Obligation $ 53,745 31,004 25,386 56,390

C5 Monotherapy Obligation

$ 332,000 191,520 — 191,520

Regeneron Technology Transfer Obligation

$ 4,000 2,307 4,000 6,307

$ 270,300 $ 59,386 $ 329,686

The fixed consideration was allocated to the obligations based on the relative estimated standalone selling prices of each obligation, over which management has applied significant judgment.

We developed the estimated standalone selling prices for the remaining Research Services Obligation, the remaining C5 License Obligation and the new Regeneron Technology Transfer Obligation primarily based on the levels of effort necessary to perform the services and the costs for full-time equivalent employees and expected resources to be committed plus a reasonable margin.

We developed the estimated standalone selling price for the cemdisiran monotherapy license granted under the C5 Monotherapy Obligation using the adjusted market assessment approach based on a discounted cash flow model that establishes the forecasted earnings during the commercial period for cemdisiran as a monotherapy adjusted for probability of success.

The transaction price of $ 191.5 million allocated to the C5 Monotherapy Obligation performance 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 and Regeneron could begin to use and benefit from the license as of that time.

A cumulative catch-up adjustment was recognized for the remaining Research Services and the remaining C5 License Obligation as of the contract modification date to reflect the measure of progress and transaction price following the modification.

The cumulative catch-up adjustment for the remaining Research Services and the remaining C5 License Obligation was not significant.

For the Research Services Obligation, the C5 License Obligation, and the Regeneron Technology Transfer 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 each obligation.

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, 2024, the total transaction price was determined to be $ 168.6 million.

Revenue recognized under this agreement is accounted for as collaboration revenue.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

The following tables provide a summary of the transaction price allocated, deferred revenue as of the balance sheet date, and revenue recognized during the period for the remaining unsatisfied performance obligations in thousands:

Transaction Price Allocated Deferred Revenue

Performance Obligations As of December 31, 2024 As of December 31, 2024 As of December 31, 2023

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,

(In thousands)

2025 2024 2023

Research Services Obligation $ 39,519 $ 39,097 $ 80,200

C5 License Obligation 21,635 38,341 ( 15,100 )

C5 Monotherapy Obligation

C5 Co-Co Obligation

Regeneron Technology Transfer Obligation

Other license programs

50,372 33,140 27,968

Total $ 113,957 $ 302,798 $ 100,468

Revenue Recognized During

Performance Obligations Year Ended December 31, 2024 Year Ended December 31, 2023 Year Ended December 31, 2022

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,

(In thousands)

Research Services Obligation $ 4,845 $ 41,156

C5 License Obligation — 12,018

Regeneron Technology Transfer Obligation

Total $ 4,845 $ 55,481

As of December 31, 2024, the aggregate amount of the transaction price allocated to the remaining Research Services Obligation, C5 License Obligation, and Regeneron Technology Transfer Obligation that was unsatisfied was $ 106.6 million, which is expected to be recognized through the term of the Regeneron Collaboration as the services are performed.

Deferred revenue related to the Regeneron Collaboration is classified as either current or non-current in the consolidated balance sheets based on the period the revenue is expected to be recognized.

2013 Collaboration with The Medicines Company

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.

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 Agreement.

We refer to this agreement, as amended through the date hereof, as the MDCO License

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

As of December 31, 2024, we have earned $ 180.0 million of milestones and 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.

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.

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.

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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.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

FAIR VALUE MEASUREMENTS

8 unchanged sentences

treasury securities 18,952 — 18,952 —

Commercial paper 22,709 — 22,709 —

government-sponsored enterprise securities 2,690 — 2,690 —

Commercial paper 1,995 — 1,995 —

Marketable debt securities:

treasury securities 653,341 — 653,341 —

government-sponsored enterprise securities 396,143 — 396,143 —

Corporate notes 333,241 — 333,241 —

government-sponsored enterprise securities 252,634 — 252,634 —

Commercial paper 7,017 — 7,017 —

Municipal securities 5,001 — 5,001 —

Marketable equity securities 8,156 8,156 — —

Restricted cash (money market funds) 917 917 — —

Total financial assets $ 1,416,233 $ 141,362 $ 1,274,871 $ —

Financial liabilities

Development derivative liability $ 486,919 $ — $ — $ 486,919

ALNYLAM PHARMACEUTICALS, INC.

9 unchanged sentences

Commercial paper 22,709 — 22,709 —

Corporate notes 762 — 762 —

government-sponsored enterprise securities 9,952 — 9,952 —

Marketable debt securities:

3 unchanged sentences

Commercial paper 35,408 — 35,408 —

Certificates of deposit 3,587 — 3,587 —

Municipal securities

5,003 — 5,003 —

Marketable equity securities 8,156 8,156 — —

4 unchanged sentences

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 in 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.

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.

MARKETABLE DEBT SECURITIES

4 unchanged sentences

treasury securities $ 670,566 $ 1,736 $ ( 9 ) $ 672,293

government-sponsored enterprise securities 405,890 575 ( 370 ) 406,095

Corporate notes 332,104 1,152 ( 15 ) 333,241

government-sponsored enterprise securities 254,829 559 ( 64 ) 255,324

Commercial paper 9,012 — — 9,012

10 unchanged sentences

Commercial paper 58,117 — — 58,117

Certificates of deposit 3,587 — — 3,587

Municipal securities 5,002 1 — 5,003

Total $ 1,787,465 $ 2,722 $ ( 1,178 ) $ 1,789,009

13 unchanged sentences

Total inventory $ 111,644 $ 115,376

As of December 31, 2024 and 2023, we had $ 36.9 million and $ 36.3 million of long-term inventory, respectively, included within other assets in our consolidated balance sheets as we anticipate it being consumed beyond our normal operating cycle.

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 consist of the following:

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

As of December 31,

10 unchanged sentences

accumulated depreciation ( 322,700 ) ( 270,364 )

Total $ 502,784 $ 526,057

Total property, plant and equipment, net

$ 513,147 $ 502,784

ALNYLAM PHARMACEUTICALS, INC.

1 unchanged sentence

Accrued Expenses

Accrued expenses consist of the following:

Accrued expenses consisted of the following:

As of December 31,

7 unchanged sentences

Other 25,572 29,375

Total $ 887,472 $ 713,013

Total accrued expenses

$ 1,080,197 $ 793,692

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 total of these amounts shown in the consolidated statements of cash flows:

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,

3 unchanged sentences

Total cash, cash equivalents, and restricted cash shown in the consolidated statements of cash flows $ 1,658,807 $ 968,652 $ 814,884

Accumulated Other Comprehensive (Loss) Income

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

Accumulated Other Comprehensive Loss

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

(In thousands) Loss on Investment in Joint Venture Defined Benefit Pension

9 unchanged sentences

— 117 ( 7 ) — 110

Net other comprehensive (loss) income

Net other comprehensive loss

— ( 1,496 ) ( 4 ) ( 9,643 ) ( 11,143 )

1 unchanged sentence

( 32,792 ) ( 4,249 ) 1,544 979 ( 34,518 )

Other comprehensive (loss) income before reclassifications

Other comprehensive income before reclassifications

— 531 3,353 11,624 15,508

Amounts reclassified from other comprehensive (loss) income

Amounts reclassified from other comprehensive income

— 450 ( 1,537 ) — ( 1,087 )

Net other comprehensive loss

Net other comprehensive income

— 981 1,816 11,624 14,421

1 unchanged sentence

$ ( 32,792 ) $ ( 3,268 ) $ 3,360 $ 12,603 $ ( 20,097 )

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

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).

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

CONVERTIBLE DEBT

CONVERTIBLE DEBT AND OTHER FINANCING

Convertible Senior Notes Due 2028

In 2022, we commenced a private offering of $ 900.0 million in aggregate principal amount of 1 % Convertible Senior Notes due 2027, or the Initial Notes.

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.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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 Indenture includes customary covenants and sets forth certain events of default after which the Notes may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving the Company after which the Notes become automatically due and payable.

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.

6 unchanged sentences

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 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 Notes will initially be 3.4941 shares of common stock per $1,000 principal amount of Notes, which is equivalent to an initial conversion price of approximately $ 286.20 per share of common stock.

The initial conversion price of the Notes represents a premium of approximately 35 % over the last reported sale price of common stock of $ 212.00 per share on September 12, 2022.

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.

We may not redeem the Notes prior to September 20, 2025.

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, as defined in the Indenture, 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 Notes to be repurchased plus accrued and unpaid interest.

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.

The conditions allowing holders of the Notes to convert were not met this quarter.

The Notes were issued at par.

As of December 31, 2024 and 2023, the Notes are classified as a long-term liability on the consolidated balance sheets and presented net of unamortized issuance costs of $ 10.4 million and $ 14.2 million, respectively.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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, 2024 and 2023, the estimated fair value of the Notes was approximately $ 1.11 billion and $ 1.02 billion, respectively.

The fair value was determined based on the last actively traded price per $100 of the Notes (Level 2) as of December 31, 2024 and 2023, respectively.

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 Initial Notes and the initial purchasers’ exercise of their option to purchase the Additional Notes, we entered into privately negotiated capped call transactions, or 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.

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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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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:

Carrying value as of January 1, 2025

Interest expense

Carrying value as of December 31, 2025

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:

Carrying value as of January 1, 2025

Interest expense

Amount received

Carrying value as of December 31, 2025

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:

Carrying value as of December 31, 2023

Amount received under the Development Funding Agreement

Amount paid under the Development Funding Agreement

Loss recorded from change in fair value

Carrying value as of December 31, 2024

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 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.

(an affiliate of The Blackstone Group Inc.), or Blackstone Royalties, pursuant to which Blackstone Royalties acquired a

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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 record the proceeds from this transaction as a debt, net of closing costs, on our consolidated balance sheets.

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 loss.

In order to determine the amortization of the liability related to the sale of future royalties, we are required to estimate the total amount of future payments to Blackstone Royalties over the life of the Purchase Agreement.

The $ 1.00 billion liability, recorded at execution of the agreement, will be accreted to the total of these royalty and commercial milestone payments as interest expense over the life of the Purchase Agreement.

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.

As payments are made to Blackstone Royalties, the balance of the liability will be effectively repaid over the life of the Purchase Agreement.

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 related to the sale of future royalties, interest expense and the time period for repayment.

We will periodically assess the expected payments to Blackstone Royalties and to the extent the amount or timing of such payments is materially different than our initial estimates, we will prospectively adjust the amortization of the liability related to the sale of future royalties and the related interest expense.

As of December 31, 2024 and 2023, the carrying value of the liability related to the sale of future royalties was $ 1.45 billion and $ 1.38 billion, net of closing costs of $ 9.1 million and $ 10.0 million, respectively.

The carrying value of the liability related to the sale of future royalties approximates fair value as of December 31, 2024 and is based on our current estimates of future royalties and commercial milestones expected to be paid to Blackstone Royalties over the life of the arrangement, which are considered Level 3 inputs.

The following table shows the activity with respect to the liability related to the sale of future royalties, in thousands:

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:

Carrying value as of December 31, 2023

Interest expense recognized 106,554

Interest expense

Payments ( 57,001 )

Carrying value as of December 31, 2024

Interest expense recognized 127,133

Interest expense

Payments ( 117,971 )

Carrying value as of December 31, 2025

DEVELOPMENT DERIVATIVE LIABILITY

In August 2020, we entered into a co-development agreement, referred to as the Funding Agreement, with BXLS V Bodyguard – PCP L.P.

As of December 31, 2024, 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.

Furthermore, Blackstone Life Sciences has the right, but is not obligated, to fund up to $ 54.0 million for development costs related to a Phase 3 clinical trial of zilebesiran.

The amount of funding ultimately provided by Blackstone Life Sciences for the Phase 3 clinical trial of zilebesiran is dependent on us achieving specified development milestones.

As 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 have agreed to pay Blackstone Life Sciences a 1 % royalty on net sales of AMVUTTRA (vutrisiran) for a 10-year term beginning upon the first

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

commercial sale following regulatory approval of vutrisiran for ATTR-cardiomyopathy, as well as fixed payments of up to 2.5 times their investment over a two-year period upon regulatory approval of vutrisiran for ATTR-cardiomyopathy in specified countries, unless vutrisiran is later withdrawn from the market following a mandatory recall.

As consideration for Blackstone Life Sciences’ funding for Phase 2 clinical development costs of zilebesiran, we have agreed to pay Blackstone Life Sciences fixed payments of up to 3.25 times their Phase 2 investment over a four-year period upon the successful completion of the Phase 2 clinical trial of zilebesiran, unless certain regulatory events affecting the continued development of zilebesiran occur.

In September 2023, we announced positive topline results from the KARDIA-1 Phase 2 clinical trial of zilebesiran, triggering the achievement of a 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 3 clinical development costs of zilebesiran, we have agreed to pay Blackstone Life Sciences fixed payments of up to 4.5 times their Phase 3 investment over a four-year period 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 Funding Agreement will be 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 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 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 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 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, or the royalty described above in the case of AMVUTTRA, should we obtain regulatory approval for zilebesiran or vutrisiran for ATTR amyloidosis with cardiomyopathy following termination.

We account for the Funding Agreement under ASC 815, Derivatives and Hedging , as a derivative liability, measured at fair value.

As of December 31, 2024 and 2023, we recorded $ 93.8 million and $ 21.1 million, respectively, within accrued expenses and $ 393.1 million and $ 303.8 million, respectively, within other liabilities on our consolidated balance sheets, based on expected timing of our payments to Blackstone Life Sciences.

The change in fair value due to the remeasurement of the development derivative liability is recorded within other expense, net on our consolidated statements of operations and comprehensive loss.

As of December 31, 2024 and 2023, the derivative liability is classified as a Level 3 financial liability in the fair value hierarchy.

The valuation method incorporates 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 AMVUTTRA, assuming regulatory approval for ATTR amyloidosis with cardiomyopathy, (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:

Carrying value as of December 31, 2022

Amount received under the Funding Agreement 24,667

Loss recorded from change in fair value

Carrying value as of December 31, 2023

Amount received under the Funding Agreement 12,333

Amount paid under the Funding Agreement

Loss recorded from change in fair value

Carrying value as of December 31, 2024

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

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.

STOCKHOLDERS' EQUITY (DEFICIT)

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Total $ 348,235 $ 272,084 $ 221,680

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

The following table summarizes stock-based compensation expense by type of award:

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Unrecognized Expense, Net of Estimated Forfeitures (in thousands) Weighted-average Recognition Period (in years)

Type of award:

Time-based restricted stock units $ 221,963 1.54

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Outstanding as of December 31, 2025 1,736 $ 219.38

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Performance-Based Restricted Stock Units

6 unchanged sentences

Outstanding as of December 31, 2025 779 $ 197.48

The performance-based restricted stock units granted during the years ended December 31, 2024 and 2023 will vest upon the later of the one-year anniversary of the date of grant and the achievement of specific clinical development, regulatory, commercial and/or financial performance events, as approved by our people, culture and compensation committee.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Certain performance-based restricted stock units will vest upon the three-year anniversary of the date of grant, with the number of shares vested dependent on the assessed level of achievement of specific clinical development, regulatory, commercial and/or financial performance events, as approved by our people, culture and compensation committee.

Certain performance-based restricted stock units will vest upon the later of the one-year anniversary of the date of grant and the achievement of specific clinical development, regulatory, commercial and/or financial performance events, as approved by our people, culture and compensation committee, with the number of shares vested established on the grant date.

Time-Based Stock Options

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We satisfy performance-based stock option exercises with newly issued shares of our common stock.

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Valuation Assumptions for Stock Options

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Treasury yield curve in effect at the time of grant.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

The following table summarizes the Black-Scholes valuation assumption inputs for employee stock options granted:

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5.1 - 7.0 years

Expected volatility 46 - 47 %

In May 2022, our stockholders approved the amendment and restatement of our 2018 Stock Incentive Plan, or, as amended, the Amended and Restated 2018 Plan, which increased the number of shares authorized for issuance thereunder by 6,000,000 shares.

The Amended and Restated 2018 Plan provides for the granting of stock options, restricted stock and restricted stock units (together, restricted stock awards), stock appreciation rights and other stock-based awards, and has a fungible share pool.

In May 2025, our stockholders approved the second amendment and restatement of our 2018 Stock Incentive Plan, or, the Second Amended and Restated 2018 Plan, which increased the number of shares authorized for issuance thereunder by 7,000,000 shares.

The Second Amended and Restated 2018 Plan provides for the granting of stock options, restricted stock and restricted stock units (together, restricted stock awards), stock appreciation rights and other stock-based awards, and has a fungible share pool.

Any award that is not a full value award is counted against the authorized share limits specified as one share for each share of common stock subject to the award, and all full value awards, defined as restricted stock awards or other stock-based awards, are counted as one and a half shares for each one share of common stock subject to such full value award.

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Expected volatility 38 % - 48 %

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Preferred Stock

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As of December 31, 2025 and 2024, there were no shares of preferred stock outstanding.

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NET INCOME (LOSS) PER COMMON SHARE

We compute basic net income (loss) per common share by dividing net income (loss) by the weighted-average number of common shares outstanding.

The following table sets forth the computation of basic and diluted net income (loss) per share:

Years Ended December 31,

(In thousands, except per share amounts)

2025 2024 2023

Net income (loss), as reported $ 313,747 $ ( 278,157 ) $ ( 440,242 )

Adjustment for the elimination of interest expense on the convertible debt

Net income (loss), for use in diluted income per share $ 313,747 $ ( 278,157 ) $ ( 440,242 )

Weighted-average common shares — basic

131,004 127,651 124,906

Effect of dilutive securities:

Options to purchase common stock, inclusive of performance-based stock options 2,265 — —

Restricted stock units, inclusive of performance-based restricted stock units

Employee stock purchase program

Weighted-average common shares — diluted

134,684 127,651 124,906

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 )

The following table sets forth the potential common shares excluded from the calculation of diluted net loss per common share because their inclusion would be anti-dilutive:

Years Ended December 31,

(In thousands) 2025 2024 2023

Options to purchase common stock, inclusive of performance-based stock options 118 5,136 7,422

Restricted stock units, inclusive of performance-based restricted stock units

7 2,679 2,058

Convertible debt 3,238 3,616 3,616

Total 3,363 11,431 13,096

The effect of the 2022 Capped Call Transactions and 2025 Capped Call Transactions was also excluded from the calculation of diluted net income (loss) per share because exercise of these transactions would potentially reduce the number of shares of our common stock outstanding and, therefore, would be anti-dilutive.

In the years ended December 31, 2025 and 2024, we excluded 6.2 million and 5.2 million shares, respectively, related to these transactions.

Overview of Significant Leases

We lease three facilities for office and laboratory space in Cambridge, Massachusetts that represent substantially all of our significant lease obligations.

An overview of these significant leases are as follows:

We lease two facilities for office and laboratory space in Cambridge, Massachusetts that represent substantially all of our significant lease obligations.

An overview of these significant leases is as follows:

675 West Kendall Street

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The lease commenced on May 1, 2018 and monthly rent payments became due commencing on February 1, 2019 upon substantial completion of the building improvements, and continue for 15 years, with options to renew for two five-year terms each.

We are not reasonably certain to exercise these options, therefore, the periods covered by the options were not included in the lease term as of December 31, 2024 or 2023.

We are not reasonably

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certain to exercise these options, therefore, the periods covered by the options were not included in the lease term as of December 31, 2025 or 2024.

300 Third Street

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We are not reasonably certain to exercise these options, therefore, the periods covered by the options were not included in the lease term as of December 31, 2025 or 2024.

101 Main Street

We lease office space on several floors at 101 Main Street, Cambridge, Massachusetts under non-cancelable real property lease agreements by and between us and RREEF America REIT II CORP.

PPP, or RREEF, entered into in 2015.

In 2020, we amended our lease agreement, pursuant to which the term of the lease with respect to two floors was extended for an additional five years , through June 2026, with an option to renew for one five-year term.

We are not reasonably certain to exercise this option, therefore, the period covered by the option was not included in the lease term as of December 31, 2024 or 2023.

In addition, we had a separate lease agreement for an additional floor at 101 Main Street, which expired in March 2024.

Other Lease Disclosures

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Operating lease cost

$ 49,816 $ 45,986 $ 46,367

Variable lease cost 24,551 19,757 20,278

Total $ 74,367 $ 65,743 $ 66,645

Our variable lease cost for the years ended December 31, 2025, 2024 and 2023 primarily related to operating expenses, taxes and insurance associated with our real estate leases.

Short-term lease costs were not material for the years ended December 31, 2025, 2024 and 2023.

Net cash paid for the amounts included in the measurement of the operating lease liabilities in our consolidated balance sheets and presented within operating activities in our consolidated statements of cash flows was $ 50.7 million, $ 51.0 million and $ 46.5 million for the years ended December 31, 2025, 2024 and 2023, respectively.

The weighted-average remaining lease term and weighted-average discount rate for all leases as of December 31, 2024 was eight years and 8 %, respectively, and as of December 31, 2023 was nine years and 8 %, respectively.

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The weighted-average remaining lease term and weighted-average discount rate for all leases as of December 31, 2025 was 8 years and 8 %, respectively, and as of December 31, 2024 was 8 years and 8 %, respectively.

Future lease payments for non-cancellable operating leases and a reconciliation to the carrying amount of the operating lease liabilities presented in the consolidated balance sheet as of December 31, 2025 were as follows, in thousands:

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Total discounted lease liability $ 270,605

Current operating lease liabilities

Non-current operating lease liabilities

Operating lease liabilities

Operating lease liabilities, net of current portion 225,087

Total $ 270,605

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

COMMITMENTS AND CONTINGENCIES

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Legal Matters

From time to time, we may be a party to litigation, arbitration or other legal proceedings in the course of our business, including the matters described below.

The claims and legal proceedings in which we could be involved include challenges to the scope, validity or enforceability of patents relating to our products or product candidates, and challenges by us to the scope, validity or enforceability of the patents held by others.

These include claims by third parties that we infringe their patents or breach our license or other agreements with such third parties.

From time to time, we may be a party to litigation, arbitration or other legal proceedings in the ordinary course of our business activities, including the following types of matters which are common to companies in our industry:

• Patent litigation, which typically involves challenges to the coverage and/or validity of patents on various products or product candidates, processes or dosage forms.

An adverse outcome could result in loss of patent protection for a product or product candidates, a significant loss of revenues from a product or impairment of the value of associated assets.

• Product liability and other product-related litigation related to our products, which could include personal injury, consumer fraud, off-label promotion, securities, antitrust and breach of contract claims, among others, and often involves highly complex issues relating to medical causation, label warnings and reliance on those warnings, scientific evidence and findings, actual, provable injury and other matters.

• Commercial and other asserted or unasserted matters, which can include acquisition-, licensing-, intellectual property-, collaboration- or co-promotion-related and product-pricing claims and environmental claims and proceedings, which can involve complexities that will vary from matter to matter.

• Government investigations, which often are related to the extensive regulation of pharmaceutical companies by national, state and local government agencies in the U.S.

and in other jurisdictions.

The outcome of any such legal proceedings, regardless of the merits, is inherently uncertain.

In addition, litigation and related matters are costly and may divert the attention of our management and other resources that would otherwise be engaged in other activities.

If we were unable to prevail in any such legal proceedings, our business, results of operations, liquidity and financial condition could be adversely affected.

Our accounting policy for accrual of legal costs is to recognize such expenses as incurred.

Patent Infringement Lawsuits

If we were unable to prevail in any such legal proceedings, it could have a materially adverse effect on our business, results of operations, liquidity and financial condition.

If we determine that it is probable that future expenditures will be made for a particular matter and such expenditures can be reasonably estimated, we accrue a loss contingency based on our best estimate of the probable range of loss.

We accrue the minimum amount within the probable range of loss if no amount within the range is more likely than another.

If we determine that future expenditures are not probable, or probable but not reasonably estimated, we do not accrue a loss contingency.

If we determine that a material loss is reasonably possible and the range of loss can be estimated, we disclose the possible range of loss.

On a quarterly basis, we evaluate developments with these claims and legal proceedings that could result in a loss contingency accrual, or an increase or decrease to a previously accrued loss contingency.

There were no material loss contingencies accrued as of December 31, 2025 or 2024.

Patent Litigations

In March 2022, we filed separate lawsuits in the U.S.

District Court for the District of Delaware against (1) Pfizer, Inc.

District Court for the District of Delaware, or the District Court, against (1) Moderna, Inc.

and its subsidiaries ModernaTX, Inc.

and Moderna US, Inc., collectively referred to as Moderna, which we refer to as the Moderna lawsuit, and (2) Pfizer, Inc.

and its subsidiary Pharmacia & Upjohn Co.

LLC, collectively referred to as Pfizer, and (2) Moderna, Inc.

and its subsidiaries ModernaTX, Inc., and Moderna US, Inc., collectively referred to as Moderna, seeking damages for infringement of U.S.

11,246,933, or ‘933 Patent, in Pfizer’s and Moderna’s manufacture and sale of their messenger RNA, or mRNA, COVID-19 vaccines.

The patent relates to the Company’s biodegradable cationic lipids that are foundational to the success of the mRNA COVID-19 vaccines.

We are seeking judgment that each of Pfizer and Moderna is infringing the ‘933 Patent, as well as damages adequate to compensate for the infringement, but in no event less than a reasonable royalty for the unlicensed uses made of our patented lipids by Pfizer and Moderna, together with interest and costs as may be awarded by the court.

As stated in the filed complaints, we are not seeking injunctive relief in these lawsuits.

On May 23, 2022, Moderna filed a partial motion to dismiss, asserting an affirmative defense under Section 1498(a).

We responded on May 27, 2022, opposing their motion arguing Moderna had significant non-government sales and the government contract ended in April 2022.

Moderna responded on June 13, 2022, requesting a partial motion to dismiss those claims for sales under Section 1498(a).

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

On May 27, 2022, Pfizer filed an answer to our complaint, denying the allegations, and asserting invalidity and non-infringement defenses.

In addition, Pfizer added BioNTech SE to the suit and added counter-claims seeking a declaratory judgment that our patent is invalid and a second claim alleging that our patent is invalid due to patent misuse.

We responded on June 10, 2022, with substantive arguments as to the validity of our claims and the lack of merit of their patent misuse claim.

On July 12, 2022, we filed an additional lawsuit against each of Pfizer and Moderna seeking damages for infringement of U.S.

11,382,979, or ‘979 patent, in Pfizer’s and Moderna’s manufacture and sale of their mRNA COVID-19 vaccines.

The parties agreed to combine the two patents in one lawsuit, separately against each of Moderna and Pfizer/BioNTech.

On February 8, 2023, we received notification from the U.S.

Patent Office that a third patent would issue on February 28, 2023, as U.S.

11,590,229, or ‘229 patent, which we also believe Pfizer and Moderna’s COVID-19 vaccines infringe upon.

On February 15, 2023, we filed a motion with the court to add this patent to the existing cases against Pfizer and Moderna, and on April 26, 2023, the court held a hearing and denied Moderna’s partial motion to dismiss those claims for sales under Section 1498(a), our motion to add the ‘229 patent to the then current lawsuits as well as a motion filed by Moderna to add certain invalidity arguments made by Pfizer in our case to supplement Moderna’s invalidity arguments previously made.

On May 26, 2023, we filed additional lawsuits against Pfizer and Moderna in Delaware seeking damages for infringing the ‘229 patent.

In addition to this patent, we also alleged infringement of U.S.

11,633,479, or the ‘479 patent, and 11,633,480 against both Pfizer and Moderna and of U.S.

11,612,657 against Pfizer only.

On August 9, 2023, a Markman hearing was held in the U.S.

District Court for the District of Delaware to consider the meaning of three disputed terms as used in the ’933 and ’979 patents.

On August 21, 2023, the court issued an order construing two of the three terms, and deferred a ruling on the third term pending an evidentiary hearing, which was held on January 4, 2024, with the final ruling deferred pending the outcome of an additional evidentiary hearing, which was held on July 12, 2024, followed by an additional evidentiary hearing, which was held on September 19, 2024, at which time the court construed the final claim term narrowly.

Following the August 21, 2023 order, we and Moderna jointly agreed to final judgment of non-infringement of two of our patents, and such judgment was entered by the court on August 30, 2023.

On September 7, 2023, we appealed the claim construction ruling to the Court of Appeals for the Federal Circuit in the initial lawsuit against Moderna.

The claim construction ruling initially did not affect one of the patents in the lawsuit filed against Moderna on May 26, 2023, but following a hearing held on August 15, 2024, on September 10, 2024 the court entered a ruling in the same manner as in the other earlier case and on October 2, 2024, we and Moderna jointly agreed to a final judgment of non-infringement of the ‘479 patent while preserving all rights to appeal.

On October 16, 2024, Moderna filed a motion seeking recovery of fees incurred by them from the time we agreed to a judgment of non-infringement in the first case until the time we agreed to a judgment of non-infringement in the second case, which period runs from approximately September 2023 to October 2024.

We opposed the motion in a reply filed on November 6, 2024.

The court has not yet ruled on the motion.

In light of the early stage of this matter, a loss is not probable or reasonably estimable at this time.

The two separate suits against Pfizer are ongoing and in September 2023, we and Pfizer agreed to consolidate the 2022 and 2023 lawsuits into one case with a trial date set for July 7, 2025.

On July 12, 2024, Acuitas Therapeutics, Inc., or Acuitas, filed a declaratory judgment action against us in the U.S.

District Court for the District of Delaware, seeking a judgment adding certain Acuitas employees as co-inventors on the patents we have asserted against Pfizer/BioNTech and Moderna in our lawsuits.

LLC, collectively referred to as Pfizer, which we refer to as the Pfizer lawsuit, seeking damages for patent infringement in Moderna’s and Pfizer’s manufacture and sale of their messenger RNA COVID-19 vaccines.

In May 2022, Pfizer added BioNTech SE to the Pfizer lawsuit.

In August 2025, we and Moderna settled all claims between the parties in the Moderna lawsuit, and in September 2025, we and Pfizer settled all claims between the parties in the Pfizer lawsuit.

On July 12, 2024, Acuitas Therapeutics, Inc., or Acuitas, filed a declaratory judgment action against us in the District Court, seeking a judgment adding certain Acuitas employees as co-inventors on the patents we have asserted against Pfizer/BioNTech and Moderna in our lawsuits.

On September 19, 2024, we filed a motion to dismiss, arguing Acuitas did not have standing to sue and failed to state a claim upon which relief could be granted.

The court has not yet ruled on our motion.

On December 12, 2024, The Board of Regents of the University of Texas System filed a lawsuit in the United States District Court for the Western District of Texas, alleging that we infringe U.S.

On July 1, 2025, the District Court granted our motion to dismiss the complaint without prejudice, finding that the plaintiffs had failed to plead facts sufficient to establish standing.

On December 12, 2024, The Board of Regents of the University of Texas System filed a lawsuit in the U.S.

District Court for the Western District of Texas, or the Texas District Court, alleging that we infringe U.S.

8,895,717 by making, using and commercializing ONPATTRO in the U.S.

On February 5, 2025, we filed a motion to dismiss the case for improper venue and an alternative motion to transfer the case to the United States District Court for the District of Massachusetts if the dismissal is not granted.

The court has not yet ruled on these motions.

In light of the early stage of this matter, a loss is not probable or reasonably estimable at this time.

Indemnifications

On February 5, 2025, we filed a motion to dismiss the case for improper

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

venue and an alternative motion to transfer the case to the U.S.

District Court for the District of Massachusetts if the dismissal is not granted.

On July 2, 2025, the Texas District Court denied the motion to dismiss and to transfer the case without prejudice, and we filed a renewed motion to dismiss and to transfer the case on September 24, 2025.

On December 15, 2025, the court granted in part and denied in part our motion to dismiss and ordered the case transferred to the U.S.

District Court for the District of Massachusetts after determining that venue was improper in the Western District of Texas.

Government Investigation

In October 2025, we received a subpoena from the U.S.

Attorney’s Office for the District of Massachusetts seeking documents pertaining to our government price reporting for AMVUTTRA, ONPATTRO, OXLUMO and GIVLAARI, including certain fee and discount arrangements with distributors, and certain other related documents and communications.

We are producing records responsive to the subpoena.

Indemnification Obligations

In connection with license agreements we may enter with companies to obtain rights to intellectual property, we may be required to indemnify such companies for certain damages arising in connection with the intellectual property rights licensed under the agreements.

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We are also a party to a number of agreements entered into in the ordinary course of business, which contain typical provisions that obligate us to indemnify the other parties to such agreements upon the occurrence of certain events, including litigation or other legal proceedings.

In addition, we have agreed to indemnify our officers and directors for expenses, judgments, fines, penalties, excise taxes, and settlement amounts paid in connection with any threatened,

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

pending or completed litigation proceedings, in which an officer or director was, is or will be involved as a party, on account of such person’s status as an officer or director, or by reason of any action taken by the officer or director while acting in such capacity, subject to certain limitations.

In addition, we have agreed to indemnify our officers and directors for expenses, judgments, fines, penalties, excise taxes, and settlement amounts paid in connection with any threatened, pending or completed litigation proceedings, in which an officer or director was, is or will be involved as a party, on account of such person’s status as an officer or director, or by reason of any action taken by the officer or director while acting in such capacity, subject to certain limitations.

These indemnification costs are charged to selling, general and administrative expense.

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We have reviewed the estimated aggregate fair value of our potential liabilities under all such indemnification provisions and have not recorded any related liability as of December 31, 2025 or 2024.

The domestic and foreign components of loss before income taxes are as follows:

The domestic and foreign components of income (loss) before income taxes were as follows:

Years Ended December 31,

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Foreign 304,852 194,551 16,794

Loss before income taxes $ ( 377,375 ) $ ( 433,517 ) $ ( 1,126,993 )

Income (loss) before income taxes

$ 323,152 $ ( 377,375 ) $ ( 433,517 )

During the year ended December 31, 2025, our foreign income of $ 304.9 million primarily relates to income generated in Switzerland.

Our Switzerland foreign income was predominately generated in the second half of 2024 due to growth from sales of AMVUTTRA driven by increased patient demand.

The benefit from (provision for) income taxes consisted of the following:

The (provision for) benefit from income taxes consisted of the following:

Years Ended December 31,

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Current provision:

Domestic $ ( 1,600 ) $ ( 4,022 ) $ —

$ ( 1,934 ) $ ( 1,600 ) $ ( 4,022 )

Foreign ( 9,669 ) ( 5,944 ) ( 3,416 )

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Total deferred benefit 2,198 106,762 713

Total benefit from (provision for) income taxes

Total (provision for) benefit from income taxes

$ ( 9,405 ) $ 99,218 $ ( 6,725 )

During the year ended December 31, 2024, we recorded a net benefit from income taxes of $ 99.2 million.

This is primarily comprised of $ 106.8 million of foreign deferred benefit, partially offset by $ 1.6 million of domestic state current provision and $ 5.9 million of foreign current provision.

During the year ended December 31, 2025, we recorded a provision for income taxes of $ 9.4 million.

This is comprised of $ 2.2 million of foreign deferred benefit, $ 1.9 million of domestic state current provision and $ 9.7 million of foreign current provision.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

As further described in Note 2, Summary of Significant Accounting Policies, we have elected to prospectively adopt the guidance in ASU 2023-09.

The following table is a reconciliation of our effective income tax rate to the statutory federal income tax rate for the year ended December 31, 2025 in accordance with the guidance in ASU 2023-09:

(In thousands) Year Ended December 31, 2025

federal statutory rate 21.0 % $ ( 67,861 )

State taxes, net of federal effect (1)

( 0.7 ) 2,103

Foreign tax effects

Statutory tax rate difference between Switzerland and United States

( 11.1 ) 35,749

Statutory permanent item

( 1.5 ) 4,932

Favorable tax ruling

( 6.4 ) 20,576

Canton taxes, Zug

Other foreign jurisdictions

1.2 ( 3,706 )

Effect of cross-border tax laws

Global Intangible Low-Taxed Income

26.7 ( 86,241 )

Subpart F Income 0.2 ( 752 )

Research and development credit

( 8.6 ) 27,654

Orphan drug credit

( 10.9 ) 35,115

Changes in valuation allowances 2.9 ( 9,373 )

Nontaxable or nondeductible items

Stock-based compensation expense

( 28.1 ) 90,695

Nondeductible officers compensation

10.2 ( 32,802 )

Loss related to convertible debt

2.8 ( 8,919 )

0.7 ( 2,153 )

Changes in unrecognized tax benefits 5.9 ( 18,993 )

( 1.3 ) 4,114

Effective income tax rate 2.9 % $ ( 9,405 )

(1) State taxes in Kentucky and Massachusetts made up the majority of the tax effect in this category.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

The following table is a reconciliation of our effective income tax rate to the statutory federal income tax rate for the years ended December 31, 2024 and 2023 in accordance with the guidance prior to the adoption of ASU 2023-09:

Years Ended December 31,

(In thousands) 2024 2023

federal statutory rate 21.0 % 21.0 %

State taxes, net of federal effect

Stock-based compensation expense

Tax credits 7.5 6.7

Nondeductible compensation ( 3.8 ) ( 3.0 )

Other permanent items ( 1.8 ) 0.8

Foreign rate differential 2.7 ( 0.7 )

Bermuda tax law enactment — 85.9

Internal reorganization of certain intellectual property rights ( 10.5 ) 12.6

Other ( 1.2 ) 1.7

Uncertain tax position reserve ( 14.3 ) —

Revaluation of deferred taxes due to rate change

Valuation allowance 7.6 ( 144.1 )

Effective income tax rate 26.3 % ( 1.5 ) %

The amounts of income tax related taxes paid, net of refunds received were as follows:

(In thousands) Year Ended December 31, 2025

Income taxes, net of amounts refunded

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Deferred income taxes reflect the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes.

We establish a valuation allowance when uncertainty exists as to whether all or a portion of the net deferred tax assets will be realized.

Components of the net deferred tax assets are as follows:

Components of the net deferred tax assets were as follows:

As of December 31,

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Research and development and other credit carryforwards 452,264 391,642

Sale of future royalties 378,657 353,974

Change in fair value of development derivative liability

Liabilities related to the sale of future royalties and development funding

426,826 378,657

Change in fair value of development derivative liability — 107,797

Operating lease liabilities

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$ 125,975 $ 116,863

Our effective income tax rate differs from the statutory federal income tax rate, as follows:

Years Ended December 31,

(In thousands) 2024 2023 2022

federal statutory rate 21.0 % 21.0 % 21.0 %

State taxes, net of federal effect 10.1 8.6 6.0

Stock-based compensation 9.6 3.9 4.4

Tax credits 7.5 6.7 2.7

Nondeductible compensation ( 3.8 ) ( 3.0 ) —

Other permanent items ( 1.8 ) 0.8 ( 1.5 )

Foreign rate differential 2.7 ( 0.7 ) ( 0.5 )

Bermuda tax law enactment — 85.9 —

Internal reorganization of certain intellectual property rights ( 10.5 ) 12.6 —

Other ( 1.2 ) 1.7 ( 0.8 )

Uncertain tax position reserve ( 14.3 ) — —

Revaluation of deferred taxes due to rate change

( 0.6 ) 5.1 ( 0.4 )

Valuation allowance 7.6 ( 144.1 ) ( 31.3 )

Effective income tax rate 26.3 % ( 1.5 ) % ( 0.4 ) %

On July 4, 2025, President Trump signed H.R.

1, the “One Big Beautiful Bill Act,” or the Act, into law.

The legislation includes several changes to federal tax law that are designed to allow for more favorable deductibility of certain business expenses and more favorable rules for determining the limitation on business interest expense.

The Act includes certain changes to the U.S.

taxation of foreign activity, including changes to foreign tax credits, global intangible low-taxed income, foreign-derived intangible income, and base erosion and anti-abuse tax, among other changes.

These changes are generally effective for tax years beginning after December 31, 2025, except for changes related to the immediate expensing of research and development expenditures and the reinstatement of 100% bonus depreciation, which were retroactively effective for tax years beginning after December 31, 2024 and for property placed in service after January 19, 2025, respectively.

The changes that were retroactively enacted were reflected in the income tax provision for the year ended December 31, 2025 and did not have a material effect on our financial statements.

On December 27, 2023, the Government of Bermuda enacted the Corporate Income Tax Act of 2023, or Corporate Income Tax Act, which introduces a corporate income tax regime in Bermuda with a statutory tax rate of 15% effective January 1, 2025.

Companies are not subject to income tax in Bermuda prior to this change and with the transition into the Corporate Income Tax Act there is an economic transition adjustment that requires the tax basis of certain Bermudian assets to be established at fair market value.

Upon the enactment of the Corporate Income Tax Act, we determined the fair market value of our identifiable intangible assets in Bermuda and recognized a deferred tax asset in our consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

recorded a full valuation allowance against this deferred tax asset as we have generated historical losses and expect to generate future losses.

We recorded a full valuation allowance against this deferred tax asset as we had generated historical losses and expected to generate future losses.

In the year ended December 31, 2024, we transferred the identifiable intangible assets in Bermuda to Switzerland.

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After assessing both the positive evidence and negative evidence, we determined it was more likely than not that certain Switzerland deferred tax assets would be realized in the future and released the associated valuation allowance during the year ended December 31, 2024, which resulted in an income tax benefit of $ 108.0 million.

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

During the year ended December 31, 2025, we continued to maintain a valuation allowance on certain Switzerland deferred tax assets that may not be realized in future periods.

As of December 31, 2025, we maintained a full valuation allowance against our U.S.

deferred tax assets.

We continue to maintain a valuation allowance on our U.S.

deferred tax assets because we have a history of cumulative losses.

On a quarterly basis, we reassess the valuation of our U.S.

deferred income tax assets weighing positive and negative evidence to assess the recoverability of the deferred tax assets.

Based on our recent financial performance and our future projections, we could potentially 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.

The valuation allowance decreased by $ 56.6 million as of December 31, 2025 compared to December 31, 2024, primarily as a result of a change in accounting method that was set up through equity in the amount of $ 71.4 million offset with an increase to the valuation allowance due to additional tax attributes generated of $ 14.8 million.

The valuation allowance decreased by $ 28.5 million as of December 31, 2024 compared to December 31, 2023, primarily as a result of the release of the valuation allowance on certain Switzerland deferred tax assets, which primarily consisted of the tax basis in intellectual property transferred from Bermuda and net operating losses, offset by an increase to the valuation allowance due to additional net operating losses in the U.S.

The valuation allowance increased by $ 623.0 million as of December 31, 2023 compared to December 31, 2022, primarily due to capitalized research and development costs and internally developed intellectual property.

As of December 31, 2025, we had federal and state net operating loss carryforwards, or NOLs, of $ 3.23 billion and $ 3.70 billion, respectively, to reduce future taxable income.

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Our reserves related to income taxes are based on a determination of whether, and how much of, a tax benefit taken by us in our tax filings or positions is more likely than not to be realized and ultimately sustained upon challenge by a taxing authority based upon its technical merits and subject to certain recognition and measurement criteria.

As of December 31, 2023, we did not have any material gross unrecognized tax benefits related to income tax reserves.

As of December 31, 2024, we have certain gross unrecognized tax benefits related to income tax reserves primarily related to federal and state research and orphan drug credit carryforwards of $ 53.1 million, of which $ 48.5 million relate to positions taken in prior years and $ 4.6 million relate to current year positions.

As of December 31, 2024, we had gross unrecognized tax benefits related to income tax reserves of $ 59.4 million primarily related to federal and state research and orphan drug credit carryforwards.

As of December 31, 2025, we had gross unrecognized tax benefits related to income tax reserves primarily related to federal and state research and orphan drug credit carryforwards of $ 78.0 million, of which $ 10.5 million relate to current year positions and $ 9.5 million relate to prior year positions.

During the year ended December 31, 2025, the Company settled an Italian audit related to tax years 2020 through 2023 in the amount of $ 1.3 million.

We do not have any other material gross unrecognized tax benefits related to income tax reserves.

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Our policy is to record interest and penalties related to unrecognized tax benefits related to income taxes in our income tax provision.

No amounts for interest or penalties related to unrecognized tax benefits have been recognized in our statements of operations and comprehensive loss for the years ended December 31, 2024, 2023 and 2022.

As of December 31, 2024, the unremitted earnings of our foreign subsidiaries are approximately $ 86.2 million.

We have not provided for U.S.

income taxes or foreign withholding taxes on these earnings as it is our current intention to permanently reinvest these earnings outside the U.S.

Any tax liability on these earnings is not expected to be material.

Events that could trigger a tax liability include, but are not limited to, distributions, reorganizations or restructurings and/or tax law changes.

The tax years 2021 through 2024 remain open to examination by the Internal Revenue Service and certain state tax authorities, although net operating loss and tax credit carryforwards generated prior to 2021 may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they have or will be used in a future period.

No amounts for interest or penalties related to unrecognized tax benefits have been recognized in our consolidated statements of operations and comprehensive income (loss) for the years ended December 31, 2025, 2024 and 2023.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

EMPLOYEE BENEFIT PLANS

Years Ended December 31,

(In thousands) 2025 2024

Beginning balance $ 59,371 $ —

Additions based on tax positions related to current period 10,460 5,080

Additions for tax positions of prior periods 9,467 54,291

Settlements ( 1,329 ) —

Ending balance $ 77,969 $ 59,371

We have not recorded a deferred tax liability with respect to excess book over tax outside basis differences, including unremitted earnings and cumulative translation adjustments, in our foreign subsidiary investments, as it is our current intention to permanently reinvest such outside basis differences with certain exceptions.

Any permanently reinvested outside basis differences could reverse if we make distributions, sell our foreign subsidiaries or various other events occur, none of which were considered probable as of December 31, 2025.

Determination of the amount of deferred tax liabilities described above is not practicable.

During the year ended December 31, 2025, we evaluated whether to repatriate cash from certain foreign subsidiaries and determined that any related deferred tax liabilities would not be material to our consolidated financial statements.

The tax years 2022 through 2025 remain open to examination by the Internal Revenue Service and certain state tax authorities, although net operating loss and tax credit carryforwards generated prior to 2022 may still be adjusted upon examination by the Internal Revenue Service or state tax authorities if they have or will be used in a future period.

EMPLOYEE BENEFITS PLANS

We maintain a retirement saving plan under Section 401(k) of the Internal Revenue Code, in which eligible U.S.

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RNAi therapeutics are comprised of siRNA that function upstream of conventional medicines by potently silencing messenger RNA, or mRNA, that encode for proteins implicated in the cause or pathway of disease, thus preventing them from being made.

To date, our efforts have yielded the approval of five first-in-class RNAi-based medicines, which generate the majority of our consolidated total revenues.

To date, our efforts have yielded the approval of six first-in-class RNAi-based medicines, which generate the majority of our consolidated total revenues.

Consistent with our operational structure, our Chief Executive Officer, or CEO, as the chief operating decision maker, or CODM, manages and allocates resources on a consolidated basis at the global corporate level.

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Consistent with our management reporting, results of our operations are reported on a consolidated basis for purposes of segment reporting.

The CEO evaluates performance and decides how to allocate resources based on consolidated net income (loss) that is reported on the consolidated statements of operations and comprehensive loss.

The CEO evaluates performance and decides how to allocate resources based on consolidated net income (loss) that is reported on the consolidated statements of operations and comprehensive income (loss).

The measure of segment assets is reported on the consolidated balance sheets as total assets.

The CEO uses consolidated net income (loss) to evaluate income generated from the Company’s business activities in deciding how to allocate company resources (such as pursuing clinical development or entering a strategic collaboration), monitoring budget versus actual results, and establishing management’s compensation.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

management’s compensation.

Please refer to the consolidated financial statements for further information related to these measures of segment performance.

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$ 1,319,775 $ 1,126,232 $ 1,004,415

ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

Selling, General and Administrative

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 8. Financial Statements and Supplementary Data