ALNYLAM PHARMACEUTICALS, INC.

1. NATURE OF BUSINESS

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

As of June 30, 2025, we havesix marketed products, includingtwo products that are commercialized by collaborators, and multiple late-stage investigational programs advancing towards potential commercialization. We currently generate worldwide product revenues from four commercialized products, AMVUTTRA, ONPATTRO, GIVLAARI and OXLUMO, primarily in the United States, or U.S., and Europe.

2. BASIS OF PRESENTATION AND PRINCIPLES OF CONSOLIDATION

The accompanying condensed consolidated financial statements of Alnylam are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, applicable to interim periods and, in the opinion of management, include all normal and recurring adjustments that are necessary to state fairly the results of operations for the reported periods. Our condensed consolidated financial statements have also been prepared on a basis substantially consistent with, and should be read in conjunction with, our audited consolidated financial statements for the year ended December 31, 2024, which were included in our Annual Report on Form 10-K that was filed with the Securities and Exchange Commission on February 13, 2025. The year-end condensed consolidated balance sheet data was derived from our audited financial statements but does not include all disclosures required by GAAP. The results of our operations for any interim period are not necessarily indicative of the results of our operations for any other interim period or for a full fiscal year.

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

Our significant accounting policies are described in Note 2 of the Notes to Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2024. There have been no material changes to our significant accounting policies during the six months ended June 30, 2025.

Use of Estimates

The preparation of financial statements in conformity with 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 condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. In our condensed 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. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.

Liquidity

Based on our current operating plan, we believe that our cash, cash equivalents and marketable securities as of June 30, 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 Quarterly Report on Form 10-Q.

Recent Accounting Pronouncements

In November 2024, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or 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 ASU 2024-04 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. The standard will be effective for annual reporting periods beginning after December 15, 2026 and interim reporting periods beginning after December 15, 2027, with early adoption permitted. The standard updates may be applied on either a prospective or retrospective basis. We are currently evaluating the disclosure requirements related to ASU 2024-03.

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 annual reporting periods beginning after December 15, 2024, with early adoption permitted. We are currently evaluating the disclosure requirements related to ASU 2023-09.

3. NET PRODUCT REVENUES

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

As of June 30, 2025 and December 31, 2024, net product revenue-related receivables of $474.7 million and $269.9 million, respectively, were included in accounts receivable, net on our condensed consolidated balance sheets.

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

4. NET REVENUES FROM COLLABORATIONS

Net revenues from collaborations consist of the following:

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

We recognized net revenues from collaborations of $13.0 million and $41.1 million in the three and six months ended June 30, 2025, respectively, and $200.0 million and $228.7 million in the three and six months ended June 30, 2024, respectively, each of which was included in the contract liability balance at the beginning of the applicable period.

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

Product Collaborations

Roche

On July 21, 2023, or the Effective Date, we entered into a Collaboration and License Agreement, or the Roche Agreement, with F. Hoffmann-La Roche Ltd. and Genentech, Inc., or, collectively, Roche, pursuant to which we and Roche established a worldwide, strategic collaboration for the joint development of zilebesiran. Zilebesiran is our investigational small interfering RNA, or siRNA, therapeutic targeting liver-expressed angiotensinogen, which is currently in Phase 2 clinical development for the treatment of hypertension.

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

We lead the global clinical development for zilebesiran. We are responsible for forty percent (40%) and Roche is responsible for the remaining sixty percent (60%) of development costs incurred in the conduct of development activities that support regulatory approval of zilebesiran globally. We and Roche share equally (50/50) all costs incurred in connection with development activities that are conducted to support regulatory approval of zilebesiran solely in the Co-Commercialization

Territory if incremental development activities are needed. Roche is solely responsible for all costs incurred in the conduct of development activities that primarily support regulatory approval in the Roche Territory. Upon regulatory approval, Roche has the exclusive right to commercialize zilebesiran in the Roche Territory and will pay us tiered, low double-digit royalties based 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.

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

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

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

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

The Roche License Obligation was satisfied at a point in time upon transfer of the license to Roche. Control of the licenses was transferred on the Effective Date and Roche could begin to use and benefit from the licenses. Because of this, all consideration allocated to the Roche License Obligation, including the upfront payment, milestones and royalties, is recognized when these amounts are no longer considered fully constrained or when the related sales occur for amounts subject to the sales-or-usage based royalty exception of ASC 606. For the Roche Development Services Obligation, we measure proportional performance over time using an input method based on cost incurred relative to the total estimated cost of the obligation, on a quarterly basis, by determining the proportion of effort incurred as a percentage of total effort we expect to expend. This ratio is applied to the transaction price allocated to the obligation. As all costs in the proportional performance model are allowable for reimbursement from Roche, and the assumptions used to determine the total estimated cost of the obligation are consistent with the assumptions used to determine the transaction price allocated to the obligation, the revenue recognized for this obligation will approximate 60% of the actual reimbursable cost incurred. Management has applied significant judgment in the process of developing our estimates. We re-evaluate the transaction price as of the end of each reporting period and as of June 30, 2025, the total transaction price was determined to be $1.31 billion.

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

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

As of June 30, 2025, the aggregate amount of the transaction price allocated to the Roche Performance Obligations that was unsatisfied was $837.3 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 $31.0 million and $60.7 million, during the three and six months ended June 30, 2025, respectively, and $26.2 million and $44.3 million, during the three and six months ended June 30, 2024, respectively.

Regeneron Pharmaceuticals, Inc.

Overview

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

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

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

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 of up toseven 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. The Regeneron Collaboration also covers a select number of RNAi therapeutic programs designed to target genes expressed in the liver.

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

In connection with the Regeneron Master Agreement, we remain eligible to receive an additional $100.0 million milestone payment upon achievement of certain criteria during early clinical development for an eye program. In addition, we and Regeneron are continuing to advance programs nominated during the Initial Research Term, and Regeneron has the right to nominate up tosix additional targets per year during this period. 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 tosix 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. The licensee will pay to the licensor certain development and/or commercialization milestone payments totaling up to $150.0 million for each collaboration product. In addition, following the first commercial sale of the applicable collaboration product under a license agreement, the licensee is required to make certain tiered royalty payments, ranging from low double-digits up to 20%, to the licensor based on the aggregate annual net sales of the collaboration product, subject to customary reductions.

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

Contract Modification

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

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

The Amended C5 License Agreement did not change the Research Services Obligation or the C5 License Obligation, which were both performance obligations at the inception of our global, strategic collaboration with Regeneron prior to the contract modification. The Amended C5 License Agreement resulted intwo 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 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 June 30, 2025, the total transaction price was determined to be $100.5 million related to this obligation. As of June 30, 2025, the aggregate amount of the transaction price that was unsatisfied was $46.8 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 consist of the following:

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

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

We incurred research and development costs related to the Regeneron Collaboration of $12.5 million and $31.5 million, during the three and six months ended June 30, 2025, respectively, and $14.3 million and $33.0 million, during the three and six months ended June 30, 2024, respectively.

Novartis AG

2013 Collaboration with The Medicines Company

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. In 2020, Novartis AG, or Novartis, completed its acquisition of MDCO and assumed all of MDCO’s rights and obligations under the MDCO License Agreement. We are entitled to royalties ranging from 10% up to 20% based on annual worldwide net sales of licensed products by Novartis, its affiliates and sublicensees, subject to reduction under specified circumstances.

Vir Biotechnology, Inc.

In March 2025, we and Vir Biotechnology, Inc., or Vir, entered into an amended and restated collaboration and license agreement, or the Amended Vir Agreement, relating to elebsiran (formerly ALN-HBV02 (VIR-2218)). Vir remains solely responsible for development, manufacturing and commercialization of elebsiran. In connection with execution of the Amended Vir Agreement, Vir made a $30.0 million payment, and we remain entitled to receive milestone payments upon the achievement of specified regulatory and commercial milestones, and royalties on the net sales of elebsiran ranging from low-to-mid teen percentages. Because the license rights have already been delivered and we have no other remaining performance obligations under the Amended Vir Agreement, the $30.0 million payment was recognized within net revenues from collaborations during the six months ended June 30, 2025.

Other

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

5. FAIR VALUE MEASUREMENTS

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

As of June 30, 2025 and December 31, 2024, the estimated fair value of our 1% Convertible Senior Notes due 2027, or the Notes, was approximately $1.35 billion and $1.11 billion, respectively. The fair value was determined based on the last actively traded price per $100 of the Notes (Level 2) as of June 30, 2025 and December 31, 2024, respectively.

During the three and six months ended June 30, 2025 and 2024, there were no transfers into or out of Level 3 financial assets or liabilities. The carrying amounts reflected on our condensed consolidated balance sheets for cash, accounts receivable, net, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term maturities.

6. MARKETABLE DEBT SECURITIES

We invest our excess cash balances in marketable debt securities and, at each balance sheet date presented, we classify all of our investments in debt securities as available-for-sale and as current assets as they represent the investment of funds available for current operations. We did not record any impairment charges related to our marketable debt securities during the three and six months ended June 30, 2025 or 2024.

The following tables summarize our marketable debt securities:

The fair values of our marketable debt securities by classification in the condensed consolidated balance sheets were as follows:

7. OTHER BALANCE SHEET DETAILS

Inventory

The components of inventory are summarized as follows:

As of June 30, 2025 and December 31, 2024, we had $28.7 million and $36.9 million of long-term inventory, respectively, included within other assets in our condensed consolidated balance sheets as we anticipate it being consumed beyond our normal operating cycle.

Cash, Cash Equivalents and Restricted Cash

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

Accumulated Other Comprehensive Loss

The following tables summarize the changes in accumulated other comprehensive loss, by component:

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 expense, net in the condensed consolidated statements of operations and comprehensive loss.

8. LIABILITY RELATED TO THE SALE OF FUTURE ROYALTIES

As of June 30, 2025 and December 31, 2024, the carrying value of the liability related to the sale of future royalties was $1.44 billion, net of closing costs of $8.7 million, and $1.45 billion, net of closing costs of $9.1 million, respectively. The carrying value of the liability related to the sale of future royalties approximates fair value as of June 30, 2025 and is based on our current estimates of future royalties expected to be paid 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:

9. DEVELOPMENT DERIVATIVE LIABILITY

As of June 30, 2025 and December 31, 2024, we recorded $120.8 million and $93.8 million, respectively, within development derivative liability and $407.5 million and $393.1 million, respectively, within development derivative liability, net of current portion on our condensed consolidated balance sheets, based on expected timing of our payments to BXLS V Bodyguard – PCP L.P. and BXLS Family Investment Partnership V – ESC L.P., collectively referred to as 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 condensed consolidated statements of operations and comprehensive loss.

As of June 30, 2025, 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, (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:

10. STOCK-BASED COMPENSATION

The following table summarizes stock-based compensation expense included in operating costs and expenses on our condensed consolidated statements of operations and comprehensive loss, and stock-based compensation charges included in additional paid-in capital on our condensed consolidated statements of stockholders' equity (deficit):

11. NET 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:

12. COMMITMENTS AND CONTINGENCIES

Technology License and Other Commitments

We have licensed from third parties the rights to use certain technologies and information in our research processes as well as in any other products we may develop. In accordance with the related license or technology agreements, we are required to make certain fixed payments to the licensor or a designee of the licensor over various agreement terms. Many of these agreement terms are consistent with the remaining lives of the underlying intellectual property that we have licensed. As of June 30, 2025, our commitments over the next five years to make fixed and cancellable payments under existing license agreements were not material.

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. 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

In March 2022, we filed separate lawsuits in the U.S. 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, 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, or mRNA, COVID-19 vaccines. In May 2022, Pfizer added BioNTech SE to the Pfizer lawsuit.

Following claim construction rulings of the District Court in the Moderna lawsuit in 2023, we and Moderna jointly agreed to final judgment of non-infringement oftwo of our patents, and we appealed the claim construction ruling to the Court of Appeals for the Federal Circuit. The claim construction ruling initially did not affect a third patent in the Moderna lawsuit, but in September 2024 the District Court entered a ruling in which it construed this third patent in the same manner as the other patents, and in October 2024 we and Moderna jointly agreed to a final judgment of non-infringement with respect to the third patent while preserving all rights to appeal.

In October 2024, Moderna filed a motion seeking recovery of fees incurred by Moderna from the time we agreed to a judgment of non-infringement with respect to the first two patents until the time we agreed to a judgment of non-infringement with respect to the third patent, which period runs from approximately September 2023 to October 2024. We opposed the motion in a reply filed on November 6, 2024. The District Court has not yet ruled on the motion. Due to uncertainty as to whether we will be liable for these fees, a loss is not probable or reasonably estimable at this time.

In June 2025, following oral argument, the Court of Appeals for the Federal Circuit affirmed the District Court’s claim construction ruling in the Moderna lawsuit. We are currently considering our options with respect to any further action on this ruling.

In the Pfizer lawsuit, the District Court issued an order in April 2025 that effectively placed the Pfizer product outside the coverage of our asserted patents. On May 13, 2025, we and Pfizer filed a joint motion seeking to stay all proceedings with a stipulation to non-infringement, which the District Court granted on the same day. On July 30, 2025, the District Court granted Pfizer’s motion for summary judgement of non-infringement and entered final judgment of non-infringement. We are currently evaluating our options, including a potential appeal to the Court of Appeals for the Federal Circuit.

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. 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. Patent No. 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 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 motions to dismiss and to transfer the case without prejudice, permitting us to refile the motions following the conclusion of venue discovery. In light of the early stage of this matter, a loss is not probable or reasonably estimable at this time.

Indemnifications

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. Under such agreements, we may be responsible for paying the costs of any litigation relating to the license agreements or the underlying intellectual property rights, including the costs associated with certain litigation regarding the licensed intellectual property. 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, 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.

Our maximum potential future liability under any such indemnification provisions is uncertain. 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 June 30, 2025.

13. SEGMENT INFORMATION

We operate in a single segment dedicated to the discovery, development, manufacturing and commercialization of RNAi therapeutics. Consistent with our management reporting, results of our operations are reported on a consolidated basis for purposes of segment reporting. Our Chief Executive Officer, or CEO, as the chief operating decision maker, or CODM, evaluates performance and decides how to allocate resources based on consolidated net income (loss) that is reported on the condensed consolidated statements of operations and comprehensive loss. The measure of segment assets is reported on the condensed consolidated balance sheets as total assets. Please refer to the condensed consolidated financial statements for further information related to these measures of segment performance. In addition, research and development and selling, general and administrative expenses are significant segment expenses regularly provided to the CEO with the following categories:

Research and Development

Selling, General and Administrative

14. SUBSEQUENT EVENTS

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 beginning in 2025, including the restoration of immediate expensing of domestic research and development expenditures, reinstatement of 100% bonus depreciation, and more favorable rules for determining the limitation on business interest expense. The Act also 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, amongst other changes. These changes are generally effective for tax years beginning after December 31, 2025 and were not reflected in the income tax provision for the period ended June 30, 2025, as enactment occurred after the balance sheet date.

We are currently evaluating the impact on future periods.