What changed in this filing

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Item 9A. Controls and Procedures

2026-02-06 compared with 2025-02-12 · 721 added, 841 removed, 2141 unchanged (42% of the section changed)

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Securities and Exchange Commission's rules and forms;

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(b) such information is accumulated and communicated to our management, including our principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosure.

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OTHER INFORMATION

RULE 10b5-1 TRADING ARRANGEMENTS

From time to time, our officers (as defined in Rule 16a-1(f)) and directors may enter into Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K).

During the fourth quarter of 2024 our officers and directors took the following actions with respect to 10b5-1 trading arrangements:

Trading Arrangement

Name and Position Action Date Rule

10b5-1 Non-Rule 10b5-1 Total Shares to be Sold Expiration Date

Sherwin , Director

Adopt 11/7/2024 X — 8,760 05/08/2025

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TRADING ARRANGEMENTS

From time to time, our officers (as defined in Rule 16a-1(f)) and directors may enter into, amend or terminate Rule 10b5-1 or non-Rule 10b5-1 trading arrangements (as each such term is defined in Item 408 of Regulation S-K).

During the fourth quarter of 2025 there were no trading arrangements for the purchase or sale of our securities entered into, amended or terminated by our officers and directors.

DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

Not Applicable.

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DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

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The response to this item is incorporated by reference from the discussion responsive thereto in the section entitled “ Proposal 2 - Ratification of the Selection of our Independent Registered Public Accounting Firm ” contained in the proxy statement for our 2026 annual meeting of stockholders.

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EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

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Not applicable.

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EXHIBIT INDEX

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Filed as Exhibit 4.2 to our Current Report on Form 8-K filed on February 16, 2021.

4.6 Fourth Supplemental Indenture, dated as of May 12, 2025, between the Company and U.S.

Bank Trust Company, National Association (as successor to U.S.

Bank, National Association), including the forms of Global Notes attached as Exhibit A, Exhibit B and Exhibit C, respectively, thereto.

Filed as Exhibit 4.2 to our Current Report on Form 8-K filed on May 12, 2025.

4.7 Description of Securities.

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10.5 Form of performance share award agreement under the Biogen Inc.

2024 Omnibus Equity P lan.

2024 Omnibus Equity Plan.

Filed as Exhibit 10.3 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2024.

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Filed as Exhibit 10.4 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2024.

10.7 F orm of non-employee dire ctor restricted stock u ni t awar d agreement under the Biogen Inc.

2024 Omni bus Equity Plan.

10.7 Form of non-employee director restricted stock unit award agreement under the Biogen Inc.

2024 Omnibus Equity Plan.

Filed as Exhibit 10.5 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2024.

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10.14 Voluntary Board of Directors Savings Plan.

Filed as Exhibit 10.14 to our Annual Report on Form 10-K for the year ended December 31, 202 4.

10.15 Biogen Inc.

Supplemental Savings Plan.

Filed as Exhibit 10.15 to our Annual Report on Form 10-K for the year ended December 31, 202 4.

10.16* Biogen Inc.

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Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended September 30, 2020.

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10.17* Annual Retainer Summary for Board of Directors (effective January 1, 2020).

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Filed as Exhibit 10.3 to our Quarterly Report on Form 10-Q for the quarter ended March 31, 2023.

10.25* L etter regarding employment arrangement of Robi n Kramer dated October 28, 2024.

Fil ed as Exhi b i t 10.1 to our Current Report on Form 8-K filed on October 30, 2024.

10.25* Letter regarding employment arrangement of Robin Kramer dated October 28, 2024.

Filed as Exhibit 10.1 to our Current Report on Form 8-K filed on October 30, 2024.

10.26 Letter regarding employment arrangement of Priya Singhal dated January 3, 2023.

Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q filed on July 31, 2025.

10.27 Amended and Restated Collaboration Agreement, dated October 22, 2017, between Biogen MA Inc.

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++ Furnished herewith.

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Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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February 6, 2026

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Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

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Christopher A.

/S/ MICHAEL R.

Executive Vice President and Chief Financial Officer (principal financial officer) February 12, 2025

Senior Vice President, Chief Accounting Officer (principal accounting officer) February 12, 2025

KRAMER Executive Vice President and Chief Financial Officer (principal financial officer) February 6, 2026

/S/ SEAN GODBOUT Vice President, Chief Accounting Officer and Global Corporate Controller

(principal accounting officer) February 6, 2026

/S/ CAROLINE D.

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Director February 6, 2026

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Report of Independent Registered Public Accounting Firm (PCAOB ID 238) F-80

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Research and development 1,778.6 1,980.3 2,445.4

Acquired in-process research and development, upfront and milestone expense 471.8 61.5 16.6

Selling, general and administrative 2,433.6 2,403.7 2,549.7

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(Gain) loss on fair value remeasurement of contingent consideration 33.6 27.7 —

Impairment of ROU asset 52.9 — —

Restructuring charges 48.6 30.2 218.8

Gain on sale of priority review voucher, net — ( 88.6 ) —

Gain on sale of building, net — — ( 503.7 )

Other (income) expense, net 305.6 343.6 315.5

Total cost and expense 8,334.1 7,769.9 8,538.8

Income before income tax (benefit) expense and equity in (income) loss of investee, net of tax 1,906.0 1,296.8 3,591.8

Income before income tax (benefit) expense 1,556.5 1,906.0 1,296.8

Income tax (benefit) expense 263.6 273.8 135.3

Equity in (income) loss of investee, net of tax — — ( 2.6 )

Net income 1,292.9 1,632.2 1,161.5

Net income (loss) attributable to noncontrolling interests, net of tax — 0.4 ( 85.3 )

Net income attributable to noncontrolling interests, net of tax — — 0.4

Net income attributable to Biogen Inc.

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See accompanying notes to these consolidated financial statements.

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Unrealized gains (losses) on cash flow hedges, net of tax ( 110.5 ) 76.6 ( 40.1 )

Gains (losses) on net investment hedges, net of tax — — ( 25.5 )

Unrealized gains (losses) on pension benefit obligation, net of tax 7.2 ( 14.0 ) ( 1.5 )

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1,247.1 1,649.7 1,172.3

Comprehensive income (loss) attributable to noncontrolling interests, net of tax — 0.4 ( 85.3 )

Comprehensive income attributable to noncontrolling interests, net of tax — — 0.4

Comprehensive income (loss) $ 1,247.1 $ 1,649.7 $ 1,172.7

See accompanying notes to these consolidated financial statements.

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Cash and cash equivalents $ 3,008.5 $ 2,375.0

Current portion of marketable securities 807.2 —

Accounts receivable, net of allowance for doubtful accounts of $ 3.0 and $ 2.2 , respectively

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Total current assets 8,974.1 7,456.8

Marketable securities 431.9 —

Property, plant and equipment, net 3,055.4 3,181.3

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Current liabilities:

Current portion of notes payable and term loan $ 1,748.6 $ 150.0

Current portion of notes payable $ — $ 1,748.6

Taxes payable 114.8 548.3

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Total current liabilities 3,349.4 5,528.8

Notes payable and term loan 4,547.2 6,788.2

Notes payable 6,286.8 4,547.2

Deferred tax liability 507.6 190.5

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See accompanying notes to these consolidated financial statements.

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Impairment of intangible assets 7.9 60.2 —

Impairment of ROU asset 52.9 — —

Excess and obsolescence charges related to inventory 29.2 101.9 124.4

Amortization of acquired inventory step-up 240.8 230.0 31.5

Acquired in-process research and development 85.0 — —

Share-based compensation 290.8 291.2 264.2

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(Gain) loss on strategic investments 19.3 101.4 277.1

(Gain) loss on equity method investment — — ( 2.6 )

Gain on sale of equity interest in Samsung Bioepis — — ( 1,505.4 )

Gain on sale of building, net — — ( 503.7 )

Gain on sale of priority review voucher, net — ( 88.6 ) —

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Proceeds from sale of equity interest in Samsung Bioepis — 406.8 788.1

Proceeds from sale of building — — 582.6

Proceeds from sale of priority review voucher, net — 88.6 —

Acquired in-process research and development ( 50.0 ) — —

Acquisitions of intangible assets ( 31.6 ) ( 206.1 ) ( 34.4 )

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Cash flow from financing activities:

Purchase of treasury stock — — ( 750.0 )

Payments related to issuance of stock for share-based compensation arrangements, net ( 10.0 ) ( 31.3 ) ( 44.3 )

Repayments of borrowings and premiums paid ( 650.0 ) ( 809.9 ) ( 1,002.2 )

Proceeds from borrowings 1,733.1 — 997.2

Repayments of borrowings ( 1,750.0 ) ( 650.0 ) ( 809.9 )

Net (distribution) contribution to noncontrolling interest — — 12.3

Contingent consideration payments ( 280.0 ) — —

Other 5.0 ( 2.2 ) ( 6.0 )

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See accompanying notes to these consolidated financial statements.

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comprehensive

income (loss)

income (loss) Retained

earnings Treasury stock Total

shareholders’

equity Noncontrolling

interests Total

Shares Amount Shares Amount Shares Amount

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Other comprehensive income (loss), net of tax — — — — — 17.5 — — — 17.5

Capital contribution from noncontrolling interest — — — — — — — — — — 12.3 12.3

Deconsolidation of noncontrolling interest — — — — — — — — — — ( 3.2 ) ( 3.2 )

Issuance of common stock under stock option and stock purchase plans — — 0.2 — 36.3 — — — — 36.3

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See accompanying notes to these consolidated financial statements.

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Capital contribution from noncontrolling interest — — — — — — — — — — 12.3 12.3

Repurchase of common stock pursuant to the 2020 Share Repurchase Program, at cost — — — — — — — ( 3.6 ) ( 750.0 ) ( 750.0 ) — ( 750.0 )

Retirement of common stock pursuant to the 2020 Share Repurchase Program, at cost — — ( 3.6 ) — ( 257.9 ) — ( 492.1 ) 3.6 750.0 — — —

Deconsolidation of noncontrolling interest — — — — — — — — — — ( 3.2 ) ( 3.2 )

Issuance of common stock under stock option and stock purchase plans — — 0.2 — 45.1 — — — — 45.1 — 45.1

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We have a broad portfolio of medicines to treat MS, have introduced the first approved treatment for SMA, co-developed treatments to address a defining pathology of Alzheimer’s disease and launched the first approved treatment to target a genetic cause of ALS.

We market the first and only drug approved in the U.S.

for the treatment of FA in adults and adolescents aged 16 years and older.

We market the first and only drug approved in the U.S., the E.U.

and certain international markets for the treatment of FA in adults and adolescents aged 16 years and older.

We are focused on advancing our pipeline in neurology, specialized immunology and rare diseases.

We support our drug discovery and development efforts through internal research and development programs, external collaborations and acquisitions.

Our marketed products include TECFIDERA, VUMERITY, AVONEX, PLEGRIDY and TYSABRI for the treatment of MS;

Our marketed products include VUMERITY, TYSABRI, TECFIDERA, AVONEX and PLEGRIDY for the treatment of MS;

SPINRAZA for the treatment of SMA;

SKYCLARYS for the treatment of FA;

QALSODY for the treatment of ALS;

and FUMADERM for the treatment of severe plaque psoriasis.

We also have collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Sage on the commercialization of ZURZUVAE for the treatment of PPD.

and QALSODY for the treatment of ALS.

We also have collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Supernus on the commercialization of ZURZUVAE for the treatment of PPD.

We have certain business and financial rights with respect to RITUXAN for the treatment of non-Hodgkin's lymphoma, CLL and other conditions;

RITUXAN HYCELA for the treatment of non-Hodgkin's lymphoma and CLL;

GAZYVA for the treatment of CLL and follicular lymphoma;

GAZYVA for the treatment of CLL, follicular lymphoma and, following its approval in October 2025, lupus nephritis;

OCREVUS for the treatment of PPMS and RMS;

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IMRALDI, an adalimumab biosimilar referencing HUMIRA;

FLIXABI, an infliximab biosimilar referencing REMICADE;

and BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS, in certain international markets, as well as TOFIDENCE, a tocilizumab biosimilar referencing ACTEMRA, in the U.S.

and certain international markets.

We also have commercialization rights related to OPUVIZ, an aflibercept biosimilar referencing EYLEA.

On July 2, 2024, we completed the acquisition of HI-Bio.

As a result of this transaction we acquired HI-Bio's lead asset, felzartamab, an anti-CD38 antibody currently being evaluated for three leading indications, AMR, PMN and IgAN.

For additional information on our acquisition of HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

and FLIXABI, an infliximab biosimilar referencing REMICADE.

For additional information on our collaboration arrangements, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

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Our consolidated financial statements reflect our financial statements, those of our wholly owned subsidiaries and variable interest entities where we are the primary beneficiary.

For consolidated entities where we own or are exposed to less than 100.0 % of the economics, we record net income (loss) attributable to noncontrolling interests, net of tax in our consolidated statements of income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties.

For consolidated entities where we own or are exposed to less than 100.0 % of the economics, we record net income attributable to noncontrolling interests, net of tax in our consolidated statements of income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties.

Intercompany balances and transactions are eliminated in consolidation.

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In November 2023 we terminated the Neurimmune Agreement, which resulted in the deconsolidation of our variable interest entity, Neurimmune.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Use of Estimates

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On an ongoing basis we evaluate our estimates, judgments and assumptions.

We base our estimates on historical experience and on various other assumptions that we believe are reasonable, the results of which form the basis for making judgments about the carrying values of assets, liabilities and equity and the amount of revenue and expense.

We base our estimates on historical experience and on various other assumptions that we believe are

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

reasonable, the results of which form the basis for making judgments about the carrying values of assets, liabilities and equity and the amount of revenue and expense.

Actual results may differ from these estimates.

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Volume related discounts primarily relate to incentives offered to downstream customers who earn discounts based upon the quarterly or annual volume of units purchased.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Contractual adjustments primarily relate to Medicaid and managed care rebates in the U.S., pharmacy rebates, co-payment (copay) assistance, VA and PHS discounts, specialty pharmacy program fees and other governmental rebates or applicable allowances.

Contractual adjustments primarily relate to Medicaid, Medicare and managed care rebates in the U.S., pharmacy rebates, co-payment (copay) assistance, VA and PHS discounts, specialty pharmacy program fees and other governmental rebates or applicable allowances.

• Medicaid rebates:

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Rebate accruals are recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a liability which is included in accrued expense and other current liabilities in our consolidated balance sheets.

Our liability for Medicaid rebates consists of estimates for claims that a state will make for the current quarter, claims for prior quarters that have been estimated for which an invoice has not been received, invoices received for claims from the prior quarters that have not been paid and an estimate of potential claims that will be made for inventory that exists in the distribution channel at period end.

Our liability for Medicaid rebates consists of estimates for claims

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

that a state will make for the current quarter, claims for prior quarters that have been estimated for which an invoice has not been received, invoices received for claims from the prior quarters that have not been paid and an estimate of potential claims that will be made for inventory that exists in the distribution channel at period end.

• Governmental rebates:

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The calculation of the accrual for these rebates is based on an estimate of the pharmacy’s buying or dispensing patterns and the resulting applicable contractual rebate rate(s) to be earned over the contractual period.

• IRA Medicare rebates:

relate to our estimated obligation under the IRA for the manufacturer’s portion of the Medicare Part D redesign.

The calculation of the accrual for these rebates is based on an estimate of our Medicare population and the estimated manufacturer portion of our obligation under the Part D Redesign.

• Other governmental rebates:

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After an anti-CD20 product is approved, we record our share of the development and sales and marketing expense related to that product as a reduction of our share of pre-tax profits in revenue from anti-CD20 therapeutic programs.

Accordingly, Biogen recorded its share of the expense incurred in connection with the development of LUNSUMIO within research and development expense and its share of pre-commercialization costs within selling, general and administrative expense through December 2022, when regulatory approval was granted by the FDA.

Beginning in January 2023 our share of pre-tax profits and losses in the U.S.

for LUNSUMIO was reflected as a component of revenue from anti-CD20 therapeutic programs within our consolidated statements of income.

For additional information on our relationship with Genentech, please read Note 19, Collaborative and Other Relationships, to these consolidated financial statements.

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Revenue under contract manufacturing agreements is recognized when the customer obtains control of the product, which may occur at a point in time or over time depending on the terms and conditions of the agreement.

During the first quarter of 2023 we began recognizing contract manufacturing revenue

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

for LEQEMBI, upon accelerated approval of LEQEMBI in the U.S.

Prior to accelerated approval, our share of contract manufacturing amounts related to LEQEMBI were recognized in research and development expense within our consolidated statements of income.

Royalty and Other Revenue

Royalty and other revenue primarily reflects royalty revenue on biosimilar products from our license arrangements with Samsung Bioepis and royalties we receive from net sales on products related to patents that we have out-licensed.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

As the royalties we receive relate to arrangements that resulted from an exchange of a license and utilize the sales and usage based royalty exception, the royalties are recognized as the underlying sales occur.

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Where we are not the principal on sales transactions with third parties, our share of the revenue, cost of sales and operating expense is recorded on a net basis as a component of other revenue in our consolidated statements of income.

Our development and commercialization arrangements with Genentech, Eisai, Sage and Samsung Bioepis represent collaborative arrangements as each party is an active participant in one or more joint operating activities and is exposed to significant risks and rewards of these arrangements.

Our development and commercialization arrangements with Genentech, Eisai, Supernus and Samsung Bioepis represent collaborative arrangements as each party is an active participant in one or more joint operating activities and is exposed to significant risks and rewards of these arrangements.

These arrangements resulted from an exchange of a license and utilize the sales and usage based royalty exception, as applicable.

Therefore, revenue relating to royalties or profit-sharing amounts received is recognized as the underlying sales occur.

For additional information on our collaboration arrangements with Genentech, Eisai, Sage and Samsung Bioepis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

For additional information on our collaboration arrangements with Genentech, Eisai, Supernus and Samsung Bioepis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Fair Value Measurements

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After completing our validation procedures, we did not adjust or override any fair value measurements provided by our pricing services as of December 31, 2025 and 2024.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Other Assets and Liabilities

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We consider only those investments that are highly liquid, readily convertible to cash and that mature within three months from date of purchase to be cash equivalents.

As of December 31, 2024 and 2023, cash equivalents were comprised of money market funds with maturities less than three months from the date of purchase.

As of December 31, 2025, cash equivalents were comprised of money market funds, overnight reverse repurchase agreements, short-term debt securities and commercial paper with maturities less than three months from the date of purchase.

As of December 31, 2024, cash equivalents were comprised of money market funds with maturities less than three months from the date of purchase.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Accounts Receivable

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Amounts determined to be uncollectible are charged or written-off against the reserve.

Receivables from Samsung BioLogics

In April 2022 we completed the sale of our 49.9 % equity interest in Samsung Bioepis to Samsung BioLogics, which resulted in a receivable of approximately $ 1.3 billion in cash to be deferred over two payments.

The first deferred payment of $ 812.5 million was received in April 2023 and the second deferred payment of $ 437.5 million was received in April 2024.

The payments due to us from Samsung BioLogics were recorded at their estimated fair values through the use of risk-adjusted discount rates.

For additional information on the accounting for the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

Concentration of Credit Risk

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Realized gains and losses are reported in other (income) expense, net on a specific identification basis.

During the third quarter of 2023 we sold all of our marketable debt securities and used the proceeds to partially fund our acquisition of Reata.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

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Marketable Equity Securities and Venture Capital Funds

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These investments are included in investments and other assets in our consolidated balance sheets.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Evaluating Marketable Debt Securities for Other-than-Temporary Impairments

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Inventory that can be used in either the production of clinical or commercial products is expensed as research and development costs when identified for use in a clinical manufacturing campaign.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Capitalization of Inventory Costs

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If the actual net realizable value is less than that estimated by us, or if it is determined that inventory utilization will further diminish based on estimates of demand, additional inventory write-downs may be required.

Additionally, our products are subject to strict quality control and monitoring that we perform throughout the manufacturing process.

Additionally, our products are subject to strict quality control and

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monitoring that we perform throughout the manufacturing process.

In the event that certain batches or units of product no longer meet quality specifications, we will record a charge to cost of sales to write-down any unmarketable inventory to its estimated net realizable value.

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If the software is an integral part of production assets, these costs are included in machinery and equipment and are amortized on a straight-line basis over the estimated useful lives of the related software, which generally range from three to five years .

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We generally depreciate or amortize the cost of our property, plant and equipment using the straight-line method over the estimated useful lives of the respective assets, which are summarized as follows:

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For certain equipment leases, such as vehicles, we apply a portfolio approach to effectively account for the operating lease assets and liabilities.

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Our operating leases are reflected in operating lease assets, accrued expense and other and long-term operating lease liabilities in our consolidated balance sheets.

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The economic consumption method is based on revenue generated from the products underlying the related intangible assets.

An analysis of the anticipated lifetime revenue of our marketed products is performed annually

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

during our long-range planning cycle and whenever events or changes in circumstances would significantly affect anticipated lifetime revenue of the relevant products.

An analysis of the anticipated lifetime revenue of our marketed products is performed annually during our long-range planning cycle and whenever events or changes in circumstances would significantly affect anticipated lifetime revenue of the relevant products.

Intangible assets related to trademarks, trade names, IPR&D prior to commercialization and priority review vouchers are not amortized because they have indefinite lives;

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If we acquire a business as defined under applicable accounting standards, then the acquired IPR&D is capitalized as an intangible asset.

If we acquire an asset or group of assets that do not meet the definition of a business under applicable accounting standards, then the acquired IPR&D is expensed on its acquisition date.

If we acquire an asset or group of assets with no alternative future use that do not meet the definition of a business under applicable accounting standards, then the acquired IPR&D is expensed on its acquisition date.

Future costs to develop these assets are recorded to research and development expense within our consolidated statements of income as they are incurred.

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Changes in estimates and assumptions used in determining the fair value of our acquired IPR&D could result in an impairment.

Impairments are recorded within amortization and impairment of acquired intangible assets in our consolidated statements of income.

Acquired IPR&D impairments are recorded within amortization and impairment of acquired intangible assets in our consolidated statements of income.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Goodwill represents the difference between the purchase price and the fair value of the identifiable tangible and intangible net assets when accounted for using the purchase method of accounting.

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Long-lived assets to be held and used, including property, plant and equipment, and definite-lived intangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets or asset group may not be recoverable.

Determination of recoverability is based on an estimate of undiscounted future cash flow resulting from the use of the asset and its eventual disposition.

Determination of recoverability is based on an estimate of undiscounted future cash flow resulting from the use of the assets and eventual disposition.

In the event that such cash flow is not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their fair values.

Long-lived assets to be disposed of are carried at fair value less costs to sell.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Contingent Consideration

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We assess at inception and on an ongoing basis, whether the derivative instruments that are used in hedging transactions are highly effective in offsetting the changes in cash flow or fair values of the hedged items.

We exclude the forward points portion of the derivative instruments used in a hedging transaction from the effectiveness test and record the fair value gain or loss related to this portion each period in our consolidated statements of income in the same line as the underlying hedged item.

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the same line as the underlying hedged item.

If we determine that a forecasted transaction is no longer probable of occurring, we discontinue hedge accounting for the affected portion of the hedge instrument, and any related unrealized gain or loss on the contract is recognized in current earnings.

Net Investment Derivative Instruments

Desi gnated net investment hedges are recognized as either assets or liabilities, at fair value, in our consolidated balance sheets.

We hedge the changes in the spot exchange rate in AOCI and exclude changes to the forward rate and amortize the forward points in other (income) expense, net in our consolidated statements of income over the term of the contract.

We classify the cash flow from these instruments in the same category as the cash flow from the hedged items.

Beginning in the second quarter of 2022 we no longer held net investment hedges as they were closed with the sale of our 49.9 % equity interest in Samsung Bioepis in April 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

For additional information on our derivative instruments and hedging activities, please read Note 10, Derivative Instruments , to these consolidated financial statements.

Translation of Foreign Currencies

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subsidiaries that transact in a functional currency other than the U.S.

dollar, assets and liabilities are translated at current rates of

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

exchange at the balance sheet date.

dollar, assets and liabilities are translated at current rates of exchange at the balance sheet date.

Income and expense items are translated at the average foreign currency exchange rates for the period.

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Accounting for Share-Based Compensation

Our share-based compensation programs grant awards that have included stock options, restricted stock units that vest based on stock performance known as MSUs, time-vested RSUs, performance-vested stock units that settle in stock or cash (PSUs) and shares issued under our ESPP.

Our share-based compensation programs grant awards that have included stock options, time-vested RSUs, performance-vested stock units that vest based upon meeting both a performance condition and a service condition and shares issued under our ESPP.

Compensation expense is recognized based on the estimated fair value of the awards at grant date.

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The estimated fair values of the stock options are then expensed over the options' vesting periods.

The fair values of our MSUs and PSUs that settle in stock and have market-based metrics are estimated using a lattice model with a Monte Carlo simulation.

We apply an accelerated attribution method to recognize share-based compensation expense over the applicable service period for these awards.

The probability of actual shares expected to be earned is considered in the grant date valuation, therefore the expense is not adjusted to reflect the actual units earned.

The fair values of our RSUs are based on the market value of our stock on the date of grant.

Compensation expense for RSUs is recognized straight-line over the applicable service period.

We apply an accelerated attribution method to recognize share-based compensation expense when accounting for our PSUs that settle in cash, and the fair value of the liability is remeasured at the end of each reporting period through expected settlement.

Compensation expense associated with PSUs that settle in cash are based upon the stock price and the number of units expected to be earned after assessing the probability that certain performance criteria will be met and the targeted payout level associated with the performance criteria expected to be achieved.

Cumulative adjustments are recorded each quarter to reflect changes in the stock price and estimated outcome of the performance-related conditions until the date results are determined and settled.

If performance criteria are not met or not expected to be met, any compensation expense previously recognized to date associated with the awards will be reversed.

The fair values of PSUs that settle in stock and do not have market-based metrics are based upon the stock price on the date of grant.

If the service condition is not met or not expected to be met, any compensation expense previously recognized to date associated with the awards will be reversed.

The fair values of our PSUs that settle in stock and have market-based metrics are estimated using a lattice model with a Monte Carlo simulation.

Compensation expense is recognized straight-line over the applicable service period for these awards.

The probability of actual shares expected to be earned is considered in the grant date valuation, therefore the expense is not adjusted to reflect the actual units earned.

The fair values of PSUs that settle in stock and do not have market-based metrics are based on the market value of our stock on the date of grant.

Compensation expense is recognized for the number of units expected to be earned after assessing the probability that certain performance criteria will be met and the targeted payout level associated with the performance criteria expected to be achieved.

Cumulative adjustments are recorded each quarter to reflect the estimated outcome of the performance-related conditions until the date results are determined and settled.

If the performance criteria are not met or not expected to be met, any compensation expense previously recognized to date associated with the awards will be reversed.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

performance criteria are not met or not expected to be met, any compensation expense previously recognized to date associated with the awards will be reversed.

Research and Development Expense

Research and development expense consists of expenses incurred in performing research and development activities, which include compensation and benefits, facilities and overhead expense, clinical trial expense and fees paid to CROs, clinical supply and manufacturing expense, write-offs of inventory that was previously capitalized in anticipation of product launch and determined to no longer be realizable and other outside expense and upfront fees and milestones paid to third-party collaborators.

Research and development expense consists of expenses incurred in performing research and development activities, which include compensation and benefits, facilities and overhead expense, clinical trial expense and fees paid to CROs, clinical supply and manufacturing expense, fair value step-up adjustment amortization of inventory used for clinical purposes and other outside expense.

Research and development expense is expensed as incurred.

Upfront and milestone payments made to third-party collaborators are expensed as incurred up to the point of regulatory approval.

Milestone payments made upon regulatory approval are capitalized and amortized over the remaining useful life of the related product.

Payments we make for research and development services prior to the services being rendered are recorded as prepaid assets in our consolidated balance sheets and are expensed as the services are provided.

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Expenses incurred by Genentech in the ongoing development of RITUXAN, GAZYVA, LUNSUMIO and other products for which an initial indication has been approved are not recorded as research and development expense, but rather reduce our share of profits recorded as a component of revenue from anti-CD20 therapeutic programs.

Acquired In-process Research and Development, Upfront and Milestone Expense

Acquired in-process research and development, upfront and milestone expense consists of upfront fees and milestones paid to third-party collaborators as well as charges associated with the acquisition of an asset or group of assets with no alternative future use that did not meet the definition of a business under applicable accounting standards.

Upfront and milestone payments made to third-party collaborators are expensed as incurred up to the point of regulatory approval.

Milestone payments made upon regulatory approval are capitalized and amortized over the remaining useful life of the related product.

Selling, General and Administrative Expense

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Advertising costs are expensed as incurred.

For the years ended December 31, 2024, 2023 and 2022, advertising costs t otaled $ 66.8 million , $ 71.4 million and $ 54.1 million, respectively.

For the years ended December 31, 2025, 2024 and 2023, advertising costs t otaled approximately $ 71.9 million , $ 66.8 million and $ 71.4 million, respectively.

The provision for income taxes includes federal, state, local and foreign taxes.

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Standard Description Effective Date Effects on the Financial Statements

2023-07, Segment Reporting (Topic 280):

Improvements to Reportable Segment Disclosure

This standard requires disclosure of significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items to reconcile to segment profit or loss and the title and position of the entity's CODM.

The amendments in this update also expand the interim segment disclosure requirements.

All disclosure requirements under this standard are also required for public entities with a single reportable segment.

The amendments in this update are required to be applied on a retrospective basis.

Annual reporting for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024.

Early adoption is permitted.

This standard became effective for us for our annual reporting period ended December 31, 2024, using the retrospective method.

The adoption of this standard resulted in additional disclosure on the significant expenses reviewed by our CODM.

The adoption did not have a material impact on our consolidated financial position or results of operations.

Refer to Note 25, Segment Information , for our updated segment presentation.

2023-09, Income Taxes (Topic 740):

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Early adoption is permitted.

We are currently evaluating the potential impact that this new standard will have on our consolidated financial statements and related disclosures.

We adopted this standard and applied the disclosure requirements on a prospective basis effective for the year ended December 31, 2025.

The adoption did not have a material impact on our consolidated financial position or results of operations.

Refer to Note 17, Income Taxes , for our updated income tax disclosure.

2024-03, Income Statement (Subtopic 220-40):

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Early adoption is permitted.

We are currently evaluating the potential impact that this new standard will have on our consolidated financial statements and related disclosures, and expect to apply this standard prospectively upon adoption.

2025-06, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40):

Targeted Improvements to the Accounting for Internal-Use Software This standard modernizes the accounting for software costs, including updating guidance on the recognition and measurement of costs incurred in connection with development and implementation activities related to internal-use software.

Annual reporting for fiscal periods beginning after December 15, 2027, and interim periods within those annual reporting periods.

Early adoption is permitted.

We are currently evaluating the potential impact that this new standard will have on our consolidated financial statements and related disclosures.

SEC Release No.

33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors

This new rule will require large accelerated filers to disclose material climate-related risks that are reasonably likely to have a material impact on their business, results of operations or financial condition.

The required information about climate-related risks will also include disclosure of material direct greenhouse gas emissions from operations owned or controlled (Scope 1) and/or material indirect greenhouse gas emissions from purchased energy consumed in owned or controlled operations (Scope 2).

Additionally, the new rules will require disclosure within the notes to the financial statements of the effects of severe weather events and other natural conditions and information on any climate-related targets or goals, subject to certain materiality thresholds.

Phased-in compliance period beginning with annual reporting for fiscal years as of December 31, 2025.

In April 2024 the SEC voluntarily stayed implementation of the new climate-related disclosure requirements pending judicial review.

Once the litigation is resolved, and if the rule remains in effect, the SEC will announce a new effective date.

We are currently evaluating the potential impact that this new rule may have on our company's disclosures.

2025-07, Derivatives and Hedging (Topic 815) and Revenue from Contracts with Customers (Topic 606):

Derivatives Scope Refinements and Scope Clarification for Share-Based Noncash Consideration from a Customer in a Revenue Contract This standard refines and expands the existing scope exceptions that exclude certain contracts, including certain R&D funding arrangements, from derivative accounting, and clarifies the accounting for share-based noncash consideration received from a customer.

Annual reporting for fiscal years beginning after December 15, 2026, and interim periods within those annual reporting periods.

Early adoption is permitted.

We have early adopted this new standard on a modified retrospective basis as of January 1, 2025.

Adoption did not have a material impact on our condensed consolidated financial statements and related disclosures.

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Alcyone Therapeutics, Inc.

In November 2025 we completed the acquisition of all of the issued and outstanding shares of Alcyone Therapeutics, Inc., a clinical-stage biotechnology company focused on pediatric care through precision CNS therapeutics and dosing platforms.

Alcyone's lead asset is ThecaFlex DRx, an implantable subcutaneous port and catheter device being investigated for the intrathecal delivery of ASOs, including SPINRAZA, which is designed to provide an alternative to repeat lumbar punctures in chronic intrathecal administration of medicines.

Total consideration for this transaction, which was recorded in acquired in-process research and development, upfront and milestone expense in our consolidated statements of income for the year ended December 31, 2025, was approximately $ 85.0 million, comprising a $ 50.0 million payment made upon closing and a $ 35.0 million payment that was considered probable as of December 31, 2025, and made upon FDA approval of a supplemental application in January 2026.

We may pay additional development and regulatory milestone payments to the former shareholders of Alcyone of up to a total of $ 75.0 million if approval is received for ThecaFlex DRx administration of SPINRAZA or other additional pipeline products.

We accounted for this transaction as an asset acquisition as the value being acquired primarily relates to a single asset.

U nder the terms of this acquisition, we will oversee the end-to-end development, manufacturing and commercialization of ThecaFlex DRx .

Alcyone's remaining therapeutic assets were divested from Alcyone into Neela Therapeutics, Inc., a newly formed independent company, prior to the closing of this acquisition.

Human Immunology Biosciences

On July 2, 2024, we completed the acquisition of all of the issued and outstanding shares of HI-Bio, a privately-held clinical-stage biotechnology company focused on targeted therapies for patients with severe immune-mediated diseases.

HI-Bio's lead asset, felzartamab, an anti-CD38 antibody, is currently being evaluated for three leading indications, AMR, PMN and IgAN.

HI-Bio's lead asset, felzartamab, an anti-CD38 antibody, is currently being evaluated for several indications, including three leading indications, AMR, PMN and IgAN.

Felzartamab has received Breakthrough Therapy Designation and ODD from the FDA for development in the treatment of PMN and AMR.

Subsequent to our acquisition, felzartamab received ODD in the E.U.

in IgAN and solid organ transplantation.

in PMN, IgAN and solid organ transplantation.

The acquisition of HI-Bio is expected to augment our pipeline and build on our expertise in immunology.

Under the terms of this acquisition, we paid shareholders of HI-Bio approximately $ 1.15 billion at closing and may pay up to an additional $ 650.0 million in potential future development and regulatory milestone payments.

The $ 1.15 billion paid includes approximately $ 74.5 million related to HI-Bio's outstanding, non-vested equity awards, inclusive of employer taxes, of which $ 56.4 million was recognized as share-based compensation payments to settle non-vested equity awards attributable to the post-acquisition service period and therefore not reflected as a component of total purchase price paid.

Under the terms of this acquisition, we paid shareholders of HI-Bio approximately $ 1.15 billion at closing and may pay up to a total of $ 650.0 million in contingent development and regulatory milestone payments.

The $ 1.15 billion paid included approximately $ 74.5 million related to HI-Bio's outstanding, non-vested equity awards, inclusive of employer taxes, of which $ 56.4 million was recognized as share-based compensation payments to settle non-vested equity awards attributable to the post-acquisition service period and therefore not reflected as a component of total purchase price paid.

Of the total $ 56.4 million, we recognized approximately $ 42.5 million as a charge to research and development expense with the remaining $ 13.9 million as a charge to selling, general and administrative expense within our consolidated statements of income for the year ended December 31, 2024 .

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We funded this acquisition through available cash on hand and accounted for this acquisition as a business combination using the acquisition method of accounting in accordance with ASC Topic 805, Business Combinations , and recorded assets acquired and liabilities assumed at their respective fair values as of the acquisition date.

In addition to the lead program felzartamab, the HI-Bio pipeline acquired includes izastobart/HIB210, an anti-C5aR1 antibody currently in a Phase 1 trial, and the potential for continued development in a range of complement-mediated diseases.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Purchase Price Consideration

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The acquisition-date fair value of these milestones was approximately $ 485.1 million and was estimated utilizing a probability-adjusted discounted cash flow calculation using an appropriate discount rate dependent on the nature and timing of the milestone payments, which ranged from 6.2 % to 7.0 %, and probabilities of technological and regulatory success ranging from 67.0 % to near-certain probability.

Of the total contingent consideration, approximately $ 279.3 million related to milestones classified as short-term and reflected as a component of accrued expense and other with the remaining $ 205.8 million reflected as a component of other long-term liabilities within our consolidated balance sheets.

The short-term liability relates to the fourth patient dosed in a phase 3 clinical trial of felzartamab in a first and s econd indication, which would trigger milestone payments of $ 150.0 million each.

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Subsequent changes in the fair value of the contingent consideration obligation will be recognized as (gain) loss on fair value remeasurement of contingent consideration within our consolidated statements of income.

This fair value measurement was based on significant inputs that are not observable in the market and thus represent Level 3 fair value measurements.

Of the total contingent consideration recorded as of the transaction close date, approximately $ 279.3 million related to milestones classified as short-term and reflected as a component of accrued expense and other with the remaining $ 205.8 million reflected as a component of other long-term liabilities within our consolidated balance sheets.

The short-term liability related to the fourth patient dosed in a Phase 3 clinical trial of felzartamab in a first and s econd indication, which would each result in the achievement of a $ 150.0 million milestone payment.

Changes in the fair value of the contingent consideration obligation subsequent to the transaction close date are being recognized as (gain) loss on fair value remeasurement of contingent consideration within our consolidated statements of income.

This fair value measurement is based on significant inputs that are not observable in the market and thus represent Level 3 fair value measurements.

For additional information related to the fair value of this obligation, please read Note 8, Fair Value Measurements , to these consolidated financial statements.

Other Contractual Commitments:

We acquired HI-Bio's pre-existing in-license commitments under third-party agreements, which include tiered royalties on potential future sales of felzartamab and izastobart/HIB210, ranging from high-single digit to mid-teen percentages, as well as potential future development, regulatory and commercial milestone payments related to felzartamab and izastobart/HIB210 of up to $ 130.0 million, $ 230.0 million and $ 640.0 million, respectively.

Because the achievement of these milestones was not considered probable as of the transaction close date, such contingencies have not been recorded in our financial statements.

Preliminary Purchase Price Allocation

The following table summarizes the preliminary purchase price allocation of the separately identifiable assets acquired and liabilities assumed as of July 2, 2024:

(In millions) Estimated Fair Value

We acquired HI-Bio's pre-existing in-license commitments under third-party agreements with MorphoSys, which include tiered royalties on potential future sales ranging from high-single digit to mid-teen percentages, as well as potential future development, regulatory and commercial milestone payments of up to $ 130.0 million, $ 230.0 million and $ 640.0 million, respectively.

At the transaction close date the achievement of these milestones was not considered probable and therefore not recorded in our financial statements.

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Purchase Price Allocation

We finalized purchase accounting for this acquisition in the second quarter of 2025.

The following table summarizes the amounts recognized for assets acquired and liabilities assumed as of the acquisition date, and reflects measurement period adjustments made to the amounts initially recorded as of the acquisition date on July 2, 2024.

The related impact to our consolidated statements of income that would have been recognized in previous periods if the adjustments were recognized as of the acquisition date is immaterial.

(In millions) Amounts Recognized as of

Acquisition Date

(as adjusted)

Cash and cash equivalents $ 62.5

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Total identifiable net assets 1,361.4

Goodwill 256.5

Total assets acquired and liabilities assumed $ 1,622.4

There were no material purchase price allocation adjustments for the year ended December 31, 2024.

(1) Includes measurement period adjustments recorded in 2025 that increased prepaid expense and other assets by $ 0.4 million, net deferred tax liability by $ 4.9 million and goodwill by $ 4.5 million.

Intang ible assets:

Intangible assets comprised of $ 1.6 billion of IPR&D related to HI-Bio's lead asset felzartamab.

Intangible assets comprised of approximately $ 1.6 billion of IPR&D related to HI-Bio's lead asset felzartamab.

This includes $ 920.0 million of IPR&D related to felzartamab indication for IgAN, $ 450.0 million of IPR&D related to felzartamab indication for AMR and $ 265.0 million of IPR&D related to felzartamab indication for PMN.

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Goodwill was calculated as the excess of the consideration transferred over the net assets recognized and represents the future economic benefits arising from the other assets acq uired that could not be individually identified and separately recognized.

We recognized goodwill of approximately $ 256.5 million, which is not deductible for tax purposes.

We recognized goodwill of approximately $ 261.0 million, which includes measurement period adjustments, and is not deductible for tax purposes.

The goodwill recognized from our acquisition of HI-Bio is primarily the result of the deferred tax consequences from the transaction recorded for financial statement purposes.

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Acquisition-related expense, primarily comprised of advisory and legal fees, and other transaction costs, totaled approximately $ 2.8 million and were recorded within selling, general and administrative expense within our consolidated statements of income for the year ended December 31, 2024.

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Assumptions in the Allocations of Purchase Price

T he results of operations of HI-Bio, along with the estimated fair values of the assets acquired and liabilities assumed in the HI-Bio acquisition, have been included in our consolidated financial statements since the closing of the HI-Bio acquisition on July 2, 2024.

Our preliminary estimate of the fair value of the specifically identifiable assets acquired and liabilities assumed as of the date of acquisition is subject to the finalization of management's analysis related to certain matters, such as finalizing our assessment of income taxes.

The final determination of these fair values will be completed as additional information becomes available but no later than one year from the acquisition date.

The final determination may result in asset and liability fair values that are different than the preliminary estimates.

Subsequent to the acquisition date, our results of operations include the results of operations of HI-Bio.

HI-Bio operations had an immaterial impact on our results of operations for the year ended December 31, 2024.

Due to the immateriality of HI-Bio's historic revenue and expenses, additional pro forma information combining the results of operations of Biogen and HI-Bio have not been included.

Reata Pharmaceuticals, Inc.

On September 26, 2023, we completed the acquisition of all of the issued and outstanding shares of Reata, a biopharmaceutical company focused on developing therapeutics that regulate cellular metabolism and inflammation in serious neurologic diseases.

As a result of this transaction we acquired SKYCLARYS (omaveloxolone), the first and only drug approved in the U.S.

for the treatment of FA in adults and adolescents aged 16 years and older, as well as other clinical and preclinical pipeline programs.

The acquisition of Reata is expected to complement our global portfolio of neuromuscular and rare disease therapies.

The addition of SKYCLARYS is anticipated to provide potential operating synergies with SPINRAZA and QALSODY.

As a result of this transaction we acquired SKYCLARYS (omaveloxolone), the first and only drug approved in the U.S., the E.U.

and certain international markets for the treatment of FA in adults and adolescents aged 16 years and older, as well as other clinical and preclinical pipeline programs.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Under the terms of this acquisition, we paid Reata shareholders $ 172.50 in cash for each issued and outstanding Reata share, which totaled approximately $ 6.6 billion.

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The fair value was determined based on the estimated selling price of the inventory, less the remaining manufacturing and selling costs and a normal profit margin on those manufacturing and selling efforts.

This fair value step-up adjustment is being amortized to cost of sales within our consolidated statements of income as the inventory is sold, which is expected to be sold over a period of approximately 4 years from the acquisition date.

For the years ended December 31, 2024 and 2023, amortization from the fair value step-up adjustment was approximately $ 230.0 million and $ 31.5 million, respectively.

For the year ended December 31, 2024, amortization from the fair value step-up adjustment includes approximately $ 48.5 million of inventory used for clinical purposes, which is reflected within research and development expense within our consolidated statements of income.

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This fair value step-up adjustment is being amortized to cost of sales as the inventory is sold or research and development expense as the inventory is used for clinical purposes within our consolidated statements of income.

We expect this amount to be fully amortized by the end of 2028.

Intang ible assets:

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The estimated fair values of the program related intangible assets were determined using a multi-period excess earnings method, a form of the income approach, utilizing a discount rate of 14.3 % and the estimated fair value of the PRV was based on recent external purchase and sale transactions of similar vouchers.

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Our valuation of the SKYCLARYS commercialization rights reflects the assumption that, using an economic consumption model, the related $ 4.2 billion intangible asset will be amortized over its expected economic life.

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We assumed responsibility for a single-tenant, build-to-suit building of approximately 327,400 square feet of office and laboratory space located in Plano, Texas, with an initial lease term of 16 years.

We recorded a lease liability of approximately $ 151.8 million, which represents the net present value of rental expense over the remaining lease term of approximately 15 years, with a corresponding right-of-use asset of approximately $ 121.2 million, which represents our estimate of the fair value for a market participant of the current rental market in the Dallas, Texas area.

Included in our estimate of the market rental rate is the value of any leasehold improvements or tenant allowances related to the building.

We recorded a lease liability of approximately $ 151.8 million, which represented the net present value of rental expense over the remaining lease term of approximately 15 years, with a corresponding right-of-use asset of approximately $ 121.2 million, which represented our estimate of the fair value for a market participant of the rental market in the Dallas, Texas area.

Included in our estimate of the market rental rate was the value of any leasehold improvements or tenant allowances related to the building.

We do not intend to occupy this building and are evaluating opportunities to sublease the property.

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The first deferred payment of $ 812.5 million was received in April 2023 and the second deferred payment of $ 437.5 million was received in April 2024.

Prior to the sale, the carrying value of our investment in Samsung Bioepis totaled $ 581.6 million.

For the year ended December 31, 2022 , we recognized a pre-tax gain of approximately $ 1.5 billion related to this transaction, which was recorded in other (income) expense, net in our consolidated statements of income.

This pre-tax gain included reclassifications from AOCI to net income of approximately $ 58.9 million in cumulative translation losses, partially offset by approximately $ 57.0 million in gains resulting from the termination of our net investment hedge.

We concluded that the divestment of Samsung Bioepis did not meet the criteria to be reported as discontinued operations in our consolidated financial statements, as our decision to divest this business did not represent a strategic shift that would have a major effect on our operations and financial results.

We elected the fair value option and measured the payments due to us from Samsung BioLogics at fair value.

As of December 31, 2023, the estimated fair value of the remaining second deferred payment using a risk-adjusted discount rate of 5.8 % was approximately $ 430.0 million .

This payment has been classified as a Level 3 fair value

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measurement and is reflected in other current assets within our consolidated balance sheets as of December 31, 2023.

For the year ended December 31, 2024, we recognized a gain of approximately $ 7.5 million to reflect the change in fair value associated with the passage of time related to the second deferred payment due to us, which was received in April 2024.

For the year ended December 31, 2023, we recognized gains of approximately $ 13.7 million and $ 24.6 million to reflect the changes in fair value associated with changes in interest rates and the passage of time related to the first and second deferred payments due to us, respectively, which were received in April 2023 and April 2024, respectively.

For the year ended December 31, 2022, we recognized a gain of approximately $ 10.7 million and a loss of approximately $ 1.4 million to reflect the changes in fair value associated with changes in interest rates and the passage of time related to the first and second deferred payments due to us, respectively, which were received in April 2023 and April 2024, respectively.

These changes were recorded in other (income) expense, net within our consolidated statements of income.

As part of this transaction, we are also eligible to receive up to an additional $ 50.0 million upon the achievement of certain commercial milestones.

Our policy for contingent payments of this nature is to recognize the payments in the period the payments become realizable, which is generally the same period in which the payments are earned.

Additionally, for the year ended December 31, 2022, we recorded a discrete tax expense of approximately $ 257.9 million related to this transaction, which is reflected in income tax (benefit) expense in our consolidated statements of income.

Sale of Priority Review Voucher

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Our net portion of approximately $ 88.6 million was recognized in gain on sale of priority review voucher, net within our consolidated statements of income for the year ended December 31, 2024.

Sale of TOFIDENCE

In March 2025 we completed the sale of our regulatory and commercial rights in the U.S.

for TOFIDENCE, a tocilizumab biosimilar referencing ACTEMRA, to Organon.

Under the terms of this transaction, we received a payment

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of approximately $ 51.0 million in July 2025 a nd recognized a de minimis loss within our consolidated statements of income for the year ended December 31, 2025.

Sale of BYOOVIZ and OPUVIZ Rights

In October 2025 we completed the sale of our remaining commercial rights to two ophthalmology assets in Europe:

BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS, and OPUVIZ, an aflibercept biosimilar referencing EYLEA.

Samsung Bioepis will have full responsibility for commercialization of BYOOVIZ upon the transfer of commercial rights from Biogen back to Samsung Bioepis, which became effective as of January 2026.

Under the terms of this transaction, we received a payment of $ 28.0 million in November 2025 and recognized a minimal gain on disposal within our consolidated statements of income for the year ended December 31, 2025.

For additional information on our license arrangements with Samsung Bioepis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Restructuring

2023 Fit for Growth Restructuring Program

In 2023 we initiated additional cost saving measures as part of our Fit for Growth program to reduce operating costs, while improving operating efficiency and effectiveness.

The Fit for Growth program is expected to generate approximately $ 1.0 billion in gross operating expense savings by the end of 2025, some of which will be reinvested in various initiatives.

The Fit for Growth program is currently estimated to include net headcount reductions of approximately 1,000 employees and we expect to incur restructuring charges ranging from approximately $ 260.0 million to $ 280.0 million.

In 2023 we initiated cost saving measures as part of our Fit for Growth program to reduce operating costs, while improving operating efficiency and effectiveness.

The Fit for Growth program generated approximately $ 1.0 billion in gross operating expense savings by the end of 2025, some of which has been reinvested in various initiatives.

The Fit for Growth program included net headcount reductions of approximately 1,400 employees and we incurred total restructuring charges of approximately $ 320.0 million by the end of 2025.

Total charges incurred from our 2023 Fit for Growth program are summarized as follows:

For the Years Ended December 31,

(In millions) Severance Costs Accelerated Depreciation and Other Costs Total Severance

Costs Accelerated Depreciation and Other Costs Total

2025 2024 2023

(In millions) Severance Costs Accelerated Depreciation and Other Total Severance Costs Accelerated Depreciation and Other Total Severance Costs Accelerated Depreciation and Other Total

Selling, general and administrative $ — $ ( 1.4 ) $ ( 1.4 ) $ — $ 13.8 $ 13.8 $ — $ 23.3 $ 23.3

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Total charges $ 48.7 $ 8.7 $ 57.4 $ 24.2 $ 25.5 $ 49.7 $ 153.4 $ 59.1 $ 212.5

includes costs associated with items such as asset abandonment and write-offs, facility closure costs, pretax gains and losses resulting from the termination of certain leases, employee non-severance expense, consulting fees and other costs.

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Includes costs associated with items such as asset abandonment and write-offs, facility closure costs, pre-tax gains and losses resulting from the termination of certain leases, employee non-severance expense, consulting fees and other costs.

Reata Integration

Following the close of our Reata acquisition in September 2023, we implemented an integration plan designed to realize operating synergies through cost savings and avoidance.

Under this initiative, we estimate we will incur total integration charges of approximately $ 35.0 million, related to severance and employment costs.

These severance and employment costs were substantially incurred during 2023.

Under this initiative, we estimated we would incur total integration charges of approximately $ 35.0 million related to severance and employment costs, which were substantially incurred during 2023.

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Total charges incurred from our Reata integration are summarized as follows:

For the Years Ended December 31,

(In millions) Severance Costs Accelerated Depreciation and Other Costs Total Severance Costs Accelerated Depreciation and Other Costs Total

2025 2024 2023

(In millions) Severance Costs Accelerated Depreciation and Other Total Severance Costs Accelerated Depreciation and Other Total Severance Costs Accelerated Depreciation and Other Total

Selling, general and administrative $ — $ 6.8 $ 6.8 $ — $ 6.3 $ 6.3 $ — $ — $ —

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For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

HI-Bio Integration

Following the close of our HI-Bio acquisition in July 2024, we implemented an integration plan designed to realize operating synergies through cost savings and avoidance.

Under this initiative, we incurred approximately $ 2.6 million of severance and employment costs, which are reflected in restructuring charges within our consolidated statements of income for the year ended December 31, 2024 .

For additional information on our acquisition of HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

2022 Cost Saving Initiatives

In December 2021 and May 2022 we announced our plans to implement a series of cost-reduction measures during 2022.

These savings are being achieved through a number of initiatives, including reductions to our workforce, the substantial elimination of our commercial ADUHELM infrastructure, deprioritization of certain research and development programs, the consolidation of certain real estate locations and operating efficiencies across our selling, general and administrative and research and development functions.

Charges related to our 2022 cost saving initiatives were substantially incurred during 2022 with remaining payments expected to be made through 2026.

Total charges incurred from our 2022 cost saving initiatives are summarized as follows:

For the Years Ended December 31,

(In millions) Severance

Costs Accelerated Depreciation and Other Costs Total Severance Costs Accumulated Depreciation and Other Costs (1)

Restructuring charges $ ( 2.2 ) $ 2.6 $ 0.4 $ 112.6 $ 18.5 $ 131.1

Total charges $ ( 2.2 ) $ 2.6 $ 0.4 $ 112.6 $ 18.5 $ 131.1

(1) Amounts reflect a gain recorded during the third quarter of 2022 of approximately $ 5.3 million related to the partial termination of a portion of our lease located at 300 Binney Street.

For additional information on our 300 Binney Street lease modification, please read Note 12, Leases , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Restructuring Reserve

Charges and spending related to workforce reductions are summarized as follows:

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Restructuring reserve, December 31, 2023

Expense 181.6

Payment ( 73.8 )

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TYSABRI 965.0 700.4 1,665.4 920.0 795.0 1,715.0 997.9 879.0 1,876.9

FAMPYRA — 71.7 71.7 — 90.5 90.5 — 96.6 96.6

— 1.4 1.4 — 71.7 71.7 — 90.5 90.5

Multiple Sclerosis 2,372.5 1,666.4 4,038.9 2,190.5 2,159.3 4,349.8 2,436.0 2,225.9 4,661.9

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FLIXABI — 52.6 52.6 — 63.2 63.2 — 77.4 77.4

23.0 13.6 36.6 29.2 2.5 31.7 4.3 — 4.3

BYOOVIZ 13.0 19.4 32.4 23.0 13.6 36.6 29.2 2.5 31.7

TOFIDENCE 0.7 — 0.7 1.1 — 1.1 — — —

1.1 — 1.1 — — — — — —

Biosimilars 13.7 715.4 729.1 24.1 769.0 793.1 29.2 740.8 770.0

72.2 — 72.2 1.6 — 1.6 — — —

ZURZUVAE 195.1 — 195.1 72.2 — 72.2 1.6 — 1.6

0.4 1.7 2.1 2.8 7.5 10.3 2.4 7.8 10.2

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Total product revenue, net $ 3,547.9 $ 3,571.5 $ 7,119.4 $ 3,237.3 $ 3,976.2 $ 7,213.5 $ 3,141.4 $ 4,105.3 $ 7,246.7

(1) SKYCLARYS was obtained as part of our acquisition of Reata in September 2023.

SKYCLARYS became commercially available in the U.S.

during the second quarter of 2023 and we began recognizing revenue from SKYCLARYS in the U.S.

during the fourth quarter of 2023, subsequent to our acquisition.

SKYCLARYS was approved and became commercially available in the E.U.

(1) Effective January 1, 2025, our collaboration and license agreement for FAMPYRA global commercialization rights was terminated.

(2) SKYCLARYS became commercially available in the E.U.

during the first quarter of 2024.

(2) QALSODY became commercially available in the U.S.

during the second quarter of 2023 and commercially available in the E.U.

during the second quarter of 2024.

(3) BYOOVIZ became commercially available in certain international markets in 2023.

(4) TOFIDENCE became commercially available in the U.S.

(3) QALSODY became commercially available in the E.U.

during the second quarter of 2024.

(5) ZURZUVAE became commercially available in the U.S.

during the fourth quarter of 2023.

(4) Other includes FUMADERM and ADUHELM.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

We recognized revenue from two wholesalers accounting for 28.0 % and 15.8 % of gross product revenue in 2025, 25.9 % and 13.4 % of gross product revenue in 2024 and 27.0 % and 9.9 % of gross product revenue in 2023, respectively.

As of December 31, 2025, two wholesale distributors individually accounted for approximately 25.4 % and 15.2 % of net accounts receivable associated with our product sales, as compared to 27.2 % and 11.7 % as of December 31, 2024, respectively.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

An analysis of the change in reserves for discounts and allowances is summarized as follows:

December 31, 2024

As of December 31, 2025

(In millions) Discounts Contractual

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Balance, December 31, 2025 $ 115.7 $ 1,046.1 $ 49.0 $ 1,210.8

December 31, 2023

As of December 31, 2024

(In millions) Discounts Contractual

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Balance, December 31, 2024 $ 162.7 $ 880.8 $ 48.1 $ 1,091.6

December 31, 2022

As of December 31, 2023

(In millions) Discounts Contractual

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Total revenue-related reserves $ 1,210.8 $ 1,091.6

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Revenue from Anti-CD20 Therapeutic Programs

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for RITUXAN, GAZYVA and LUNSUMIO 420.2 392.0 409.4

392.0 409.4 547.0

Other revenue from anti-CD20 therapeutic programs 25.5 18.4 14.0

Total revenue from anti-CD20 therapeutic programs $ 1,860.6 $ 1,749.9 $ 1,689.6

(1) LUNSUMIO became commercially available in the U.S.

during the first quarter of 2023.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Approximately 18.8 %, 18.1 % and 17.2 % of our total revenue in 2025, 2024 and 2023, respectively, was derived from our collaboration arrangements with Genentech.

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during the first quarter of 2023.

For the year ended December 31, 2024, we recognized approximately $ 59.9 million of Alzheimer's collaboration revenue within our consolidated statements of income.

For the years ended December 31, 2025 and 2024, we recognized Alzheimer's collaboration revenue of approximately $ 177.7 million and $ 59.9 million, respectively, within our consolidated statements of income.

For the year ended December 31, 2023, our share of LEQEMBI product revenue, net, was fully offset by our share of cost of sales, including royalties, resulting in a zero net impact to Alzheimer's collaboration revenue within our consolidated statements of income.

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Contract Manufacturing Revenue

Contract manufacturing revenue primarily reflects amounts earned under contract manufacturing agreements with our strategic customers.

During the first quarter of 2023 we began recognizing contract manufacturing revenue for LEQEMBI, upon accelerated approval of LEQEMBI in the U.S.

Prior to accelerated approval, our share of contract manufacturing amounts related to LEQEMBI were recognized in research and development expense within our consolidated statements of income.

During the third quarter of 2019, we amended our agreement with a contract manufacturing customer pursuant to which we licensed certain of our manufacturing-related intellectual property to the customer.

In the second quarter of 2020, the customer received regulatory approval for its product that is being manufactured using certain of our manufacturing-related intellectual property.

As a result we were entitled to $ 500.0 million in a series of three payments.

The third and final payment became due upon the second anniversary of the regulatory approval and was received during the second quarter of 2022.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Contract manufacturing revenue primarily reflects amounts earned under contract manufacturing agreements with our strategic customers and batches of LEQEMBI related to our collaboration with Eisai.

Royalty and Other Revenue

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For additional information on our license arrangements with Samsung Bioepis and our collaboration arrangements with Eisai, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The components of inventory are summarized as follows:

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Long-term inventory is included in investments and other assets within our consolidated balance sheets.

We recorded approximately $ 1.3 billion of acquired inventory, which includes measurement period adjustments, related to SKYCLARYS as a result of our acquisition of Reata in September 2023.

For the years ended December 31, 2024 and 2023, amortization from the fair value step-up adjustment was approximately $ 230.0 million and $ 31.5 million, respectively.

As a result of our acquisition of Reata in September 2023 we recorded a fair value step-up adjustment related to the acquired inventory of SKYCLARYS of approximately $ 1.3 billion.

We expect this amount to be fully amortized by the end of 2028.

For the years ended December 31, 2025, 2024 and 2023, amortization from the fair value step-up adjustment was approximately $ 240.8 million, $ 230.0 million and $ 31.5 million, respectively.

For the years ended December 31, 2025 and 2024, amortization from the fair value step-up adjustment includes approximately $ 23.9 million and $ 48.5 million, respectively, of inventory used for clinical purposes, which is reflected in research and development expense within our consolidated statements of income.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

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Inventory amounts written down as a result of excess, obsolescence or unmarketability are charged to cost of sales, and totaled $ 29.2 million, $ 101.9 million and $ 124.4 million for the years ended December 31, 2025, 2024 and 2023, respectively.

During the first quarter of 2022 we wrote-off approximately $ 275.0 million of inventory related to ADUHELM, as a result of the final NCD, which was recognized in cost of sales within our consolidated statements of income for the year ended December 31, 2022.

We recognized approximately $ 136.0 million related to Eisai's 45.0 % share of these charges in collaboration profit sharing/(loss reimbursement) within our consolidated statements of income for the year ended December 31, 2022.

For additional information on our collaboration with Eisai, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Intangible Assets and Goodwill

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Amortization of acquired intangible assets, excluding impairment charges, totaled $ 507.1 million, $ 386.5 million and $ 240.6 million for the years ended December 31, 2025, 2024 and 2023, respectively.

The increase in amortization of acquired intangible assets, excluding impairment charges, was primarily due to amortization for the Reata acquisition acquired intangible assets associated with SKYCLARYS.

For the year ended December 31, 2024 , amortization and impairment of acquired intangible assets reflects the impact of a $ 40.0 million impairment charge related to intangible assets from other clinical programs we acquired from Reata, reducing the remaining book value of these IPR&D intangible assets to zero , and a $ 20.2 million impairment charge related to intangible assets associated with Samsung Bioepis commercialization rights terminated during the third quarter of 2024.

The increase in

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

amortization of acquired intangible assets, excluding impairment charges, was primarily due to amortization for the acquired intangible assets associated with SKYCLARYS and TYSABRI.

For the year ended December 31, 2025, amortization and impairment of acquired intangible assets reflects the impact of $ 7.9 million in impairment charges related to compounds acquired from HI-Bio.

For the year ended December 31, 2024, amortization and impairment of acquired intangible assets reflects the impact of a $ 40.0 million impairment charge related to intangible assets from other clinical programs we acquired from Reata, reducing the remaining book value of these IPR&D intangible assets to zero , and a $ 20.2 million impairment charge related to intangible assets associated with the termination of Samsung Bioepis' commercialization rights during the third quarter of 2024.

For the year ended December 31, 2023, we had no impairment charges.

For the year ended December 31, 2022, amortization and impairment of acquired intangible assets reflects the impact of a $ 119.6 million impairment charge related to vixotrigine (BIIB074) for the potential treatment of DPN, which was discontinued during the fourth quarter of 2022 based on regulatory, development and commercialization challenges, reducing the remaining book value of this IPR&D intangible asset to zero.

We also adjusted the value of our contingent consideration obligations related to this asset resulting in a pre-tax gain of approximately $ 209.1 million , which was recognized in (gain) loss on fair value remeasurement of contingent consideration within our consolidated statements of income for the year ended December 31, 2022.

We monitor events and expectations regarding product performance.

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Completed technology primarily relates to our other marketed products and programs acquired through asset acquisitions, licenses and business combinations.

Completed technology intangible assets are amortized over their estimated useful lives, which range between 1 to 31 years, with a remaining weighted average useful life of 13 years.

In connection with our acquisition of Reata in September 2023 we acquired SKYCLARYS, a commercially-approved product in the U.S., with an estimated fair value of approximately $ 4.2 billion , which includes measurement period adjustments.

During the first quarter of 2024 SKYCLARYS was approved in the E.U.

and became commercially available, which resulted in the reclassification of the related intangible asset, with an estimated fair value of approximately $ 2.3 billion, from IPR&D to completed technology.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Completed technology intangible assets are amortized over their estimated useful lives, which range between approximately 1 to 30 years, with a remaining weighted average useful life of 12 years, as of December 31, 2025.

IPR&D Related to Business Combinations

IPR&D represents the fair value assigned to research and development assets that we acquired as part of a business combination and had not yet reached technological feasibility at the date of acquisition.

Included in IPR&D balances are adjustments related to foreign currency exchange rate fluctuations.

We review amounts capitalized as acquired IPR&D for impairment annually, as of October 31, and whenever events or changes in circumstances indicate to us that the carrying value of the assets might not be recoverable.

The carrying value associated with our IPR&D assets as of December 31, 2024, relates to the IPR&D programs we acquired in connection with our acquisition of HI-Bio in July 2024, with an estimated fair value of approximately $ 1.6 billion.

The carrying value associated with our IPR&D assets as of December 31, 2023, relates to the IPR&D programs we acquired in connection with our acquisition of Reata in September 2023 with an estimated fair value of approximately $ 2.3 billion , which includes measurement period adjustments.

During the first quarter of 2024 SKYCLARYS was approved in the E.U.

and became commercially available, which resulted in the reclassification of the related intangible asset from IPR&D to completed technology.

The carrying value associated with our IPR&D assets as of December 31, 2025 and 2024, primarily relates to the IPR&D programs we acquired in connection with our acquisition of HI-Bio in July 2024, with an estimated fair value of approximately $ 1.6 billion.

Priority Review Voucher

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We recorded the PRV based on its estimated fair value of $ 100.0 million as an intangible asset.

The estimated fair value of the PRV was based on recent external purchase and sale transactions of similar vouchers.

For additional information on our acquisitions of Reata and HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

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(In millions) As of December 31, 2025

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The following table provides a roll forward of the changes in our goodwill balance:

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Goodwill resulting from Reata acquisition (2)

Other ( 1.5 ) 5.7

Goodwill, December 31 $ 6,491.1 $ 6,478.9

(1) Goodwill resulting from Reata acquisition for the year ended December 31, 2024, relates to Reata measurement period adjustments recognized during 2024.

(1) Goodwill resulting from the HI-Bio acquisition for the year ended December 31, 2025, relates to HI-Bio measurement period adjustments recognized during 2025.

(2) Goodwill resulting from the Reata acquisition for the year ended December 31, 2024, relates to Reata measurement period adjustments recognized during 2024.

(3) Other includes adjustments related to foreign currency exchange rate fluctuations.

For additional information on our acquisitions of Reata and HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

As of December 31, 2025 and 2024, we had no accumulated impairment losses related to goodwill.

Other includes adjustments related to foreign currency exchange rate fluctuations.

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Cash equivalents $ 2,233.2 $ — $ 2,233.2 $ —

Marketable debt securities:

Corporate debt securities 537.6 — 537.6 —

Government securities 648.8 — 648.8 —

Mortgage and other asset backed securities 52.7 — 52.7 —

Marketable equity securities 118.1 118.1 — —

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Other non-current assets:

Convertible notes (1)

35.0 — — 35.0

Plan assets for deferred compensation 52.2 — 52.2 —

Derivative contracts 0.4 — 0.4 —

Total $ 3,688.0 $ 118.1 $ 3,534.9 $ 35.0

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Derivative contracts $ 56.7 $ — $ 56.7 $ —

Contingent consideration obligations 291.2 — — 291.2

Other non-current liabilities:

Derivative contracts 2.2 — 2.2 —

Contingent consideration obligations 246.4 — — 246.4

Total $ 305.3 $ — $ 58.9 $ 246.4

(1) Convertible notes includes a $ 30.0 million convertible note we invested in as part of our strategic research arrangement with City Therapeutics during 2025, as well as a $ 5.0 million convertible note we invested into Neela Therapeutics, Inc.

We elected the fair value option for both convertible notes.

For additional information on the arrangement with City Therapeutics, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Fair Value Measurements on a Recurring Basis

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Other current assets:

Receivable from Samsung BioLogics (1)

430.0 — — 430.0

Derivative contracts 62.5 — 62.5 —

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Total $ 1,949.9 $ 179.7 $ 1,770.2 $ —

Other current liabilities:

Derivative contracts $ 11.7 $ — $ 11.7 $ —

Contingent consideration obligations 291.2 — — 291.2

Other non-current liabilities:

Contingent consideration obligations 221.6 — — 221.6

Total $ 524.5 $ — $ 11.7 $ 512.8

(1) Represents the fair value of the second deferred payment due from Samsung BioLogics as a result of the sale of our 49.9 % equity interest in Samsung Bioepis to Samsung BioLogics during the second quarter of 2022, for which we elected the fair value option.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

Our marketable equity securities represent investments in publicly traded equity securities.

Our ability to liquidate our investments in Denali and Sage may be limited by the size of our interest, the volume of market related activity, our

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

concentrated level of ownership and potential restrictions resulting from our status as a collaborator.

Our ability to liquidate our investments in Denali may be limited by the size of our interest, the volume of market-related activity, our concentrated level of ownership and potential restrictions resulting from our status as a collaborator.

Therefore, we may realize significantly less than the current value of such investments.

For additional information on our investments in Denali, Sangamo and Sage common stock, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

For additional information on our investments in Denali common stock, please read Note 9, Financial Instruments , and Note 18, Other Consolidated Financial Statement Detail , to these consolidated financial statements.

There have been no material impairments of our assets measured and carried at fair value as of December 31, 2025 and 2024.

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Level 3 Assets and Liabilities Held at Fair Value

The following table presents quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our Level 3 financial assets and liabilities measured at fair value on a recurring basis:

The following tables present quantitative information, as of the dates indicated, about the valuation techniques and significant unobservable inputs used in the valuation of our Level 3 financial assets and liabilities measured at fair value on a recurring basis:

Quantitative Information about Level 3 Fair Value Measurements

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Expected timing of achievement of development milestones 2028 - 2030

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Quantitative Information about Level 3 Fair Value Measurements

As of December 31, 2024

(In millions) Fair Value Valuation Technique Significant

Unobservable Input(s) Range Weighted

Contingent consideration obligations $ 512.8 Discounted cash flow Discount rate 6.2 % - 6.3 %

Expected timing of achievement of development milestones 2025 - 2030

The weighted average discount rates were calculated based on the relative fair values of each distinct contingent consideration obligation related to our acquisition of HI-Bio in July 2024.

In addition, we apply various probabilities of technological and regulatory success to the valuation models to estimate the fair values of these contingent consideration obligations, which ranged from 68.3 % to near certain probability as of December 31, 2024.

In addition, we apply various probabilities of technological and regulatory success to the valuation models to estimate the fair values of these contingent consideration obligations, which ranged from approximate ly 70.0 % to 95.0 % as of December 31, 2025.

There were no transfers of assets or liabilities into or out of Level 3 as of December 31, 2025 and 2024.

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The following table provides a roll forward of the fair value of our contingent consideration obligations, which were classified as Level 3 measurements:

(In millions) As of December 31, 2024

As of December 31,

(In millions) 2025 2024

Fair value, beginning of year $ 512.8 $ —

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Changes in fair value 33.6 27.7

Payments ( 300.0 ) —

Fair value, end of year $ 246.4 $ 512.8

Changes in the fair values of our contingent consideration obligations are recorded in (gain) loss on fair value remeasurement of contingent consideration in our consolidated statements of income.

Changes in the fair values of our contingent consideration obligations, other than changes due to payments, are recognized as a (gain) loss on fair value remeasurement of contingent consideration within our consolidated statements of income.

The fair values of the contingent consideration liabilities were based on a probability-adjusted discounted cash flow calculation using Level 3 fair value measurements and inputs.

For additional information on the valuation techniques and inputs utilized in the valuation of our financial assets and liabilities, please read Note 1, Summary of Significant Accounting Policies, to these consolidated financial statements.

As of December 31, 2024, approximately $ 291.2 million of the fair value of the total contingent consideration obligation was classified as short-term and reflected as a component of accrued expense and other within our consolidated balance sheets with the remaining $ 221.6 million reflected as a component of other long-term liabilities in our consolidated balance sheets.

As of December 31, 2025, the total remaining fair value of our contingent consideration obligations of $ 246.4 million was classified as long-term and reflected as a component of other long-term liabilities within our consolidated balance sheets.

As of December 31, 2024, approximately $ 291.2 million of the fair value of our total contingent consideration obligations was classified as short-term and reflected as a component of accrued expense and other with the remaining $ 221.6 million reflected as a component of other long-term liabilities within our consolidated balance sheets.

For the year ended December 31, 2025, changes in the fair value of our contingent consideration obligations were primarily due to changes in interest rates used to revalue our contingent consideration liabilities and the passage of time.

For the year ended December 31, 2024, changes in the fair value of our contingent consideration obligations were primarily due to changes in interest rates used to revalue our contingent consideration liabilities, the passage of time and updates to the expected timing of achieving certain milestones which will trigger contingent consideration payments.

During the second quarter of 2025 the first milestone related to the fourth patient dosed in a Phase 3 clinical trial of felzartamab for AMR was achieved, resulting in a $ 150.0 million milestone payment made to the former shareholders of HI-Bio, which was paid during the third quarter of 2025.

In October 2025 the second milestone related to the fourth patient dosed in a Phase 3 clinical trial of felzartamab for IgAN was achieved, resulting in a

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

For the year ended December 31, 2024, the changes in the fair value of our contingent consideration obligations were primarily due to changes in interest rates used to revalue our contingent consideration liabilities, the passage of time and updates to the expected timing of achieving certain milestones which will trigger contingent consideration payments.

$ 150.0 million milestone payment made to the former shareholders of HI-Bio, which was paid during the fourth quarter of 2025.

Financial Instruments Not Carried at Fair Value

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Current portion:

2023 Term Loan 364-day tranche $ — $ 150.0

4.050 % Senior Notes due September 15, 2025 (1)

Current portion of notes payable and term loan 1,741.0 150.0

$ — $ 1,741.0

Current portion of notes payable — 1,741.0

Non-current portion:

2023 Term Loan three-year tranche — 500.0

4.050 % Senior Notes due September 15, 2025

2.250 % Senior Notes due May 1, 2030

1,378.7 1,295.6

5.050 % Senior Notes due January 15, 2031 (1)

5.750 % Senior Notes due May 15, 2035 (1)

5.200 % Senior Notes due September 15, 2045

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3.150 % Senior Notes due May 1, 2050

943.7 1,049.0

3.250 % Senior Notes due February 15, 2051

Non-current portion of notes payable and term loan 3,696.2 6,137.7

Total notes payable and term loan $ 5,437.2 $ 6,287.7

In connection with our acquisition of Reata we drew $ 1.0 billion from our 2023 Term Loan, comprised of a $ 500.0 million floating rate 364-day tranche and a $ 500.0 million floating rate three-year tranche.

As of December 31, 2024, our 2023 Term Loan was repaid in full.

For additional information on our 2023 Term Loan, please read Note 13, Indebtedness , to these consolidated financial statements.

6.450 % Senior Notes due May 15, 2055 (1)

Non-current portion of notes payable 5,678.1 3,696.2

Total notes payable $ 5,678.1 $ 5,437.2

(1) In May 2025 we issued our 2025 Senior Notes for an aggregate principal amount of $ 1.75 billion.

In June 2025 we used the net proceeds from the sale of our 2025 Senior Notes to redeem in full our 4.050 % Senior Notes due September 15, 2025, prior to maturity.

For additional information, please read Note 13, Indebtedness , to these consolidated financial statements.

The fair values of each of our series of Senior Notes were determined through market, observable and corroborated sources.

The changes in the fair values of our Senior Notes as of December 31, 2024, compared to 2023, are primarily related to increases in U.S.

treasury yields partially offset by a decrease in credit spreads used to value our Senior Notes since December 31, 2023.

The changes in the fair values of our Senior Notes as of December 31, 2025, compared to 2024, are primarily related to decreases in credit spreads used to value our Senior Notes since December 31, 2024.

For additional information related to our Senior Notes, please read Note 13, Indebtedness , to these consolidated financial statements.

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Money market funds $ 2,027.7 $ 1,664.9

Overnight reverse repurchase agreements 70.0 —

Short-term debt securities 15.4 —

Commercial paper 120.1 —

Total $ 2,233.2 $ 1,664.9

The carrying value of our money market funds approximates fair value due to their short-term maturities.

The carrying value of our money market funds, overnight reverse repurchase agreements, short-term debt securities and commercial paper, including accrued interest, approximates fair value due to their short-term maturities.

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Our marketable equity securities gains (losses) are recorded in other (income) expense, net in our consolidated statements of income.

The following tables summarize our available-for-sale marketable equity securities:

The following tables summarize our marketable debt and equity securities, classified as available-for-sale:

As of December 31, 2025

(In millions) Amortized

Marketable debt securities:

Corporate debt securities:

Current $ 246.8 $ — $ — $ 246.8

Non-current 290.6 0.2 — 290.8

Government securities:

Current 560.4 — — 560.4

Non-current 88.4 — — 88.4

Mortgage and other asset backed securities:

Non-current 52.7 — — 52.7

Total marketable debt securities $ 1,238.9 $ 0.2 $ — $ 1,239.1

Marketable equity securities:

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Marketable equity securities:

Marketable equity securities, current $ 31.6 $ — $ ( 21.0 ) $ 10.6

Marketable equity securities, non-current $ 668.7 $ — $ ( 489.0 ) $ 179.7

Total marketable equity securities $ 668.7 $ — $ ( 489.0 ) $ 179.7

Summary of Contractual Maturities:

Available-for-Sale Debt Securities

The estimated fair value and amortized cost of our marketable debt securities classified as available-for-sale by contractual maturity are summarized as follows:

As of December 31, 2025

(In millions) Estimated

Fair Value Amortized

Due in one year or less $ 807.2 $ 807.2

Due after one year through five years 419.5 419.3

Due after five years 12.4 12.4

Total marketable debt securities $ 1,239.1 $ 1,238.9

The average maturity of our marketable debt securities classified as available-for-sale as of December 31, 2025, was approximately 5 months.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Proceeds from Marketable Debt Securities

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Realized losses — — 18.4

We partially funded our Reata acquisition through available cash, cash equivalents and marketable securities.

As of December 31, 2023, we had sold all of our marketable debt securities.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

Realized losses for the year ended December 31, 2023, primarily relate to sales of U.S.

treasuries and corporate bonds.

Realized losses for the year ended December 31, 2022, primarily relate to sales of corporate bonds, agency mortgage-backed securities and other asset-backed securities.

Strategic Investments

Our strategic investment portfolio includes investments in equity securities of certain biotechnology companies, which are reflected within our disclosures included in Note 8, Fair Value Measurements , to these consolidated financial statements, as well as venture capital funds where the underlying investments are in equity securities of certain biotechnology companies and non-marketable equity securities.

As of December 31, 2024, our strategic investment portfolio was comprised of investments totaling $ 226.7 million which are included in investments and other assets in our consolidated balance sheets.

As of December 31, 2023, our strategic investment portfolio was comprised of investments totaling $ 460.7 million which are included in other current assets and investments and other assets in our consolidated balance sheets.

The decrease in our strategic investment portfolio for the year ended December 31, 2024, was primarily due to the decrease in the fair value of our investment in Sage common stock, partially offset by an increase in the fair value of our investment in Denali common stock.

Additionally, during 2024 we sold a portion of our Denali common stock and the remaining portion of our Sangamo common stock.

For additional information on our investments in Denali, Sangamo and Sage common stock, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

As of December 31, 2025 and 2024, our strategic investment portfolio was comprised of investments totaling $ 186.6 million and $ 226.7 million, respectively, which are included in investments and other assets within our consolidated balance sheets.

The decrease in our strategic investment portfolio as of December 31, 2025, compared to 2024, was primarily due to the decrease in the fair value of our investment in Denali common stock as well as the sale of our remaining investment in Sage common stock during the third quarter of 2025.

For additional information on our investments in Denali and Sage common stock, please read Note 8, Fair Value Measurements , and Note 18, Other Consolidated Financial Statement Detail , to these consolidated financial statements.

Derivative Instruments

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We enter into foreign currency forward contracts and foreign currency options with financial institutions with the primary objective to mitigate the impact of foreign currency exchange rate fluctuations on our international revenue and operating expense.

Foreign currency forward contracts and foreign currency options in effect as of December 31, 2024 and 2023, had durations of 1 to 12 months.

Foreign currency forward contracts and foreign currency options in effect as of December 31, 2025 and 2024, had durations of 1 to 21 months and 1 to 12 months, respectively.

These contracts have been designated as cash flow hedges and unrealized gains and losses on the portion of these foreign currency forward contracts and foreign currency options that are included in the effectiveness test are reported in AOCI.

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We recognize all cash flow hedge reclassifications from AOCI and fair value changes of excluded portions in the same line item in our consolidated statements of income that have been impacted by the hedged item.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The notional amount of foreign currency forward contracts and foreign currency options that were entered into to hedge forecasted revenue and operating expense is summarized as follows:

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Net unrealized gains (losses) $ ( 73.3 ) $ 50.3 $ ( 34.8 )

We expect the net unrealized gains of approximately $ 50.3 million to be settled over the next 12 months, with any amounts in AOCI to be reported as an adjustment to revenue or operating expense.

We expect the net unrealized losses of approximately $ 73.3 million to be settled over the next 15 months, of which approximately $ 68.5 million of these net unrealized losses are expected to be settled over the next 12 months, with any amounts in AOCI to be reported as an adjustment to revenue or operating expense.

We consider the impact of our and our counterparties’ credit risk on the fair value of the contracts as well as the ability of each party to execute its contractual obligations.

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Operating expense 21.3 ( 12.9 ) 3.7 Operating expense — — —

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Net Investment Hedges - Hedging Instruments

In February 2012 we entered into a joint venture agreement with Samsung BioLogics establishing an entity, Samsung Bioepis, to develop, manufacture and market biosimilar products.

Our investment in the equity of Samsung Bioepis related to this transaction was exposed to the currency fluctuations in the South Korean won.

In order to mitigate the currency fluctuations between the U.S.

dollar and South Korean won, we entered into foreign currency forward contracts.

These contracts were designated as net investment hedges.

In April 2022 we completed the sale of our 49.9 % equity interest in Samsung Bioepis to Samsung BioLogics and closed these foreign currency forward contracts.

Upon completing this sale, the cumulative gains on our net investment hedges of $ 57.0 million were reclassified from AOCI and reflected within the total pre-tax gain recognized from the sale, which was recorded in other (income) expense, net in our consolidated statements of income for the year ended December 31, 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

The following table summarizes the effect of our net investment hedges in our consolidated financial statements:

For the Year Ended December 31, 2022

Net Gains/(Losses)

Recognized in Other Comprehensive Income (Effective Portion) (in millions) Net Gains/(Losses)

Recognized in Other Comprehensive Income (Amounts Excluded from Effectiveness Testing) (in millions) Net Gains/(Losses)

Recognized in Net Income

(Amounts Excluded from Effectiveness Testing) (in millions)

Location 2022 Location 2022 Location 2022

Gains (losses) on net investment hedge (1)

$ 20.4 Gains (losses) on net investment hedge (1)

$ ( 3.2 ) Other (income) expense (1)

(1) Beginning in the second quarter of 2022 we no longer held net investment hedges as they were closed with the sale of our 49.9 % equity interest in Samsung Bioepis in April 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

For additional information on our collaboration arrangements with Samsung Bioepis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Foreign Currency Forward Contracts - Other Derivative Instruments

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The aggregate notional amount of these outstanding foreign currency forward contracts was $ 1,193.7 million and $ 738.7 million as of December 31, 2025 and 2024, respectively.

Net losses of $ 49.7 million, net gains of $ 3.8 million and net losses of $ 34.7 million related to these contracts were recorded as a component of other (income) expense, net for the years ended December 31, 2024, 2023 and 2022, respectively.

Net gains of $ 33.5 million, net losses of $ 49.7 million and net gains of $ 3.8 million related to these contracts were recorded as a component of other (income) expense, net for the years ended December 31, 2025, 2024 and 2023, respectively.

Summary of Derivative Instruments

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The amounts in the table below would not be substantially different if the derivative assets and liabilities were offset.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The following table summarizes the fair value and presentation in our consolidated balance sheets of our outstanding derivative instruments, including those designated as hedging instruments:

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Asset derivative instruments Other current assets $ 0.1 $ 58.4

Investments and other assets 0.4 —

Liability derivative instruments Accrued expense and other 54.0 0.3

Other long-term liabilities 2.2 —

Other Derivative Instruments:

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Liability derivative instruments Accrued expense and other 2.7 11.4

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Property, Plant and Equipment

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Total cost (1)

5,986.6 5,852.1

accumulated depreciation ( 2,931.2 ) ( 2,670.8 )

Total property, plant and equipment, net $ 3,055.4 $ 3,181.3

(1) During the first quarter of 2024 the second manufacturing suite at our Solothurn, Switzerland facility become operational, resulting in approximately $ 717.3 million of fixed assets being placed into service.

Depreciation expense totaled $ 272.8 million, $ 286.7 million and $ 254.2 million for the years ended December 31, 2025, 2024 and 2023, respectively.

For the years ended December 31, 2025, 2024 and 2023, we capitalized interest costs related to construction in progress totaling approximately $ 3.4 million, $ 3.2 million and $ 21.7 million, respectively.

Solothurn, Switzerland Manufacturing Facility

In order to support our future growth and drug development pipeline, we built a large-scale biologics manufacturing facility in Solothurn, Switzerland.

This facility includes 393,000 square feet related to a large-scale biologics manufacturing facility, 290,000 square feet of warehouse, utilities and support space and 51,000 square feet of administrative space.

As of December 31, 2023, we had approximately $ 728.8 million capitalized as construction in progress related to this facility.

In the second quarter of 2021 a portion of this facility (the first manufacturing suite) received a GMP multi-product license from SWISSMEDIC and was placed into service.

The second manufacturing suite, which was also licensed to operate by SWISSMEDIC, became operational in the first quarter of 2024, resulting in approximately $ 717.3 million of fixed assets being placed into service.

Solothurn has been approved for the manufacture of LEQEMBI.

125 Broadway Building Sale

In September 2022 we completed the sale of our building and land parcel located at 125 Broadway for an aggregate sales price of approximately $ 603.0 million, which is inclusive of a $ 10.8 million tenant allowance.

This sale resulted in a pre-tax gain on sale of approximately $ 503.7 million, net of transaction costs, which is reflected within gain on sale of building, net in our consolidated statements of income for the year ended December 31, 2022.

This transaction included approximately $ 79.2 million of property, plant and equipment, net, which comprised of approximately $ 72.6 million for buildings, approximately $ 1.6 million for land and approximately $ 5.0 million for machinery and equipment.

We lease real estate, including laboratory and office space, and certain equipment.

Our leases have remaining lease terms ranging from less than one year to fourteen years .

Certain leases include one or more options to renew, exercised at our sole discretion, with renewal terms that can extend the lease term from less than one year to ten years .

Our leases have remaining lease terms ranging from less than one year to twenty-two years .

Certain leases include one or more options to renew, exercised at our sole discretion, with renewal terms that can extend the lease term from less than one year to fifteen years .

In addition, we sublease certain real estate to third parties.

Our sublease portfolio consists of operating leases, with remaining lease terms ranging from less than one year to five years .

Our sublease portfolio consists of operating leases, with remaining lease terms ranging from three years to four years .

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Operating lease assets obtained in exchange for lease obligations 30.7 16.9 146.0

6100 Legacy Drive Lease

In connection with our acquisition of Reata in September 2023 we assumed responsibility for a single-tenant, build-to-suit building of approximately 327,400 square feet of office and laboratory space located in Plano, Texas, with an initial lease term of 16 years.

Included in our estimate of the market rental rate is the value of any leasehold improvements or tenant allowances related to the building.

We do not intend to occupy this building and are evaluating opportunities to sublease the property.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

125 Broadway Building Sale and Leaseback Transaction

In connection with the sale of our 125 Broadway building during the third quarter of 2022, we simultaneously leased back the building for a term of approximately 5.5 years, which resulted in the recognition of approximately $ 168.2 million in a new lease liability and right-of-use asset recorded within our consolidated balance sheets as of December 31, 2022.

The sale and immediate leaseback of this building qualified for sale and leaseback treatment and is classified as an operating lease.

For additional information on the sale of our 125 Broadway building, please read Note 11, Property, Plant and Equipment , to these consolidated financial statements.

300 Binney Street Lease Modification

In September 2022 we entered into an agreement to partially terminate a portion of our lease located at 300 Binney Street, as well as to reduce the lease term for the majority of the remaining space.

The agreement was driven by our 2022 efforts to reduce costs by consolidating real estate locations.

The transaction was treated as a lease modification as of the effective date and resulted in the derecognition of a right-of-use asset of approximately $ 47.4 million and a lease liability of approximately $ 52.7 million, which resulted in a gain of approximately $ 5.3 million, which was recorded within restructuring charges in our consolidated statements of income for the year ended December 31, 2022.

As of December 31, 2024, we no longer lease any portion of this space.

New Corporate Headquarters Lease

In March 2025 we entered into a lease agreement with MIT Investment Management Company and BioMed Realty for the lease of approximately 580,000 square feet of office and research and development space located at 75 Broadway, Cambridge, Massachusetts, which will be used as our new global corporate headquarters, as well as integrating our research and development and technical operations teams alongside our North American commercial organization.

As part of a multi-year real estate consolidation plan that is expected to result in a reduction of approximately 40 % of our real estate footprint in Massachusetts, this new lease is intended to replace two existing leases, both in Cambridge, Massachusetts, including our current corporate headquarters.

We expect the initial lease term of approximately 15.5 years to commence on May 31, 2028.

The estimated minimum lease payments as a result of the new lease total approximately $ 1.5 billion over the initial lease term.

We have an option to extend the lease for three extension periods of five years each and one six-month short-term extension, at then market-based rates.

We will account for this lease as a right-of-use asset and lease liability upon the lease commencement date.

For additional information on our accounting policies relating to leases, please read Note 1, Summary of Significant Accounting Policies - Leases , to these consolidated financial statements.

As part of our acquisition of Reata, we assumed responsibility for a single-tenant, build-to-suit building of approximately 327,400 square feet of office and laboratory space located in Plano, Texas, with an initial lease term of 16 years.

We recorded a lease liability of approximately $ 151.8 million, with a corresponding right-of-use asset of approximately $ 121.2 million.

We are continuing to evaluate opportunities to sublease the property.

During the fourth quarter of 2025 we performed an impairment assessment for this right-of use asset.

This assessment involved estimating undiscounted future cash flows, including potential sublease income and remaining lease obligations.

Given the carrying value exceeded the estimated undiscounted cash flows, primarily as the result of lower expected sublease income, we determined fair value using market data for similar properties and a probability-adjusted discounted cash flow calculation using a discount rate of 5.0 %.

As a result of this impairment assessment, we recorded an impairment charge of approximately $ 52.9 million related to this Reata lease, which is included in impairment of ROU asset within our consolidated statements of income for the year ended December 31, 2025.

This fair value measurement was based on significant inputs that are not observable in the market and thus represent a Level 3 fair value measurement.

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Current portion:

2023 Term Loan 364-day tranche $ — $ 150.0

4.050 % Senior Notes due September 15, 2025

Current portion of notes payable and term loan $ 1,748.6 $ 150.0

$ — $ 1,748.6

Current portion of notes payable $ — $ 1,748.6

Non-current portion:

2023 Term Loan three-year tranche $ — $ 500.0

4.050 % Senior Notes due September 15, 2025

2.250 % Senior Notes due May 1, 2030

$ 1,495.7 $ 1,494.7

5.050 % Senior Notes due January 15, 2031

5.750 % Senior Notes due May 15, 2035

5.200 % Senior Notes due September 15, 2045

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3.250 % Senior Notes due February 15, 2051

Non-current portion of notes payable and term loan $ 4,547.2 $ 6,788.2

As of December 31, 2024, our 2023 Term Loan was repaid in full.

As of December 31, 2024, we were in compliance with our senior note covenants and term loan covenants.

6.450 % Senior Notes due May 15, 2055

Non-current portion of notes payable $ 6,286.8 $ 4,547.2

As of December 31, 2025, we were in compliance with our senior note covenants.

2025 Senior Notes

On May 12, 2025, we issued senior unsecured notes for an aggregate principal amount of $ 1.75 billion, consisting of the following:

• $ 400.0 million of 5.050 % Senior Notes due January 15, 2031, valued at 99.981 % of par;

• $ 650.0 million of 5.750 % Senior Notes due May 15, 2035, valued at 99.924 % of par;

• $ 700.0 million of 6.450 % Senior Notes due May 15, 2055, valued at 99.657 % of par.

Our 2025 Senior Notes are senior unsecured obligations and may be redeemed at our option at any time at 100 % of the principal amount plus accrued interest and, until a specified period before maturity, a specified make-whole amount.

Our 2025 Senior Notes contain a change-of-control provision that, under certain circumstances, may require us to purchase our 2025 Senior Notes at a price equal to 101 % of the principal amount plus accrued and unpaid interest to the date of repurchase.

We incurred approximately $ 13.9 million of costs associated with this offering which have been recorded as a reduction to the carrying amount of the debt on our consolidated balance sheets.

These costs will be amortized as additional interest expense using the effective interest rate method over the period from issuance through maturity.

The discounts will be amortized as additional interest expense over the period from issuance through maturity using the effective interest rate method.

Interest on our 2031 Senior Notes is payable January 15 and July 15 of each year, commencing January 15, 2026.

Interest on our 2035 Senior Notes and 2055 Senior Notes is payable May 15 and November 15 of each year, commencing on November 15, 2025.

2023 Term Loan Credit Agreement

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The remaining $ 150.0 million portion of the 364-day tranche was repaid during the first quarter of 2024.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Additionally, during the first quarter of 2024 we repaid $ 250.0 million of the three-year tranche, with the remaining $ 250.0 million portion being subsequently repaid in full during the second quarter of 2024.

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Interest on our 2021 Exchange Offer Senior Notes is payable February 15 and August 15 of each year, commencing August 15, 2021.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

2020 Senior Notes

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• $ 1.12 billion aggregate principal amount of 5.200 % Senior Notes due September 15, 2045, valued at 99.294 % of par.

• $ 1.12 billion aggregate principal amount of 5.20 % Senior Notes due September 15, 2045, valued at 99.294 % of par.

Our 2015 Senior Notes are senior unsecured obligations and may be redeemed at our option at any time at 100.0 % of the principal amount plus accrued interest and a specified make-whole amount.

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Interest on our 2015 Senior Notes is payable March 15 and September 15 of each year, commencing March 15, 2016.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

4.050 % Senior Notes due September 15, 2025

On September 15, 2015, we issued $ 1.0 billion aggregate principal amount of our 3.625 % Senior Notes due September 15, 2022, at 99.920 % of par.

Our 3.625 % Senior Notes were senior unsecured obligations.

In July 2022 we redeemed our 3.625 % Senior Notes prior to their maturity and recognized a net pre-tax charge of approximately $ 2.4 million upon the extinguishment of these Senior Notes, which primarily reflects the payment of an early call premium as well as the write-off of remaining unamortized original debt issuance costs and discount balances.

These charges were recognized as interest expense in other (income) expense, net in our consolidated statements of income for the year ended December 31, 2022.

On September 15, 2015, we issued $ 1.75 billion aggregate principal amount of 4.050 % Senior Notes due September 15, 2025, at 99.764 % of par.

In June 2025 we used the net proceeds from the sale of our 2025 Senior Notes to redeem our 4.050 % Senior Notes due September 15, 2025, prior to maturity.

No gain or loss was recognized upon redemption.

2024 Revolving Credit Facility

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As of December 31, 2025, we had no outstanding borrowings and were in compliance with all covenants under this facility.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Debt Maturity

The total gross payments due under our debt arrangements are as follows:

The total gross principal payments due under our debt arrangements are as follows:

(In millions) As of December 31, 2025

2025 $ 1,750.0

2031 and thereafter 5,067.3

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All shares repurchased under our 2020 Share Repurc hase Program were retired.

Under our 2020 Share Repurchase Program, we repurchased and retired approximately 3.6 million shares of our common stock at a cost of approximately $ 750.0 million during the year ended December 31, 2022 .

There were no share repurchases of our common stock during the years ended December 31, 2024 and 2023.

Approximately $ 2.1 billion remained available under our 2020 Share Repurchase Program as of December 31, 2024.

Amounts paid to repurchase shares in excess of their par value are allocated between additional paid-in-capital and retained earnings, with payments in excess of our additional paid-in-capital balance recorded as a reduction to retained earnings.

There were no

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

repurchases of our common stock during the years ended December 31, 2025, 2024 and 2023.

Approximately $ 2.1 billion remained available under our 2020 Share Repurchase Program as of December 31, 2025.

Accumulated Other Comprehensive Income (Loss)

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December 31, 2025

(In millions) Unrealized Gains (Losses) on Cash Flow Hedges,

(In millions) Unrealized Gains (Losses) on Securities Available for Sale, Net of Tax Unrealized Gains (Losses) on Cash Flow Hedges,

Net of Tax Unrealized Gains (Losses) on Pension Benefit Obligation,

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December 31, 2024

(In millions) Unrealized Gains (Losses) on Securities Available for Sale, Net of Tax Unrealized Gains (Losses) on Cash Flow Hedges,

(In millions) Unrealized Gains (Losses) on Cash Flow Hedges,

Net of Tax Unrealized Gains (Losses) on Pension Benefit Obligation,

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Net of Tax Unrealized Gains (Losses) on Cash Flow Hedges,

Net of Tax Gains (Losses) on Net Investment Hedges,

Net of Tax (1)

Unrealized Gains (Losses) on Pension Benefit Obligation,

Net of Tax Unrealized Gains (Losses) on Pension Benefit Obligation,

Net of Tax Currency Translation Adjustments,

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Balance, December 31, 2023 $ — $ ( 25.0 ) $ ( 2.6 ) $ ( 126.1 ) $ ( 153.7 )

(1) Beginning in the second quarter of 2022 we no longer held net investment hedges as they were closed with the sale of our 49.9 % equity interest in Samsung Bioepis in April 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

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5.5 ( 0.6 ) ( 1.7 ) Income tax (benefit) expense

Gains (losses) on net investment hedges (1)

— — 38.1 Other (income) expense, net

Currency translation adjustments — — ( 58.9 ) Other (income) expense, net

Total reclassifications, net of tax $ ( 45.9 ) $ 4.2 $ ( 0.1 )

(1) Beginning in the second quarter of 2022 we no longer held net investment hedges as they were closed with the sale of our 49.9% equity interest in Samsung Bioepis in April 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

Earnings per Share

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Time-vested restricted stock units 0.5 0.3 0.7

Market stock units — — 0.1

Performance stock units settled in stock 0.1 — 0.2

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Amounts excluded from the calculation of net income per diluted share because their effects were anti-dilutive were insignificant.

Earnings per share for the year ended December 31, 2022, reflects the repurchase of approximately 3.6 million shares of our common stock, respectively, under our 2020 Share Repurchase Program.

There were no share repurchases of our common stock during the years ended December 31, 2024 and 2023.

For additional information on our 2020 Share Repurchase Program, please read Note 14, Equity , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Share-Based Payments

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$ 234.1 $ 279.0 $ 525.6

In connection with our acquisition of HI-Bio in July 2024 we recognized HI-Bio equity-based compensation expense, inclusive of employer taxes, of approximately $ 56.4 million attributable to the post-acquisition service period, of which $ 42.5 million was recognized as a charge to research and development expense with the remaining $ 13.9 million as a charge to selling, general and administrative expense within our consolidated statements of

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

income for the year ended December 31, 2024.

These amounts were associated with the accelerated vesting of stock options and RSUs previously granted to HI-Bio employees and required no future services to vest.

In connection with our acquisition of Reata in September 2023 we recognized Reata equity-based compensation expense, inclusive of employer taxes, of approximately $ 393.4 million attributable to the post-acquisition service period, of which $ 196.4 million was recognized as a charge to selling, general and administrative expense with the remaining $ 197.0 million as a charge to research and development expense within our consolidated statements of income for the year ended December 31, 2023.

These amounts were associated with the accelerated vesting of stock options and RSUs previously granted to Reata employees that required no future services to vest.

These amounts were associated with the accelerated vesting of stock options and RSUs previously granted to HI-Bio employees and required no future services to vest.

For additional information on our acquisitions of HI-Bio and Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

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For additional information on our acquisitions of Reata and HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

As of December 31, 2025, unrecognized compensation cost related to unvested share-based compensation was approximately $ 292.6 million, net of estimated forfeitures.

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Awards granted from the 2024 Omnibus Equity Plan may include stock options, shares of restricted stock, restricted stock units, performance shares, stock appreciation rights and other awards in such amounts and with such terms and conditions as may be determined by a committee of our Board of Directors, subject to the provisions of the plan.

Shares of common stock available for grant under the 2024 Omnibus Equity Plan consist of 3.7 million shares reserved for this purpose, plus shares of common stock that remained available for grant under our 2017 Omnibus Equity Plan (including shares available by reason of a predecessor plan) on the date that our shareholders approved the 2024 Omnibus Equity Plan, plus shares that were subject to awards under the 2017 Omnibus Equity Plan (including shares available by reason of a predecessor plan) that remain unissued upon the cancellation, surrender, exchange, termination or forfeiture of such awards.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

reason of a predecessor plan) on the date that our shareholders approved the 2024 Omnibus Equity Plan, plus shares that were subject to awards under the 2017 Omnibus Equity Plan (including shares available by reason of a predecessor plan) that remain unissued upon the cancellation, surrender, exchange, termination or forfeiture of such awards.

The 2024 Omnibus Equity Plan provides that awards other than stock options and stock appreciation rights will be counted against the total number of shares available under the plan in a 1.5 -to-1 ratio.

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Exercisable at December 31, 2025 81,000 $ 301.85 6.9 years

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Market Stock Units

MSUs awarded to employees in 2014 and thereafter vest in three equal annual increments beginning on the first anniversary of the grant date, and participants may ultimately earn between zero and 200.0 % of the target number of units granted based on actual stock performance.

The vesting of these awards is subject to the respective employee’s continued employment.

The number of MSUs granted represents the target number of units that are eligible to be earned based on the attainment of certain market-based criteria involving our stock price.

The number of MSUs earned is calculated at each annual anniversary from the date of grant over the respective vesting periods, resulting in multiple performance periods.

Accordingly, additional MSUs may be issued or currently outstanding MSUs may be cancelled upon final determination of the number of awards earned.

MSUs awarded to employees in 2014 and thereafter vested in three equal annual increments beginning on the first anniversary of the grant date, and participants could ultimately earn between zero and 200.0 % of the target number of units granted based on actual stock performance.

The vesting of these awards was subject to the respective employee’s continued employment.

Beginning in 2022 we no longer grant MSUs as part of our long term incentive program and have replaced with granting performance-vested RSUs.

The following table summarizes our MSU activity:

December 31, 2024

Shares Weighted Average

Grant Date Fair Value

Unvested at December 31, 2023 34,000 $ 359.77

Vested ( 29,000 ) 375.59

Forfeited ( 5,000 ) 375.20

Unvested at December 31, 2024 — $ —

The fair values of MSUs vested in 2024, 2023 and 2022 totaled $ 6.3 million, $ 20.7 million and $ 18.8 million, respectively.

The fair values of the remaining MSUs vested in 2024 and 2023 totaled $ 6.3 million and $ 20.7 million, respectively.

Performance Stock Units

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Accordingly, additional PSUs may be issued or currently outstanding PSUs may be cancelled upon final determination of the number of units earned.

Beginning in 2022 we no longer grant MSUs as part of long term incentive program and have replaced with granting PSUs with a performance metric based on a three-year cumulative relative total shareholder return (rTSR) metric.

Beginning in 2024 we began granting PSUs with a performance metric based on the three-year cumulative aggregate growth rate of our earnings per share during the performance period.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Beginning in 2022 we no longer grant MSUs as part of our long term incentive program and have replaced with granting PSUs with a performance metric based on a three-year cumulative relative total shareholder return (rTSR) metric.

Beginning in 2024 we began granting PSUs with a performance metric based on the three-year cumulative aggregate growth rate of our earnings per share during the performance period.

The following table summarizes our PSUs that settle in stock activity:

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477,000 161.28

Vested ( 59,000 ) 277.05

Forfeited ( 222,000 ) 176.41

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Range of expected stock price volatility 34.5 %

44.0 % - 45.9 %

Range of risk-free interest rates 4.2 %

1.8 % - 3.9 %

30 calendar day average stock price on grant date $ 146.46

$ 231.31 - $ 294.86

Weighted-average per share grant date fair value $ 196.13

The fair values of PSUs settled in stock that vested in 2024, 2023 and 2022 totaled $ 13.2 million, $ 28.6 million and $ 9.5 million, respectively.

The fair values of PSUs settled in stock that vested in 2024 and 2023 totaled $ 13.2 million and $ 28.6 million, respectively.

PSUs Settled in Cash

During the first quarter of 2018 we began granting awards for performance-vested restricted stock units that will settle in cash.

PSUs awarded to employees have three performance periods and vest on the third anniversary of the grant date.

The vesting of these awards is subject to the respective employee’s continued employment.

The number of PSUs granted represents the target number of units that are eligible to be earned based on the achievement of three annual performance measures established when the performance objectives are defined, which will be at the beginning of each year and will end on December 31 of such year.

Participants may ultimately earn between zero and 200.0 % of the target number of PSUs granted based on the degree of achievement of the applicable performance metric.

Accordingly, additional PSUs may be issued or currently outstanding PSUs may be cancelled upon final determination of the number of units earned.

PSUs are classified as liability awards and will be settled in cash based on the 30 calendar day average closing stock price through the vesting date, once the actual vested and earned number of PSUs is determined.

Since no shares are issued, these awards do not dilute equity.

Beginning in 2022 we no longer grant this type of PSUs as part of our long term incentive program and have replaced with granting time-vested RSUs.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The following table summarizes our PSUs that settle in cash activity:

December 31, 2024

Unvested at December 31, 2023 41,000

Vested ( 39,000 )

Forfeited ( 2,000 )

Unvested at December 31, 2024 —

The fair values of PSUs settled in cash that vested in 2024, 2023 and 2022 totaled $ 9.5 million, $ 11.7 million and $ 11.0 million, respectively.

During the first quarter of 2018 we began granting awards for performance-vested restricted stock units that would settle in cash.

PSUs awarded to employees had three performance periods and vested on the third anniversary of the grant date.

The vesting of these awards was subject to the respective employee’s continued employment.

PSUs were classified as liability awards and were settled in cash based on the 30 calendar day average closing stock price through the vesting date, once the actual vested and earned number of PSUs was determined.

Since no shares were issued, these awards did not dilute equity.

Beginning in 2022 we no longer grant PSUs settled in cash as part of our long term incentive program and have replaced with granting time-vested RSUs.

The fair values of the remaining PSUs settled in cash that vested in 2024 and 2023 totaled $ 9.5 million and $ 11.7 million, respectively.

Time-Vested Restricted Stock Units

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Shares of our common stock will be delivered to the employee upon vesting, subject to payment of applicable withholding taxes.

RSUs awarded to directors for service on our Board of Directors vest on the first anniversary of the date of grant, provided in each case that the director continues to serve on our Board of Directors through the vesting date.

RSUs awarded to directors for service on

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

our Board of Directors vest on the first anniversary of the date of grant, provided in each case that the director continues to serve on our Board of Directors through the vesting date.

Shares of our common stock will be delivered to the director upon vesting and are not subject to any withholding taxes.

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Total income tax (benefit) expense $ 263.6 $ 273.8 $ 135.3

The lower Federal current provision in 2025 reflects the impact of a tax deduction for certain previously deferred capitalized research and development expenditures under the OBBBA and the impact of recording a capital loss on our sale of Sage common stock.

Foreign current benefit reflects the non-cash benefit of current year valuation allowance changes.

Transition Toll Tax

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Earnings in the form of cash and cash equivalents were taxed at a rate of 15.5% and all other earnings were taxed at a rate of 8.0%.

As of December 31, 2024 and 2023, we have accrued income tax liabilities of $ 234.0 million and $ 419.5 million, respectively, under the Transition Toll Tax.

The amount accrued as of December 31, 2024, is expected to be paid within one year.

The Transition Toll Tax is being paid in installments over an eight--year period, which started in 2018, and will not accrue interest.

As of December 31, 2024, we accrued income tax liabilities of approximately $ 234.0 million under the Transition Toll Tax, which was subsequently paid in full in April 2025.

Unremitted Earnings

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and therefore recorded deferred tax liabilities associated with an estimate of the total withholding taxes expected as a result of our repatriation of earnings.

Other than for earnings, we are permanently reinvested for book/tax basis differences of approximately $ 1.5 billion as of December 31, 2024, primarily arising through the impacts of purchase accounting.

Other than for earnings, we are permanently reinvested for book/tax basis differences, primarily arising through the impacts of purchase accounting.

These permanently reinvested basis differences could reverse through sales of the foreign subsidiaries, as well as various other events, none of which were considered probable as of December 31, 2025.

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Intangibles, net 886.5 989.6

IRC Section 174 capitalized research and development 733.9 570.8

Capitalized research and development 457.2 733.9

Net operating loss 1,082.8 1,357.2

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$ ( 1,456.1 ) $ ( 1,529.6 )

Samsung Bioepis investment installments — ( 35.5 )

GILTI ( 891.3 ) ( 1,054.8 )

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The net income tax impact of the changes in the valuation allowance was a benefit of approximately $ 37.9 million for the year ended December 31, 2025.

The change in the valuation allowance between December 31, 2024 and 2023, was primarily driven by movements in net operating loss deferred tax assets in Switzerland.

The net income tax impact of the changes in the valuation allowance was a benefit of approximately $ 56.8 million for the year ended December 31, 2024.

The change in the valuation allowance between December 31, 2023 and 2022, was primarily driven by a reduction of approximately $ 470.3 million related to the elimination of Neurimmune's tax basis in ADUHELM as a result of its deconsolidation and reduction of approximately $ 230.3 million due to movements in net operating loss deferred tax assets in Switzerland.

The net income tax impact of the changes in the valuation allowance was an expense of approximately $ 7.4 million for the year ended December 31, 2023.

The change in the valuation allowance between December 31, 2022 and 2021, was primarily driven by an addition of $ 85.0 million related to Neurimmune's tax basis in ADUHELM.

For additional information on the deconsolidation and our collaboration arrangement with Neurimmune, please read Note 20, Investments in Variable Interest Entities , to these consolidated financial statements.

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As of December 31, 2025 and 2024, the total deferred charges were $ 498.8 million and $ 273.1 million, respectively.

Inflation Reduction Act

In August 2022 the IRA was signed into law in the U.S.

The IRA introduced new tax provisions, including a 15.0% corporate alternative minimum tax and a 1.0% excise tax on stock repurchases.

The provisions of the IRA are effective for periods after December 31, 2022.

The IRA did not result in any material adjustments to our income tax provision or income tax balances as of December 31, 2024 and 2023.

Preliminary guidance has been issued by the IRS and we expect additional guidance and regulations to be issued in future periods.

We will continue to assess its potential impact on our business and results of operations as further information becomes available.

2025 OBBBA Tax Provisions

On July 4, 2025, the U.S.

signed into law the H.R.1 legislation formally titled "An Act to Provide for Reconciliation Pursuant to Title II of H.

14", commonly referred to as the OBBBA.

The OBBBA contains tax provisions, such as the permanent extension or revision of certain expiring provisions of the Tax Cuts and Jobs Act enacted in 2017, modifications to the international tax framework and the restoration of favorable tax treatment for certain business provisions.

The provisions of the OBBBA have multiple effective dates, with certain provisions effective in 2025 and others implemented through 2027.

The OBBBA did not result in any material adjustments to our total income tax provision for the year ended December 31, 2025, and we have adjusted our deferred tax balances to reflect the impacts of the OBBBA enactment.

AND SUBSIDIARIES

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The OECD has issued model rules, which generally provide for a jurisdictional minimum effective tax rate of 15.0% as defined in those rules.

Various countries have or are in the process of enacting legislation intended to implement the principles effective January 1, 2024.

Our income tax provision for the year ended December 31, 2024, reflects currently enacted legislation and guidance related to the OECD model rules.

This enacted legislation and guidance related to the OECD model rules did not result in any material adjustments to our income tax provision or income tax balances as of December 31, 2024.

A reconciliation between the U.S.

federal statutory tax rate and our effective tax rate is summarized as follows:

Various countries have or are in the process of enacting legislation intended to implement the principles.

Our income tax provision for the years ended December 31, 2025 and 2024, reflects currently enacted legislation and guidance related to the OECD model rules including the Pillar Two side-by-side package announced by the OECD in January 2026.

This enacted legislation and guidance related to the OECD model rules did not result in any material adjustments to our income tax provision or income tax balances as of December 31, 2025 and 2024.

For the year ended December 31, 2025, we adopted ASU 2023-09 on a prospective basis.

In preparing the tabular rate reconciliation, we are presenting the effects of cross-border tax laws net of the related U.S.

The tax effects for all jurisdictions of changes in judgment related to tax positions taken in prior annual reporting periods, and associated interest, are reported in the changes in unrecognized tax benefits category.

Unrecognized tax benefits related to current year tax positions are shown net with the reconciling item that relates to the uncertain tax position.

The following table is a reconciliation of the U.S.

federal statutory rate of 21.0% to our effective tax rate for the year ended December 31, 2025, in accordance with the guidance in ASU 2023-09.

For the Year Ended December 31, 2025

(In millions, except percentages) Amount Rate

Statutory rate $ 326.9 21.0 %

State and local income taxes, net of federal income tax effect (1)

Foreign tax effects:

Withholding tax ( 20.4 ) ( 1.3 )

Other 1.8 0.1

Statutory tax rate difference ( 22.1 ) ( 1.4 )

Cantonal tax impact 11.9 0.8

Pillar Two taxes ( 17.2 ) ( 1.1 )

Changes in valuation allowances ( 190.2 ) ( 12.2 )

Taxable intercompany dividend 22.8 1.5

Other ( 6.1 ) ( 0.4 )

Litigation matter 21.0 1.3

Other foreign jurisdictions 9.5 0.6

Effects of changes in tax laws or rates ( 11.5 ) ( 0.7 )

Effects of cross-border tax laws

GILTI, net of foreign tax credits 88.0 5.7

Other, net of foreign tax credits 18.5 1.2

Orphan drug credits ( 31.3 ) ( 2.0 )

Other credits ( 4.5 ) ( 0.3 )

Nontaxable or nondeductible items

Equity compensation 18.9 1.2

Other permanent differences 16.9 1.1

Changes in unrecognized tax benefits 9.6 0.6

Other adjustments 11.9 0.7

Income tax expense and effective tax rate $ 263.6 16.9 %

(1) State taxes in Tennessee, Massachusetts, Kentucky and North Carolina made up the majority (greater than 50.0%) of the tax effect in this category.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The following table is a reconciliation of the U.S.

federal statutory tax rate of 21.0% to our effective tax rate for the years ended December 31, 2024 and 2023, in accordance with the guidance prior to the adoption of ASU 2023-09:

For the Years Ended December 31,

2024 2023 2022

Statutory rate 21.0 % 21.0 %

4 unchanged sentences

GILTI ( 1.6 ) ( 0.6 )

Sale of Samsung Bioepis — — ( 1.6 )

Litigation settlement agreement — — 2.6

Neurimmune tax impacts — — 2.3

Internal reorganization — ( 0.1 )

1 unchanged sentence

Effective tax rate 14.4 % 10.4 %

In the reconciliation for the year ended December 31, 2025, in accordance with the guidance in ASU 2023-09, the GILTI foreign tax credit impacts of changes in foreign valuation allowances are included within the GILTI, net of foreign tax credits line.

For reconciliation for the years ended December 31, 2024 and 2023, the GILTI foreign tax credit impacts of changes in foreign valuation allowances are included within the taxes on foreign earnings, including valuation allowances line.

Changes in Tax Rate

For the year ended December 31, 2025, compared to 2024, the increase in our effective tax rate was partially driven by changes in the territorial mix of our profitability and the impact of certain share-based compensation awards that vested during the first quarter of 2025, partially offset by the impact of the elimination of Italian withholding tax.

For the year ended December 31, 2024, compared to 2023, the increase in our effective tax rate was partially driven by the relative deferred tax effects of the changes in the value of our equity investments and amortization of purchased intangible assets and inventory.

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This was partially offset by a 2024 benefit related to a decrease in our valuation allowance related to projected future foreign taxable income, as discussed in the Deferred Tax Assets and Liabilities section above.

For the year ended December 31, 2023, compared to 2022, the decrease in our effective tax rate was driven by the impact of the non-cash changes in the value of our equity investments, the impact of Fit for Growth related expenses and Reata acquisition-related expenses, as well as the combined net unfavorable tax rate impacts in 2022 related to a litigation settlement agreement, the sale of our equity interest in Samsung Bioepis, the impact of a Neurimmune valuation allowance, as discussed below, and an international reorganization to align with global tax developments.

The change also benefits from the resolution of an uncertain tax matter during the first quarter of 2023 related to tax credits.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

For additional information on the litigation settlement agreement, please read Note 18, Other Consolidated Financial Statement Detail , to these consolidated financial statements.

Neurimmune Deferred Tax Asset

During the first quarter of 2022, upon issuance of the final NCD related to ADUHELM, we recorded an increase in a valuation allowance of approximately $ 85.0 million to reduce the net value of a previously recorded deferred tax asset in Switzerland on Neurimmune's tax basis in ADUHELM, the realization of which was dependent on future sales of ADUHELM, to zero.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

This adjustment to our net deferred tax asset was recorded with an equal and offsetting amount assigned to net income (loss) attributable to noncontrolling interests, net of tax in our consolidated statements of income, resulting in a zero net impact to net income attributable to Biogen Inc.

During the fourth quarter of 2023 Neurimmune was deconsolidated from our consolidated financial statements.

Tax Attributes

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Based upon the level of historical taxable income and income tax liability and projections for future taxable income over the periods in which the deferred tax assets are utilizable, we believe it is more likely than not that we will realize the net benefits of the deferred tax assets of our wholly owned subsidiaries, net of the recorded valuation allowance.

In the event that actual results differ from our estimates or we adjust our estimates in future periods, we may need to adjust or establish a valuation allowance, which could materially impact our consolidated financial position and results of operations.

In the event that actual results differ from our estimates or we adjust our estimates in future

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

periods, we may need to adjust or establish a valuation allowance, which could materially impact our consolidated financial position and results of operations.

Income Taxes Paid

The following table presents income taxes paid (net of refunds received) for the year ended December 31, 2025.

(In millions) For the Year Ended December 31, 2025

Federal $ 721.0

Total $ 864.0

No individual state or foreign jurisdiction accounted for 5.0% or more of the total taxes paid in 2025.

Accounting for Uncertainty in Income Taxes

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As of December 31, 2022, the unrecognized tax benefits related to a deferred tax asset for Swiss tax purposes for Neurimmune's tax basis in ADUHELM was approximately $ 450.0 million.

This unrecognized tax benefit was recorded as a reduction to the gross deferred tax asset, resulting in the net deferred tax asset, as discussed above, and not as a separate liability on our consolidated balance sheets.

This unrecognized tax benefit was recorded as a reduction to the gross deferred tax asset, resulting in a net deferred tax asset and not as a separate liability on our consolidated balance sheets.

During the year ended December 31, 2023, we decreased our gross unrecognized tax benefits by approximately $ 450.0 million related to this item as a result of the deconsolidation of Neurimmune.

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income tax examinations for years before 2013.

Internal Revenue Service and other national tax authorities routinely examine our intercompany transfer pricing with respect to intellectual property related transactions and it is possible that they may disagree with one or more positions we have taken with respect to such valuations.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Included in the balance of unrecognized tax benefits as of December 31, 2025, 2024 and 2023, are $ 127.6 million, $ 139.3 million and $ 147.6 million (net of the federal benefit on state issues), respectively, of unrecognized tax benefits that, if recognized, would affect the effective income tax rate in future periods.

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It is reasonably possible that we will adjust the value of our uncertain tax positions related to certain transfer pricing, collaboration matters, withholding taxes and other issues as we receive additional information from various taxing authorities, including reaching settlements with such authorities.

We estimate that it is reasonably possible that our gross unrecognized tax benefits, exclusive of interest, could decrease by up to approximately $ 45.0 million in the next 12 months as a result of various audit closures, settlements and expiration of the statute of limitations.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Other Consolidated Financial Statement Detail

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(Gains) losses on investments, net 19.7 100.4 291.2

Litigation related expense 139.5 26.3 3.9

Foreign exchange (gains) losses, net 28.6 30.9 50.4

Gain on sale of equity interest in Samsung Bioepis (1)

— — ( 1,505.4 )

Litigation settlement agreement and settlement fees — — 917.0

Other, net ( 24.7 ) 3.3 ( 0.4 )

Total other (income) expense, net $ 305.6 $ 343.6 $ 315.5

(1) Reflects the pre-tax gain, net of transaction costs, recognized from the sale of our 49.9 % equity interest in Samsung Bioepis to Samsung BioLogics in April 2022.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

The (gains) losses on investments, net, as reflected in the table above, relate to debt securities, equity securities of certain biotechnology companies, venture capital funds where the underlying investments are in equity securities of certain biotechnology companies and non-marketable equity securities.

During the second quarter of 2022 we recorded a pre-tax charge of $ 900.0 million, plus settlement fees and expenses, related to a litigation settlement agreement to resolve a qui tam litigation relating to conduct prior to 2015.

This charge is included within other (income) expense, net in our consolidated statements of income for the year ended December 31, 2022.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The following table summarizes our (gains) losses on investments, net that relates to our equity securities held during the following periods:

In 2025 we recorded $ 139.5 million related to various litigation matters, including our agreement in principle to resolve all claims relating to Biogen's acquisition of Convergence.

For additional information on our legal matters, please read Note 21, Litigation , to these consolidated financial statements.

The following table summarizes our (gains) losses on investments, net that relate to our equity securities held during the following periods:

For the Years Ended December 31,

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Net unrealized (gains) losses recognized on equity securities $ 18.2 $ 102.4 $ 270.0

The net unrealized losses recognized during the year ended December 31, 2024, primarily reflect a decrease in the aggregate fair value of our investments in Sage common stock of approximately $ 101.4 million, partially offset by an increase in the fair value of Denali and Sangamo common stock of approximately $ 7.5 million.

The net unrealized losses recognized during the year ended December 31, 2025, primarily reflect a decrease in the aggregate fair value of our investment in Denali common stock of approximately $ 27.7 million, partially offset by an increase in the fair value of Sage common stock of approximately $ 23.0 million.

The net unrealized losses recognized during the year ended December 31, 2024, primarily reflect a decrease in the aggregate fair value of our investment in Sage common stock of approximately $ 101.4 million, partially offset by an increase in the fair value of Denali and Sangamo common stock of approximately $ 7.5 million.

The net unrealized losses recognized during the year ended December 31, 2023, primarily reflect a decrease in the aggregate fair value of our investments in Sage, Denali, Sangamo and Ionis common stock of approximately $ 248.5 million.

The net unrealized losses recognized during the year ended December 31, 2022, primarily reflect a decrease in the aggregate fair value of our investments in Denali and Sangamo common stock of approximately $ 278.0 million, partially offset by an increase in the fair value of Ionis and Sage common stock of approximately $ 27.3 million.

Other Current Assets

Other current assets includes prepaid taxes of $ 693.6 million and $ 307.2 million as of December 31, 2025 and 2024, respectively.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Accrued Expense and Other

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Total accrued expense and other $ 2,802.6 $ 2,807.7

Other Long-term Liabilities

Other long-term liabilities were $ 748.5 million and $ 732.3 million as of December 31, 2025 and 2024, respectively, and included accrued income taxes totaling $ 166.4 million and $ 156.7 million, respectively.

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RITUXAN HYCELA for the treatment of non-Hodgkin's lymphoma and CLL;

GAZYVA for the treatment of CLL and follicular lymphoma;

GAZYVA for the treatment of CLL, follicular lymphoma and, following its approval in October 2025, lupus nephritis;

OCREVUS for the treatment of PPMS and RMS;

LUNSUMIO for the treatment of relapsed or refractory follicular lymphoma;

COLUMVI, a bispecific antibody for the treatment of non-Hodgkin's lymphoma, which was granted accelerated approval by the FDA during the second quarter of 2023;

and have the option to add other potential anti-CD20 therapies, pursuant to our collaboration arrangements with

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Genentech, a wholly-owned member of the Roche Group.

COLUMVI, a bispecific antibody for the treatment of non-Hodgkin's lymphoma;

and have the option to add other potential anti-CD20 therapies, pursuant to our collaboration arrangements with Genentech, a wholly owned member of the Roche Group.

For purposes of this footnote, we refer to RITUXAN and RITUXAN HYCELA collectively as RITUXAN.

If we undergo a change in control, as defined in our collaboration agreement, Genentech has the right to present an offer to buy the rights to RITUXAN and we must either accept Genentech’s offer or purchase Genentech’s rights on the same terms as its offer.

Genentech will also be deemed concurrently to have purchased our rights to the remaining products in the collaboration on the terms set forth below.

Our collaboration with Genentech was created through a contractual arrangement and not through a joint venture or other legal entity.

Under our collaboration with Genentech, we are entitled to a tiered share of co-promotion operating profits and losses of RITUXAN in the U.S., as summarized in the table below.

Genentech and its affiliates are responsible for the worldwide manufacture of RITUXAN as well as all development and commercialization activities as follows:

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We have co-exclusively licensed our rights to develop, commercialize and market RITUXAN in Canada.

The Roche Group and its sub-licensees maintain sole responsibility for the development, manufacture and commercialization of GAZYVA in the U.S.

Genentech will also be deemed concurrently to have purchased our rights to the remaining products in the collaboration on the terms set forth below.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The Roche Group and its sub-licensees maintain sole responsibility for the development, manufacture and commercialization of GAZYVA and we are entitled to a tiered share of co-promotion operating profits and losses of GAZYVA in the U.S.

The level of gross sales of GAZYVA in the U.S.

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only, until the 11 year anniversary of the first commercial sale of OCREVUS in the U.S.

LUNSUMIO (mosunetuzumab)

In January 2022 we exercised our option with Genentech to participate in the joint development and commercialization of LUNSUMIO.

Under our collaboration with Genentech, we were responsible for 30.0 % of development costs for LUNSUMIO prior to FDA approval and will be entitled to a tiered share of co-promotion operating profits and losses in the U.S., as summarized in the table below.

Under our collaboration with Genentech, we are entitled to a tiered share of co-promotion operating profits and losses in the U.S., as summarized in the table below.

In addition, we receive low-single digit royalties on sales of LUNSUMIO outside the U.S.

In December 2022 LUNSUMIO was granted accelerated approval by the FDA for the treatment of relapsed or refractory follicular lymphoma.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Prior to regulatory approval, we record our share of the expense incurred by the collaboration for the development of anti-CD20 products in research and development expense and pre-commercialization costs within selling, general and administrative expense in our consolidated statements of income.

For the year ended December 31, 2022, we recorded approximately $ 28.4 million in research and development expense and approximately $ 13.0 million in sales and marketing expense in our consolidated statements of income related to this collaboration.

For the year ended December 31, 2023, we began to record our share of LUNSUMIO development and sales and marketing expense as a reduction of our share of pre-tax profits in revenue from anti-CD20 therapeutic programs within our consolidated statements of income.

If we undergo a change in control, as defined in our collaboration agreement, Genentech will be deemed to have purchased our rights to LUNSUMIO in exchange for 30.0 % of the U.S.

co-promotion operating profits or losses until the 11 year anniversary of the first commercial sale of LUNSUMIO in the U.S.

COLUMVI (glofitamab)

In December 2022 we entered into an agreement with Genentech related to the commercialization and sharing of economics for COLUMVI, a bispecific antibody for the treatment of B-cell non-Hodgkin's lymphoma, which was subsequently granted accelerated approval by the FDA in June 2023.

Under the terms of this agreement, we will have no payment obligations.

Genentech will have sole decision-making rights on the commercialization of COLUMVI within the U.S.

and we will receive tiered royalties in the mid-single digit range on net sales of COLUMVI in the U.S.

Genentech has sole decision-making rights on the commercialization of COLUMVI within the U.S.

and we receive tiered royalties in the mid-single digit range on net sales of COLUMVI in the U.S.

The commercialization of COLUMVI does not impact the percentage of the co-promotion profits we receive for RITUXAN, LUNSUMIO or GAZYVA.

1 unchanged sentence

only, until the 11 year anniversary of the first commercial sale of the product in the U.S.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Profit-sharing Formulas

RITUXAN and LUNSUMIO Profit Share

Our current pretax co-promotion profit-sharing formula for RITUXAN and LUNSUMIO in the U.S.

Our current pre-tax co-promotion profit-sharing formula for RITUXAN and LUNSUMIO in the U.S.

provides for a 30.0 % share on the first $ 50.0 million of combined co-promotion operating profits earned each calendar year.

As a result of the FDA approval of LUNSUMIO our share of the combined annual co-promotion profits for RITUXAN and LUNSUMIO in excess of $ 50.0 million varies upon the following events, as summarized in the table below:

Our share of the combined annual co-promotion profits for RITUXAN and LUNSUMIO in excess of $ 50.0 million varies upon the following events, as summarized in the table below:

After LUNSUMIO Approval until the First Threshold Date 37.5 %

1 unchanged sentence

After Second Threshold Date 30.0 %

First Threshold Date means the earlier of (i) the first day of the calendar quarter following the date U.S.

gross sales of GAZYVA within any consecutive 12-month period have reached $ 500.0 million or (ii) the first date in any calendar year in which U.S.

In March 2023 the First Threshold Date was achieved when U.S.

gross sales of GAZYVA within a consecutive 12-month period reached $ 500.0 million.

As a result, beginning in April 2023 the pre-tax profit share for RITUXAN and LUNSUMIO has been 35.0 %.

The Second Threshold Date would be achieved on the first date in any calendar year in which U.S.

gross sales of LUNSUMIO have reached $ 350.0 million.

Second Threshold Date means the later of (i) the first date the gross sales in any calendar year in which U.S.

gross sales of LUNSUMIO reach $ 350.0 million or (ii) January 1 of the calendar year following the calendar year in which the First Threshold Date occurs.

In March 2023 the First Threshold Date was achieved.

As a result, beginning in April 2023 the pre-tax profit share for RITUXAN and LUNSUMIO was 35.0 %.

Our share of RITUXAN pre-tax profits in the U.S.

in excess of $ 50.0 million for the year ended December 31, 2022, was 37.5 %.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

GAZYVA Profit Share

Our current pretax profit-sharing formula for GAZYVA provides for a 35.0 % share on the first $ 50.0 million of operating profits earned each calendar year.

Our share of annual co-promotion profits in excess of $ 50.0 million varies upon the following events, as summarized in the table below:

Until Second GAZYVA Threshold Date 37.5 %

After Second GAZYVA Threshold Date 35.0 %

Second GAZYVA Threshold Date means the first day of the calendar quarter following the date U.S.

gross sales of GAZYVA within any consecutive 12-month period have reached $ 500.0 million.

The Second GAZYVA Threshold Date can be achieved regardless of whether GAZYVA has been approved in a non-CLL indication.

In March 2023 the Second GAZYVA Threshold Date was achieved.

As a result, beginning in April 2023 the pre-tax profit share for GAZYVA was 35.0 %.

Our share of GAZYVA pre-tax profits in excess of $ 50.0 million for the year ended December 31, 2022, was 37.5 %.

Our current pretax profit-sharing formula for GAZYVA provides for a 35.0 % share on the first $ 50.0 million of operating profits earned in the U.S.

in each calendar year.

In March 2023 U.S.

gross sales of GAZYVA within a consecutive 12-month period reached $ 500.0 million.

As a result, beginning in April 2023 the pre-tax profit share for GAZYVA decreased from 37.5 % to 35.0 %.

Revenue from Anti-CD20 Therapeutic Programs

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for RITUXAN, GAZYVA and LUNSUMIO 420.2 392.0 409.4

392.0 409.4 547.0

Other revenue from anti-CD20 therapeutic programs 25.5 18.4 14.0

Total revenue from anti-CD20 therapeutic programs $ 1,860.6 $ 1,749.9 $ 1,689.6

(1) LUNSUMIO became commercially available in the U.S.

during the first quarter of 2023.

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In June 2018 we entered into a 10-year exclusive collaboration agreement with Ionis to develop novel ASO drug candidates for a broad range of neurological diseases for a total payment of $ 1.0 billion, consisting of an upfront payment of $ 375.0 million and the purchase of approximately 11.5 million shares of Ionis common stock at a cost of $ 625.0 million.

We have the option to license therapies arising out of this agreement and will be responsible for the development and commercialization of such therapies.

We may pay development milestones to Ionis of up to $ 125.0 million or $ 270.0 million for each program, depending on the indication plus an annual license fee, as well as royalties on potential net commercial sales.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

We have the option to license therapies arising out of this agreement and will be responsible for the development and commercialization of such therapies.

During the years ended December 31, 2025, 2024 and 2023, we incurred milestones of $ 7.5 million, $ 7.5 million and $ 7.5 million, respectively, related to the advancement of neurological targets identified under this agreement, which were recorded as research and development expense in our consolidated statements of income.

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In December 2017 we entered into a collaboration agreement with Ionis to identify new ASO drug candidates for the potential treatment of SMA.

Under this agreement, we have the option to license therapies arising out of this collaboration and will be responsible for their development and commercialization of such therapies.

We may pay Ionis up to $ 260.0 million in additional development and regulatory milestone payments if new drug candidates advance to marketing approval.

Upon commercialization, we may also pay Ionis up to $ 800.0 million in additional performance-based milestone payments and tiered royalties on potential net sales of such therapies.

In December 2021 we exercised our option with Ionis and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize BIIB115, an investigational ASO in development for SMA.

Under this agreement, we have options to license therapies arising out of this collaboration and will be responsible for the development and commercialization of such therapies.

In December 2021 we exercised our option with Ionis and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize salanersen (BIIB115), an investigational ASO in development for SMA.

We may pay Ionis up to $ 155.0 million in additional development and regulatory milestone payments related to salanersen, including a $ 45.0 million milestone payment due upon the initiation of a Phase 3 trial.

Upon commercialization, we may also pay Ionis up to $ 400.0 million in additional performance-based milestone payments and tiered royalties on potential net sales of such therapies ranging from the mid-teens to high-twenties percentages.

2013 Long-term Strategic Research Agreement

In September 2013 we entered into a six-year research collaboration agreement with Ionis under which both companies collaborate to perform discovery level research and subsequent development and commercialization activities of antisense or other therapeutics for the potential treatment of neurological diseases.

Under this agreement, Ionis performs research on a set of neurological targets identified within the agreement.

Ionis is eligible to receive milestone payments, license fees and royalty payments for all product candidates developed through this collaboration, with the specific amount dependent upon the modality of the product candidate advanced by us under the terms of the agreement.

For non-ALS antisense product candidates, Ionis is responsible for global development through the completion of a Phase 2 trial and we provide advice on the clinical trial design and regulatory strategy.

For ALS antisense product candidates, we are responsible for global development, clinical trial design and regulatory strategy.

We have an option to license a product candidate until completion of the Phase 2 trial.

If we exercise our option, we will pay Ionis up to a $ 70.0 million license fee and assume global development, regulatory and commercialization responsibilities.

Ionis could receive additional milestone payments upon the achievement of certain regulatory milestones of up to $ 130.0 million, plus additional amounts related to the cost of clinical trials conducted by Ionis under the collaboration, and royalties on future sales if we successfully develop the product candidate after option exercise.

In September 2013 we entered into a six-year research collaboration agreement with Ionis under which both companies collaborated to perform discovery level research and subsequent development and commercialization activities of antisense or other therapeutics for the potential treatment of neurological diseases.

In December 2018 we exercised our option with Ionis and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize QALSODY (tofersen), for the treatment of ALS with SOD1 mutations.

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During the year ended December 31, 2024, we incurred a milestone payment of $ 20.0 million to Ionis following the approval of QALSODY in the E.U., which was recorded within intangible assets, net in our consolidated balance sheets.

Additionally, during the year ended December 31, 2024, we accrued a milestone payment of $ 10.0 million to Ionis following the approval of QALSODY in Japan, which was recorded within intangible assets, net in our consolidated balance sheets, and is expected to be paid during the first quarter of 2025.

During the year ended December 31, 2023, we incurred a milestone payment of $ 16.0 million to Ionis following the FDA's approval of QALSODY, which was recorded within intangible assets, net in our consolidated balance sheets.

During the year ended December 31, 2022, we incurred a milestone payment of $ 17.0 million related to the advancement of a program under this agreement, which was recorded in research and development expense within our consolidated statements of income.

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2012 Ionis Agreement

In December 2012 we entered into an agreement with Ionis for the development and commercialization of up to three gene targets.

Under this agreement, Ionis is responsible for global development of any product candidate through the completion of a Phase 2 trial and we will provide advice on the clinical trial design and regulatory strategy.

We have an option to license the product candidate until completion of the Phase 2 trial.

If we exercise our option, we will pay a license fee of up to $ 70.0 million to Ionis and assume global development, regulatory and commercialization responsibilities.

Ionis is eligible to receive up to $ 130.0 million in additional milestone payments upon the achievement of certain regulatory milestones as well as royalties on future sales if we successfully develop the product candidate after option exercise.

In December 2019 we exercised our option with Ionis and obtained a worldwide, exclusive, royalty-bearing license to develop and commercialize BIIB080 (tau ASO), which is currently in Phase 2 development for the potential treatment of Alzheimer's disease.

In connection with the option exercise, we made a payment of $ 45.0 million to Ionis, which was recorded in research and development expense within our consolidated statements of income.

Following the option exercise, we are solely responsible for global development, regulatory and commercialization.

Future payments may include additional milestone payments of up to $ 155.0 million and royalties on future sales in the low- to mid-teens if we successfully develop the product candidate after option exercise.

During the year ended December 31, 2022, we incurred a milestone payment of $ 10.0 million, related to the advancement of BIIB080 under this agreement, which was recorded in research and development expense within our consolidated statements of income.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Eisai Co., Ltd.

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LEQEMBI (lecanemab) Collaboration

We have a collaboration agreement with Eisai to jointly develop and commercialize LEQEMBI (lecanemab), an anti-amyloid antibody for the treatment of Alzheimer's disease (the LEQEMBI Collaboration).

Eisai serves as the lead of LEQEMBI development and regulatory submissions globally with both companies co-commercializing and co-promoting the product, and Eisai having final decision-making authority.

We have a collaboration agreement with Eisai to jointly develop and commercialize LEQEMBI (lecanemab), an anti-amyloid antibody for the treatment of Alzheimer's disease.

The FDA granted traditional approval of LEQEMBI in July 2023.

Prior to receiving traditional approval, LEQEMBI had been granted accelerated approval by the FDA in January 2023, at which time it became commercially available in the U.S.

Outside of the U.S., LEQEMBI is now approved in the E.U.

(April 2025), Australia (September 2025), China (January 2024), Japan (September 2023) and other international markets.

LEQEMBI monthly IV maintenance dosing for the treatment of early Alzheimer's disease was approved in the U.S.

and China in January 2025 and September 2025, respectively, and LEQEMBI subcutaneous autoinjector (IQLIK) for weekly maintenance dosing was approved in the U.S.

in August 2025.

All costs, including research, development, sales and marketing expense, are shared equally between us and Eisai.

We and Eisai co-promote LEQEMBI and share profits and losses equally.

We currently manufacture LEQEMBI drug substance and drug product and in March 2022 we extended our supply agreement with Eisai related to LEQEMBI from five years to ten years for the manufacture of LEQEMBI drug substance.

The LEQEMBI Collaboration also provided Eisai with an option to jointly develop and commercialize ADUHELM (aducanumab) (ADUHELM Option), and an option to jointly develop and commercialize one of our anti-tau monoclonal antibodies (Anti-Tau Option).

In October 2017 Eisai exercised its ADUHELM Option and we entered into a new collaboration agreement for the joint development and commercialization of ADUHELM (aducanumab) (the ADUHELM Collaboration Agreement).

In March 2022 we amended our ADUHELM Collaboration Agreement with Eisai.

As of the amendment date, we have sole decision making and commercialization rights worldwide on ADUHELM, and beginning January 1, 2023, Eisai receives only a tiered royalty based on net sales of ADUHELM, and no longer participates in sharing ADUHELM's global profits and losses.

In March 2022 we also amended the LEQEMBI Collaboration Agreement with Eisai to eliminate the Anti-Tau Option.

We also share profits and losses equally.

We currently have a supply agreement with Eisai to manufacture LEQEMBI drug substance and drug product through the end of 2031.

Subject to the limitations in the LEQEMBI Collaboration Agreement, Eisai has final decision-making authority on all matters relating to the collaboration and serves as the lead of LEQEMBI development and regulatory submissions globally.

We co-commercialize and co-promote LEQEMBI with Eisai.

Our Collaboration Agreement provides that each commercialization plan shall allocate the responsibilities for the activities under the plan in an equitable fashion taking into account Biogen's and Eisai's respective capabilities and provides a meaningful role for each party.

Upon commercialization of LEQEMBI in the U.S., we began recognizing our 50.0 % share of LEQEMBI product revenue, net and cost of sales, including royalties, within Alzheimer's collaboration revenue in our consolidated statements of income, as we are not the principal.

Our share of LEQEMBI sales and marketing expense and development expense are recorded within selling, general and administrative expense and research and development expense, respectively, within our consolidated statements of income.

If either company undergoes a change of control, as defined in our LEQEMBI Collaboration Agreement, the non-acquired party may elect to initiate an operational separation, as defined in the LEQEMBI Collaboration Agreement.

In the event of an operational separation, we would work with Eisai to effect a timely transition of any development, manufacturing or commercial responsibilities regarding LEQEMBI from us to Eisai.

In this scenario, as of six months following the change of control, our ongoing responsibility for LEQEMBI related cost-sharing would be reduced to an

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

amount equal to 80.0 % of what we would have owed prior to the operational separation, and all other economic rights would remain unchanged.

In this scenario, as of six months following the change of control, our ongoing responsibility for LEQEMBI related cost-sharing would be reduced to an amount equal to 80.0 % of what we would have owed prior to the operational separation, and all other economic rights would remain unchanged.

In addition, in the event either company undergoes a change of control in which the acquirer is engaged in commercialization of a competing product, as defined in the LEQEMBI Collaboration Agreement, the non-acquired party may also request that the acquired party cease commercializing the competing product.

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Furthermore, in the event we are the non-acquired party, we may choose either to sell our interest in LEQEMBI to Eisai or purchase Eisai's interest in LEQEMBI, subject to the parameters set forth in the LEQEMBI Collaboration Agreement.

In July 2023 the FDA granted traditional approval of LEQEMBI.

Prior to receiving traditional approval, LEQEMBI had been granted accelerated approval by the FDA in January 2023, at which time it became commercially available in the U.S.

Outside of the U.S., LEQEMBI is now approved in Japan (September 2023), China (January 2024), South Korea (May 2024), Hong Kong (July 2024), Israel (July 2024), United Arab Emirates (August 2024), Great Britain (August 2024) and Mexico (December 2024).

Additionally, in January 2025 the FDA approved LEQEMBI monthly IV maintenance dosing for the treatment of early Alzheimer's disease.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

A summary of development and sales and marketing expense related to the LEQEMBI Collaboration is as follows:

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Biogen's share of the LEQEMBI Collaboration sales and marketing expense reflected in selling, general and administrative expense in our consolidated statements of income 350.8 323.5 152.2

ADUHELM Collaboration Agreement

The LEQEMBI Collaboration also provided Eisai with an option to jointly develop and commercialize ADUHELM (aducanumab) (ADUHELM Option).

In October 2017 Eisai exercised its ADUHELM Option and we entered into a new collaboration agreement for the joint development and commercialization of ADUHELM (the ADUHELM Collaboration Agreement).

Under our initial ADUHELM Collaboration Agreement, we would lead the ongoing development of ADUHELM, and we and Eisai would co-promote ADUHELM with a region-based profit split.

Beginning in 2019, Eisai was reimbursing us for 45.0 % of development and sales and marketing expense incurred by the collaboration for the advancement of ADUHELM.

In March 2022 we amended our ADUHELM Collaboration Agreement with Eisai.

Eisai's share of development, commercialization and manufacturing expense was limited to $ 335.0 million for the period from January 1, 2022 to December 31, 2022, which was achieved as of December 31, 2022.

Once this limit was achieved, we became responsible for all ADUHELM related costs.

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

A summary of development expense, sales and marketing expense and milestone payments related to our initial ADUHELM Collaboration Agreement is as follows:

(In millions) For the Year Ended December 31, 2022

Total ADUHELM Collaboration development expense $ 149.4

Biogen's share of the ADUHELM Collaboration development expense reflected in research and development expense in our consolidated statements of income 82.2

Total sales and marketing expense incurred by the ADUHELM Collaboration 134.2

Biogen's share of the ADUHELM Collaboration sales and marketing expense reflected in selling, general and administrative expense and collaboration profit sharing/(loss reimbursement) in our consolidated statements of income 71.5

ADUHELM Co-promotion Profits and Losses

Under our initial ADUHELM Collaboration Agreement, we recognized revenue on sales of ADUHELM in the U.S.

to third parties as a component of product revenue, net in our consolidated statements of income.

We also recorded the related cost of revenue and sales and marketing expense in our consolidated statements of income as these costs were incurred.

Payments made to and received from Eisai for its 45.0 % share of the co-promotion profits or losses in the U.S.

were recognized in collaboration profit sharing/(loss reimbursement) in our consolidated statements of income.

For the year ended December 31, 2022, we recognized net reductions to our operating expense of approximately $ 224.7 million to reflect Eisai's 45.0 % share of net collaboration losses in the U.S.

During the first quarter of 2022, as a result of the final NCD, we recorded approximately $ 275.0 million of charges associated with the write-off of inventory and purchase commitments in excess of forecasted demand related to ADUHELM.

Additionally, for the year ended December 31, 2022, we recorded approximately $ 111.0 million of aggregate gross idle capacity charges related to ADUHELM.

These charges were recorded in cost of sales within our consolidated statements of income for the year ended December 31, 2022.

We recognized approximately $ 197.0 million related to Eisai's 45.0 % share of inventory, idle capacity charges and contractual commitments in collaboration profit sharing/(loss reimbursement) within our consolidated statements of income for the year ended December 31, 2022.

Amounts receivable from Eisai related to the agreements discussed above we re approximately $ 90.2 million a nd $ 16.7 million as of December 31, 2025 and 2024, respectively.

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Biogen's share of the UCB collaboration development expense reflected in research and development expense in our consolidated statements of income 39.9 38.7 30.3

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Merz Therapeutics (previously Acorda Therapeutics, Inc.)

In June 2009 we entered into a collaboration and license agreement with Acorda to develop and commercialize products containing fampridine, such as FAMPYRA, in markets outside the U.S.

Under this agreement, we pay tiered royalties based on the level of ex-U.S.

net sales and we may pay potential milestone payments based on the successful achievement of certain regulatory and commercial milestones.

In January 2024 we notified Acorda of our decision to terminate our collaboration and license agreement, effective January 1, 2025, whereby Acorda regained global commercialization rights to FAMPYRA.

On April 1, 2024, Acorda filed for bankruptcy protection and announced its intention to sell substantially all of Acorda's assets to a third party.

On July 10, 2024, Merz Therapeutics announced that its subsidiary Merz Pharmaceuticals LLC had completed the acquisition of FAMPYRA, and related assets from Acorda.

We are now working with Merz Therapeutics on the transition of global commercialization rights of FAMPYRA and we expect to recognize minimal revenue in 2025.

For the years ended December 31, 2024, 2023 and 2022, total cost of sales related to royalties and commercial supply of FAMPYRA reflected in our consolidated statements of income were approximately $ 52.4 million, $ 55.2 million and $ 46.1 million, respectively.

Sage Therapeutics, Inc.

In November 2020 we entered into a global collaboration and license agreement with Sage to jointly develop and commercialize ZURZUVAE (zuranolone) for the treatment of PPD and potential treatment of MDD and BIIB124 (SAGE-324) for the potential treatment of essential tremor with potential in other neurological conditions such as epilepsy.

In July 2024 we and Sage announced that the Phase 2 KINETIC 2 dose-range study of BIIB124 did not meet its endpoints.

Based on these results, we discontinued our further development of BIIB124 and terminated our rights under the collaboration and license agreement specific to BIIB124, effective February 17, 2025.

In connection with the closing of this transaction in December 2020 we purchased $ 650.0 million of Sage common stock, or approximately 6.2 million shares at approximately $ 104.14 per share, which were initially subject to transfer restrictions.

We may pay Sage development and commercial milestone payments that could total up to approximately $ 700.0 million if all the specified milestones set forth in this collaboration are achieved.

In August 2023 the FDA approved ZURZUVAE for adults with PPD, pending DEA scheduling, which was completed in October 2023.

Supernus Pharmaceuticals, Inc.

(previously Sage Therapeutics, Inc.)

In November 2020 we entered into a global collaboration and license agreement with Sage to jointly develop and commercialize ZURZUVAE (zuranolone) for the treatment of PPD.

In July 2025 Sage was acquired by Supernus.

ZURZUVAE was approved in the U.S.

in August 2023 and in the E.U.

in September 2025.

Upon approval, ZURZUVAE became the first and only oral, once-daily, 14-day treatment that can provide rapid improvements in depressive symptoms by day 15 for women with PPD.

ZURZUVAE for PPD became commercially available in the U.S.

during the fourth quarter of 2023.

Additionally, the FDA issued a CRL for the NDA for zuranolone in the treatment of adults with MDD.

In October 2024 we and Sage agreed to not pursue further development of zuranolone for the potential treatment of MDD.

This decision was based on the significant new investment and time we expect would be needed to conduct the additional studies required to support approval of this indication.

Under this collaboration, both companies will share equal responsibility and costs for development as well as profits and losses for commercialization in the U.S.

Outside of the U.S., we are responsible for development and commercialization, excluding Japan, Taiwan and South Korea, with respect to zuranolone and may pay Sage potential tiered royalties in the high teens to low twenties.

Outside of the U.S., we are responsible for development and commercialization, excluding Japan, Taiwan and South Korea, with respect to zuranolone and may pay Supernus potential tiered royalties in the high-teens to low-twenties percentages.

During the fourth quarter of 2023 we accrued a milestone payment due to Sage of $ 75.0 million upon the first commercial sale of ZURZUVAE for PPD in the U.S., which was recorded within intangible assets, net in our consolidated balance sheets, and subsequently paid in January 2024.

We may pay Supernus development and commercial milestone payments that could total up to approximately $ 700.0 million if all the specified milestones set forth in this collaboration are achieved.

We reflect revenue on sales of ZURZUVAE to third parties in product revenue, net in our consolidated statements of income and record the related cost of revenue and sales and marketing expense in our consolidated statements of income to their respective line items when these costs are incurred.

We share 50.0 % of the profit or loss related to our global collaboration and license agreement with Sage, which is recognized in collaboration profit sharing/(loss reimbursement) in our consolidated statements of income.

For the years ended December 31, 2024 and 2023, we recognized net profit-sharing expense of approximately $ 27.0 million and net loss reimbursement of approximately $ 4.7 million, respectively, to reflect Sage's 50.0 % share

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

of net collaboration losses in the U.S., which are recognized in collaboration profit sharing/(loss reimbursement) in our consolidated statements of income.

A summary of development and sales and marketing expense related to the Sage collaboration is as follows:

We share 50.0 % of the net collaboration results in the U.S.

with Supernus, which are recognized in collaboration profit sharing/(loss reimbursement) in our consolidated statements of income.

For the years ended December 31, 2025, 2024 and 2023, we recognized net profit-sharing expense of approximately $ 71.0 million and $ 27.0 million, and net loss reimbursement of approximately $ 4.7 million, respectively, to reflect Supernus' 50.0 % share of net collaboration results in the U.S.

A summary of development and sales and marketing expense related to the Supernus collaboration is as follows:

For the Years Ended December 31,

(In millions) 2025 2024 2023

Total Sage collaboration development expense $ 34.2 $ 176.7 $ 173.3

Biogen's share of the Sage collaboration development expense reflected in research and development expense in our consolidated statements of income 17.1 88.3 86.7

Total sales and marketing expense incurred by the Sage collaboration 118.5 187.0 109.9

Biogen's share of the Sage collaboration sales and marketing expense reflected in selling, general and administrative expense and collaboration profit sharing/(loss reimbursement) in our consolidated statements of income 59.2 93.5 55.0

Total Supernus collaboration development expense $ 2.7 $ 34.2 $ 176.7

Biogen's share of the Supernus collaboration development expense reflected in research and development expense in our consolidated statements of income 1.3 17.1 88.3

Total sales and marketing expense incurred by the Supernus collaboration 173.0 118.5 187.0

Biogen's share of the Supernus collaboration sales and marketing expense reflected in selling, general and administrative expense and collaboration profit sharing/(loss reimbursement) in our consolidated statements of income 86.5 59.2 93.5

Denali Therapeutics Inc.

In August 2020 we entered into a collaboration and license agreement with Denali to co-develop and co-commercialize Denali's small molecule inhibitors of LRRK2 for Parkinson's disease (LRRK2 Collaboration) and also entered into a separate agreement to obtain an exclusive option to license two preclinical programs from Denali's Transport Vehicle platform, including its ATV-enabled anti-amyloid beta program and a second program utilizing its Transport Vehicle technology.

In July 2024 we terminated our license with Denali for the ATV-enabled anti-amyloid beta program.

This termination also resulted in the termination of the exclusive option agreement, as discussed above.

As part of this collaboration we purchased $ 465.0 million of Denali common stock in September 2020, or approximately 13 million shares at approximately $ 34.94 per share, which were initially subject to transfer restrictions.

In August 2020 we entered into a collaboration and license agreement with Denali to co-develop and co-commercialize BIIB122, a small molecule inhibitor of LRRK2 for Parkinson's disease (LRRK2 Collaboration).

We may pay Denali development and commercial milestone payments that could total up to approximately $ 1.1 billion if the milestones related to the LRRK2 Collaboration are achieved.

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Biogen's share of the Denali collaboration development expense reflected in research and development expense in our consolidated statements of income 26.5 31.9 39.0

Sangamo Therapeutics, Inc.

In February 2020 we entered into a collaboration and license agreement with Sangamo to pursue certain neurological targets leveraging Sangamo’s proprietary zinc finger protein technology delivered via adeno-associated virus to modulate the expression of key genes involved in neurological diseases.

In connection with the closing of this transaction in April 2020 we purchased $ 225.0 million of Sangamo common stock, or approximately 24 million shares at approximately $ 9.21 per share, which were initially subject to transfer restrictions.

These restrictions have now lapsed.

In March 2023 we terminated our collaboration and license agreement with Sangamo.

A summary of development expense related to the Sangamo collaboration is as follows:

For the Years Ended December 31,

(In millions) 2023 2022

Total Sangamo collaboration development expense $ 4.1 $ 19.1

Biogen's share of the Sangamo collaboration development expense reflected in research and development expense in our consolidated statements of income 2.4 12.1

Stoke Therapeutics, Inc.

In February 2025 we entered into a collaboration and license agreement with Stoke to co-develop and commercialize zorevunersen, an investigational ASO that targets the SCN1A gene for the potential treatment of Dravet syndrome, a rare form of genetic epilepsy associated with refractory seizures and neurodevelopmental impairments.

Zorevunersen dosed its first patient in August 2025, advancing zorevunersen to a global Phase 3 trial.

Under the terms of this agreement, Stoke will continue to lead global development and retain exclusive development and commercialization rights for zorevunersen in the U.S., Canada and Mexico and we will have exclusive rights to commercialize zorevunersen in the rest of the world.

Both companies will share responsibility for external clinical development costs, where Stoke is responsible for 70.0 % of these development costs and we are responsible for the remaining 30.0 % of these development costs.

In connection with the closing of this transaction we made an upfront payment of $ 165.0 million to Stoke, which was recognized in acquired in-process research and development, upfront and milestone expense within our consolidated statements of income for the year ended December 31, 2025.

We may also pay Stoke potential development and commercial milestone payments of up to $ 50.0 million and $ 335.0 million, respectively, if all the specified milestones set forth in this collaboration are achieved.

In addition, we may pay Stoke tiered royalties on potential net sales of any products developed under this collaboration in the low-double digit to high-teen percentages.

We also have an exclusive option to license certain future follow-on ASO products targeting the SCN1A gene in all territories worldwide other than the U.S., Canada and Mexico, in exchange for separate milestone, cost sharing and royalty considerations.

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Other Research and Discovery Arrangements

These arrangements may include the potential for future milestone payments based on the achievement of certain clinical and commercial development payable over a period of several years.

For the years ended December 31, 2024, 2023 and 2022, we recorded approximately $ 54.0 million , $ 4.1 million and $ 39.2 million, respectively, as research and development expense in our consolidated statements of income related to other research and discovery related arrangements.

A summary of development expense related to the Stoke collaboration agreement is as follows:

(In millions) For the Year Ended December 31, 2025

Total Stoke collaboration development expense $ 39.4

Biogen's share of the Stoke collaboration development expense reflected in research and development expense in our consolidated statements of income 11.8

Samsung Bioepis Co., Ltd.

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In February 2012 we entered into a joint venture agreement with Samsung BioLogics establishing an entity, Samsung Bioepis, to develop, manufacture and market biosimilar products.

Samsung BioLogics contributed 280.5 billion South Korean won (approximately $ 250.0 million) for an 85.0 % ownership interest in Samsung Bioepis and we contributed 49.5 billion South Korean won (approximately $ 45.0 million) for the remaining 15.0 % ownership interest.

In June 2018 we exercised our option under our joint venture agreement to increase our ownership percentage in Samsung Bioepis from approximately 5.0 %, which reflected the effect of previous equity financings in which we did not participate, to approximately 49.9 %.

The share purchase transaction was completed in November 2018 and, upon closing, we paid 759.5 billion South Korean won ($ 676.6 million) to Samsung BioLogics.

In April 2022 we completed the sale of our 49.9 % equity interest in Samsung Bioepis to Samsung BioLogics in exchange for total consideration of approximately $ 2.3 billion.

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The first deferred payment of $ 812.5 million was received in April 2023 and the second deferred payment of $ 437.5 million was received in April 2024.

As part of this transaction, we are also eligible to receive up to an additional $ 50.0 million upon the achievement of certain commercial milestones.

Our policy for contingent payments of this nature is to recognize the payments in the period that they become realizable, which is generally the same period in which the payments are earned.

Prior to this sale, we recognized our share of the results of operations related to our investment in Samsung Bioepis under the equity method of accounting one quarter in arrears when the results of the entity became available, which was reflected as equity in (income) loss of investee, net of tax in our consolidated statements of income.

Upon our November 2018 investment, the equity method of accounting required us to identify and allocate differences between the fair value of our investment and the carrying value of our interest in the underlying net assets of the investee.

These basis differences were being amortized over their economic life, until the completion of the sale in April 2022, as discussed above.

The total basis difference was approximately $ 675.0 million and related to inventory, developed technology, IPR&D and deferred tax balances.

The basis differences related to inventory were amortized, net of tax, over their estimated useful lives of 1.5 years, and the basis differences related to developed technology and IPR&D for marketed products were being amortized, net of tax, over their estimated useful lives of 15 years.

For the year ended December 31, 2022, we recognized net income on our investment of $ 2.6 million, reflecting our share of Samsung Bioepis' operating profits, net of tax, totaling $ 17.0 million offset by amortization of basis differences totaling $ 14.4 million.

Following the sale of Samsung Bioepis we no longer recognize gains or losses associated with Samsung Bioepis' results of operations and amortization related to basis differences.

For additional information on the sale of our equity interest in Samsung Bioepis, please read Note 3, Dispositions , to these consolidated financial statements.

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The agreement established that Samsung Bioepis will be responsible for development and will supply both products to us at a pre-specified gross margin of approximately 45.0 %.

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In October 2024 we notified Samsung Bioepis of our decision to terminate our 2019 Development and Commercialization Agreement (the DCA Agreement) solely within the U.S.

As a result of this termination we recognized impairment charges of approximately $ 20.2 million, which were recorded within amortization and impairment of acquired intangible assets within our consolidated statements of income for the year ended December 31, 2024.

Biogen will transfer commercialization rights for BYOOVIZ and OPUVIZ in the U.S.

and Canada back to Samsung Bioepis over a period of up to 18 months.

During this transition period, we will continue to commercialize BYOOVIZ.

The termination does not impact the other markets in the DCA Agreement.

In the fourth quarter of 2024 we made a milestone payment of $ 15.0 million to Samsung Bioepis related to the approval of OPUVIZ in the E.U., which was recorded within intangible assets, net in our consolidated balance sheets.

We may also pay Samsung Bioepis up to approximately $ 150.0 million in additional development, regulatory and sales-based milestones associated with the remaining major markets covered by the agreement.

We reflect revenue on sales of BYOOVIZ to third parties in product revenue, net in our consolidated statements of income and record the related cost of revenue and sales and marketing expense in our consolidated statements of income to their respective line items when these costs are incurred.

The transfer of commercialization rights for BYOOVIZ and OPUVIZ in the U.S.

and Canada back to Samsung Bioepis was completed as of December 31, 2025.

In October 2025 we completed the sale of our remaining commercial rights to two ophthalmology assets in Europe:

BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS, and OPUVIZ, an aflibercept biosimilar referencing EYLEA.

Samsung Bioepis will have full responsibility for commercialization of BYOOVIZ upon the transfer of commercial rights from Biogen back to Samsung Bioepis, which became effective as of January 2026.

We reflected revenue on sales of BYOOVIZ to third parties in product revenue, net in our consolidated statements of income and recorded the related cost of revenue and sales and marketing expense in our consolidated statements of income to their respective line items when these costs were incurred.

2013 Commercial Agreement

In December 2013 we entered into an agreement with Samsung Bioepis to commercialize, over a 10-year term, 3 anti-TNF biosimilar product candidates which includes IMRALDI, an adalimumab biosimilar referencing HUMIRA, FLIXABI, an infliximab biosimilar referencing REMICADE, and BENEPALI, an etanercept biosimilar referencing ENBREL, in Europe.

In December 2013 we entered into an agreement with Samsung Bioepis to commercialize, over a 10-year term, three anti-TNF biosimilar product candidates which includes IMRALDI, an adalimumab biosimilar referencing HUMIRA, FLIXABI, an infliximab biosimilar referencing REMICADE, and BENEPALI, an etanercept biosimilar referencing ENBREL, in Europe.

In July 2024 we exercised an option to extend this agreement by an additional five years and paid Samsung Bioepis an option exercise fee of $ 60.0 million, which was recorded within intangible assets, net within our consolidated balance sheets as of December 31, 2024.

We reflect revenue on sales of BENEPALI, IMRALDI and FLIXABI to third parties in product revenue, net in our consolidated statements of income and record the related cost of revenue and sales and marketing expense in our consolidated statements of income to their respective line items when these costs are incurred.

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consolidated statements of income to their respective line items when these costs are incurred.

Royalty payments to AbbVie on sales of IMRALDI are recognized in cost of sales within our consolidated statements of income.

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Royalty revenue under the license agreement is recognized as a component of contract manufacturing, royalty and other revenue in our consolidated statements of income.

For the years ended December 31, 2024, 2023 and 2022, we recognized approximately $ 14.4 million, $ 13.6 million and $ 20.6 million, respectively, as a component of contract manufacturing, royalty and other revenue in our consolidated statements of income related to the license agreement and other services performed under our collaboration with Samsung Bioepis.

For the years ended December 31, 2025, 2024 and 2023, we recognized approximately $ 15.5 million , $ 14.4 million and $ 13.6 million, respectively, as a component of contract manufacturing, royalty and other revenue in our consolidated statements of income related to the license agreement.

Amounts receivable from Samsung Bioepis related to the agreements discussed above were approximately $ 4.4 million and $ 7.6 million as of December 31, 2025 and 2024, respectively.

Amounts payable to Samsung Bioepis related to the agreements discussed above were approximately $ 42.7 million and $ 60.8 million as of December 31, 2025 and 2024, respectively.

Merz Therapeutics (previously Acorda Therapeutics, Inc.)

In June 2009 we entered into a collaboration and license agreement with Acorda to develop and commercialize products containing fampridine, such as FAMPYRA, in markets outside the U.S.

Under this agreement, we pay tiered royalties based on the level of ex-U.S.

net sales and we may pay potential milestone payments based on the successful achievement of certain regulatory and commercial milestones.

In January 2024 we notified Acorda of our decision to terminate our collaboration and license agreement, effective January 1, 2025, whereby Acorda regained global commercialization rights to FAMPYRA.

On April 1, 2024, Acorda filed for bankruptcy protection and announced its intention to sell substantially all of Acorda's assets to a third party.

On July 10, 2024, Merz Therapeutics announced that its subsidiary Merz Pharmaceuticals LLC had completed the acquisition of FAMPYRA, and related assets from Acorda, and in 2025 we transitioned the global commercialization rights of FAMPYRA to Merz Therapeutics.

For the years ended December 31, 2024 and 2023, total cost of sales related to royalties and commercial supply of FAMPYRA reflected in our consolidated statements of income were approximately $ 52.4 million and $ 55.2 million, respectively.

Other Research and Discovery Arrangements and Funding Arrangements

These arrangements may include the potential for future milestone payments based on the achievement of certain clinical and commercial development payable over a period of several years.

For the years ended December 31, 2025, 2024 and 2023, we recorded approximately $ 13.4 million , $ 54.0 million and $ 4.1 million, respectively, as research and development expense in our consolidated statements of income related to other research and discovery related arrangements.

Royalty Pharma Funding Arrangement

In February 2025 we entered into a funding agreement with Royalty Pharma under which we received $ 200.0 million in 2025 and will receive up to $ 50.0 million in 2026 to co-fund our development costs for the litifilimab program.

As there is a substantive transfer of risk to the financial partner for the amount invested, the development funding will be recognized by us as an obligation to perform contractual services.

This funding is being recognized as a reduction to research and development expense within our consolidated statements of income, proportionate to the related

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For the year ended December 31, 2025 , we recorded a reduction to research and development e xpense of $ 200.0 million within our consolidated statements of income.

If the litifilimab clinical trials are successful for the indications based on the applicable clinical trials, upon regulatory approval in the U.S.

or certain major markets in the world, Royalty Pharma will be eligible to receive approval-based fixed milestone payments of up to $ 250.0 million.

The milestone payments due upon approval will be recorded as a component of other (income) expense, net within our consolidated statements of income, when incurred.

If litifilimab receives regulatory approval, Royalty Pharma will be eligible to receive royalties of a mid-single digit percentage of the applicable net sales.

Royalties on net sales will be recorded as cost of sales within our consolidated statements of income.

As part of our acquisition of HI-Bio in July 2024, we acquired HI-Bio's pre-existing in-license commitments under third-party agreements with MorphoSys, which included tiered royalties on potential future sales ranging from high-single digit to mid-teen percentages, as well as potential development, regulatory and commercial milestone payments of up to $ 130.0 million, $ 230.0 million and $ 640.0 million, respectively.

These amounts included milestone payments due upon the first patient dosed in a Phase 3 clinical trial of felzartamab in a first and second indication of $ 35.0 million and $ 30.0 million, respectively.

During 2025 we made milestone payments to MorphoSys of $ 35.0 million and $ 30.0 million upon the first patient dosed in a Phase 3 clinical trial of felzartamab for the treatment of AMR and IgAN, respectively, which were recognized in acquired in-process research and development, upfront and milestone expense within our consolidated statements of income for the year ended December 31, 2025.

City Therapeutics, Inc.

In May 2025 we entered into a strategic research arrangement with City Therapeutics to develop select novel RNAi therapies.

Through this arrangement, City Therapeutics will leverage its next-generation RNAi engineering technologies to develop an RNAi trigger molecule (or molecules) combined with our proprietary drug delivery technology.

The collaboration will initially focus on a single target that mediates key CNS diseases, utilizing tissue enhanced delivery technologies with the aim of allowing for systemic administration of medicines.

We will be responsible for IND-enabling studies and global clinical development along with any regulatory submissions and all activities related to commercialization, including manufacturing.

In connection with the closing of this transaction we made an upfront payment of $ 16.0 million to City Therapeutics, which was recognized in acquired in-process research and development, upfront and milestone expense within our consolidated statements of income for the year ended December 31, 2025 , and invested $ 30.0 million in exchange for a City Therapeutics convertible note, representing a minority equity interest in City Therapeutics, if converted.

This convertible note was recorded as a component of investments and other assets within our consolidated balance sheets as of December 31, 2025.

We may also pay City Therapeutics potential research, development and sales-based milestone payments of up to $ 21.5 million, $ 360.0 million and $ 625.0 million, respectively, plus tiered royalties on potential future net sales, ranging from high-single digit to low-double digit percentages.

We also have the option to select one additional target in the collaboration, subject to an additional payment and availability of the target.

Dayra Therapeutics, Inc.

In October 2025 we entered into a research collaboration with Dayra to discover and develop oral macrocyclic peptides for priority targets in immunological conditions.

Under the terms of this agreement, both companies will collaborate to identify, validate and optimize oral macrocycle candidates for high-priority immunological targets, with our company advancing the molecules through further development and potential commercialization, including manufacturing.

In connection with the closing of this transaction we made an upfront payment of $ 50.0 million to Dayra, which was recognized in acquired in-process research and development, upfront and milestone expense within our consolidated statements of income for the year ended December 31, 2025.

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This agreement also provides us with the option to acquire the development candidates from Dayra, subject to additional payments per program.

Dayra will also be eligible to receive potential preclinical and clinical development milestone payments per program.

Vanqua Bio, Inc.

In October 2025 we entered into a license agreement with Vanqua granting us exclusive worldwide rights to further develop, manufacture and commercialize Vanqua's preclinical oral C5aR1 antagonist compound.

In connection with the closing of this transaction we made an upfront payment of $ 70.0 million to Vanqua, which was recognized in acquired in-process research and development, upfront and milestone expense within our consolidated statements of income for the year ended December 31, 2025.

We may pay Vanqua potential development, regulatory or commercial, and sales milestone payments of up to $ 135.0 million, $ 295.0 million and $ 560.0 million, respectively, if all the specified milestones set forth in this collaboration are achieved.

In addition, we may pay Vanqua tiered royalties on potential net sales of any licensed product under this collaboration in the mid-single digit to low-double digit percentages.

Investments in Variable Interest Entities

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As a result, we recorded a net gain on the deconsolidation of Neurimmune of approximately $ 3.0 million, which was recorded in other (income) expense, net within our consolidated statements of income for the year ended December 31, 2023.

Excluding the impact of the Neurimmune deferred tax asset, the assets and liabilities of Neurimmune are not significant to our consolidated financial position or results of operations as it is a research and development organization.

We have provided no financing to Neurimmune other than contractually required amounts.

Research and development costs for which we reimbursed Neurimmune are reflected in research and development expense in our consolidated statements of income.

For the years ended December 31, 2023 and 2022, amounts reimbursed were immaterial.

For additional information on our collaboration arrangements with Eisai, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Research and development costs for which we reimbursed Neurimmune were reflected in research and development expense in our consolidated statements of income.

For the year ended December 31, 2023, amounts reimbursed were immaterial.

Unconsolidated Variable Interest Entities

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As of December 31, 2025 and 2024, the carrying value of our investments in certain biotechnology companies representing potential unconsolidated variable interest entities totaled $ 49.8 million and $ 23.6 million, respectively.

The increase was primarily due to convertible note investments entered into during 2025, including a $ 30.0 million convertible note invested in City Therapeutics as part of our strategic research arrangement and a $ 5.0 million convertible note invested in Neela Therapeutics, Inc.

For additional information on our arrangement with City Therapeutics, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Our maximum exposure to loss related to these variable interest entities is limited to the carrying value of our investments.

We have also entered into research collaboration agreements with certain variable interest entities where we are required to fund certain development activities.

These development activities are included in research and development expense in our consolidated statements of income as they are incurred.

We have provided no financing to these variable interest entities other than previous contractually required amounts.

We are currently involved in various claims, investigations and legal proceedings, including the matters described below.

For information as to our accounting policies relating to claims and legal proceedings, including use of

These development activities are included in research and

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estimates and contingencies, please read Note 1, Summary of Significant Accounting Policies , to these consolidated financial statements.

development expense in our consolidated statements of income as they are incurred.

We have provided no financing to these variable interest entities other than previous contractually required amounts.

We are currently involved in various claims, investigations and legal proceedings, including the matters described below.

For information as to our accounting policies relating to claims and legal proceedings, including use of estimates and contingencies, please read Note 1, Summary of Significant Accounting Policies , to these consolidated financial statements.

With respect to some loss contingencies, an estimate of the possible loss or range of loss cannot be made until management has further information, including, for example, (i) which claims, if any, will survive dispositive motion practice;

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Loss Contingencies

Securities Litigation asserted against Biogen

We and certain current and former officers are defendants in three securities actions pending in the District Court, one filed by Nadia Shash and Amjad Khan in November 2020 and related to statements about ADUHELM, one filed by the Oklahoma Firefighters Pension and Retirement System in February 2022 and related to statements about ADUHELM, and one filed by Thomas Allen Gray in June 2024 and related to statements about LEQEMBI, TECFIDERA and VUMERITY.

Securities Litigation

We and certain current and former officers are defendants in three securities actions pending in the District Court, one filed by Nadia Shash and Amjad Khan in November 2020, which relates to statements about ADUHELM, one filed by the Oklahoma Firefighters Pension and Retirement System in February 2022, which relates to statements about ADUHELM, and one filed by Thomas Allen Gray in June 2024, which relates to statements about LEQEMBI, TECFIDERA and VUMERITY.

All allege violations of federal securities laws under 15 U.S.C.

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Derivative Actions

We and members of the Board of Directors are named as defendants in five derivative actions pending in the District Court, one filed by The Booth Family Trust in February 2022, one filed by Elaine Wang in July 2022, one filed by Jonathan Blaufarb (Blaufarb I) in July 2024, one filed by Lawrence Hollin in October 2024 and one filed by Jonathan Blaufarb (Blaufarb II) in October 2024.

We and members of the Board of Directors are named as defendants in five derivative actions pending in the District Court, one filed by The Booth Family Trust (Booth) in February 2022, one filed by Elaine Wang (Wang) in July 2022, one filed by Jonathan Blaufarb (Blaufarb I) in July 2024, one filed by Lawrence Hollin (Hollin) in October 2024 and one filed by Jonathan Blaufarb (Blaufarb II) in October 2024.

The Booth, Wang and Blaufarb II actions relate to ADUHELM and other matters, and the Blaufarb I and Hollin actions relate to statements about LEQEMBI, our compliance controls, 2023 earnings guidance and other matters.

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The actions seek declaratory and injunctive relief, monetary relief payable to Biogen, and attorneys’ fees and costs payable to the plaintiffs.

The Booth and Wang actions are stayed.

All derivative actions are stayed.

IMRALDI Patent Litigation

In June 2024, the Technical Boards of Appeal of the European Patent Office upheld the validity of Fresenius Kabi Deutschland GmbH's (Fresenius Kabi's) European Patent 3 145 488 (the EP '488 Patent), which expires in May 2035.

In June 2022 Fresenius Kabi filed a claim for damages and injunctive relief against Biogen France SAS in the Tribunal de Grande Instance de Paris alleging that IMRALDI, the adalimumab biosimilar product of Samsung Bioepis that Biogen commercializes in Europe, infringes the French counterpart of the EP ‘488 Patent.

In March 2024 the Düsseldorf Regional Court dismissed Fresenius Kabi's claim of infringement of the German counterpart of the EP '488 Patent and Fresenius Kabi has appealed to the Higher Regional Court of Düsseldorf.

IMRALDI is an adalimumab biosimilar manufactured by Samsung Bioepis that Biogen commercializes in Europe.

In June 2022, Fresenius Kabi filed a claim for damages and injunctive relief against Biogen France SAS in the Tribunal de Grande Instance de Paris alleging infringement of the French counterpart of EP ‘3 145 488 Patent (the EP '488 Patent) by a formulation of IMRALDI no longer commercialized in France.

Fresenius Kabi alleges damages of € 13,450,000 plus interest and costs.

Biogen disputes infringement and the validity of the patent.

Trial is set for June 2026.

In May 2025 the Higher Regional Court of Düsseldorf, Germany held that a formulation of IMRALDI we no longer commercialize in Germany infringed the German counterpart of the EP '488 Patent, enjoined infringement and declared Fresenius Kabi's right to seek damages.

Biogen has requested review of the decision by Germany's Federal Court of Justice and has challenged the validity of the patent in a separate proceeding.

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Litigation with Former Convergence Shareholders

In 2015 Biogen acquired Convergence, a U.K.

In 2019 Shareholder Representative Services LLC, on behalf of the former shareholders of Convergence, asserted claims of $ 200.0 million for alleged breaches of the contract pursuant to which we acquired Convergence.

In June 2023 Shareholder Representative Services LLC and 24 former shareholders filed a suit against us in the High Court of Justice of England and Wales asserting one of the 2019 claims and seeking payment of $ 49.9 million, interest and costs.

In 2019 Shareholder Representative Services LLC, on behalf of former shareholders of Convergence, asserted claims of $ 200.0 million for alleged breaches of the contract pursuant to which we acquired Convergence and in June 2023 it and former Convergence shareholders filed a suit against us in the High Court of Justice of England and Wales asserting one of the 2019 claims and seeking payment of $ 49.9 million, plus interest and costs.

The parties have reached an agreement in principle to resolve all claims relating to Biogen's acquisition of Convergence.

Humana Patient Assistance Litigation

In March 2023 the District Court dismissed the previously disclosed action filed against us by Humana in September 2020.

Humana had alleged damages related to our providing MS patients with free medications and making

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charitable contributions to non-profit organizations that assist MS patients and had alleged violations of the federal RICO Act and state laws.

In January 2025 the United States Court of Appeals for the First Circuit affirmed the District Court's dismissal of this action.

In February 2025 Humana filed suit against Biogen Inc., Biogen U.S.

and Advanced Care Scripts, Inc.

in Jefferson Circuit Court in Kentucky alleging damages related to providing MS patients with free medications and to charitable contributions to non-profit organizations that provide financial assistance to MS patients.

Humana alleges breach of contract, fraud and other claims under various state laws and seeks damages, attorneys' fees and costs.

Genentech Litigation

In February 2023 Genentech Inc.

filed suit against us in the U.S.

District Court for the Northern District of California and claims that it is owed royalties of approximately $ 92.7 million on sales of TYSABRI that occurred after the expiration of a patent licensed by Genentech to Biogen, plus interest and costs.

filed suit in the U.S.

District Court for the Northern District of California claiming that it was owed royalties on sales of TYSABRI that occurred after the expiration of a patent licensed by Genentech to Biogen.

In November 2025 the court entered judgment against us for approximately $ 124.3 million.

We appealed and the appeal is pending.

Lender Litigation

In April 2024, BioPharma Credit PLC, BPCR Limited Partnership, and BioPharma Credit Investments V (Master) LP filed suit against us and Reata Pharmaceuticals, Inc.

in the Supreme Court of the State of New York alleging breach of a loan agreement with Reata and seeking payment of approximately $ 23.2 million, plus interest, costs and attorneys' fees.

In April 2025, by agreement of the parties, the Supreme Court of the State of New York discontinued with prejudice the suit filed in 2024 by BioPharma Credit PLC, BPCR Limited Partnership, and BioPharma Credit Investments V (Master) LP against us and Reata Pharmaceuticals, Inc.

alleging breach of a loan agreement.

Antitrust Litigation

In August and September 2024, four suits were filed against us in the U.S.

District Court for the Northern District of Illinois and have been consolidated for pretrial purposes.

Plaintiffs are Local No.

1 Health Fund, the Mayor and City Council of Baltimore, Teamsters Local 237 Welfare Fund and Teamsters Local 237 Retirees' Benefit Fund, New York State Teamsters Council Health and Hospital Fund, and UFCW Local 1500 Welfare Fund.

Plaintiffs allege violations of federal antitrust laws including 15 U.S.C.

§§ 1, 2 and 13(c) and of various state laws, based on contracts with pharmacy benefit managers related to TECFIDERA and VUMERITY.

In October 2025 Local No.

1 Health Fund, the Mayor and City Council of Baltimore, Teamsters Local 237 Welfare Fund, Teamsters Local 237 Retirees' Benefit Fund, UFCW Local 1500 Welfare Fund, and Jacksonville Police Officers and Fire Fighters Health Insurance Trust filed an amended complaint against us in now consolidated proceedings in the U.S.

District Court for the Northern District of Illinois (the Illinois federal court).

The first complaint was filed in August 2024.

The plaintiffs allege violations of federal antitrust laws including 15 U.S.C.

§§ 1, 2 and 13(c), the Racketeer Influenced and Corrupt Organizations Act, 18 U.S.C.

§1962(c) and of various state laws, based on allegations about our contracts with pharmacy benefit managers related to TECFIDERA and VUMERITY and other allegations.

Plaintiffs seek declarations of the actions as class actions, monetary, declaratory and equitable relief, and attorneys' fees and costs.

In addition, in September 2025 Walgreen Co.

and The Kroger Co.

sued us in the Illinois federal court, alleging violations of 15 U.S.C.

§§ 1 and 2 based on allegations about our contracts with pharmacy benefit managers related to TECFIDERA and VUMERITY and other allegations.

They seek monetary, declaratory and equitable relief, and attorneys' fees and costs.

Neurimmune Litigation

In May 2025 we sued Neurimmune Holding AG and Neurimmune Subone AG (collectively, "Neurimmune") in the District Court seeking declaratory judgment and permanent injunctive relief regarding our rights under a terminated collaboration agreement related to aducanumab.

In September 2025 Neurimmune counterclaimed for declaratory judgment, breach of contract and unfair competition under Massachusetts G.L.

93A and seeking monetary, declaratory and equitable relief and attorneys' fees and costs.

TECFIDERA E.U.

In November 2023 we sued Neuraxpharm Pharmaceuticals S.L.

and Neuraxpharm Netherlands B.V.

(collectively, Neuraxpharm), Zaklady Farmaceutyzne Polpharma S.A.

(Polpharma), Sandoz B.V.

(Sandoz), Mylan Ireland Ltd.

and Mylan B.V.

in the District Court of Amsterdam Netherlands for damages for sales of generic versions of TECFIDERA in violation of our regulatory marketing protection.

Neuraxpharm, Polpharma and Sandoz counterclaimed for damages based on our actions to enforce TECFIDERA's regulatory marketing protection.

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In June 2024 we sued Sandoz A/S in the Danish Maritime and Commercial High Court for damages for sales of its generic version of TECFIDERA in violation of our regulatory marketing protection.

Sandoz A/S counterclaimed for damages based on our actions to enforce TECFIDERA's regulatory marketing protection.

These cases are stayed.

In September 2025 the European General Court annulled the May 2023 European Commission decision granting TECFIDERA an additional year of regulatory marketing protection extending until February 2025.

We and the European Commission appealed and the appeal is pending.

Germany Tax Matter

In December 2025 and January 2026 a German tax authority issued assessments against us of approximately $ 246.5 million including interest, which continues to accrue.

We are challenging the assessments.

Other Matters

Government Investigations

We have received subpoenas from the SEC seeking information relating to ADUHELM and its launch, and our equity plans.

We have also received subpoenas from the DOJ and SEC seeking information relating to our business operations in several foreign countries.

The Italian Competition Authority is investigating Biogen and other companies in relation to our biosimilar product BYOOVIZ.

In April 2025 the SEC Division of Enforcement informed us that it has closed the matter in which we had received subpoenas seeking information relating to ADUHELM and its launch and our equity plans, and in April and May 2025 the DOJ and SEC informed us that they closed the matters in which we had received subpoenas seeking information relating to our business operations in several foreign countries.

In May 2024 the Italian Competition Authority informed us that it is investigating Biogen and other companies in relation to our biosimilar product BYOOVIZ.

In September 2025 we received a Civil Investigative Demand from the Louisiana Department of Justice for information regarding our policies relating to the purchase of drugs by healthcare organizations that are covered entities under Section 340B of the Public Health Service Act.

In January 2026 we received a request for information regarding TECFIDERA from the European Commission Directorate-General for Competition.

TYSABRI Biosimilar Patent Matter

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§262, seeking a declaratory judgment of patent infringement.

Trial against Sandoz Inc.

is scheduled for April 2027.

Hatch-Waxman Act Litigation relating to VUMERITY Orange-Book Listed Patents

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8,669,281, 9,090,558 and 10,080,733) pursuant to the Drug Price Competition and Patent Term Restoration Act of 1984 (the Hatch-Waxman Act) in the U.S.

District Court for the District of Delaware against Zydus Worldwide DMCC.

District Court for the District of Delaware against Zydus Worldwide DMCC, Zydus Pharmaceuticals (USA) Inc.

and Zydus Lifesciences Limited.

In July 2025 the parties reached a settlement and the court dismissed the case pursuant to the parties' stipulation of dismissal.

In June 2025 we filed a request for arbitration in the International Court of Arbitration of the International Chamber of Commerce seeking adoption of a budget and commercialization plan for the European Territory that allocates commercialization activities to Biogen and Eisai in an equitable fashion taking into account our respective capabilities and provides a meaningful role for each party.

Product Liability and Other Legal Proceedings

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Royalty payments are recognized as cost of sales in our consolidated statements of income.

We make royalty payments to Ionis on annual worldwide net sales of SPINRAZA using a tiered royalty rate between 11.0 % and 15.0 %, which are recognized as cost of sales in our consolidated statements of income.

We make royalty payments to Ionis on annual worldwide net sales of SPINRAZA using a tiered royalty rate between 11.0 % and 15.0 %, which are recognized in cost of sales within our consolidated statements of income.

For additional information on our collaboration arrangements with Ionis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

We make royalty payments to Ionis on annual worldwide net sales of QALSODY using a tiered royalty rate between 11.0 % and 15.0 %, which are recognized as cost of sales in our consolidated statements of income.

We make royalty payments to Ionis on annual worldwide net sales of QALSODY using a tiered royalty rate between 11.0 % and 15.0 %, which are recognized in cost of sales within our consolidated statements of income.

For additional information on our collaboration arrangements with Ionis, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

We make royalty payments to Alkermes on worldwide net sales of VUMERITY using a royalty rate of 15.0 %, which are recognized as cost of sales in our consolidated statements of income.

Royalties payable on net sales of VUMERITY are subject, under certain circumstances, to tiered minimum annual payment requirements for a period of five years following FDA approval.

In October 2019 we entered into a new supply agreement and amended our license and collaboration agreement with Alkermes for VUMERITY.

We have elected to initiate a technology transfer and, following a transition period, to manufacture VUMERITY or have VUMERITY manufactured by a third party we have engaged in exchange for paying an increased royalty rate to Alkermes on any portion of future worldwide net commercial sales of VUMERITY that is manufactured by us or our designee.

For additional information on our collaboration arrangement with Alkermes, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

We make royalty payments to Alkermes on worldwide net sales of VUMERITY using a royalty rate of 15.0 % on product that Alkermes has manufactured and 16.0 % on product manufactured by us or a third-party designee, which are recognized as cost of sales in our consolidated statements of income.

In connection with our acquisition of Reata in September 2023 we assumed additional contractual obligations related to royalty payments.

Reata entered into agreements to pay royalties on future sales of SKYCLARYS, which will cumulatively range in the low- to mid-single digits.

Reata entered into agreements to pay royalties on annual worldwide net sales of SKYCLARYS, which will cumulatively range in the low to mid-single digit percentages.

Royalty payments are recognized as cost of sales in our consolidated statements of income.

For additional information on our acquisition of Reata, please read Note 2, Acquisitions , to these consolidated financial statements.

Lease Commitments

For additional information on our leases, please read Note 12, Leases , to these consolidated financial statements.

Contingent Consideration related to Business Combinations

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We recognized the contingent consideration obligations associated with this acquisition at its fair value on the acquisition date and we revalue this obligation each reporting period.

We may pay up to an additional $ 650.0 million in potential future development and regulatory milestone payments.

We may pay up to a total of $ 650.0 million in contingent development and regulatory milestone payments.

The acquisition-date fair value of these milestones was approximately $ 485.1 million.

Regulatory and Commercial Milestone Payments

Based on our development plans as of December 31, 2024, we could trigger potential future milestone payments to third parties of up to approximately $ 3.8 billion, including approximately $ 0.5 billion in development milestones, approximately $ 0.5 billion in regulatory milestones and approximately $ 2.8 billion in commercial milestones, as part

In October 2025 the second milestone related to the fourth patient dosed in a Phase 3 clinical trial of felzartamab for IgAN was achieved, resulting in a

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NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

of our various collaborations, including licensing and development programs and HI-Bio's pre-existing commitments, as discussed below.

$ 150.0 million milestone payment made to the former shareholders of HI-Bio, which was paid during the fourth quarter of 2025.

For additional information on our acquisition of HI-Bio, please read Note 2, Acquisitions , to these consolidated financial statements.

Contingent Development, Regulatory and Commercial Milestone Payments

Based on our development plans as of December 31, 2025, we could make potential future milestone payments to third parties of up to approximately $ 5.3 billion, including approximately $ 0.7 billion in development milestones, approximately $ 0.8 billion in regulatory milestones and approximately $ 3.8 billion in commercial milestones, as part of our various collaborations, including licensing and development programs.

Payments under these agreements generally become due and payable upon achievement of certain development, regulatory or commercial milestones.

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Amounts related to contingent milestone payments are not considered contractual obligations as they are contingent on the successful achievement of certain development, regulatory or commercial milestones.

If certain clinical and commercial milestones are met, we may pay up to approximately $ 73.6 million in milestones in 2025 under our current agreements, excluding opt-in payments.

This amount includes potential milestone payments due upon the first patient dosed in a phase 3 clinical trial of felzartamab in a first and second indication of $ 35.0 million and $ 30.0 million, respectively.

If certain research milestones are met, we may pay up to approximately $ 67.5 million in additional milestones in 2026 under our current agreements, excluding opt-in payments.

This amount includes a $ 45.0 million milestone payment due upon the initiation of a Phase 3 trial of salanersen.

Other Funding Commitments

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As of December 31, 2025, we have approximately $ 166.8 million of liabilities associated with uncertain tax positions.

As of December 31, 2024 and 2023, we have accrued income tax liabilities of approximately $ 234.0 million and $ 419.5 million, respectively, under the Transition Toll Tax.

The amount accrued as of December 31, 2024, is expected to be paid within one year.

The Transition Toll Tax is being paid in installments over an eight--year period, which started in 2018, and will not accrue interest.

As of December 31, 2024, we accrued income tax liabilities of approximately $ 234.0 million under the Transition Toll Tax, which was subsequently paid in full in April 2025.

For additional information on the Transition Toll Tax, please read Note 17, Income Taxes , to these consolidated financial statements.

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Our estimates of liabilities and expense for these plans incorporate a number of assumptions, including expected rates of return on plan assets and interest rates used to discount future benefits.

AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

401(k) Savings Plan

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Participants may make voluntary contributions.

We make matching contributions according to the 401(k)

AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Savings Plan’s matching formula.

We make matching contributions according to the 401(k) Savings Plan’s matching formula.

All matching contributions and participant contributions vest immediately.

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We are also supported by corporate staff functions.

Our CEO, as the CODM, manages and allocates resources to the operations of our company on a total company basis by assessing the overall level of resources available and how to best deploy these resources across functions, therapeutic areas and research and development projects that are in line with our long-term company-wide strategic goals.

In making these decisions, our CEO uses consolidated financial information for purposes of evaluating performance, forecasting future period financial results, allocating resources and setting incentive targets.

Our CEO, as the CODM, manages and allocates resources to the operations of our company on a total company basis by assessing the overall level of resources available and deciding how to best deploy these resources across

AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

CODM performs this assessment based on the segment’s net income.

functions, therapeutic areas and research and development projects that are in line with our long-term company-wide strategic goals.

In making these decisions, our CEO is provided with and uses consolidated financial information for purposes of evaluating performance, forecasting future period financial results, allocating resources and setting incentive targets.

The CODM performs this assessment based on the segment’s net income.

Through this analysis, which includes a comparison to budgeted results, the CODM assesses performance and how to allocate resources across the functions discussed above.

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Long-Lived Assets

As of December 31, 2024, 2023 and 2022, approximately $ 2,056.2 million, $ 2,156.4 million and $ 2,198.5 million, respectively, of our long-lived assets were related to the construction of our large-scale biologics manufacturing facility in Solothurn, Switzerland.

For additional information on our Solothurn manufacturing facility, please read Note 11, Property, Plant and Equipment, to these consolidated financial statements.

As of December 31, 2025, 2024 and 2023, approximately $ 2.0 billion, $ 2.1 billion and $ 2.2 billion, respectively, of our long-lived assets were related to the construction of our large-scale biologics manufacturing facility in Solothurn, Switzerland.

AND SUBSIDIARIES

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Research and development:

Milestone and upfront expense 61.5 16.6 76.2

Research and discovery 183.2 201.5 212.5

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692.9 747.8 855.3

Acquired in-process research and development, upfront and milestone expense 471.8 61.5 16.6

Selling, general and administrative 2,433.6 2,403.7 2,549.7

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(gain) loss on fair value remeasurement of contingent consideration;

impairment of ROU asset;

restructuring charges;

gain on sale of priority review voucher, net;

gain on sale of building, net;

other (income) expense, net;

income tax (benefit) expense;

equity in (income) loss of investee, net of tax;

and net income (loss) attributable to noncontrolling interests, net of tax.

Subsequent Events

In February 2025 we entered into an arrangement with Royalty Pharma under which we will receive up to $ 200.0 million in 2025 and up to $ 50.0 million in 2026 to co-fund our development costs for the litifilimab program.

Following potential regulatory approval, Royalty Pharma will be eligible for regulatory milestones and royalties of a mid-single digits percentage of the applicable net sales.

and net income attributable to noncontrolling interests, net of tax.

Report of Independent Registered Public Accounting Firm

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A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company;

(ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made

only in accordance with authorizations of management and directors of the company;

and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

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Critical Audit Matters

The critical audit matters communicated below are matters arising from the current period audit of the consolidated financial statements that were communicated or required to be communicated to the audit committee and that (i) relate 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 matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

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.

Reserves for Medicaid and Managed Care Rebates in the U.S.

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and (iii) testing, on a sample basis, rebate claims paid by the Company, including evaluating the claims for consistency with the contractual terms of the Company’s rebate agreements.

Acquisition of Human Immunology Biosciences, Inc.

(HI-Bio) - Valuation of In-Process Research and Development Intangible Assets

As described in Notes 1 and 2 to the consolidated financial statements, on July 2, 2024, the Company completed the acquisition of HI-Bio for total consideration of $1,622.4 million.

In-process research and development (IPR&D) intangible assets of $1,635.0 million were recorded, which include $920.0 million related to felzartamab indication for immunoglobulin A.

nephropathy (IgAN), $450.0 million related to felzartamab indication for antibody-mediated rejection (AMR), and $265.0 million related to felzartamab indication for primary membranous nephropathy (PMN).

Management uses the multi-period excess earnings method, which is a form of the income approach, utilizing post-tax cash flows and discount rates in estimating the fair value of identifiable intangible assets acquired when allocating the purchase consideration paid for the acquisition.

The estimates of the fair value of identifiable intangible assets involve significant judgment by management and include assumptions with measurement uncertainty, such as the amount and timing of projected cash flow, long-term sales forecasts, discount rates, and the timing and probability of regulatory and commercial success.

The principal considerations for our determination that performing procedures relating to the valuation of IPR&D intangible assets acquired in the acquisition of HI-Bio is a critical audit matter are (i) the significant judgment by management due to the significant measurement uncertainty when developing the fair value estimate of the IPR&D intangible assets acquired;

(ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating management’s significant assumptions related to long-term sales forecasts, discount rate, and the probability of regulatory and commercial success for the IPR&D intangible assets acquired;

and (iii) the audit effort involved the use of professionals with specialized skill and knowledge.

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 acquisition accounting, including controls over management’s valuation of the IPR&D intangible assets acquired.

These procedures also included, among others (i) reading the purchase agreement;

(ii) testing management’s process for developing the fair value estimate of the IPR&D intangible assets acquired;

(iii) evaluating the appropriateness of the multi-period excess earnings method used by management;

(iv) testing the completeness and accuracy of certain of the data used in the multi-period excess earnings method;

and (v) evaluating the reasonableness of the significant assumptions used by management related to long-term sales forecasts, discount rate, and the probability of regulatory and commercial success for the IPR&D intangible assets acquired.

Evaluating management's assumptions related to long-term sales forecasts and the probability of regulatory and commercial success for the IPR&D intangible assets acquired involved evaluating whether the assumptions used by management were reasonable considering (i) the current and past performance of the acquired business and (ii) whether the assumptions were consistent with evidence obtained in other areas of the audit.

Evaluating management’s assumption related to long-term sales forecasts also involved considering the consistency with external market and industry data.

Professionals with specialized skill and knowledge were used to assist in evaluating (i) the appropriateness of the multi-period excess earnings method and (ii) the reasonableness of the discount rate significant assumption for the IPR&D intangible assets acquired.

/s/ PricewaterhouseCoopers LLP

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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 9A. Controls and Procedures