BIIB 10-K Fiscal year
ended Dec. 31, 2024

Portions of the definitive proxy statement for our 2025 Annual Meeting of Stockholders are incorporated by reference into Part III of this report.

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We maintain a technology and cybersecurity program, which includes information security, as part of our overall risk management process with the aim that our information systems, including those of our vendors and other third-parties, will be resilient, effective and capable of safeguarding against emerging risks and cybersecurity threats. We endeavor to assure our program is appropriately resourced and to attract and retain expert talent to execute it.

In designing, operating, evaluating and maintaining our program we use internal and external resources and frameworks, including cybersecurity expert consultants, industry working groups, the U.S. NIST Cybersecurity Framework and the U.S. Cybersecurity Agency's National Cyber Incident Scoring System model to benchmark, inform and evaluate the design of our program, our operational capabilities and our program maturity.

Consistent with NIST 800-53, our technology and cybersecurity program and controls include a third party and vendor risk management component . As part of our vendor risk management program, we conduct security assessments prior to engagement of high-risk vendors and other third-party providers and have a monitoring program to evaluate ongoing compliance with our cybersecurity standards.

When a potential threat or incident is identified, our cyber security incident response team will assign a risk level classification and initiate the escalation and other steps called for by our plan. All incidents that are initially assessed by the cybersecurity incident response team as potentially high-risk are escalated promptly to our CISO . Our CISO, Chief Legal Officer and Chief Financial Officer, will determine whether and what elements of our cybersecurity crisis response and management plan should be activated, including escalation to other senior management or our Executive Committee. Our Executive Committee will inform our Board of Directors of cybersecurity incidents, as appropriate, considering a variety of factors, including financial, operational, legal or reputational impact.

Our program's maturity and operational readiness are regularly evaluated by independent experts using the U.S. NIST's CyberSecurity Framework and penetration tests. Our program, and the results of these independent evaluations and testing, are regularly reviewed by our senior management and members of our Board of Directors.

CYBERSECURITY RISK GOVERNANCE

We are committed to appropriate cybersecurity governance and oversight. Our technology and cybersecurity program is the principal responsibility of our Chief Information Officer and CISO , each of whom have over 20 years of experience in information systems, including cybersecurity training and experience . Additionally, we have a Cybersecurity steering committee that includes senior representatives from our Legal, Finance and IT departments, which meets regularly to discuss cybersecurity matters.

Our Board of Directors oversees management's processes for identifying and mitigating risks, including cybersecurity and information security risks. Our Board of Directors regularly reviews our technology and cybersecurity program and effectiveness, internal audits of our program, independent external expert evaluations of our program's maturity and operational readiness and the results of penetration testing. Our Board of Directors also receives cybersecurity updates and education on a broad range of topics, including:

• Current cybersecurity landscape and emerging threats;

• Status of ongoing cybersecurity initiatives and strategies;

• Incident report and learnings from any cybersecurity events; and

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• Compliance with regulatory requirements and industry standards.

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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

Stephen A. Sherwin , Director

Adopt

11/7/2024

X

—

8,760

05/08/2025

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Note 1:			Summary of Significant Accounting Policies

References in these notes to "Biogen," the "company," "we," "us" and "our" refer to Biogen Inc. and its consolidated subsidiaries.

Business Overview

Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex diseases. 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. and the E.U. 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; 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. 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; 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; 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.

We commercialize a portfolio of biosimilars of advanced biologics including: BENEPALI, an etanercept biosimilar referencing ENBREL; 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.

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

Consolidation

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. Intercompany balances and transactions are eliminated in consolidation.

In determining whether we are the primary beneficiary of a variable interest entity, we apply a qualitative approach that determines whether we have both (1) the power to direct the economically significant activities of the entity and (2) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to that entity. We continuously assess whether we are the primary beneficiary of a variable interest entity as changes to existing relationships or future transactions may result in us consolidating or deconsolidating one or more of our collaborators or partners. In November 2023 we terminated the Neurimmune Agreement, which resulted in the deconsolidation of our variable interest entity, Neurimmune.

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Use of Estimates

The preparation of our consolidated financial statements requires us to make estimates, judgments and assumptions that may affect the reported amounts of assets, liabilities, equity, revenue and expense and related disclosure of contingent assets and liabilities. 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. Actual results may differ from these estimates.

Revenue Recognition

We recognize revenue when our customer obtains control of promised goods or services, in an amount that reflects the consideration which we expect to receive in exchange for those goods or services. We recognize revenue following the five-step model prescribed under FASB ASC 606, Revenue from Contracts with Customers : (i) identify contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) we satisfy the performance obligations.

Product Revenue

In the U.S., we sell our products primarily to wholesale and specialty distributors and specialty pharmacies. In other countries, we sell our products primarily to wholesale distributors, hospitals, pharmacies and other third-party distribution partners. These customers subsequently resell our products to health care providers and patients. In addition, we enter into arrangements with health care providers and payors that provide for government-mandated or privately-negotiated discounts and allowances related to our products.

Product revenue is recognized when the customer obtains control of our product, which occurs at a point in time, typically upon delivery to the customer. We expense incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that we would have recognized is one year or less or the amount is immaterial.

Reserves for Discounts and Allowances

Product revenue is recorded net of reserves established for applicable discounts and allowances that are offered within contracts with our customers, health care providers or payors, including those associated with the implementation of pricing actions in certain of the international markets in which we operate.

Product revenue reserves, which are classified as a reduction in product revenue, are generally characterized in the following categories: discounts, contractual adjustments and returns.

These reserves are based on estimates of the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable (if the amount is payable to our customer) or a liability (if the amount is payable to a party other than our customer). Our estimates of reserves established for variable consideration are calculated based upon a consistent application of our methodology utilizing the expected value method. These estimates reflect our historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. The transaction price, which includes variable consideration reflecting the impact of discounts and allowances, may be subject to constraint and is included in the net sales price only to the extent that it is probable that a significant reversal of the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts may ultimately differ from our estimates. If actual results vary, we adjust these estimates, which could have an effect on earnings in the period of adjustment.

Discounts include trade term discounts, wholesaler incentives and volume related discounts. Trade term discounts and wholesaler incentives primarily relate to estimated obligations for credits to be granted to wholesalers for remitting payment on their purchases within established incentive periods and credits to be granted to wholesalers for compliance with various contractually-defined inventory management practices, respectively. We determine these reserves based on our historical experience, including the timing of customer payments. 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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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.

• Medicaid rebates: relate to our estimated obligations to states under established reimbursement arrangements. 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.

• Governmental rebates: or chargebacks, including VA and PHS discounts, represent our estimated obligations resulting from contractual commitments to sell products to qualified healthcare providers at prices lower than the list prices we charge to wholesalers which provide those products. The wholesaler charges us for the difference between what the wholesaler pays for the products and the ultimate selling price to the qualified healthcare providers. Rebate and chargeback reserves are established in the same period as the related revenue is recognized, resulting in a reduction of product revenue and a reduction in the net accounts receivable. Chargeback amounts are generally determined at the time of resale to the qualified healthcare provider from the wholesaler, and we generally issue credits for such amounts within a few weeks of the wholesaler notifying us about the resale. Our reserves for VA, PHS and other chargebacks consist of amounts for inventory that exists at the wholesalers that we expect will be sold to qualified healthcare providers and chargebacks that wholesalers have claimed for which we have not issued a credit.

• Managed care rebates: represent our estimated obligations to third parties, primarily pharmacy benefit managers. 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. These rebates result from performance-based goals, formulary position and price increase limit allowances (price protection). The calculation of the accrual for these rebates is based on an estimate of the coverage patterns and the resulting applicable contractual rebate rate(s) to be earned over a contractual period.

• Copay assistance: represents financial assistance to qualified patients, assisting them with prescription drug co-payments required by insurance. The calculation of the accrual for copay is based on an estimate of claims and the cost per claim that we expect to receive associated with inventory that exists in the distribution channel at period end.

• Pharmacy rebates: represent our estimated obligations resulting from contractual commitments to sell products to specific pharmacies. 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. These rebates result from contracted discounts on product purchased or product dispensed. 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.

• Other governmental rebates: non-U.S. pharmaceutical taxes or applicable allowances primarily relate to mandatory rebates and discounts in international markets where government-sponsored healthcare systems are the primary payors for healthcare.

Product return reserves are established for returns made by wholesalers and are recorded in the period the related revenue is recognized, resulting in a reduction to product revenue. In accordance with contractual terms, wholesalers are permitted to return product for reasons such as damaged or expired product. The majority of wholesaler returns are due to product expiration. Expired product return reserves are estimated through a comparison of historical return data to their related sales on a production lot basis. Historical rates of return are determined for each product and are adjusted for known or expected changes in the marketplace specific to each product.

In addition to discounts, rebates and product returns, we also maintain certain customer service contracts with distributors and other customers in the distribution channel that provide us with inventory management, data and distribution services, which are generally reflected as a reduction of revenue. To the extent we can demonstrate a

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separable benefit and fair value for these services we classify these payments in selling, general and administrative expense in our consolidated statements of income.

Revenue from Anti-CD20 Therapeutic Programs

Our collaboration with Genentech is within the scope of ASC 808, Collaborative Agreements , which provides guidance on the presentation and disclosure of collaborative arrangements. For purposes of this footnote, we refer to RITUXAN and RITUXAN HYCELA collectively as RITUXAN.

Our share of the pre-tax co-promotion profits on RITUXAN, GAZYVA and LUNSUMIO and royalty revenue on sales of OCREVUS, resulted from an exchange of a license. As we do not have future performance obligations under the license or collaboration agreement, revenue is recognized as the underlying sales occur.

Revenue from anti-CD20 therapeutic programs consist of:

(i)     our share of pre-tax profits and losses in the U.S. for RITUXAN, GAZYVA and LUNSUMIO;

(ii)    royalty revenue on sales of OCREVUS; and

(ii)     other revenue from anti-CD20 therapeutic programs, which consists of our share of pre-tax co-promotion profits on RITUXAN in Canada, royalties on net sales of COLUMVI in the U.S. and royalties on sales of LUNSUMIO outside the U.S.

Pre-tax co-promotion profits on RITUXAN, GAZYVA and LUNSUMIO are calculated and paid to us by Genentech and the Roche Group. Pre-tax co-promotion profits consist of net sales to third-party customers less applicable costs to manufacture, third-party royalty expense, distribution, selling and marketing expense and joint development expense incurred by Genentech and the Roche Group. Our share of the pre-tax profits on RITUXAN, GAZYVA and LUNSUMIO include estimates that are based on information received from Genentech and the Roche Group. These estimates are subject to change and actual results may differ.

We recognize royalty revenue on sales of OCREVUS based on our estimates from third party and market research data of OCREVUS sales occurring during the corresponding period. Differences between actual and estimated royalty revenue will be adjusted for in the period in which they become known, which is generally expected to be the following quarter.

Prior to regulatory approval, we record our share of the expense incurred by the collaboration for the development of anti-CD20 products within research and development expense and pre-commercialization costs within selling, general and administrative expense in our consolidated statements of income. 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.

Alzheimer's Collaboration Revenue

Alzheimer's collaboration revenue consists of our 50.0 % share of LEQEMBI product revenue, net and cost of sales, including royalties, as we are not the principal. We began recognizing Alzheimer's collaboration revenue upon the accelerated approval of LEQEMBI in the U.S. during the first quarter of 2023.

Contract Manufacturing, Royalty and Other Revenue

Contract Manufacturing Revenue

We record contract manufacturing revenue primarily from amounts earned under contract manufacturing agreements with our strategic customers. 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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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.

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.

Collaborative and Other Relationships

We also have a number of significant collaborative and other third-party relationships for revenue and for the development, regulatory approval, commercialization and marketing of certain of our products and product candidates. Where we are the principal on sales transactions with third parties, we recognize revenue, cost of sales and operating expense on a gross basis in their respective lines in our consolidated statements of income. 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. 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.

Fair Value Measurements

We have certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.

• Level 1 — Fair values are determined utilizing quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access;

• Level 2 — Fair values are determined by utilizing quoted prices for identical or similar assets and liabilities in active markets or other market observable inputs such as interest rates, yield curves, foreign currency spot rates and option pricing valuation models; and

• Level 3 — Prices or valuations that require inputs that are both significant to the fair value measurement and unobservable.

The majority of our financial assets have been classified as Level 2, and have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, utilizing third-party pricing services or option pricing valuation models. The pricing services utilize industry standard valuation models, including both income and market-based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events.

We validate the prices provided by our third-party pricing services by understanding the models used, obtaining market values from other pricing sources and analyzing pricing data in certain instances. The option pricing valuation models use assumptions within the model, including the term, stock price volatility, constant maturity risk-free interest rate and dividend yield. After completing our validation procedures, we did not adjust or override any fair value measurements provided by our pricing services as of December 31, 2024 and 2023.

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Other Assets and Liabilities

The carrying amounts reflected in our consolidated balance sheets for current accounts receivable, due from anti-CD20 therapeutic programs, other current assets, accounts payable and accrued expense and other, approximate fair value due to their short-term maturities.

Cash and Cash Equivalents

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.

Accounts Receivable

The majority of our accounts receivable arise from product sales and primarily represent amounts due from our wholesale and other third-party distributors, public hospitals, pharmacies and other government entities and have standard payment terms that generally require payment within 30 to 90 days.

We do not adjust our receivables for the effects of a significant financing component at contract inception if we expect to collect the receivables in one year or less from the time of sale.

We provide reserves against accounts receivable for estimated losses that may result from a customer's inability to pay. 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

Financial instruments that potentially subject us to concentrations of credit risk include cash and cash equivalents, investments, derivatives and accounts receivable. We attempt to minimize the risks related to cash and cash equivalents and investments by investing in a broad and diverse range of financial instruments as previously defined by us. We have established guidelines related to credit ratings and maturities intended to safeguard principal balances and maintain liquidity. Our investment portfolio is maintained in accordance with our investment policy, which defines allowable investments, specifies credit quality standards and limits the credit exposure of any single issuer. We minimize credit risk resulting from derivative instruments by choosing only highly rated financial institutions as counterparties.

Concentrations of credit risk with respect to receivables, which are typically unsecured, are somewhat mitigated due to the wide variety of customers and markets using our products, as well as their dispersion across many different geographic areas. We monitor the financial performance and creditworthiness of our customers so that we can properly assess and respond to changes in their credit profile. We continue to monitor these conditions and assess their possible impact on our business.

Marketable Securities and Other Investments

Marketable Debt Securities

Available-for-sale marketable debt securities are recorded at fair market value and unrealized gains and losses are included in AOCI in equity, net of related tax effects, unless the security has experienced a credit loss, we have determined that we have the intent to sell the security or we have determined that it is more likely than not that we will have to sell the security before its expected recovery. 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

Our marketable equity securities are recorded at fair market value and unrealized gains and losses are included in other (income) expense, net in our consolidated statements of income. Our marketable equity securities represent investments in publicly traded equity securities and are included in investments and other assets in our consolidated balance sheets.

Our investments in venture capital funds are recorded at net asset value, which approximates fair value, and unrealized gains and losses are included in other (income) expense, net in our consolidated statements of income. The underlying investments of the venture capital funds in which we invest are in equity securities of certain biotechnology companies and are included in investments and other assets in our consolidated balance sheets.

Non-Marketable Equity Securities

We also invest in equity securities of companies whose securities are not publicly traded and where fair value is not readily available. These investments are recorded using either the equity method of accounting or the cost minus impairment adjusted for observable price changes, depending on our ownership percentage and other factors that suggest we have significant influence. We monitor these investments to evaluate whether any increase or decline in their value has occurred, based on the implied value of recent company financings, public market prices of comparable companies and general market conditions. These investments are included in investments and other assets in our consolidated balance sheets.

Evaluating Marketable Debt Securities for Other-than-Temporary Impairments

When we hold marketable debt securities, we conduct periodic reviews to identify and evaluate each investment that has an unrealized loss, in accordance with the meaning of other-than-temporary impairment. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. Unrealized losses on available-for-sale debt securities that are determined to be temporary, and not related to credit loss, are recorded, net of tax, in AOCI.

For available-for-sale debt securities with unrealized losses, management performs an analysis to assess whether we intend to sell or whether we would more likely than not be required to sell the security before the expected recovery of the amortized cost basis. Where we intend to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is reflected in earnings as an impairment loss.

Regardless of our intent to sell a security, we perform additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where we do not expect to receive cash flows sufficient to recover the amortized cost basis of a security.

Equity Method of Accounting

In circumstances where we have the ability to exercise significant influence over the operating and financial policies of a company in which we have an investment, we utilize the equity method of accounting for recording investment activity. In assessing whether we exercise significant influence, we consider the nature and magnitude of our investment, the voting and protective rights we hold, any participation in the governance of the other company and other relevant factors such as the presence of a collaborative or other business relationship. Under the equity method of accounting, we record in our consolidated statements of income our share of income or loss of the other company. If our share of losses exceeds the carrying value of our investment, we will suspend recognizing additional losses and will continue to do so unless we commit to providing additional funding.

Inventory

Inventories are stated at the lower of cost or net realizable value with cost based on the first-in, first-out method. We classify our inventory costs as long-term when we expect to utilize the inventory beyond our normal operating cycle and include these costs in investments and other assets in our consolidated balance sheets. 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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Capitalization of Inventory Costs

We capitalize inventory costs associated with our products prior to regulatory approval, when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. We consider numerous attributes in evaluating whether the costs to manufacture a particular product should be capitalized as an asset. We assess the regulatory approval process and where the particular product stands in relation to that approval process, including any known safety or efficacy concerns, potential labeling restrictions and other impediments to approval. We evaluate our anticipated research and development initiatives and constraints relating to the product and the indication in which it will be used. We consider our manufacturing environment including our supply chain in determining logistical constraints that could hamper approval or commercialization. We consider the shelf life of the product in relation to the expected timeline for approval and we consider patent related or contract issues that may prevent or delay commercialization. We also base our judgment on the viability of commercialization, trends in the marketplace and market acceptance criteria. Finally, we consider the reimbursement strategies that may prevail with respect to the product and assess the economic benefit that we are likely to realize. We expense previously capitalized costs related to pre-approval inventory upon changes in such judgments, due to, among other potential factors, a denial or significant delay of approval by necessary regulatory bodies.

Obsolescence and Unmarketable Inventory

At each reporting period we review our inventories for excess or obsolescence and write-down obsolete or otherwise unmarketable inventory to its estimated net realizable value. 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. 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. In all cases, product inventory is carried at the lower of cost or its estimated net realizable value. Amounts written-down due to unmarketable inventory are charged to cost of sales in our consolidated statements of income.

Property, Plant and Equipment

Property, plant and equipment are carried at cost, subject to reviews for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. The cost of normal, recurring or periodic repairs and maintenance activities related to property, plant and equipment are expensed as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if the repair will result in future economic benefits.

Interest costs incurred during the construction of major capital projects are capitalized until the underlying asset is ready for its intended use, at which point the interest costs are amortized as depreciation expense over the life of the underlying asset. We also capitalize certain direct and incremental costs associated with the validation effort required for licensing by regulatory agencies of new manufacturing equipment for the production of a commercially approved drug. These costs primarily include direct labor and material and are incurred in preparing the equipment for its intended use. The validation costs are either amortized over the life of the related equipment or expensed as cost of sales when the product produced in the validation process is sold.

In addition, we capitalize certain internal use computer software development costs. 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:

Asset Category			Useful Lives
Land			Not depreciated
Buildings			15 to 40 years
Leasehold Improvements			Lesser of the useful life or the term of the respective lease
Furniture and Fixtures			5 to 7 years
Machinery and Equipment			5 to 20 years
Computer Software and Hardware			3 to 5 years

When we dispose of property, plant and equipment, we remove the associated cost and accumulated depreciation from the related accounts in our consolidated balance sheets and include any resulting gain or loss in our consolidated statements of income.

Leases

We determine if an arrangement is a lease at contract inception. Operating lease assets represent our right to use an underlying asset for the lease term and operating lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease assets and liabilities are recognized at the commencement date of the lease based upon the present value of lease payments over the lease term. When determining the lease term, we include options to extend or terminate the lease when it is reasonably certain that they will be exercised.

We use the implicit rate when readily determinable and use our incremental borrowing rate when the implicit rate is not readily determinable based upon the information available at the commencement date in determining the present value of the lease payments. Our incremental borrowing rate is determined using a secured borrowing rate for the same currency and term as the associated lease.

The lease payments used to determine our operating lease assets may include lease incentives, stated rent increases and escalation clauses linked to rates of inflation when determinable and are recognized in our operating lease assets in our consolidated balance sheets. Our lease agreements may include both lease and non-lease components, which we account for as a single lease component when the payments are fixed. Variable payments included in the lease agreement are expensed as incurred. For certain equipment leases, such as vehicles, we apply a portfolio approach to effectively account for the operating lease assets and liabilities.

Our operating leases are reflected in operating lease assets, accrued expense and other and long-term operating lease liabilities in our consolidated balance sheets. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.

We also have real estate lease agreements which are subleased to third parties. Operating leases for which we are the sublessor are included in accrued expense and other and other long-term liabilities in our consolidated balance sheets. We recognize sublease income on a straight-line basis over the lease term in our consolidated statements of income.

For additional information on our leases, please read Note 12, Leases , to these consolidated financial statements.

Intangible Assets

Our intangible assets primarily consist of completed technology (comprising of acquired and in-licensed rights and patents, and developed technology), IPR&D acquired after January 1, 2009, acquired priority review vouchers and trademarks and trade names. Our intangible assets are recorded at fair value at the time of their acquisition and are stated in our consolidated balance sheets net of accumulated amortization and impairments, if applicable.

Intangible assets related to completed technology are amortized over their estimated useful lives using the economic consumption method if anticipated future revenue can be reasonably estimated. The straight-line method is used when revenue cannot be reasonably estimated. Amortization is recorded within amortization and impairment of acquired intangible assets in our consolidated statements of income.

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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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; however, they are subject to review for impairment. We review our intangible assets with indefinite lives for impairment annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable.

Acquired In-process Research and Development

Acquired IPR&D represents the fair value assigned to research and development assets that have not reached technological feasibility. The value assigned to acquired IPR&D is determined by estimating the costs to develop the acquired technology into commercially viable products, estimating the resulting revenue from the projects and discounting the net cash flow to present value. The revenue and cost projections used to value acquired IPR&D are, as applicable, reduced based on the probability of success of developing a new drug. Additionally, the projections consider the relevant market sizes and growth factors, expected trends in technology and the nature and expected timing of new product introductions by us and our competitors. The rates utilized to discount the net cash flow to present value are commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections. Upon the acquisition of IPR&D, we complete an assessment of whether our acquisition constitutes the purchase of a single asset or a group of assets. We consider multiple factors in this assessment, including the nature of the technology acquired, the presence or absence of separate cash flow, the development process and stage of completion, quantitative significance and our rationale for entering into the transaction.

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

When performing our impairment assessment, we calculate the fair value using the same methodology as described above. If the carrying value of our acquired IPR&D exceeds its fair value, then the intangible asset is written down to its fair value. 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.

Goodwill

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. Goodwill is not amortized, but is reviewed for impairment annually, as of October 31, and whenever events or changes in circumstances indicate that the carrying value of the goodwill may not be recoverable.

We compare the fair value of our reporting unit to its carrying value. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of our reporting unit, we would record an impairment loss equal to the difference. As described in Note 25, Segment Information, to these consolidated financial statements, we operate as one operating segment, which is our only reporting unit.

Impairment of Long-Lived Assets

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. 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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Contingent Consideration

The consideration for our acquisitions often includes future payments that are contingent upon the occurrence of a particular event or events. We record an obligation for such contingent payments at fair value on the acquisition date. We estimate the fair value of contingent consideration obligations through valuation models that incorporate probability-adjusted assumptions related to the achievement of the milestones and thus likelihood of making related payments. We revalue our contingent consideration obligations each reporting period. Changes in the fair value of our contingent consideration obligations are recognized in our consolidated statements of income. Changes in the fair value of the contingent consideration obligations can result from changes to one or multiple inputs, including adjustments to the discount rates, changes in the amount or timing of expected expenditures associated with product development, changes in the amount or timing of cash flow and reserves associated with products upon commercialization, changes in the assumed achievement or timing of any cumulative sales-based and development milestones, changes in the probability of certain clinical events and changes in the assumed probability associated with regulatory approval.

Discount rates in our valuation models represent a measure of the credit risk associated with settling the liability. The period over which we discount our contingent obligations is based on the current development stage of the product candidates, our specific development plan for that product candidate adjusted for the probability of completing the development step and when the contingent payments would be triggered. In estimating the probability of success, we utilize data regarding similar milestone events from several sources, including industry studies and our own experience. These fair value measurements are based on significant inputs not observable in the market. Significant judgment is employed in determining the appropriateness of these assumptions as of the acquisition date and for each subsequent period.

Derivative Instruments and Hedging Activities

Cash Flow and Fair Value Derivative Instruments

We recognize all derivative instruments as either assets or liabilities at fair value in our consolidated balance sheets. Changes in the fair value of our derivative instruments are recognized each period in current earnings or AOCI, depending on whether the derivative instrument is designated as part of a hedge transaction and, if so, the type of hedge transaction. We classify the cash flow from these instruments in the same category as the cash flow from the hedged items. We do not hold or issue derivative instruments for trading or speculative purposes.

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. 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

The functional currency for most of our foreign subsidiaries is their local currency. For our non-U.S. 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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exchange at the balance sheet date. Income and expense items are translated at the average foreign currency exchange rates for the period. Adjustments resulting from the translation of the financial statements of our foreign operations into U.S. dollars are excluded from the determination of net income and are recorded in AOCI, as a separate component of equity. For subsidiaries where the functional currency of the assets and liabilities differ from the local currency, non-monetary assets and liabilities are translated at the rate of exchange in effect on the date assets were acquired while monetary assets and liabilities are translated at current rates of exchange as of the balance sheet date. Income and expense items are translated at the average foreign currency rates for the period. Translation adjustments of these subsidiaries are included in other (income) expense, net in our consolidated statements of income.

Royalty Cost of Sales

We make royalty payments to a number of third parties under license or purchase agreements associated with our acquisition of intellectual property. These royalty payments are typically calculated as a percentage (royalty rate) of the sales of our products in a particular year. That royalty rate may remain constant, increase or decrease within each year based on the total amount of sales during the annual period. Each quarterly period, we estimate our total royalty obligation for the full year and recognize the proportional amount as cost of sales based on actual quarterly sales as a percentage of full year estimated sales. For example, if the level of net sales in any calendar year increases the royalty rate within the year, we will record our cost of sales at an even rate over the year, based on the estimated blended royalty rate.

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. Compensation expense is recognized based on the estimated fair value of the awards at grant date. We recognize compensation expense for the number of awards expected to vest after taking into consideration an estimate of award forfeitures over the requisite service period, which is generally the vesting period. Where awards are made with non-substantive vesting periods (for instance, where a portion of the award vests upon retirement eligibility), we estimate and recognize expense based on the period from the grant date to the date the employee becomes retirement eligible.

The fair values of our stock option grants are estimated as of the date of grant using a Black-Scholes option valuation model. 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. 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

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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 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. We also accrue the costs of ongoing clinical trials associated with programs that have been terminated or discontinued for which there is no future economic benefit at the time the decision is made to terminate or discontinue the program.

From time to time, we enter into development agreements in which we share expenses with a collaborative partner. We record payments received from our collaborative partners for their share of the development costs as a reduction of research and development expense, except as discussed in Note 19, Collaborative and Other Relationships, to these consolidated financial statements. 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.

Selling, General and Administrative Expense

Selling, general and administrative expense is primarily comprised of compensation and benefits associated with sales and marketing, finance, human resources, legal, information technology and other administrative personnel, outside marketing, advertising and legal expense and other general and administrative costs.

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.

Income Taxes

The provision for income taxes includes federal, state, local and foreign taxes. Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. We evaluate the realizability of our deferred tax assets and establish a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. We recognize deferred taxes associated with our GILTI tax calculations.

The income tax consequences from the intra-entity transfers of inventory within our consolidated group, both current and deferred, are recorded as a prepaid tax or deferred charge and recognized through our consolidated statements of income when the inventory is sold to a third party. The income tax consequences from the intra-entity transfer of assets other than inventory and associated changes to deferred taxes are recognized when the transfer occurs.

We account for uncertain tax positions using a “more likely than not” threshold for recognizing and resolving uncertain tax positions. We evaluate uncertain tax positions on a quarterly basis and consider various factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, information obtained during in process audit activities and changes in facts or circumstances related to a tax position. We also accrue for potential interest and penalties related to unrecognized tax benefits in income tax (benefit) expense in our consolidated statements of income.

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Contingencies

We are currently involved in various claims and legal proceedings. Loss contingency provisions are recorded if the potential loss from any claim, asserted or unasserted, or legal proceeding is considered probable and the amount can be reasonably estimated or a range of loss can be determined. These accruals represent management’s best estimate of probable loss. Disclosure also is provided when it is reasonably possible that a loss will be incurred or when it is reasonably possible that the amount of a loss will exceed the recorded provision. On a quarterly basis, we review the status of each significant matter and assess its potential financial exposure. Significant judgment is required in both the determination of probability and as to whether an exposure is reasonably estimable. Because of uncertainties related to these matters, accruals are based only on the best information available at the time. As additional information becomes available, we reassess the potential liability related to pending claims and litigation and may change our estimates. Legal costs associated with legal proceedings are expensed when incurred.

Earnings per Share

Basic earnings per share is computed by dividing undistributed net income attributable to Biogen Inc. by the weighted-average number of common shares outstanding during the period. Diluted earnings per share is computed based on the treasury method by dividing net income by the weighted-average number of common shares outstanding during the period plus potentially dilutive common equivalent shares outstanding.

Business Combinations

Business combinations are recorded using the acquisition method of accounting. The results of operations of the acquired company are included in our results of operations beginning on the acquisition date, and assets acquired and liabilities assumed are recognized on the acquisition date at their respective fair values. Any excess of consideration transferred over the net carrying value of the assets acquired and liabilities assumed as of the acquisition date is recognized as goodwill.

We use the multi-period excess earnings method, which is a form of the income approach, utilizing post-tax cash flow 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 additionally for IPR&D intangible assets, the timing and probability of regulatory and commercial success.

We use the net realizable value method in estimating the fair value of acquired finished goods and work-in-process inventory. Raw materials acquired are valued using the replacement cost method.

Transaction and restructuring costs related to business combinations are expensed as incurred. The fair value of assets acquired and liabilities assumed in certain cases may be subject to revision based on the final determination of fair value during a period of time not to exceed 12 months from the acquisition date. If we determine the assets acquired do not meet the definition of a business, the transaction will be accounted for as an asset acquisition rather than a business combination.

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New Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that we adopt as of the specified effective date. Unless otherwise discussed below, we do not believe that the adoption of recently issued standards have or may have a material impact on our consolidated financial statements or disclosures.

Standard

Description

Effective Date

Effects on the financial statements

ASU No. 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.

ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures

This standard establishes incremental disaggregation of income tax disclosures pertaining to the effective tax rate reconciliation and income taxes paid. The amendments in this update are required to be applied on a prospective basis with the option to apply it retrospectively.

Annual reporting for fiscal years beginning after December 15, 2024. 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.

ASU No. 2024-03, Income Statement (Subtopic 220-40): Reporting Comprehensive Income - Expense Disaggregation Disclosures

This standard requires disclosure in the notes to the financial statements, at each interim and annual reporting period, of specified information about certain costs and expense including purchases of inventory, employee compensation, depreciation and intangible asset amortization included in each relevant expense caption. This standard also requires a qualitative description of the amounts remaining in relevant expense captions that are not separately disaggregated, as well as disclosure of the total amount of selling expenses, and, in annual reporting periods, an entity’s definition of selling expenses.

Annual reporting for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. 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.

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Note 2:			Acquisitions

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. 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. 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. 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 . 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.

Upon closing we also paid an additional $ 43.7 million related to working capital adjustments as of the transaction close date, which was included as a component of total purchase price paid.

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.

Purchase Price Consideration

Total consideration transferred for the acquisition of HI-Bio is summarized as follows:

(In millions)						As of July 2, 2024
Cash consideration paid to HI-Bio shareholders (1)						$	1,137.3
Contingent consideration						485.1
Total consideration						$	1,622.4

(1) Represents total consideration paid to shareholders of HI-Bio of $ 1.15 billion, plus an additional $ 43.7 million related to working capital adjustments as of the transaction close date, less $ 56.4 million of cash paid for HI-Bio's outstanding, non-vested equity awards, inclusive of employer taxes, which were recognized as compensation attributable to the post-acquisition service period and therefore not reflected as a component of total consideration.

Contingent Consideration: We may make certain contingent payments to the former shareholders of HI-Bio upon the achievement of certain development and regulatory milestones. As of the acquisition date, the maximum aggregate amount payable for these potential milestones was $ 650.0 million . 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. 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 as of July 2, 2024
Cash and cash equivalents																		$	62.5
Intangible assets:
IPR&D - felzartamab (IgAN)																		920.0
IPR&D - felzartamab (AMR)																		450.0
IPR&D - felzartamab (PMN)																		265.0
Other clinical programs																		7.9
Prepaid expense and other assets																		1.0
Operating lease assets																		1.2
Accounts payable																		( 1.1 )
Accrued liabilities																		( 35.0 )
Deferred tax liability																		( 304.4 )
Operating lease liabilities																		( 1.2 )
Total identifiable net assets																		1,365.9
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.

Intang ible assets: Intangible assets comprised of $ 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. 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 cash flow analyses and a discount rate of 14.5 %. These fair value measurements were based on significant inputs that are not observable in the market and thus represent Level 3 fair value measurements.

Goodwill: 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. 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.

Acquisition-related expense: 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. and the E.U. 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.

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. In addition, we agreed to pay approximately $ 983.9 million in cash for Reata's outstanding equity awards, inclusive of employer taxes, of which approximately $ 590.5 million was attributable to pre-acquisition services and is therefore reflected as a component of total purchase price paid. Of the $ 983.9 million paid to Reata's equity award holders, we recognized approximately $ 393.4 million as compensation 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.

We funded this acquisition through available cash, cash equivalents and marketable securities, supplemented by the issuance of a $ 1.0 billion term loan under our 2023 Term Loan. For additional information on our 2023 Term Loan, please read Note 13, Indebtedness , to these consolidated financial statements.

We 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.

Purchase Price Consideration

Total consideration transferred for the acquisition of Reata is summarized as follows:

(In millions)						As of September 26, 2023
Cash consideration paid to Reata shareholders (1)						$	6,602.9
Fair value of Reata equity compensation pre-acquisition services and related taxes (2)						590.5
Total consideration						$	7,193.4

(1) Represents cash consideration transferred of $ 172.50 per outstanding Reata ordinary share based on 38.3 million Reata shares outstanding at closing.

(2) Represents the fair value of Reata stock options and stock units issued to Reata equity award holders and the related taxes attributable to pre-acquisition vesting services.

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Purchase Price Allocation

We finalized purchase accounting for this acquisition in the third quarter of 2024. 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 September 26, 2023. The measurement period adjustments summarized below resulted from updates to our valuation assumptions related to the estimated amounts and timing of future cash flows associated with certain intangible assets, updates of our assumptions related to the quantities, selling location and remaining manufacturing and selling costs of acquired inventory, and other assets and liabilities. 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						$	267.3
Accounts receivable						15.9
Inventory						1,259.0
Other current assets (1)						54.6
Intangible assets:
Completed technology for SKYCLARYS (U.S.)						4,200.0
In-process research and development (omaveloxolone)						2,300.0
Priority review voucher						100.0
Other clinical programs						40.0
Operating lease assets						121.2
Accrued expense and other (1)						( 110.3 )
Debt payable						( 159.9 )
Contingent payable to Blackstone						( 300.0 )
Deferred tax liability (1)						( 909.3 )
Operating lease liabilities						( 151.8 )
Other assets and liabilities, net						( 2.5 )
Total identifiable net assets						6,724.2
Goodwill (1)						469.2
Total assets acquired and liabilities assumed						$	7,193.4

(1) Includes measurement period adjustments recorded in 2024 that increased other current assets by $ 1.0 million, accrued expense and other by $ 8.8 million and goodwill by $ 4.7 million, and decreased deferred tax liability by $ 3.1 million.

Inventory: Total inventory acquired was approximately $ 1.3 billion, which reflects a step-up in the fair value of finished goods and work-in-process inventory for SKYCLARYS. 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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Intang ible assets: Intangible assets are comprised of $ 4.2 billion related to SKYCLARYS commercialization rights in the U.S., $ 2.3 billion of IPR&D related to the omaveloxolone program outside the U.S., which had not yet received regulatory approval in the E.U. as of the acquisition date, $ 100.0 million related to a rare pediatric disease PRV which may be used to obtain priority review by the FDA for a future regulatory submission or sold to a third party and $ 40.0 million related to other clinical programs. 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.

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. Upon SKYCLARYS receiving regulatory approval in the E.U. in February 2024, we began selling the product in certain countries in Europe, and began amortizing the $ 2.3 billion IPR&D asset related to the program outside the U.S. over its expected economic life using an economic consumption model.

These fair value measurements were based on significant inputs not observable in the market and thus represent Level 3 fair value measurements.

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

Goodwill: 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 acquired that could not be individually identified and separately recognized. We recognized goodwill of approximately $ 469.2 million, which includes measurement period adjustments, and is not deductible for tax purposes. The goodwill recognized from our acquisition of Reata is primarily the result of the deferred tax consequences from the transaction recorded for financial statement purposes.

Acquisition-related expense: Acquisition-related expense, primarily comprised of regulatory, advisory and legal fees, and other transaction costs, totaled approximately $ 28.4 million and were recorded in selling, general and administrative expense within our consolidated statements of income for the year ended December 31, 2023.

Note 3:			Dispositions

Sale of Joint Venture Equity Interest in Samsung Bioepis

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. Under the terms of this transaction, we received approximately $ 1.0 billion in cash at closing, with 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.

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

In April 2024 we completed the sale of our rare pediatric disease PRV, generated by the development associated with SPINRAZA, to a third party. In consideration for the PRV we received a cash payment of $ 103.0 million upon the closing of the PRV purchase, of which approximately $ 14.4 million was paid to Ionis. 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.

Note 4:			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.

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

						For the Years Ended December 31,
						2024																		2023
(In millions)						Severance Costs						Accelerated Depreciation and Other Costs						Total						Severance Costs						Accelerated Depreciation and Other Costs						Total
Selling, general and administrative						$	—					$	13.8					$	13.8					$	—					$	23.3					$	23.3
Research and development						—						11.7						11.7						—						1.2						1.2
Restructuring charges						24.2						—						24.2						153.4						34.6						188.0
Total charges						$	24.2					$	25.5					$	49.7					$	153.4					$	59.1					$	212.5

Other Costs: 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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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.

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

						For the Years Ended December 31,
						2024																		2023
(In millions)						Severance Costs						Accelerated Depreciation and Other Costs						Total						Severance Costs						Accelerated Depreciation and Other Costs						Total
Selling, general and administrative						$	—					$	6.3					$	6.3					$	—					$	—					$	—
Research and development						—						11.9						11.9						—						—						—
Restructuring charges						3.4						—						3.4						30.4						—						30.4
Total charges						$	3.4					$	18.2					$	21.6					$	30.4					$	—					$	30.4

In connection with 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 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.

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,
						2023																		2022
(In millions)						Severance Costs						Accelerated Depreciation and Other Costs						Total						Severance Costs						Accumulated Depreciation and Other Costs (1)						Total
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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Charges and spending related to workforce reductions are summarized as follows:

(In millions)						Workforce Reductions
Restructuring reserve, December 31, 2022						$	35.9
Expense						181.6
Payment						( 140.5 )
Foreign currency and other adjustments						( 1.6 )
Restructuring reserve, December 31, 2023						75.4
Expense						30.2
Payment						( 73.8 )
Foreign currency and other adjustments						0.1
Restructuring reserve, December 31, 2024						$	31.9

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Note 5:			Revenue

Product Revenue

Revenue by product are summarized as follows:

						For the Years Ended December 31,
						2024																		2023																		2022
(In millions)						United States						Rest of World						Total						United States						Rest of World						Total						United States						Rest of World						Total
Multiple Sclerosis:
TECFIDERA						$	169.2					$	797.9					$	967.1					$	263.1					$	749.4					$	1,012.5					$	417.7					$	1,026.2					$	1,443.9
VUMERITY						538.6						89.4						628.0						512.1						64.2						576.3						521.3						32.1						553.4
Total Fumarate						707.8						887.3						1,595.1						775.2						813.6						1,588.8						939.0						1,058.3						1,997.3
AVONEX						451.3						256.2						707.5						536.7						274.3						811.0						649.2						324.3						973.5
PLEGRIDY						111.4						149.1						260.5						126.2						168.5						294.7						148.4						183.5						331.9
Total Interferon						562.7						405.3						968.0						662.9						442.8						1,105.7						797.6						507.8						1,305.4
TYSABRI						920.0						795.0						1,715.0						997.9						879.0						1,876.9						1,123.4						907.5						2,030.9
FAMPYRA						—						71.7						71.7						—						90.5						90.5						—						96.6						96.6
Subtotal: Multiple Sclerosis						2,190.5						2,159.3						4,349.8						2,436.0						2,225.9						4,661.9						2,860.0						2,570.2						5,430.2
Rare Disease:
SPINRAZA						625.7						947.5						1,573.2						610.5						1,130.7						1,741.2						600.2						1,193.3						1,793.5
SKYCLARYS (1)						301.1						81.4						382.5						55.9						—						55.9						—						—						—
QALSODY (2)						20.9						11.5						32.4						5.8						0.1						5.9						—						—						—
Subtotal: Rare Disease						947.7						1,040.4						1,988.1						672.2						1,130.8						1,803.0						600.2						1,193.3						1,793.5
Biosimilars:
BENEPALI						—						479.1						479.1						—						438.8						438.8						—						441.0						441.0
IMRALDI						—						213.1						213.1						—						222.1						222.1						—						224.5						224.5
FLIXABI						—						63.2						63.2						—						77.4						77.4						—						81.3						81.3
BYOOVIZ (3)						23.0						13.6						36.6						29.2						2.5						31.7						4.3						—						4.3
TOFIDENCE (4)						1.1						—						1.1						—						—						—						—						—						—
Subtotal: Biosimilars						24.1						769.0						793.1						29.2						740.8						770.0						4.3						746.8						751.1
Other:
ZURZUVAE (5)						72.2						—						72.2						1.6						—						1.6						—						—						—
Other (6)						2.8						7.5						10.3						2.4						7.8						10.2						4.8						8.2						13.0
Subtotal: Other						75.0						7.5						82.5						4.0						7.8						11.8						4.8						8.2						13.0
Total product revenue, net						$	3,237.3					$	3,976.2					$	7,213.5					$	3,141.4					$	4,105.3					$	7,246.7					$	3,469.3					$	4,518.5					$	7,987.8

(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. 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. during the second quarter of 2024.

(5) ZURZUVAE became commercially available in the U.S. during the fourth quarter of 2023.

(6) Other includes FUMADERM and ADUHELM.

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We recognized revenue from two wholesalers accounting for 25.9 % and 13.4 % of gross product revenue in 2024, 27.0 % and 9.9 % of gross product revenue in 2023 and 26.8 % and 11.1 % of gross product revenue in 2022, respectively.

As of December 31, 2024, two wholesale distributors individually accounted for approximately 27.2 % and 11.7 % of net accounts receivable associated with our product sales, as compared to 24.6 % and 11.6 % as of December 31, 2023, respectively.

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

						December 31, 2024
(In millions)						Discounts						Contractual Adjustments						Returns						Total
Balance, December 31, 2023						$	173.3					$	857.1					$	31.6					$	1,062.0
Current provisions relating to sales in current year						824.2						2,687.5						23.6						3,535.3
Adjustments relating to prior years						8.0						( 38.7 )						14.2						( 16.5 )
Payments/credits relating to sales in current year						( 670.9 )						( 1,989.7 )						( 0.6 )						( 2,661.2 )
Payments/credits relating to sales in prior years						( 171.9 )						( 635.4 )						( 20.7 )						( 828.0 )
Balance, December 31, 2024						$	162.7					$	880.8					$	48.1					$	1,091.6

						December 31, 2023
(In millions)						Discounts						Contractual Adjustments						Returns						Total
Balance, December 31, 2022						$	153.8					$	857.7					$	23.5					$	1,035.0
Current provisions relating to sales in current year						735.6						2,720.1						19.0						3,474.7
Adjustments relating to prior years						( 0.4 )						( 38.4 )						19.2						( 19.6 )
Payments/credits relating to sales in current year						( 572.9 )						( 1,944.8 )						( 2.1 )						( 2,519.8 )
Payments/credits relating to sales in prior years						( 142.8 )						( 737.5 )						( 28.0 )						( 908.3 )
Balance, December 31, 2023						$	173.3					$	857.1					$	31.6					$	1,062.0

						December 31, 2022
(In millions)						Discounts						Contractual Adjustments						Returns						Total
Balance, December 31, 2021						$	137.7					$	759.6					$	38.0					$	935.3
Current provisions relating to sales in current year						666.6						2,715.5						12.3						3,394.4
Adjustments relating to prior years						( 2.8 )						1.4						( 7.2 )						( 8.6 )
Payments/credits relating to sales in current year						( 514.9 )						( 2,060.7 )						( 1.2 )						( 2,576.8 )
Payments/credits relating to sales in prior years						( 132.8 )						( 558.1 )						( 18.4 )						( 709.3 )
Balance, December 31, 2022						$	153.8					$	857.7					$	23.5					$	1,035.0

The total reserves above, which are included in our consolidated balance sheets, are summarized as follows:

						As of December 31,
(In millions)						2024						2023
Reduction of accounts receivable						$	154.1					$	135.5
Component of accrued expense and other						937.5						926.5
Total revenue-related reserves						$	1,091.6					$	1,062.0

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Revenue from Anti-CD20 Therapeutic Programs

Revenue from anti-CD20 therapeutic programs is summarized in the table below. For purposes of this footnote, we refer to RITUXAN and RITUXAN HYCELA collectively as RITUXAN.

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Royalty revenue on sales of OCREVUS						$	1,339.5					$	1,266.2					$	1,136.3
Biogen's share of pre-tax profits in the U.S. for RITUXAN, GAZYVA and LUNSUMIO (1)						392.0						409.4						547.0
Other revenue from anti-CD20 therapeutic programs						18.4						14.0						17.2
Total revenue from anti-CD20 therapeutic programs						$	1,749.9					$	1,689.6					$	1,700.5

(1) LUNSUMIO became commercially available in the U.S. during the first quarter of 2023.

Approximately 18.1 %, 17.2 % and 16.7 % of our total revenue in 2024, 2023 and 2022, respectively, was derived from our collaboration arrangements with Genentech. For additional information on our collaboration arrangements with Genentech, please read Note 19, Collaborative and Other Relationships , to these consolidated financial statements.

Alzheimer's Collaboration Revenue

Alzheimer's collaboration revenue consists of our 50.0 % share of LEQEMBI product revenue, net and cost of sales, including royalties, as we are not the principal. We began recognizing Alzheimer's collaboration revenue upon the accelerated approval of LEQEMBI in the U.S. 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 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.

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

Contract Manufacturing, Royalty and Other Revenue

Contract manufacturing, royalty and other revenue is summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Contract manufacturing revenue						$	592.1					$	848.2					$	417.7
Royalty and other revenue						60.5						51.1						67.4
Total contract manufacturing, royalty and other revenue						$	652.6					$	899.3					$	485.1

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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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.

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.

Note 6:			Inventory

The components of inventory are summarized as follows:

						As of December 31,
(In millions)						2024						2023
Raw materials						$	317.8					$	426.9
Work in process						1,882.8						1,926.8
Finished goods						353.8						255.4
Total inventory						$	2,554.4					$	2,609.1
Balance Sheet Classification:
Inventory						$	2,460.5					$	2,527.4
Investments and other assets						93.9						81.7
Total inventory						$	2,554.4					$	2,609.1

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

Write Downs and Other Charges

Inventory amounts written down as a result of excess, obsolescence or unmarketability are charged to cost of sales, and totaled $ 101.9 million, $ 124.4 million and $ 336.2 million for the years ended December 31, 2024, 2023 and 2022, 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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Note 7:			Intangible Assets and Goodwill

Intangible Assets

Intangible assets, net of accumulated amortization, impairment charges and adjustments are summarized as follows:

												As of December 31, 2024																		As of December 31, 2023
(In millions)						Estimated Life						Cost						Accumulated Amortization						Net						Cost						Accumulated Amortization						Net
Completed technology						1 - 31 years						$	14,138.4					$	( 6,254.1 )					$	7,884.3					$	11,728.8					$	( 5,869.8 )					$	5,859.0
In-process research and development						Indefinite until commercialization						1,642.9						—						1,642.9						2,340.0						—						2,340.0
Priority review voucher						Indefinite						100.0						—						100.0						100.0						—						100.0
Trademarks and trade names						Indefinite						64.0						—						64.0						64.0						—						64.0
Total intangible assets												$	15,945.3					$	( 6,254.1 )					$	9,691.2					$	14,232.8					$	( 5,869.8 )					$	8,363.0

Amortization and Impairments

Amortization and impairment of acquired intangible assets totaled $ 446.7 million, $ 240.6 million and $ 365.9 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Amortization of acquired intangible assets, excluding impairment charges, totaled $ 386.5 million, $ 240.6 million and $ 246.3 million for the years ended December 31, 2024, 2023 and 2022, 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. 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. If new information indicates that the assumptions underlying our most recent analysis are substantially different than those utilized in our current estimates, our analysis would be updated and may result in a significant change in the anticipated lifetime revenue of the relevant products. The occurrence of an adverse event could substantially increase the amount of amortization expense related to our acquired intangible assets as compared to previous periods or our current expectations, which may result in a significant negative impact on our future results of operations.

Completed Technology

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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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.

Priority Review Voucher

In connection with our acquisition of Reata in September 2023 we acquired a rare pediatric disease PRV which may be used to obtain priority review by the FDA for a future regulatory submission or sold to a third party . 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.

Estimated Future Amortization of Intangible Assets

The estimated future amortization of finite-lived intangible assets for the next five years is expected to be as follows:

(In millions)						As of December 31, 2024
2025						$	525.0
2026						560.0
2027						600.0
2028						630.0
2029						665.0

Goodwill

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

						As of December 31,
(In millions)						2024						2023
Goodwill, January 1						$	6,219.2					$	5,749.0
Goodwill resulting from HI-Bio acquisition						256.5						—
Goodwill resulting from Reata acquisition (1)						4.7						464.5
Other						( 1.5 )						5.7
Goodwill, December 31						$	6,478.9					$	6,219.2

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

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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Note 8:			Fair Value Measurements

The tables below present information about our assets and liabilities that are regularly measured and carried at fair value and indicate the level within the fair value hierarchy of the valuation techniques we utilized to determine such fair value:

						Fair Value Measurements on a Recurring Basis
						As of December 31, 2024
(In millions)						Total						Quoted Prices in Active Markets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents						$	1,664.9					$	—					$	1,664.9					$	—
Marketable equity securities						179.7						179.7						—						—
Other current assets:
Derivative contracts						62.5						—						62.5						—
Other non-current assets:
Plan assets for deferred compensation						42.8						—						42.8						—
Total						$	1,949.9					$	179.7					$	1,770.2					$	—
Liabilities:
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

						Fair Value Measurements on a Recurring Basis
						As of December 31, 2023
(In millions)						Total						Quoted Prices in Active Markets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents						$	610.7					$	—					$	610.7					$	—
Marketable equity securities						416.8						416.8						—						—
Other current assets:
Receivable from Samsung BioLogics (1)						430.0						—						—						430.0
Derivative contracts						11.9						—						11.9						—
Other non-current assets:
Plan assets for deferred compensation						37.5						—						37.5						—
Total						$	1,506.9					$	416.8					$	660.1					$	430.0
Liabilities:
Derivative contracts						$	31.6					$	—					$	31.6					$	—
Total						$	31.6					$	—					$	31.6					$	—

(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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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.

There have been no material impairments of our assets measured and carried at fair value as of December 31, 2024 and 2023. In addition, there have been no changes to our valuation techniques as of December 31, 2024 and 2023.

For a description of our validation procedures related to prices provided by third-party pricing services and our option pricing valuation model, please read Note 1, Summary of Significant Accounting Policies - Fair Value Measurements, to these consolidated financial statements.

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:

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 Average

Liabilities:

Contingent consideration obligations

$

512.8

Discounted cash flow

Discount rate

6.2 % - 6.3 %

6.2 %

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.

There were no transfers of assets or liabilities into or out of Level 3 as of December 31, 2024 and 2023.

Contingent Consideration Obligations

In connection with our acquisition of HI-Bio in July 2024 we agreed to make additional payments based upon the achievement of certain milestone events. 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
Fair value, beginning of year						$	—
Contingent consideration resulting from HI-Bio acquisition						485.1
Changes in fair value						27.7
Fair value, end of year						$	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. 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.

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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.

Financial Instruments Not Carried at Fair Value

Other Financial Instruments

Due to the short-term nature of certain financial instruments, the carrying value reflected in our consolidated balance sheets for current accounts receivable, due from anti-CD20 therapeutic programs, other current assets, accounts payable and accrued expense and other, approximates fair value.

Debt Instruments

The fair values of our debt instruments, which are Level 2 liabilities, are summarized as follows:

						Fair Value As of December 31,
(In millions)						2024						2023
Current portion:
2023 Term Loan 364-day tranche						$	—					$	150.0
4.050 % Senior Notes due September 15, 2025						1,741.0						—
Current portion of notes payable and term loan						1,741.0						150.0
Non-current portion:
2023 Term Loan three-year tranche						—						500.0
4.050 % Senior Notes due September 15, 2025						—						1,721.5
2.250 % Senior Notes due May 1, 2030						1,295.6						1,279.3
5.200 % Senior Notes due September 15, 2045						1,008.0						1,089.7
3.150 % Senior Notes due May 1, 2050						943.7						1,049.0
3.250 % Senior Notes due February 15, 2051						448.9						498.2
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.

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

Note 9:			Financial Instruments

The following table summarizes our financial assets with maturities of less than 90 days from the date of purchase included in cash and cash equivalents in our consolidated balance sheets:

						As of December 31,
(In millions)						2024						2023
Money market funds						$	1,664.9					$	610.7
Total						$	1,664.9					$	610.7

The carrying value of our money market funds 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:

						As of December 31, 2024
(In millions)						Amortized Cost						Gross Unrealized Gains						Gross Unrealized Losses						Fair Value
Marketable equity securities:
Marketable equity securities, non-current						$	668.7					$	—					$	( 489.0 )					$	179.7
Total marketable equity securities						$	668.7					$	—					$	( 489.0 )					$	179.7

						As of December 31, 2023
(In millions)						Amortized Cost						Gross Unrealized Gains						Gross Unrealized Losses						Fair Value
Marketable equity securities:
Marketable equity securities, current						$	31.6					$	—					$	( 21.0 )					$	10.6
Marketable equity securities, non-current						948.3						—						( 542.1 )						406.2
Total marketable equity securities						$	979.9					$	—					$	( 563.1 )					$	416.8

Proceeds from Marketable Debt Securities

The proceeds from maturities and sales of marketable debt securities and resulting realized gains and losses are summarized as follows:

												For the Years Ended December 31,
(In millions)												2023						2022
Proceeds from maturities and sales												$	7,380.8					$	3,671.0
Realized gains												1.4						—
Realized losses												18.4						12.6

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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Note 10:			Derivative Instruments

Foreign Currency Forward Contracts - Hedging Instruments

Due to the global nature of our operations, portions of our revenue and operating expense are recorded in currencies other than the U.S. dollar. The value of revenue and operating expense measured in U.S. dollars is therefore subject to changes in foreign currency exchange rates. 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. 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. Realized gains and losses of such contracts and options are recognized in revenue when the sale of product in the currency being hedged is recognized and in operating expense when the expense in the currency being hedged is recorded. 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.

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:

						Notional Amount As of December 31,
(In millions)						2024						2023
Euro						$	1,062.6					$	1,169.0
British pound						133.8						—
Canadian dollar						38.6						—
Total foreign currency forward contracts and options						$	1,235.0					$	1,169.0

The pre-tax portion of the fair value of these foreign currency forward contracts and foreign currency options that were included in AOCI in total equity is summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Unrealized gains						$	50.6					$	—					$	29.9
Unrealized (losses)						( 0.3 )						( 34.8 )						( 21.3 )
Net unrealized gains (losses)						$	50.3					$	( 34.8 )					$	8.6

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 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. As of December 31, 2024 and 2023, credit risk did not materially change the fair value of our foreign currency forward contracts and forward currency options.

The following table summarizes the effect of foreign currency forward contracts and forward currency options designated as hedging instruments in our consolidated statements of income:

For the Years Ended December 31,
Net Gains/(Losses) Reclassified from AOCI into Operating Income (in millions)																								Net Gains/(Losses) Excluded from Effectiveness Testing and Recognized in Operating Income (in millions)
Location						2024						2023						2022						Location						2024						2023						2022
Revenue						$	18.1					$	11.6					$	201.6					Revenue						$	( 0.8 )					$	( 2.4 )					$	( 8.6 )
Operating expense						( 12.9 )						3.7						( 5.5 )						Operating expense						—						—						—

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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)																		$	( 4.6 )

(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

We also enter into other foreign currency forward contracts, usually with durations of one month or less, to mitigate the foreign currency risk related to certain balance sheet positions. We have not elected hedge accounting for these transactions.

The aggregate notional amount of these outstanding foreign currency forward contracts was $ 738.7 million and $ 1,301.5 million as of December 31, 2024 and 2023, 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.

Summary of Derivative Instruments

While certain of our derivative instruments are subject to netting arrangements with our counterparties, we do not offset derivative assets and liabilities in our consolidated balance sheets. The amounts in the table below would not be substantially different if the derivative assets and liabilities were offset.

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:

												As of December 31,
(In millions)						Balance Sheet Location						2024						2023
Cash Flow Hedging Instruments:
Asset derivative instruments						Other current assets						$	58.4					$	0.3
Liability derivative instruments						Accrued expense and other						0.3						26.5
Other Derivative Instruments:
Asset derivative instruments						Other current assets						4.1						11.6
Liability derivative instruments						Accrued expense and other						11.4						5.1

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Note 11:			Property, Plant and Equipment

Property, plant and equipment are recorded at historical cost, net of accumulated depreciation. Components of property, plant and equipment, net are summarized as follows:

						As of December 31,
(In millions)						2024						2023
Land						$	202.4					$	202.4
Buildings						1,963.7						1,601.3
Leasehold improvements						137.8						135.7
Machinery and equipment						2,109.8						1,703.8
Computer software and hardware						1,070.5						1,032.1
Furniture and fixtures						59.5						61.5
Construction in progress						308.4						975.4
Total cost						5,852.1						5,712.2
Less: accumulated depreciation						( 2,670.8 )						( 2,402.5 )
Total property, plant and equipment, net						$	3,181.3					$	3,309.7

Depreciation expense totaled $ 286.7 million, $ 254.2 million and $ 272.4 million for the years ended December 31, 2024, 2023 and 2022, respectively.

For the years ended December 31, 2024, 2023 and 2022, we capitalized interest costs related to construction in progress totaling approximately $ 3.2 million, $ 21.7 million and $ 17.1 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.

Note 12:			Leases

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 .

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 .

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All of our leases qualify as operating leases. The following table summarizes the presentation in our consolidated balance sheets of our operating leases:

									As of December 31,
(In millions)			Balance sheet location						2024						2023
Assets:
Operating lease assets			Operating lease assets						$	356.4					$	420.0
Liabilities
Current operating lease liabilities			Accrued expense and other						$	86.4					$	90.3
Non-current operating lease liabilities			Long-term operating lease liabilities						334.5						400.0
Total operating lease liabilities									$	420.9					$	490.3

The following table summarizes the effect of lease costs in our consolidated statements of income:

												For the Years Ended December 31,
(In millions)						Income Statement Location						2024						2023						2022
Operating lease cost						Research and development						$	2.4					$	2.0					$	2.0
						Selling, general and administrative						110.1						128.1						95.9
Variable lease cost						Research and development						0.4						0.5						0.4
						Selling, general and administrative						31.2						37.3						25.4
Sublease income						Selling, general and administrative						( 14.8 )						( 23.5 )						( 24.0 )
						Other (income) expense, net						( 4.0 )						( 4.1 )						( 4.1 )
Net lease cost												$	125.3					$	140.3					$	95.6

Variable lease cost primarily related to operating expense, taxes and insurance associated with our operating leases. As these costs are generally variable in nature, they are not included in the measurement of the operating lease asset and related lease liability.

The minimum lease payments for the next five years and thereafter are expected to be as follows:

(In millions)						As of December 31, 2024
2025						$	103.4
2026						88.5
2027						88.3
2028						50.2
2029						21.9
Thereafter						152.4
Total lease payments						$	504.7
Less: interest						83.8
Present value of operating lease liabilities						$	420.9

The weighted average remaining lease term and weighted average discount rate of our operating leases are as follows:

						As of December 31,
						2024						2023
Weighted average remaining lease term in years						7.20						7.37
Weighted average discount rate						4.5		%				4.5		%

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Supplemental disclosure of cash flow information related to our operating leases included in cash flow provided by operating activities in our consolidated statements of cash flow is as follows:

						As of December 31,
(In millions)						2024						2023						2022
Cash paid for amounts included in the measurement of lease liabilities						$	115.8					$	116.4					$	107.4
Operating lease assets obtained in exchange for lease obligations						16.9						146.0						108.3

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. 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 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

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Note 13:			Indebtedness

Our indebtedness is summarized as follows:

						As of December 31,
(In millions)						2024						2023
Current portion:
2023 Term Loan 364-day tranche						$	—					$	150.0
4.050 % Senior Notes due September 15, 2025						1,748.6						—
Current portion of notes payable and term loan						$	1,748.6					$	150.0
Non-current portion:
2023 Term Loan three-year tranche						$	—					$	500.0
4.050 % Senior Notes due September 15, 2025						—						1,746.6
2.250 % Senior Notes due May 1, 2030						1,494.7						1,493.8
5.200 % Senior Notes due September 15, 2045						1,101.1						1,100.7
3.150 % Senior Notes due May 1, 2050						1,475.0						1,474.3
3.250 % Senior Notes due February 15, 2051						476.4						472.8
Non-current portion of notes payable and term loan						$	4,547.2					$	6,788.2

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.

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

2023 Term Loan Credit Agreement

In connection with our acquisition of Reata in September 2023 we entered into a $ 1.5 billion term loan credit agreement. On the closing date of the Reata acquisition we drew $ 1.0 billion from the 2023 Term Loan, comprised of a $ 500.0 million floating rate 364-day tranche and a $ 500.0 million floating rate three-year tranche. The remaining unused commitment of $ 500.0 million was terminated. As of December 31, 2023, we repaid $ 350.0 million of the 364-day tranche. The remaining $ 150.0 million portion of the 364-day tranche was repaid during the first quarter of 2024.

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

2021 Exchange Offer Senior Notes

The following is a summary of our currently outstanding senior unsecured notes issued in 2021 as part of our Exchange Offer (the 2021 Exchange Offer Senior Notes), consisting of the following:

• $ 700.7 million aggregate principal amount of 3.25 % Senior Notes due February 15, 2051, valued at 99.298 % of par.

Our 2021 Exchange Offer 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. Our 2021 Exchange Offer Senior Notes contain a change of control provision that may require us to purchase the notes at a price equal to 101.0 % of the principal amount plus accrued and unpaid interest to the date of purchase under certain circumstances.

The costs associated with this exchange offer of approximately $ 5.4 million have been recorded as a reduction to the carrying amount of the debt in our consolidated balance sheets. These costs along with the discounts will be amortized as additional interest expense using the effective interest rate method over the period from issuance through maturity. 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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2020 Senior Notes

The following is a summary of our currently outstanding senior unsecured notes issued in 2020 (2020 Senior Notes), consisting of the following:

• $ 1.5 billion aggregate principal amount of 2.25 % Senior Notes due May 1, 2030, valued at 99.973 % of par; and

• $ 1.5 billion aggregate principal amount of 3.15 % Senior Notes due May 1, 2050, valued at 99.174 % of par.

Our 2020 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, until a specified period before maturity, a specified make-whole amount. Our 2020 Senior Notes contain a change-of-control provision that, under certain circumstances, may require us to purchase our 2020 Senior Notes at a price equal to 101.0 % of the principal amount plus accrued and unpaid interest to the date of repurchase.

The original costs associated with this offering of approximately $ 24.4 million have been recorded as a reduction to the carrying amount of the debt in our consolidated balance sheets. These costs along with the discounts will be amortized as additional interest expense using the effective interest rate method over the period from issuance through maturity. Interest on our 2020 Senior Notes is payable May 1 and November 1 of each year, commencing November 1, 2020.

2015 Senior Notes

The following is a summary of our currently outstanding senior unsecured notes issued in 2015 (the 2015 Senior Notes), consisting of the following:

• $ 1.75 billion aggregate principal amount of 4.05 % Senior Notes due September 15, 2025, valued at 99.764 % of par; and

• $ 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. Our 2015 Senior Notes contain a change of control provision that may require us to purchase the notes at a price equal to 101.0 % of the principal amount plus accrued and unpaid interest to the date of purchase under certain circumstances.

The original costs associated with this offering of approximately $ 47.5 million, of which approximately $ 23.6 million pertains to our currently outstanding notes, have been recorded as a reduction to the carrying amount of the debt in our consolidated balance sheets. These costs along with the discounts will be amortized as additional interest expense using the effective interest rate method over the period from issuance through maturity. Interest on our 2015 Senior Notes is payable March 15 and September 15 of each year, commencing March 15, 2016.

3.625 % Senior Notes due September 15, 2022

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.

2024 Revolving Credit Facility

In August 2024 we entered into a $ 1.5 billion, five-year senior unsecured revolving credit facility under which we are permitted to draw funds for working capital and general corporate purposes. The terms of the revolving credit facility include a financial covenant that requires us not to exceed a maximum consolidated leverage ratio. This revolving credit facility replaced the revolving credit facility that we entered into in January 2020. As of December 31, 2024, we had no outstanding borrowings and were in compliance with all covenants under this facility.

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Debt Maturity

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

(In millions)						As of December 31, 2024
2025						$	1,750.0
2026						—
2027						—
2028						—
2029						—
2030 and thereafter						4,817.3
Total current and non-current debt						6,567.3
Less: debt discount and issuance fees						( 271.5 )
Total current and non-current debt, net						$	6,295.8

The fair value of our debt is disclosed in Note 8, Fair Value Measurements, to these consolidated financial statements.

Note 14:			Equity

Preferred Stock

We have 8.0 million shares of Preferred Stock authorized, of which 1.75 million shares are authorized as Series A, 1.0 million shares are authorized as Series X junior participating and 5.25 million shares are undesignated. Shares may be issued without a vote or action of shareholders from time to time in classes or series with the designations, powers, preferences and the relative, participating, optional or other special rights of the shares of each such class or series and any qualifications, limitations or restrictions thereon as set forth in the instruments governing such shares. Any such Preferred Stock may rank prior to common stock as to dividend rights, liquidation preference or both, and may have full or limited voting rights and may be convertible into shares of common stock. No shares of Preferred Stock were issued and outstanding during 2024, 2023 and 2022.

Common Stock

The following table describes the number of shares authorized, issued and outstanding of our common stock as of December 31, 2024, 2023 and 2022:

As of December 31, 2024

As of December 31, 2023

As of December 31, 2022

(In millions)

Authorized

Issued

Outstanding

Authorized

Issued

Outstanding

Authorized

Issued

Outstanding

Common stock

1,000.0

169.5

145.8

1,000.0

168.7

144.9

1,000.0

167.9

144.0

Share Repurchases

In October 2020 our Board of Directors authorized our 2020 Share Repurchase Program, which is a program to repurchase up to $ 5.0 billion of our common stock. Our 2020 Share Repurchase Program does not have an expiration date. 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.

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Accumulated Other Comprehensive Income (Loss)

The following tables summarize the changes in AOCI, net of tax by component:

												December 31, 2024
(In millions)												Unrealized Gains (Losses) on Cash Flow Hedges, Net of Tax						Unrealized Gains (Losses) on Pension Benefit Obligation, Net of Tax						Currency Translation Adjustments, Net of Tax						Total
Balance, December 31, 2023												$	( 25.0 )					$	( 2.6 )					$	( 126.1 )					$	( 153.7 )
Other comprehensive income (loss) before reclassifications												80.8						( 14.0 )						( 45.1 )						21.7
Amounts reclassified from AOCI												( 4.2 )						—						—						( 4.2 )
Net current period other comprehensive income (loss)												76.6						( 14.0 )						( 45.1 )						17.5
Balance, December 31, 2024												$	51.6					$	( 16.6 )					$	( 171.2 )					$	( 136.2 )

						December 31, 2023
(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, Net of Tax						Currency Translation Adjustments, Net of Tax						Total
Balance, December 31, 2022						$	( 15.7 )					$	15.1											$	( 1.1 )					$	( 163.2 )					$	( 164.9 )
Other comprehensive income (loss) before reclassifications						2.3						( 26.8 )												( 1.5 )						37.1						11.1
Amounts reclassified from AOCI						13.4						( 13.3 )												—						—						0.1
Net current period other comprehensive income (loss)						15.7						( 40.1 )												( 1.5 )						37.1						11.2
Balance, December 31, 2023						$	—					$	( 25.0 )											$	( 2.6 )					$	( 126.1 )					$	( 153.7 )

						December 31, 2022
(In millions)						Unrealized Gains (Losses) on Securities Available for Sale, 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						Currency Translation Adjustments, Net of Tax						Total
Balance, December 31, 2021						$	( 2.2 )					$	53.8					$	25.5					$	( 44.8 )					$	( 139.0 )					$	( 106.7 )
Other comprehensive income (loss) before reclassifications						( 23.5 )						137.3						12.6						43.7						( 83.1 )						87.0
Amounts reclassified from AOCI						10.0						( 176.0 )						( 38.1 )						—						58.9						( 145.2 )
Net current period other comprehensive income (loss)						( 13.5 )						( 38.7 )						( 25.5 )						43.7						( 24.2 )						( 58.2 )
Balance, December 31, 2022						$	( 15.7 )					$	15.1					$	—					$	( 1.1 )					$	( 163.2 )					$	( 164.9 )

(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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The following table summarizes the amounts reclassified from AOCI:

(In millions)						Amounts Reclassified from AOCI																		Income Statement Location
						For the Years Ended December 31,
						2024						2023						2022
Gains (losses) on securities available for sale						$	—					$	( 17.0 )					$	( 12.6 )					Other (income) expense, net
						—						3.6						2.6						Income tax (benefit) expense
Gains (losses) on cash flow hedges						18.1						11.6						201.6						Revenue
						( 12.9 )						3.7						( 5.5 )						Operating expense
						( 0.4 )						( 0.3 )						( 0.3 )						Other (income) expense, net
						( 0.6 )						( 1.7 )						( 19.8 )						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						$	4.2					$	( 0.1 )					$	145.2

(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.

Note 15:			Earnings per Share

Basic and diluted shares outstanding used in our earnings per share calculation are calculated as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Numerator:
Net income attributable to Biogen Inc.						$	1,632.2					$	1,161.1					$	3,046.9
Denominator:
Weighted-average number of common shares outstanding						145.6						144.7						145.3
Effect of dilutive securities:
Time-vested restricted stock units						0.3						0.7						0.5
Market stock units						—						—						0.1
Performance stock units settled in stock						—						0.2						0.1
Dilutive potential common shares						0.3						0.9						0.7
Shares used in calculating diluted earnings per share						145.9						145.6						146.0

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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Note 16:			Share-Based Payments

Share-Based Compensation Expense

The following table summarizes share-based compensation expense included in our consolidated statements of income:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Research and development						$	154.1					$	296.7					$	98.5
Selling, general and administrative						198.6						371.7						175.1
Subtotal						352.7						668.4						273.6
Capitalized share-based compensation costs						( 10.3 )						( 10.2 )						( 9.3 )
Share-based compensation expense included in total cost and expense						342.4						658.2						264.3
Income tax effect						( 63.4 )						( 132.6 )						( 49.2 )
Share-based compensation expense included in net income attributable to Biogen Inc.						$	279.0					$	525.6					$	215.1

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.

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 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.

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

The following table summarizes share-based compensation expense associated with each of our share-based compensation programs:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Time-vested restricted stock units						$	236.4					$	220.0					$	202.3
Performance stock units settled in stock						48.4						35.5						35.0
Performance stock units settled in cash						( 2.5 )						6.8						10.1
Employee stock purchase plan						9.7						10.5						12.7
Stock options						3.7						3.7						0.3
Market stock units						0.6						4.9						13.2
Reata equity awards (1)						—						387.0						—
HI-Bio equity awards (1)						56.4						—						—
Subtotal						352.7						668.4						273.6
Capitalized share-based compensation costs						( 10.3 )						( 10.2 )						( 9.3 )
Share-based compensation expense included in total cost and expense						$	342.4					$	658.2					$	264.3

(1) Relates to the Reata and HI-Bio equity-based compensation expense attributable to the post-acquisition service period, associated with the accelerated vesting of stock options and RSUs previously granted to Reata and HI-Bio employees that required no future services to vest. 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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As of December 31, 2024, unrecognized compensation cost related to unvested share-based compensation was approximately $ 292.2 million, net of estimated forfeitures. We expect to recognize the cost of these unvested awards over a weighted-average period of 1.8 years.

Share-Based Compensation Plans

We have two share-based compensation plans pursuant to which awards are currently being made: (i) the Biogen Inc. 2024 Omnibus Equity Plan (2024 Omnibus Equity Plan); and (ii) the Biogen Inc. 2024 Employee Stock Purchase Plan (2024 ESPP).

We have three share-based compensation plans pursuant to which outstanding awards have been made, but from which no further awards can or will be made: (i) the Biogen Inc. 2006 Non-Employee Directors Equity Plan (2006 Directors Plan); (ii) the Biogen Inc. 2017 Omnibus Equity Plan (2017 Omnibus Equity Plan); and (iii) the Biogen Inc. 2015 Employee Stock Purchase Plan (2015 ESPP).

2024 Omnibus Equity Plan

In June 2024 our shareholders approved the 2024 Omnibus Equity Plan for share-based awards to our prospective and current employees, non-employee directors, officers or consultants. 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. 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.

We have not made any awards pursuant to the 2017 Omnibus Equity Plan or the Directors Plan since our shareholders approved the 2024 Omnibus Equity Plan, and do not intend to make any awards pursuant to the 2017 Omnibus Equity Plan or the Directors Plan in the future, except that unused shares under the 2017 Omnibus Equity Plan have been carried over for use under the 2024 Omnibus Equity Plan. Awards outstanding under the 2017 Omnibus Equity Plan and the Directors Plan as of the date our shareholders approved the 2024 Omnibus Equity Plan will remain outstanding and subject to the terms and conditions of the 2017 Omnibus Equity Plan and the Directors Plan, as applicable, and the relevant award agreements.

Stock Options

In 2022 we granted approximately 81,000 stock options to our CEO (2022 CEO Grant) under the 2017 Omnibus Plan with a grant date fair value of $ 139.10 per option for a total of approximately $ 11.2 million. The fair value of the stock option grant is estimated as of the date of grant using a Black-Scholes option valuation model. The estimated fair value of the stock option is then expensed over the options' vesting periods. The 2022 CEO Grant is eligible to vest in equal annual installments over a three-year period from the grant date, subject to the CEO’s continued employment. The outstanding stock option has a 10-year term and is exercisable at a price per share not less than the fair market value of the underlying common stock on the date of grant.

						December 31, 2024
						Shares						Weighted Average Exercise Price						Weighted Average Remaining Contractual Term
Outstanding at December 31, 2023						81,000						$	301.85					8.9 years
Granted						—						—
Exercised						—						—
Forfeited						—						—
Outstanding at December 31, 2024						81,000						$	301.85					7.9 years
Exercisable at December 31, 2024						54,000						$	301.85					7.9 years

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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.

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
Granted			—						—
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.

Performance Stock Units

PSUs Settled in Stock

During the first quarter of 2018 we began granting awards for performance-vested RSUs that will settle in stock. PSUs awarded to employees have a three-year performance period 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 cumulative three-year performance measures established at the beginning of the performance period, which ends on December 31 of the third year of the performance period.

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.

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

			December 31, 2024
			Shares						Weighted Average Grant Date Fair Value
Unvested at December 31, 2023			389,000						$	325.73
Granted (1)			266,000						280.60
Vested			( 59,000 )						277.05
Forfeited			( 46,000 )						308.84
Unvested at December 31, 2024			550,000						$	310.61

(1) PSUs settled in stock granted in 2024 include awards granted in conjunction with our annual awards made in February 2024 and PSUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.

PSUs settled in stock granted in 2023 and 2022 had weighted average grant date fair values of $ 383.61 and $ 294.43 , respectively.

We value grants of PSUs with a performance metric based on a three-year cumulative rTSR metric using a lattice model with a Monte Carlo simulation. This valuation methodology utilizes several key assumptions, the 30 calendar day average closing stock price on the date of grant for PSUs, expected volatility of our stock price, risk-free rates of return and expected dividend yield.

The assumptions used in our valuation are summarized as follows:

						For the Years Ended December 31,
						2024						2023						2022
Expected dividend yield						— %						— %						— %
Range of expected stock price volatility						35.1 %						44.7 %						44.0 % - 45.9 %
Range of risk-free interest rates						4.1 %						4.1 %						1.8 % - 3.9 %
30 calendar day average stock price on grant date						$ 251.69						$ 283.93						$ 231.31 - $ 294.86
Weighted-average per share grant date fair value						$ 280.60						$ 383.61						$ 294.43

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.

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

			December 31, 2024
			Shares
Unvested at December 31, 2023			41,000
Granted			—
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.

Time-Vested Restricted Stock Units

RSUs awarded to employees generally vest no sooner than one-third per year over three years on the anniversary of the date of grant, or upon the third anniversary of the date of the grant, provided the employee remains continuously employed with us, except as otherwise provided in the plan. 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. Shares of our common stock will be delivered to the director upon vesting and are not subject to any withholding taxes.

The following table summarizes our RSU activity:

			Shares						Weighted Average Grant Date Fair Value
Unvested at December 31, 2023			1,856,000						$	256.74
Granted (1)			1,300,000						235.82
Vested			( 830,000 )						254.33
Forfeited			( 275,000 )						249.22
Unvested at December 31, 2024			2,051,000						$	246.22

(1) RSUs granted in 2024 primarily represent RSUs granted in conjunction with our annual awards made in February 2024 and awards made in conjunction with the hiring of new employees. RSUs granted in 2024 also include approximately 11,200 RSUs granted to our Board of Directors.

RSUs granted in 2023 and 2022 had weighted average grant date fair values of $ 282.92 and $ 221.28 , respectively.

The fair values of RSUs vested in 2024, 2023 and 2022 totaled $ 193.6 million, $ 232.1 million and $ 116.3 million, respectively.

Employee Stock Purchase Plan

2024 Employee Stock Purchase Plan

In June 2024 our shareholders approved the 2024 ESPP. The 2024 ESPP, which became effective on July 1, 2024, replaced the 2015 ESPP, which expired on June 30, 2024. The maximum number of shares of our common stock that may be purchased under the 2024 ESPP is 2.5 million.

The following table summarizes our ESPP activity:

						For the Years Ended December 31,
(In millions, except share amounts)						2024						2023						2022
Shares issued under the 2024 ESPP						40,000						—						—
Shares issued under the 2015 ESPP						175,000						199,000						241,000
Cash received under the 2024 ESPP						$	5.1					$	—					$	—
Cash received under the 2015 ESPP						$	31.2					$	45.1					$	44.2

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Note 17:			Income Taxes

Income Tax Expense

Income before income tax (benefit) expense and the income tax (benefit) expense consist of the following:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Income before income tax (benefit) expense:
Domestic						$	853.4					$	192.4					$	1,842.0
Foreign						1,052.6						1,104.4						1,749.8
Total income before income tax (benefit) expense						$	1,906.0					$	1,296.8					$	3,591.8
Income tax (benefit) expense:
Current:
Federal						$	448.9					$	377.6					$	694.5
State						50.5						15.1						39.0
Foreign						( 67.5 )						48.4						67.9
Total current						431.9						441.1						801.4
Deferred:
Federal						( 154.5 )						( 587.4 )						( 328.3 )
State						( 17.3 )						( 12.7 )						2.5
Foreign						13.7						294.3						157.2
Total deferred						( 158.1 )						( 305.8 )						( 168.6 )
Total income tax (benefit) expense						$	273.8					$	135.3					$	632.8

Transition Toll Tax

The Tax Cuts and Jobs Act of 2017 eliminated the deferral of U.S. income tax on the historical unrepatriated earnings by imposing the one-time mandatory deemed repatriation tax on accumulated foreign subsidiaries' previously untaxed foreign earnings. The Transition Toll Tax was assessed on our share of our foreign corporations' accumulated foreign earnings that were not previously taxed. 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.

Unremitted Earnings

At December 31, 2024, we considered our earnings not to be permanently reinvested outside the U.S. 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. 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, 2024. The residual U.S. tax liability, if these differences reverse, would be between $ 300.0 million and $ 400.0 million as of December 31, 2024.

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Deferred Tax Assets and Liabilities

Significant components of our deferred tax assets and liabilities are summarized as follows:

						As of December 31,
(In millions)						2024						2023
Deferred tax assets:
Tax credits						$	294.0					$	252.8
Inventory, other reserves and accruals						219.2						203.7
Intangibles, net						989.6						1,153.9
IRC Section 174 capitalized research and development						733.9						570.8
Net operating loss						1,357.2						1,700.4
Share-based compensation						34.4						36.1
Other						318.4						293.3
Valuation allowance						( 1,013.7 )						( 1,278.7 )
Total deferred tax assets						$	2,933.0					$	2,932.3
Deferred tax liabilities:
Purchased inventory valuation step-up and intangible assets						$	( 1,529.6 )					$	( 1,257.4 )
Samsung Bioepis investment installments						—						( 35.5 )
GILTI						( 1,054.8 )						( 1,136.9 )
Depreciation, amortization and other						( 214.9 )						( 215.7 )
Total deferred tax liabilities						$	( 2,799.3 )					$	( 2,645.5 )

As of December 31, 2024, 2023, 2022 and 2021, we had a valuation allowance of $ 1,013.7 million, $ 1,278.7 million, $ 2,003.3 million and $ 1,961.3 million, respectively, related to net operating losses in Switzerland and Neurimmune's tax basis in ADUHELM.

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.

In addition to deferred tax assets and liabilities, we have recorded deferred charges related to intra-entity sales of inventory. As of December 31, 2024 and 2023, the total deferred charges were $ 273.1 million and $ 69.3 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.

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Pillar Two

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.

Tax Rate

A reconciliation between the U.S. federal statutory tax rate and our effective tax rate is summarized as follows:

						For the Years Ended December 31,
						2024						2023						2022
Statutory rate						21.0		%				21.0		%				21.0		%
State taxes						1.8						1.1						1.1
Taxes on foreign earnings, including valuation allowances						( 7.6 )						( 5.9 )						( 4.9 )
Tax credits						( 2.2 )						( 7.3 )						( 1.7 )
Purchased inventory valuation step-up and intangible assets						2.1						0.7						0.3
GILTI						( 1.6 )						( 0.6 )						0.7
Sale of Samsung Bioepis						—						—						( 1.6 )
Litigation settlement agreement						—						—						2.6
Neurimmune tax impacts						—						—						2.3
Internal reorganization						—						( 0.1 )						( 1.4 )
Other, including permanent items						0.9						1.5						( 0.8 )
Effective tax rate						14.4		%				10.4		%				17.6		%

Changes in Tax Rate

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. Further, 2023 benefited from the combined impacts of Reata acquisition-related expenses and the resolution of an uncertain tax matter related to tax credits. 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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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. 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.

Tax Attributes

As of December 31, 2024, we had credit carry forwards for U.S. federal income tax purposes of approximately $ 163.0 million that begin to expire in 2030 and net operating losses of approximately $ 513.4 million that do not expire. For U.S. state income tax purposes, we had research and investment credit carry forwards of approximately $ 165.5 million that begin to expire in 2027 and net operating losses of approximately $ 220.9 million that begin to expire in 2028. For foreign income tax purposes, we had $ 10.7 billion of federal net operating loss carryforwards that begin to expire in 2027 and $ 10.1 billion of Swiss cantonal net operating loss carryforwards that begin to expire in 2027.

In assessing the realizability of our deferred tax assets, we have considered whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. In making this determination, under the applicable financial reporting standards, we are allowed to consider the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies. 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.

Accounting for Uncertainty in Income Taxes

A reconciliation of the beginning and ending amount of our unrecognized tax benefits is summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Beginning balance						$	173.4					$	606.4					$	563.4
Additions based on tax positions related to the current period						1.2						5.2						36.3
Additions for tax positions of prior periods						31.5						60.2						23.4
Reductions for tax positions of prior periods						( 3.1 )						( 485.0 )						( 14.9 )
Statute expirations						( 12.7 )						( 2.1 )						( 1.6 )
Settlement refund (payment)						( 4.0 )						( 11.3 )						( 0.2 )
Ending balance						$	186.3					$	173.4					$	606.4

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. 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.

We file income tax returns in various U.S. states and in U.S. federal and other foreign jurisdictions. With few exceptions, we are no longer subject to U.S. federal tax examination for years before 2021 or state, local or non-U.S. income tax examinations for years before 2013.

The U.S. 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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Included in the balance of unrecognized tax benefits as of December 31, 2024, 2023 and 2022, are $ 139.3 million, $ 147.6 million and $ 134.0 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.

We recognize potential interest and penalties related to unrecognized tax benefits in income tax (benefit) expense within our consolidated statements of income. During the years ended December 31, 2024, 2023 and 2022, we recognized total interest and penalty expense of $ 13.8 million, $ 5.1 million and $ 0.7 million, respectively. We have accrued $ 40.7 million and $ 30.2 million for the payment of interest and penalties as of December 31, 2024 and 2023, respectively.

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.

Note 18:			Other Consolidated Financial Statement Detail

Supplemental Cash Flow Information

Supplemental disclosure of cash flow information is summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Cash paid during the year for:
Interest						$	245.4					$	252.2					$	262.5
Income taxes						355.1						740.7						932.9

Other (Income) Expense, Net

Components of other (income) expense, net, are summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Interest income						$	( 67.6 )					$	( 276.5 )					$	( 89.3 )
Interest expense						250.3						246.9						246.6
(Gains) losses on investments, net						100.4						291.2						277.3
Foreign exchange (gains) losses, net						30.9						50.4						35.5
Gain on sale of equity interest in Samsung Bioepis (1)						—						—						( 1,505.4 )
Litigation settlement agreement and settlement fees						—						—						917.0
Other, net						29.6						3.5						10.1
Total other (income) expense, net						$	343.6					$	315.5					$	( 108.2 )

(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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The following table summarizes our (gains) losses on investments, net that relates to our equity securities held during the following periods:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Net (gains) losses recognized on equity securities						$	100.4					$	275.2					$	264.7
Less: Net (gains) losses realized on equity securities						( 2.0 )						5.2						—
Net unrealized (gains) losses recognized on equity securities						$	102.4					$	270.0					$	264.7

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, 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.

Accrued Expense and Other

Accrued expense and other consists of the following:

						As of December 31,
(In millions)						2024						2023
Revenue-related reserves for discounts and allowances						$	937.5					$	926.5
Employee compensation and benefits						375.8						335.1
Collaboration expense						309.0						214.6
Royalties and licensing fees						190.2						191.5
Current portion of contingent consideration obligations						291.2						—
Other						704.0						955.9
Total accrued expense and other						$	2,807.7					$	2,623.6

Other long-term liabilities were $ 732.3 million and $ 781.1 million as of December 31, 2024 and 2023, respectively, and included accrued income taxes totaling $ 156.7 million and $ 403.2 million, respectively.

Note 19:			Collaborative and Other Relationships

In connection with our business strategy, we have entered into various collaboration agreements that provide us with rights to develop, produce and market products using certain know-how, technology and patent rights maintained by our collaborative partners. Terms of the various collaboration agreements may require us to make milestone payments upon the achievement of certain product research and development objectives and pay royalties on future sales, if any, of commercial products resulting from the collaboration.

Depending on the collaborative arrangement, we may record funding receivable or payable balances with our collaboration partners, based on the nature of the cost-sharing mechanism and activity within the collaboration. Our significant collaborative arrangements are discussed below.

Genentech, Inc. (Roche Group)

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; 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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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.

RITUXAN

Genentech and its affiliates are responsible for the worldwide manufacture of RITUXAN as well as all development and commercialization activities as follows:

• U.S.: We have co-exclusively licensed our rights to develop, commercialize and market RITUXAN in the U.S.

• Canada: We have co-exclusively licensed our rights to develop, commercialize and market RITUXAN in Canada.

GAZYVA

The Roche Group and its sub-licensees maintain sole responsibility for the development, manufacture and commercialization of GAZYVA in the U.S. The level of gross sales of GAZYVA in the U.S. has impacted our percentage of the co-promotion profits for RITUXAN and LUNSUMIO, as summarized in the table below.

If we undergo a change in control, as defined in our collaboration agreement, Genentech will be deemed to have purchased our rights to GAZYVA in exchange for the continued payment of the current compensation payable for GAZYVA under the collaboration arrangement until the 11 year anniversary of the first commercial sale of GAZYVA in the U.S.

OCREVUS

Pursuant to the terms of our collaboration arrangements with Genentech, we receive a tiered royalty on U.S. net sales from 13.5 % and increasing up to 24.0 % if annual net sales exceed $ 900.0 million. There will be a 50.0 % reduction to these royalties upon the first entry of an FDA approved biosimilar to OCREVUS.

In addition, we receive a gross 3.0 % royalty on net sales of OCREVUS outside the U.S., with the royalty period lasting 11 years from the first commercial sale of OCREVUS on a country-by-country basis.

The commercialization of OCREVUS does not impact the percentage of the co-promotion profits we receive for RITUXAN, LUNSUMIO or GAZYVA. Genentech is solely responsible for development and commercialization of OCREVUS and funding future costs. Genentech cannot develop OCREVUS in CLL, non-Hodgkin's lymphoma or rheumatoid arthritis.

OCREVUS royalty revenue is based on our estimates from third party and market research data of OCREVUS sales occurring during the corresponding period. Differences between actual and estimated royalty revenue will be adjusted for in the period in which they become known, which is generally expected to be the following quarter.

If we undergo a change in control, as defined in our collaboration agreement, Genentech will be deemed to have purchased our rights to OCREVUS in exchange for the continued payment of the current royalties on net sales (as defined in our collaboration agreement and summarized above) in the U.S. 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. 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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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. 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.

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. The commercialization of COLUMVI does not impact the percentage of the co-promotion profits we receive for RITUXAN, LUNSUMIO or GAZYVA.

If we undergo a change in control, as defined in our collaboration agreement, Genentech will be deemed to have purchased our rights to COLUMVI in exchange for a mid-single digit royalty on net sales (as defined in our collaboration agreement) in the U.S. only, until the 11 year anniversary of the first commercial sale of the product in the U.S.

Profit-sharing Formulas

RITUXAN and LUNSUMIO Profit Share

Our current pretax 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:

After LUNSUMIO Approval until the First Threshold Date			37.5		%
After First Threshold Date until the Second Threshold Date			35.0		%
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. gross sales of LUNSUMIO have reached $ 150.0 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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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 %.

Revenue from Anti-CD20 Therapeutic Programs

Revenue from anti-CD20 therapeutic programs is summarized as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Royalty revenue on sales of OCREVUS						$	1,339.5					$	1,266.2					$	1,136.3
Biogen's share of pre-tax profits in the U.S. for RITUXAN, GAZYVA and LUNSUMIO (1)						392.0						409.4						547.0
Other revenue from anti-CD20 therapeutic programs						18.4						14.0						17.2
Total revenue from anti-CD20 therapeutic programs						$	1,749.9					$	1,689.6					$	1,700.5

(1) LUNSUMIO became commercially available in the U.S. during the first quarter of 2023.

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. 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.

Ionis Pharmaceuticals, Inc.

SPINRAZA

In January 2012 we entered into a collaboration and license agreement with Ionis pursuant to which we have an exclusive, worldwide license to develop and commercialize SPINRAZA for the treatment of SMA.

Under our agreement with Ionis, 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. Royalty cost of sales related to sales of SPINRAZA for the years ended December 31, 2024, 2023 and 2022, totaled approximately $ 216.1 million, $ 240.2 million and $ 243.1 million, respectively.

2018 Ionis Agreement

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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During the years ended December 31, 2024, 2023 and 2022, we incurred milestones of $ 7.5 million, $ 7.5 million and $ 10.0 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.

2017 SMA Collaboration Agreement

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.

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 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. Following the option exercise, we are solely responsible for the costs and expense related to the development, manufacturing and commercialization of QALSODY.

In April 2023 the FDA approved QALSODY for the treatment of ALS in adults who have a mutation in the SOD1 gene. This indication is approved under accelerated approval based on reduction in plasma neurofilament light chain observed in patients treated with QALSODY. Continued approval for this indication may be contingent upon verification of clinical benefit in confirmatory trial(s). Under this agreement, 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.

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. 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.

Eisai Co., Ltd.

During the first quarter of 2023 we accrued a $ 31.0 million payable to Eisai related to the termination of an agreement whereby Eisai co-promoted or distributed our MS products in certain Asia-Pacific markets and settings. As of December 31, 2023, we paid approximately $ 16.0 million of the $ 31.0 million payable. The remaining portion was subsequently paid in January 2024. This termination fee is included in selling, general and administrative expense in our consolidated statements of income for the year ended December 31, 2023.

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. 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.

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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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. Should the acquired party elect to continue commercializing the competing product, the non-acquired party may terminate the LEQEMBI Collaboration Agreement. 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.

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.

A summary of development and sales and marketing expense related to the LEQEMBI Collaboration is as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Total development expense incurred by the collaboration related to the advancement of LEQEMBI						$	329.6					$	371.9					$	347.2
Biogen's share of the LEQEMBI Collaboration development expense reflected in research and development expense in our consolidated statements of income						164.8						186.0						173.6
Total sales and marketing expense incurred by the LEQEMBI Collaboration						647.0						304.4						104.6
Biogen's share of the LEQEMBI Collaboration sales and marketing expense reflected in selling, general and administrative expense in our consolidated statements of income						323.5						152.2						52.3

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. 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. 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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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. for ADUHELM.

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 $ 16.7 million a nd $ 1.4 million as of December 31, 2024 and 2023, respectively. Amounts payable to Eisai related to the agreements discussed above we re approximately $ 138.0 million a nd $ 118.4 million as of December 31, 2024 and 2023, respectively.

UCB

We have a collaboration agreement with UCB, effective November 2003, to jointly develop and commercialize dapirolizumab pegol, an anti-CD40L pegylated Fab, for the potential treatment of SLE and other future agreed indications. Either we or UCB may propose development of dapirolizumab pegol in additional indications. If the parties do not agree to add an indication as an agreed indication to the collaboration, we or UCB may, at the sole expense of the applicable party, pursue development in such excluded indication(s), subject to an opt-in right of the non-pursuing party after proof of clinical activity.

All costs incurred for agreed indications, including research, development, sales and marketing expense, are shared equally between us and UCB. If marketing approval is obtained, both companies will jointly commercialize dapirolizumab pegol and share profits and losses equally.

A summary of development expense related to the UCB collaboration agreement is as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Total UCB collaboration development expense						$	77.5					$	60.7					$	68.0
Biogen's share of the UCB collaboration development expense reflected in research and development expense in our consolidated statements of income						38.7						30.3						34.0

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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. 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. 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 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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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:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
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

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. 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.

Under the LRRK2 Collaboration, both companies share responsibility and costs for global development based on specified percentages as well as profits and losses for commercialization in the U.S. and China. Outside the U.S. and China we are responsible for commercialization and may pay Denali potential tiered royalties.

A summary of development expense related to the Denali collaboration is as follows:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Total Denali collaboration development expense						$	53.1					$	65.0					$	75.1
Biogen's share of the Denali collaboration development expense reflected in research and development expense in our consolidated statements of income						31.9						39.0						43.8

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

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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.

Other

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.

Samsung Bioepis Co., Ltd.

Joint Venture Agreement

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. Under the terms of this transaction, we received approximately $ 1.0 billion in cash at closing, with 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.

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.

2019 Development and Commercialization Agreement

In December 2019 we completed a transaction with Samsung Bioepis and secured the exclusive rights to commercialize two potential ophthalmology biosimilar products, BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS, and OPUVIZ, an aflibercept biosimilar referencing EYLEA, in major markets worldwide, including the U.S., Canada, Europe, Japan and Australia. 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. and Canada. 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.

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 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. Royalty payments to AbbVie on sales of IMRALDI are recognized in cost of sales within our consolidated statements of income.

We share 50.0 % of the profit or loss related to our 2013 commercial agreement with Samsung Bioepis, which is recognized in collaboration profit sharing/(loss reimbursement) in our consolidated statements of income. For the years ended December 31, 2024, 2023 and 2022, we recognized net profit-sharing expense o f approximately $ 227.4 million , $ 223.5 million and $ 217.4 million, respectively, to reflect Samsung Bioepis' 50.0 % sharing of the net collaboration profits.

Other Services

Simultaneous with the formation of Samsung Bioepis, we also entered into a license agreement with Samsung Bioepis. Under this license agreement, we granted Samsung Bioepis an exclusive license to use, develop, manufacture and commercialize biosimilar products created by Samsung Bioepis using Biogen product-specific technology. In exchange, we receive single digit royalties on biosimilar products developed and commercialized by Samsung Bioepis. 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.

Amounts receivable from Samsung Bioepis related to the agreements discussed above were approximately $ 7.6 million and $ 9.9 million as of December 31, 2024 and 2023, respectively. Amounts payable to Samsung Bioepis related to the agreements discussed above were approximately $ 60.8 million and $ 73.7 million as of December 31, 2024 and 2023, respectively.

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Note 20:			Investments in Variable Interest Entities

Consolidated Variable Interest Entities

Our consolidated financial statements include the financial results of variable interest entities in which we are the primary beneficiary. The following are our significant variable interest entities.

Neurimmune SubOne AG

Beginning in 2007 we consolidated the results of Neurimmune as we determined we were the primary beneficiary because we had the power through the collaboration to direct the activities that most significantly impacted the entity's economic performance and we were required to fund 100.0 % of the research and development costs incurred in support of the collaboration. The collaboration and license agreement with Neurimmune was for the development and commercialization of antibodies for the potential treatment of Alzheimer's disease, including ADUHELM (as amended, the Neurimmune Agreement).

In November 2023 we notified Neurimmune of our decision to terminate the Neurimmune Agreement. Subsequent to the termination, we reconsidered our relationship with Neurimmune and determined that we were no longer the primary beneficiary of the variable interest entity. 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.

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. 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.

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.

Unconsolidated Variable Interest Entities

We have relationships with various variable interest entities that we do not consolidate as we lack the power to direct the activities that significantly impact the economic success of these entities. These relationships include investments in certain biotechnology companies and research collaboration agreements.

As of December 31, 2024 and 2023, the carrying value of our investments in certain biotechnology companies representing potential unconsolidated variable interest entities totaled $ 23.6 million and $ 16.4 million, respectively. 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.

Note 21:			Litigation

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

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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; (ii) information to be obtained through discovery; (iii) information as to the parties' damages claims and supporting evidence; (iv) the parties’ legal theories; and (v) the parties' settlement positions. If an estimate of the possible loss or range of loss can be made at this time, it is included in the potential loss contingency description below.

The claims and legal proceedings in which we are involved also include challenges to the scope, validity or enforceability of the patents relating to our products, pipeline or processes and challenges to the scope, validity or enforceability of the patents held by others. These include claims by third parties that we infringe their patents. An adverse outcome in any of these proceedings could result in one or more of the following and have a material impact on our business or consolidated results of operations and financial position: (i) loss of patent protection; (ii) inability to continue to engage in certain activities; and (iii) payment of significant damages, royalties, penalties and/or license fees to third parties.

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. All allege violations of federal securities laws under 15 U.S.C. §78j(b) and §78t(a) and 17 C.F.R. §240.10b-5 and seek declarations of the actions as class actions and monetary relief.

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. 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. The actions allege breach of fiduciary duty, waste of corporate assets and other common law claims, and violations of the Securities Exchange Act of 1934, 15 U.S.C. §78a et seq. 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.

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.

Litigation with Former Convergence Shareholders

In 2015 Biogen acquired Convergence, a U.K. company. 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.

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.

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.

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.

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. Plaintiffs seek declarations of the actions as class actions, monetary, declaratory and equitable relief, and attorneys' fees and costs.

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.

TYSABRI Biosimilar Patent Matter

In September 2022 we filed an action in the U.S. District Court for the District of Delaware against Sandoz Inc., other Sandoz entities and Polpharma Biologics S.A. under the Biologics Price Competition and Innovation Act, 42 U.S.C. §262, seeking a declaratory judgment of patent infringement.

Hatch-Waxman Act Litigation relating to VUMERITY Orange-Book Listed Patents

In July 2023 Biogen and Alkermes Pharma Ireland Limited filed patent infringement proceedings relating to VUMERITY Orange-Book listed patents (U.S. Patent Nos. 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.

Product Liability and Other Legal Proceedings

We are also involved in product liability claims and other legal proceedings incidental to our normal business activities. While the outcome of any of these proceedings cannot be accurately predicted, we do not believe the ultimate resolution of any of these existing matters would have a material adverse effect on our business or financial condition.

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Note 22:			Commitments and Contingencies

Royalty Payments

TYSABRI

We are obligated to make contingent payments of 18.0 % on annual worldwide net sales of TYSABRI up to $ 2.0 billion and 25.0 % on annual worldwide net sales of TYSABRI that exceed $ 2.0 billion. Royalty payments are recognized as cost of sales in our consolidated statements of income.

SPINRAZA

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.

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

QALSODY

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.

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

VUMERITY

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.

SKYCLARYS

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.

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

Contingent Consideration related to Business Combinations

In connection with our acquisition of HI-Bio in July 2024 we may make additional payments based upon the achievement of certain milestone events. 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. 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

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of our various collaborations, including licensing and development programs and HI-Bio's pre-existing commitments, as discussed below. Payments under these agreements generally become due and payable upon achievement of certain development, regulatory or commercial milestones. Because the achievement of these milestones was not considered probable as of December 31, 2024, such contingencies have not been recorded in our financial statements. 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.

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. 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.

Other Funding Commitments

As of December 31, 2024, we have several ongoing clinical studies in various clinical trial stages. Our most significant clinical trial expenditures are to CROs. The contracts with CROs are generally cancellable, with notice, at our option. We recorded accrued expense of approximately $ 21.7 million in our consolidated balance sheets for expenditures incurred by CROs as of December 31, 2024. We have approximately $ 509.2 million in cancellable future commitments based on existing CRO contracts as of December 31, 2024.

Tax Related Obligations

We exclude liabilities pertaining to uncertain tax positions from our summary of contractual obligations as we cannot make a reliable estimate of the period of cash settlement with the respective taxing authorities. As of December 31, 2024, we have approximately $ 173.8 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. For additional information on the Transition Toll Tax, please read Note 17, Income Taxes , to these consolidated financial statements.

Note 23:			Guarantees

As of December 31, 2024 and 2023, we did not have significant liabilities recorded for guarantees.

We enter into indemnification provisions under our agreements with other companies in the ordinary course of business, typically with business partners, contractors, clinical sites and customers. Under these provisions, we generally indemnify and hold harmless the indemnified party for losses suffered or incurred by the indemnified party as a result of our activities. These indemnification provisions generally survive termination of the underlying agreement. The maximum potential amount of future payments we could be required to make under these indemnification provisions is unlimited. However, to date we have not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. As a result, the estimated fair value of these agreements is minimal. Accordingly, we have no liabilities recorded for these agreements as of December 31, 2024 and 2023.

Note 24:			Employee Benefit Plans

We sponsor various retirement and pension plans. 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.

401(k) Savings Plan

We maintain a 401(k) Savings Plan, which is available to substantially all regular employees in the U.S. over the age of 21 . Participants may make voluntary contributions. We make matching contributions according to the 401(k)

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Savings Plan’s matching formula. All matching contributions and participant contributions vest immediately. The 401(k) Savings Plan also holds certain transition contributions on behalf of participants who previously participated in the Biogen, Inc. Retirement Plan. The expense related to our 401(k) Savings Plan primarily consists of our matching contributions.

Expense related to our 401(k) Savings Plan totaled approximately $ 51.5 million, $ 55.9 million and $ 56.0 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Deferred Compensation Plan

We maintain a non-qualified deferred compensation plan, known as the SSP, which allows a select group of management employees in the U.S. to defer a portion of their compensation. The SSP also provides certain credits to highly compensated U.S. employees that are paid by the company. These credits are known as the Restoration Match. The deferred compensation amounts are accrued when earned. Such deferred compensation is distributable in cash in accordance with the rules of the SSP. Deferred compensation amounts under such plan as of December 31, 2024 and 2023, totaled approximately $ 140.6 million and $ 134.6 million, respectively, and are included in other long-term liabilities in our consolidated balance sheets. The SSP also holds certain transition contributions on behalf of participants who previously participated in the Biogen, Inc. Retirement Plan. The Restoration Match and participant contributions vest immediately. Distributions to participants can be either in one lump sum payment or annual installments as elected by the participants.

Pension Plans

Our retiree benefit plans include defined benefit plans for employees in our affiliates in Switzerland and Germany as well as other insignificant defined benefit plans in certain other countries where we maintain an operating presence.

Our Swiss plan is a government-mandated retirement fund that provides employees with a minimum investment return. The minimum investment return is determined annually by the Swiss government and was 1.00 % in 2024, 1.75 % in 2023 and 2.00 % in 2022. Under the Swiss plan, both we and certain of our employees with annual earnings in excess of government determined amounts are required to make contributions into a fund managed by an independent investment fiduciary. Employer contributions must be in an amount at least equal to the employee’s contribution. Minimum employee contributions are based on the respective employee’s age, salary and gender. As of December 31, 2024 and 2023, the Swiss plan had an unfunded net pension obligation of $ 61.5 million and $ 51.5 million, respectively, and plan assets that totaled $ 224.7 million and $ 239.6 million, respectively. In 2024, 2023 and 2022 we recognized net expense totaling $ 17.5 million, $ 17.6 million and $ 20.0 million, respectively, related to our Swiss plan, of which $ 6.0 million, $ 5.1 million and $ 5.3 million, respectively, was included in other (income) expense, net in our consolidated statements of income.

The obligations under the German plans are unfunded and totaled $ 45.6 million and $ 46.5 million as of December 31, 2024 and 2023, respectively. Net periodic pension cost related to the German plans totaled $ 3.8 million, $ 3.6 million and $ 5.9 million for the years ended December 31, 2024, 2023 and 2022, respectively, of which $ 1.1 million, $ 0.8 million and $ 1.8 million, respectively, was included in other (income) expense, net in our consolidated statements of income.

Note 25:			Segment Information

We operate and are managed as one operating segment, and derive revenue from activities related to the discovery, development and delivery of innovative therapies for people living with serious and complex diseases.

Our research and development organization is responsible for the research and discovery of new product candidates and supports development and registration efforts for potential future products. Our pharmaceutical, operations and technology organization manages the development of the manufacturing processes, clinical trial supply, commercial product supply, distribution, buildings and facilities. Our commercial organization is responsible for U.S. and international development of our commercial products. 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. The

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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. The measure of segment assets used in determining how to manage and allocate resources is reported within our consolidated balance sheets as total assets.

The tables presented below, which were prepared in accordance with the accounting policies discussed in Note 1, Summary of Significant Accounting Policies , contain additional information on enterprise-wide disclosures about product revenue, other revenue and long-lived assets, as well as our segment’s revenue and profits, including significant segment expense and other segment items. Revenue is primarily attributed to individual countries based on location of the customer or licensee.

Geographic Information

The following tables contain certain financial information by geographic area:

						December 31, 2024
(In millions)						U.S.						Europe (1)						Germany						Asia						Other						Total
Product revenue from external customers						$	3,237.3					$	2,171.5					$	955.6					$	366.9					$	482.2					$	7,213.5
Revenue from anti-CD20 therapeutic programs						1,673.6						0.6						—						—						75.7						1,749.9
Contract manufacturing, royalty and other revenue						395.0						0.4						—						257.2						—						652.6
Long-lived assets						1,366.1						2,139.2						13.3						8.5						10.6						3,537.7
						December 31, 2023
(In millions)						U.S.						Europe (1)						Germany						Asia						Other						Total
Product revenue from external customers						$	3,141.4					$	2,127.4					$	868.0					$	649.4					$	460.5					$	7,246.7
Revenue from anti-CD20 therapeutic programs						1,618.5						0.4						—						—						70.7						1,689.6
Contract manufacturing, royalty and other revenue						673.6						11.7						—						214.0						—						899.3
Long-lived assets						1,443.0						2,248.0						17.5						8.3						12.9						3,729.7
						December 31, 2022
(In millions)						U.S.						Europe (1)						Germany						Asia						Other						Total
Product revenue from external customers						$	3,469.3					$	2,401.3					$	926.2					$	672.1					$	518.9					$	7,987.8
Revenue from anti-CD20 therapeutic programs						1,636.4						0.1						—						—						64.0						1,700.5
Contract manufacturing, royalty and other revenue						425.8						11.7						—						47.6						—						485.1
Long-lived assets						1,369.4						2,275.8						21.0						13.7						22.6						3,702.5

(1) Represents amounts related to Europe less those attributable to Germany.

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.

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Additional Segment Information

The following table includes additional information about reported segment revenue, significant segment expense and segment measure of profitability:

						For the Years Ended December 31,
(In millions)						2024						2023						2022
Total revenue						$	9,675.9					$	9,835.6					$	10,173.4
Less cost and expense:
Cost of sales, excluding amortization and impairment of acquired intangible assets:
Product cost of sales						1,604.2						1,787.2						1,504.8
Royalty cost of sales						706.2						746.2						773.5
Research and development:
Milestone and upfront expense						61.5						16.6						76.2
Research and discovery						201.5						212.5						289.4
Early stage programs						286.6						361.0						289.9
Late stage programs						209.7						250.5						484.5
Marketed products						534.7						766.1						361.5
Other research and development costs (1)						747.8						855.3						729.6
Selling, general and administrative						2,403.7						2,549.7						2,403.6
Other segment expense (2)						1,287.8						1,129.4						213.5
Net Income attributable to Biogen Inc.						$	1,632.2					$	1,161.1					$	3,046.9

(1) Other research and development costs primarily consist of indirect costs incurred in support of overall research and development activities and non-specific programs, including activities that benefit multiple programs, such as management costs, as well as depreciation, information technology and facility-based expenses and are not allocated to a specific program or stage.

(2) Other segment expense includes: amortization and impairment of acquired intangible assets; collaboration profit sharing/(loss reimbursement); (gain) loss on fair value remeasurement of contingent consideration; 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.

Note 26:			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.

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