BIOGEN INC.

Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex diseases. The company operates in the neurology, specialized immunology, and rare disease therapeutic areas, with a broad portfolio of medicines to treat multiple sclerosis (MS), the first approved treatment for spinal muscular atrophy (SMA), co-developed treatments to address a defining pathology of Alzheimer’s disease, and the first approved treatment to target a genetic cause of ALS. Biogen also markets the first and only drug approved in the U.S., the E.U., and certain international markets for the treatment of Friedreich ataxia (FA) in adults and adolescents aged 16 years and older. The company supports its drug discovery and development efforts through internal research and development programs, external collaborations, and acquisitions.

Competition in the biopharmaceutical industry and the markets in which Biogen operates is intense. The company faces competition from many companies, including biotechnology and pharmaceutical companies, some of which may have substantially greater financial, marketing, research and development, and other resources. Biogen’s products face increasing competition from the introduction of new originator therapies, generics, prodrugs, and biosimilars of existing products. Multiple TECFIDERA generic entrants are now in North America, Brazil, and certain European countries and have deeply discounted prices compared to TECFIDERA. A biosimilar entrant of TYSABRI was approved in the U.S. and the E.U. in 2023. In the Alzheimer’s disease market, a competing product, KISUNLA, developed by Eli Lilly and Company, was approved in the U.S. in 2024 and in the E.U. in 2025. In the rare disease space, SPINRAZA faces competition from an oral product EVRYSDI (risdiplam) and a gene therapy product ZOLGENSMA (onasemnogene abeparvovec-xioi).

Biogen generates revenue primarily through the sale of its marketed pharmaceutical products, including VUMERITY, TYSABRI, TECFIDERA, AVONEX, and PLEGRIDY for MS; SPINRAZA for SMA; SKYCLARYS for FA; and QALSODY for ALS. The company also earns revenue from anti-CD20 therapeutic programs through collaboration arrangements with Genentech, which entitle Biogen to certain business and financial rights with respect to RITUXAN, RITUXAN HYCELA, GAZYVA, OCREVUS, LUNSUMIO, and COLUMVI. Additionally, Biogen generates Alzheimer’s collaboration revenue from its 50.0% ¹ share of LEQEMBI product revenue, net and cost of sales, including royalties, under its collaboration with Eisai. The company also earns contract manufacturing, royalty, and other revenue from manufacturing agreements with strategic customers and license arrangements with Samsung Bioepis.

Biogen’s multiple sclerosis (MS) product portfolio includes TECFIDERA, VUMERITY, AVONEX, PLEGRIDY, TYSABRI, and FAMPYRA. For the year ended December 31, 2025, global MS product revenue was $4,038.9 million ², a decrease of 7.1% ³ compared to 2024. Global VUMERITY revenue increased 18.9% ⁴ to $746.8 million ⁵ in 2025, primarily due to an increase in global demand and a favorable change in estimate of approximately $20.3 million ⁶ related to rebates and discounts in the U.S. Global TYSABRI revenue decreased 2.9% ⁷ to $1,665.4 million ⁸ in 2025, primarily due to increased competition in rest of world, including the impacts from a biosimilar entrant of TYSABRI in Europe. Global TECFIDERA revenue decreased 29.7% ⁹ to $679.7 million ¹⁰ in 2025, driven by a decrease in global demand as a result of multiple TECFIDERA generic entrants. Global Interferon revenue decreased 2.3% ¹¹ to $945.6 million ¹² in 2025.

Biogen’s rare disease product portfolio includes SPINRAZA for SMA, SKYCLARYS for FA, and QALSODY for ALS. For the year ended December 31, 2025, global rare disease product revenue was $2,154.2 million ¹³, an increase of 8.4% ¹⁴ compared to 2024. Global SKYCLARYS revenue increased 36.1% ¹⁵ to $520.5 million ¹⁶ in 2025, primarily related to an increase in rest of world sales volumes driven by the continued launch in Europe and certain markets in the Middle East. Global QALSODY revenue increased 168.2% ¹⁷ to $86.9 million ¹⁸ in 2025, primarily related to an increase in rest of world sales volumes driven by the continued launch in international markets as well as patient growth in the U.S. U.S. SPINRAZA revenue was $625.5 million ¹⁹ in 2025, a decrease of $0.2 million ²⁰ from 2024. Rest of world SPINRAZA revenue decreased 2.8% ²¹ to $921.3 million ²² in 2025. Biosimilars revenue, including BENEPALI, IMRALDI, FLIXABI, BYOOVIZ, and TOFIDENCE, was $729.1 million ²³ in 2025, a decrease of 8.1% ²⁴ compared to 2024. Other product revenue, including ZURZUVAE, FUMADERM, and ADUHELM, was $197.2 million ²⁵ in 2025. U.S. ZURZUVAE revenue increased 170.2% ²⁶ to $195.1 million ²⁷ in 2025.

In November 2025, Biogen completed the acquisition of Alcyone Therapeutics, Inc. for total consideration of approximately $85.0 million ²⁸, comprising a $50.0 million ²⁹ payment made upon closing and a $35.0 million ³⁰ payment that was considered probable as of December 31, 2025, and made upon FDA approval of a supplemental application in January 2026. In February 2025, Biogen entered into a collaboration and license agreement with Stoke Therapeutics, Inc. to co-develop and commercialize zorevunersen, making an upfront payment of $165.0 million ³¹ to Stoke. In October 2025, Biogen entered into a research collaboration with Dayra Therapeutics, Inc., making an upfront payment of $50.0 million ³² to Dayra. Also in October 2025, Biogen entered into a license agreement with Vanqua Bio, Inc., making an upfront payment of $70.0 million ³³ to Vanqua. In May 2025, Biogen entered into a strategic research arrangement with City Therapeutics, Inc., making an upfront payment of $16.0 million ³⁴ to City Therapeutics and investing $30.0 million ³⁵ in exchange for a City Therapeutics convertible note. In February 2025, Biogen entered into a funding agreement with Royalty Pharma under which it received $200.0 million ³⁶ in 2025 and will receive up to $50.0 million ³⁷ in 2026 to co-fund development costs for the litifilimab program. On May 12, 2025, Biogen issued senior unsecured notes for an aggregate principal amount of $1.75 billion ³⁸. In March 2025, Biogen completed the sale of its regulatory and commercial rights in the U.S. for TOFIDENCE to Organon, receiving a payment of approximately $51.0 million ³⁹. In October 2025, Biogen completed the sale of its remaining commercial rights to BYOOVIZ and OPUVIZ in Europe, receiving a payment of $28.0 million ⁴⁰.

For the year ended December 31, 2025, total revenue was $9,890.6 million ⁴¹, an increase of 2.2% ⁴² compared to $9,675.9 million ⁴³ in 2024. Product revenue, net was $7,119.4 million ⁴⁴, a decrease of 1.3% ⁴⁵ compared to $7,213.5 million ⁴⁶ in 2024. Revenue from anti-CD20 therapeutic programs was $1,860.6 million ⁴⁷, an increase of 6.3% ⁴⁸ compared to $1,749.9 million ⁴⁹ in 2024. Alzheimer’s collaboration revenue was $177.7 million ⁵⁰, an increase of 196.7% ⁵¹ compared to $59.9 million ⁵² in 2024. Contract manufacturing, royalty and other revenue was $732.9 million ⁵³, an increase of 12.3% ⁵⁴ compared to $652.6 million ⁵⁵ in 2024. Net income attributable to Biogen Inc. was $2,039.7 million ⁵⁶ for 2025, compared to $2,596.5 million ⁵⁷ in 2024. Diluted earnings per share was $8.77 ⁵⁸ for 2025, compared to $11.16 ⁵⁹ in 2024.

A key growth vector for Biogen is the continued commercialization and expansion of LEQEMBI (lecanemab) for the treatment of Alzheimer’s disease. In January 2025, the FDA approved LEQEMBI monthly IV maintenance dosing for the treatment of early Alzheimer’s disease. In August 2025, the FDA approved the BLA for LEQEMBI subcutaneous autoinjector, LEQEMBI IQLIK, for weekly maintenance dosing. In April 2025, the EC approved LEQEMBI in the E.U. for the treatment of adult patients with a clinical diagnosis of mild cognitive impairment and mild dementia due to Alzheimer’s disease who are apolipoprotein E ε4 non-carriers or heterozygotes with confirmed amyloid pathology. In January 2026, the FDA accepted for review the supplemental BLA for LEQEMBI subcutaneous autoinjector for weekly starting dose, with a PDUFA action date of May 24, 2026 ⁶⁰. In January 2026, the BLA for LEQEMBI subcutaneous autoinjector was accepted for review by the NMPA in China. Biogen and Eisai share equally all costs, including research, development, sales and marketing expense, and share profits and losses equally. Biogen expects growth in rare disease revenue due to the continued launch of SKYCLARYS in the U.S., Europe, and other international markets as well as the continued launch of QALSODY in Europe. Biogen anticipates global SPINRAZA revenue growth to be relatively flat in 2026. Biogen expects growth in U.S. ZURZUVAE revenue as total patients are expected to continue to increase in 2026.

Another major growth vector is Biogen’s pipeline in neurology, specialized immunology, and rare diseases. Key late-stage programs include felzartamab, an anti-CD38 mAb in Phase 3 trials for antibody-mediated rejection (AMR), immunoglobulin A nephropathy (IgAN), and primary membranous nephropathy (PMN). In March 2025, Biogen announced the initiation of dosing in the global Phase 3 TRANSCEND study for felzartamab in AMR, and in connection with this, paid a $35.0 million ⁶¹ milestone payment to MorphoSys in April 2025. In June 2025, Biogen announced the initiation of dosing in the global Phase 3 PREVAIL study for felzartamab in IgAN and the global Phase 3 PROMINENT study for felzartamab in PMN. In connection with the initiation of the PREVAIL study, Biogen paid a $30.0 million ⁶² milestone payment to MorphoSys in July 2025. Litifilimab, an anti-BDCA2 antibody, is in Phase 3 trials for systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). In February 2025, Biogen entered into a funding agreement with Royalty Pharma under which it received $200.0 million ⁶³ in 2025 and will receive up to $50.0 million ⁶⁴ in 2026 to co-fund development costs for the litifilimab program. Zorevunersen, an investigational ASO for Dravet syndrome, dosed its first patient in August 2025, advancing to a global Phase 3 trial. Salanersen (BIIB115), an ASO for SMA, showed positive interim topline results from a Phase 1b study in June 2025, and a Phase 3 registrational study is expected to begin in 2026. In June 2025, Biogen announced the initiation of dosing in the global Phase 3 BRAVE study of omaveloxolone in children with FA.

Biogen’s cost of sales, as a percentage of total revenue, was 24.3% ⁶⁵ for the year ended December 31, 2025, compared to 23.9% ⁶⁶ in 2024. The increase in cost of sales was primarily due to a charge recorded during 2025 of approximately $104.9 million ⁶⁷ related to a litigation matter and product mix, including higher contract manufacturing revenue driven by the timing of batch releases. Research and development expense decreased 10.2% ⁶⁸ to $1,778.6 million ⁶⁹ in 2025, primarily driven by continued cost reduction measures realized in connection with portfolio prioritization initiatives and the Fit for Growth program, offset in part by higher spend on clinical trials, including litifilimab and felzartamab. Higher clinical trial spend related to litifilimab was offset by $200.0 million ⁷⁰ in R&D funding received from Royalty Pharma in 2025. Selling, general and administrative expense increased 1.2% ⁷¹ to $2,433.6 million ⁷² in 2025, primarily due to an increase in operational spending on sales and marketing activities in support of LEQEMBI and SKYCLARYS. Restructuring charges were $48.6 million ⁷³ in 2025, compared to $30.2 million ⁷⁴ in 2024.

Biogen seeks to ensure an uninterrupted supply of medicines to patients around the world. The company’s manufacturing facilities include a large-scale biologics manufacturing facility in Solothurn, Switzerland, which is operational and has been approved for the manufacture of LEQEMBI and TYSABRI. Biogen continues to invest to modernize, automate, and support the capacity requirements for its pipeline and existing products at its manufacturing facilities in Research Triangle Park (RTP), North Carolina. In 2025, Biogen acquired a sterile fill finish manufacturing facility in Athlone, Ireland. Biogen has an oligonucleotide synthesis manufacturing facility in RTP, which gives it the capability to manufacture both commercial and clinical ASOs, including QALSODY, and beginning in 2026 this facility will manufacture SPINRAZA. As of December 31, 2025, Biogen had approximately 7,500 ⁷⁵ employees worldwide. Approximately 4,200 ⁷⁶ employees were employed in the U.S. and approximately 3,300 ⁷⁷ employees were employed in foreign countries.

Research and development expense was $1,778.6 million ⁷⁸ for the year ended December 31, 2025. Capital expenditure plans are not explicitly quantified in the filing for the upcoming period. In October 2020, Biogen’s Board of Directors authorized a share repurchase program to repurchase up to $5.0 billion ⁷⁹ of its common stock. As of December 31, 2025, approximately $2.1 billion ⁸⁰ remained available under this program. There were no repurchases of Biogen’s common stock during the years ended December 31, 2025, 2024, and 2023. Biogen has not paid cash dividends since its inception and does not have a current intention to pay cash dividends.

Biogen faces significant headwinds from increasing competition for many of its MS products in both the U.S. and rest of world markets. The company expects TECFIDERA revenue will be adversely impacted by accelerating generic competition in certain markets in the E.U. Additionally, a biosimilar entrant of TYSABRI was approved in the U.S. and the E.U. in 2023, and Biogen expects that future sales of TYSABRI will continue to be adversely affected by the entrance of this biosimilar worldwide. The IRA’s drug pricing controls and Medicare Part D redesign had an adverse impact on Biogen’s sales, particularly for products that are more substantially reliant on Medicare reimbursement. The IRA Medicare Part D redesign had a modest net unfavorable impact to Biogen’s 2025 revenue of approximately $90.0 million ⁸¹, concentrated in its SKYCLARYS and MS portfolio product revenue, approximately a quarter of which was associated with SKYCLARYS. The full extent of the IRA’s impacts on Biogen’s sales and business remains uncertain. Biogen also faces risks from the potential impact of the OBBBA and an executive order aiming to establish an MFN drug pricing policy.

Biogen’s operations are subject to the risks of doing business internationally, including the impact of geopolitical tensions related to Russia’s invasion of Ukraine and the military conflict in the Middle East. Revenue generated from sales in Russia and Ukraine represent less than 2.0% ⁸² of total revenue for the years ended December 31, 2025, 2024, and 2023. Revenue generated from sales in the broader Middle East region represents less than 2.0% ⁸³ of total revenue for the years ended December 31, 2025, 2024, and 2023. Biogen also faces risks from global trade disputes and tariffs. The U.S. has imposed a baseline tariff on imports from all countries, and the U.S. Secretary of Commerce has initiated an investigation under Section 232 of the Trade Expansion Act of 1962 into the effects on national security of imports of pharmaceuticals and pharmaceutical ingredients. As of the date of the filing, Biogen does not expect the tariffs currently applicable to its business to result in a material adverse effect on its operations in 2026.

Biogen is substantially dependent on revenue from its products, and a significant portion of revenue is concentrated on sales in increasingly competitive markets. The introduction of generic and biosimilar competitors, such as multiple TECFIDERA generic entrants and a TYSABRI biosimilar entrant approved in the U.S. and E.U. in 2023, has significantly reduced and is expected to continue to reduce revenue from these products. The IRA’s drug pricing controls and Medicare Part D redesign had a net unfavorable impact to 2025 revenue of approximately $90.0 million ⁸⁴, concentrated in SKYCLARYS and the MS portfolio. Biogen’s long-term success depends on the successful development of new products, which is expensive and involves high uncertainty; only a small number of research and development programs result in commercialization. The company also faces risks from its reliance on collaborative and third-party relationships for revenue and development, as disputes or failures in these relationships could adversely affect business. Additionally, a breakdown or breach of information systems could subject Biogen to liability or interrupt business operations, and the increasing use of AI-based software presents new risks and challenges.

Management’s message emphasizes Biogen’s focus on advancing its pipeline in neurology, specialized immunology, and rare diseases, supported by internal research and development programs, external collaborations, and acquisitions. Key strategic priorities include the successful commercialization of LEQEMBI for Alzheimer’s disease in collaboration with Eisai, the continued launch of SKYCLARYS for FA and QALSODY for ALS, and the advancement of late-stage pipeline programs such as felzartamab, litifilimab, and zorevunersen. Management also highlights the Fit for Growth cost-saving program initiated in 2023 and the execution of strategic business development transactions, including the acquisitions of Alcyone Therapeutics and the collaborations with Stoke Therapeutics, Dayra Therapeutics, Vanqua Bio, and City Therapeutics.