BIOGEN INC. (BIIB)

ITEM 2.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion should be read in conjunction with our unaudited condensed consolidated financial statements (condensed consolidated financial statements) and the accompanying notes beginning on page 8 of this quarterly report on Form 10-Q and our audited consolidated financial statements and the accompanying notes included in our 2025 Form 10-K.

The results and operations of Apellis, along with the estimated fair values of the assets acquired and liabilities assumed in the Apellis acquisition, have been included in our condensed consolidated financial statements since the closing of the Apellis acquisition on May 14, 2026.

EXECUTIVE SUMMARY

INTRODUCTION

Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex diseases. We are focused on advancing our pipeline, including significant late stage programs, in neurology, specialized immunology and rare diseases across multiple modalities. Our drug discovery and development efforts are supported by internal research and development programs, external collaborations and acquisitions of businesses and assets.

Our marketed products include VUMERITY, TYSABRI, TECFIDERA, AVONEX and PLEGRIDY for the treatment of MS; SPINRAZA for the treatment of SMA; SKYCLARYS for the treatment of FA; QALSODY for the treatment of ALS; SYFOVRE for the treatment of GA; and EMPAVELI for the treatment of PNH, C3G and primary IC-MPGN.

We also have collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Supernus on the commercialization of ZURZUVAE for the treatment of PPD. We have certain business and financial rights with current and other potential anti-CD20 therapies, pursuant to our collaboration arrangements with Genentech, a wholly owned member of the Roche Group. Under the collaboration arrangements, we currently recognize revenue from the following products: OCREVUS, GAZYVA, RITUXAN, RITUXAN HYCELA, LUNSUMIO and COLUMVI.

On May 14, 2026, we completed the acquisition of Apellis. As a result of this acquisition we acquired SYFOVRE for the treatment of geographic atrophy, or GA, an immune-mediated retinal disease; and EMPAVELI for the treatment of paroxysmal nocturnal hemoglobinuria, or PNH, a rare blood disorder, and C3 glomerulopathy, or C3G, and primary immune complex membranoproliferative glomerulonephritis, or primary IC-MPGN, in rare immune-mediated kidney diseases. For additional information on the acquisition of Apellis, please read Note 2, Acquisitions, to these condensed consolidated financial statements.

We commercialize a portfolio of biosimilars of advanced biologics including: BENEPALI, an etanercept biosimilar referencing ENBREL; IMRALDI, an adalimumab biosimilar referencing HUMIRA; and FLIXABI, an infliximab biosimilar referencing REMICADE.

For additional information on our collaboration arrangements, please read Note 18, Collaborative and Other Relationships, to our condensed consolidated financial statements included in this report.

BUSINESS ENVIRONMENT

The biopharmaceutical industry and the markets in which we operate are intensely competitive. Many of our competitors are working to develop or have commercialized products similar to those we market. In addition, the commercialization of certain of our own approved products, products of our collaborators and pipeline product candidates may negatively impact future sales of our existing products.

Our products and revenue streams continue to face increasing competition in many markets from the introduction of new originator therapies, generics, biosimilars of existing products and products approved under abbreviated regulatory pathways. Some of these products are likely to be sold at substantially lower prices than branded products. Accordingly, the introduction of such products as well as other lower-priced competing products has significantly reduced, and in the future may significantly reduce, both the price that we are able to charge for our products and the volume of products we sell, which can negatively impact our revenue. In addition, in some markets, when a generic or biosimilar version of one of our products is commercialized, it may be automatically substituted for our product and significantly reduce our revenue in a short period of time.

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Sales of our products depend, to a significant extent, on the availability and extent of adequate coverage, pricing and reimbursement from government health administration authorities, private health insurers and other organizations. When a new pharmaceutical product is approved, the availability of government and private reimbursement for that product may be uncertain, as is the pricing and the amount for which that product will be reimbursed.

Our future revenue growth will depend upon the successful clinical development, regulatory approval and launch of new commercial products as well as additional indications for our existing products, our ability to obtain and maintain patents and other rights related to our marketed products, assets originating from our research and development efforts and/or successful execution of external business development opportunities.

We seek to ensure an uninterrupted supply of medicines to patients around the world. To that end, we regularly review our manufacturing capacity, capabilities, processes and facilities. In order to support our future growth and drug development pipeline, we expanded our large molecule production capacity and built a large-scale biologics manufacturing facility in Solothurn, Switzerland. The Solothurn facility is operational and has been approved for the manufacture of LEQEMBI and TYSABRI. We believe that the Solothurn facility will support our anticipated near to mid-term needs for the manufacturing of biologic assets. The plant represents a significant increase in our overall manufacturing capacity. Additionally, we continue to invest to modernize, automate and support the capacity requirements for our pipeline and existing products at our existing manufacturing facilities in RTP, North Carolina. If we are unable to fully utilize our manufacturing facilities, we will incur additional excess capacity charges which would have a negative effect on our financial condition and results of operations.

For a detailed discussion on our business environment, please read Item 1. Business, in our 2025 Form 10-K. For additional information on our competition and pricing risks that could negatively impact our product sales, please read Item 1A. Risk Factors included in this report.

TYSABRI

A biosimilar entrant of TYSABRI was approved in the U.S. and the E.U. in 2023. We expect the future sales of TYSABRI will continue to be adversely affected by the entrance of this biosimilar.

TECFIDERA

In November 2025 the Technical Boards of Appeal of the European Patent Office revoked our EP 2 653 873 patent related to TECFIDERA, after which we stopped enforcing this patent and its national counterparts. Multiple TECFIDERA generic entrants are now in North America, Brazil and the E.U. and have deeply discounted prices compared to TECFIDERA. The generic competition for TECFIDERA has significantly reduced our TECFIDERA revenue compared to prior periods, and we expect that TECFIDERA revenue will continue to decline.

For additional information, please read Note 20, Litigation, to our condensed consolidated financial statements included in this report.

BUSINESS UPDATE REGARDING MACROECONOMIC CONDITIONS AND OTHER POTENTIAL DISRUPTIONS

Significant portions of our business are conducted in Europe, Asia and other international geographies. Factors such as global health outbreaks, adverse weather events, geopolitical events or conflicts, tariffs, inflation, labor or raw material shortages and other supply chain disruptions could result in product shortages or other difficulties and delays or increased costs in manufacturing or distributing our products.

Economic conditions remain uncertain as markets continue to be impacted in part by continued inflationary pressures, higher interest rates, extreme weather events, global supply chain uncertainties and risks associated with geopolitical conflicts. Global supply chain disruptions, such as strikes, work stoppages, port congestion, port closures, trade restrictions, capacity constraints and other logistical problems, may affect our ability to do business.

INTERNATIONAL TRADE

Global conflicts or disputes and interruptions in international relationships, including tariffs, trade protection measures, economic embargoes, import or export licensing requirements and the imposition of trade sanctions or similar restrictions, may affect our ability to do business and the costs that we incur in providing products to our patients.

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In 2025 the U.S. imposed a series of tariffs on imports from nearly all countries, including tariffs pursuant to the IEEPA subject to certain exemptions. Trade-related tensions between the U.S. and China have also led to a series of tariffs and sanctions being imposed by the U.S. on imports from China and retaliatory tariffs imposed by China on U.S. imports, subject as well to exemptions.

Furthermore, in 2025, the U.S. reached a series of Framework Agreements with some countries and trading blocs including the E.U., Switzerland, the U.K., Japan and South Korea, carving U.S. tariff rates for certain import categories between 10.0% and 15.0%.

In February 2026 the U.S. Supreme Court issued a ruling striking down tariffs previously imposed under the IEEPA. The ultimate availability, timing and amount of any potential refunds of such tariffs remain highly uncertain and could be subject to further legal, regulatory and administrative developments. The amount of IEEPA tariff refunds, if any, that we ultimately recover may differ from the full amount we previously paid. Furthermore, any potential refunds or recoveries may be offset by refunds due to customers for payments made in connection with the IEEPA tariffs. As of this filing date, we have not recorded a receivable for any refund of IEEPA tariffs.

Following the Supreme Court's decision, the U.S. Administration imposed a 10% baseline tariff on imports from nearly all countries, in addition to any existing non-IEEPA tariffs. The baseline tariff expired on July 24, 2026. Effective July 24, 2026, the U.S. Administration imposed new tariffs of 10.0% to 12.5% on goods from approximately 60 economies under Section 301 of the Trade Act of 1974, subject to certain exemptions, and reduced rates for goods from certain economies where we have significant operations or commercial presence, such as the E.U. and Switzerland. There remains substantial uncertainty regarding the duration of existing and newly announced tariffs, potential changes or pauses to such tariffs, tariff levels and whether further additional tariffs or other retaliatory actions may be imposed, modified or suspended and the impacts of such actions on our business.

The U.S. Secretary of Commerce previously initiated an investigation to determine the effects on the national security of imports of pharmaceuticals and pharmaceutical ingredients, including finished drug products, medical countermeasures, critical inputs such as active pharmaceutical ingredients, key starting materials and derivative products of those items, under Section 232 of the Trade Expansion Act of 1962. In April 2026 after the investigation concluded, the U.S. Administration issued a Proclamation imposing a 100% tariff on imports of patented pharmaceuticals, biologics and associated ingredients, subject to certain exemptions and reduced rates. The Proclamation tariffs are effective for certain categories on July 31, 2026, and others on September

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ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion should be read in conjunction with our consolidated financial statements and the accompanying notes beginning on page F-1 of this report.

For our discussion of the year ended December 31, 2024, compared to the year ended December 31, 2023, please read Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations located in our Annual Report on Form 10-K for the year ended December 31, 2024.

EXECUTIVE SUMMARY

INTRODUCTION

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., the E.U. and certain international markets for the treatment of FA in adults and adolescents aged 16 years and older. We are focused on advancing our pipeline in neurology, specialized immunology and rare diseases. We support our drug discovery and development efforts through internal research and development programs, external collaborations and acquisitions.

Our marketed products include VUMERITY, TYSABRI, TECFIDERA, AVONEX and PLEGRIDY for the treatment of MS; SPINRAZA for the treatment of SMA; SKYCLARYS for the treatment of FA; and QALSODY for the treatment of ALS.

We also have collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Supernus on the commercialization of ZURZUVAE for the treatment of PPD. We have certain business and financial rights with respect to RITUXAN for the treatment of non-Hodgkin's lymphoma, CLL and other conditions; RITUXAN HYCELA for the treatment of non-Hodgkin's lymphoma and CLL; GAZYVA for the treatment of CLL, follicular lymphoma and, following its approval in October 2025, lupus nephritis; OCREVUS for the treatment of PPMS and RMS; LUNSUMIO for the treatment of relapsed or refractory follicular lymphoma; COLUMVI, a bispecific antibody for the treatment of non-Hodgkin's lymphoma; 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; and FLIXABI, an infliximab biosimilar referencing REMICADE.

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

We seek to ensure an uninterrupted supply of medicines to patients around the world. To that end, we regularly review our manufacturing capacity, capabilities, processes and facilities. In order to support our future growth and drug development pipeline, we expanded our large molecule production capacity and built a large-scale biologics manufacturing facility in Solothurn, Switzerland. The Solothurn facility is operational and has been approved for the manufacture of LEQEMBI and TYSABRI. We believe that the Solothurn facility will support our anticipated near to mid-term needs for the manufacturing of biologic assets. The plant represents a significant increase in our overall manufacturing capacity. Additionally, we continue to invest to modernize, automate and support the capacity requirements for our pipeline and existing products at our existing manufacturing facilities in RTP. If we are unable to fully utilize our manufacturing facilities, we will incur additional excess capacity charges which would have a negative effect on our financial condition and results of operations.

In the longer term, our revenue growth will depend upon the successful clinical development, regulatory approval and launch of new commercial products as well as additional indications for our existing products, our ability to obtain and maintain patents and other rights related to our marketed products, assets originating from our research and development efforts and/or successful execution of external business development opportunities.

BUSINESS ENVIRONMENT

For a detailed discussion on our business environment, please read Item 1. Business, included in this report. For additional information on our competition and pricing risks that could negatively impact our product sales, please read Item 1A. Risk Factors, included in this report.

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TECFIDERA

Multiple TECFIDERA generic entrants are now in North America, Brazil and certain European countries and have deeply discounted prices compared to TECFIDERA. The generic competition for TECFIDERA has significantly reduced our TECFIDERA revenue and we expect that TECFIDERA revenue will continue to decline. In November 2025 the Technical Boards of Appeal of the European Patent Office revoked our EP 2 653 873 patent related to TECFIDERA, after which we stopped enforcing this patent and its national counterparts.

For additional information, please read Note 21, Litigation, to our consolidated financial statements included in this report.

TYSABRI

A biosimilar entrant of TYSABRI was approved in the U.S. and the E.U. in 2023. We expect the future sales of TYSABRI will continue to be adversely affected by the entrance of this biosimilar.

GOODWILL

We review our goodwill 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. As part of this analysis, we compare the fair value of our one reporting unit to its carrying value through the assessment of qualitative, and, if necessary, quantitative factors. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of our reporting unit, we will record an impairment loss equal to the difference. As of our most recent annual impairment analysis, we had no accumulated impairment losses related to goodwill.

An interim goodwill impairment test based on quantitative factors may be required if adverse events indicate an impairment might be present. We monitor changes to our stock price between annual impairment tests, and we believe that general deterioration in macroeconomic and industry-specific conditions may not be indicators of a goodwill impairment, as such conditions may not represent a significant adverse change to our underlying operating performance, cash flows, financial condition or liquidity. Should our market capitalization decline below the carrying value of our net assets for a sustained period, we would consider the length and severity of the decline and the reason for the decline when assessing whether potential goodwill impairment exists.

For additional information on goodwill, please read Note 7, Intangible Assets and Goodwill, to our consolidated financial statements included in this report.

INTERNATIONAL TRADE

Global disputes and interruptions in international relationships, including tariffs, trade protection measures, embargoes, import or export licensing requirements and the imposition of trade sanctions or similar restrictions, may affect our ability to do business and the costs that we incur in providing products to our patients.

The U.S. has imposed a baseline tariff on imports from all countries, subject to certain exceptions. Trade-related tensions between the U.S. and China have led to a series of tariffs and sanctions being imposed by the U.S. on imports from China and retaliatory tariffs imposed by China on U.S. imports.

The U.S. Secretary of Commerce has further initiated an investigation to determine the effects on the national security of imports of pharmaceuticals and pharmaceutical ingredients, including finished drug products, medical countermeasures, critical inputs such as active pharmaceutical ingredients, key starting materials and derivative products of those items, under Section 232 of the Trade Expansion Act of 1962.

There is a high degree of uncertainty concerning what future steps countries and economic blocs will take in response to changes in global trade rules and economics.

We have a significant manufacturing presence in the U.S. While our portfolio is evolving, approximately three quarters of our 2025 U.S. product revenue was attributable to products which were largely manufactured in the U.S. However, we, and the pharmaceutical industry, do utilize partners and production facilities located outside the U.S. for certain raw materials, ingredients, processes and components for our pharmaceutical products and their delivery devices. Engaging alternative suppliers may involve seeking additional regulatory approvals and incurring additional costs and risks associated with new suppliers. This may be costly in terms of time and resources needed or result in delays.

Key products that are currently manufactured mainly outside the U.S. are TECFIDERA, VUMERITY and LEQEMBI. In 2024 we initiated a technology transfer process to enable us to manufacture LEQEMBI in the U.S., which was approved in January 2026.

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Although certain starting materials for SKYCLARYS rely on a single supplier based in China, the manufacturing process, including active pharmaceutical ingredients and drug substance, is primarily conducted in the U.S.

We are working to mitigate potential exposure from tariffs across our network.

As of the date of this filing, we do not expect the tariffs currently applicable to our business to result in a material adverse effect on our operations in 2026. This is based on existing tariffs either in place or potential tariffs as previously announced by the U.S. Administration, our manufacturing footprint, and our inventory levels and positioning. Should significant additional tariffs be enacted, our business could be impacted in the future and differ materially from our current expectations. We will continue to monitor the current and future global tariff landscape as it evolves.

GEOPOLITICAL TENSIONS

The ongoing geopolitical tensions related to Russia's invasion of Ukraine and the military conflict in the Middle East and other global geopolitical developments have resulted in global business disruptions and economic volatility. For example, sanctions and other restrictions have been levied on the government and businesses in Russia. Although we do not have affiliates or employees in either Russia or Ukraine, we do provide various therapies to patients in Russia through a distributor. Government sanctions on the export of certain manufacturing materials to Russia may delay or limit our ability to get new products approved. The impact of the conflict on our operations and financial performance remains uncertain and will depend on future developments, including the severity and duration of the conflict between Russia and Ukraine, its impact on regional and global economic conditions and whether the conflict spreads or has effects on countries outside Ukraine and Russia.

We will continue to monitor the ongoing conflict between Russia and Ukraine as well as the military conflict in the Middle East and other global geopolitical developments and assess any potential impacts on our business, supply chain, partners or customers, as well as any factors that could have an adverse effect on our results of operations. Revenue generated from sales in Russia and Ukraine represent less than 2.0% of total revenue for the years ended December 31, 2025, 2024 and 2023. Additionally, revenue generated from sales in the broader Middle East region represents less than 2.0% of total revenue for t

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