Biogen (BIIB) 10-K risk factor changes: FY2024 vs FY2023

[removed: LEQEMBI and SKYCLARYS are in the early stages of commercial launch in the U.S.] In addition to risks associated with new product launches and the other factors described in these Risk Factors, Biogen’s and Eisai’s ability to successfully commercialize LEQEMBI and our ability to successfully commercialize SKYCLARYS may be adversely affected due to:

- Eisai’s and Biogen’s ability to maintain a positive reputation among patients, healthcare providers and others in the Alzheimer’s disease community, which may be impacted by pricing and reimbursement decisions relating to LEQEMBI, which are made by [removed: Eisai;][added: Eisai and/or third parties;]

Our long-term success will depend upon the successful development of new products from our research and development activities or our licenses or acquisitions from [removed: third-parties,] [added: third parties,] as well as additional indications for our existing products.

The development of novel approaches for the treatment of diseases, including development efforts in new modalities such as those based on the antisense oligonucleotide platform and gene therapy, [removed: may present] [added: presents] additional challenges and risks, including obtaining approval from regulatory authorities that have limited experience with the development of such therapies.

For example, we are currently seeking approval of [removed: SKYCLARYS] [added: LEQEMBI] in Europe and [added: the approval of a subcutaneous formulation of LEQEMBI in the U.S. and] any delays or challenges [removed: regarding its approval in Europe] may [removed: adversely] impact our ability to realize the anticipated benefits from [removed: the Reata acquisition.][added: LEQEMBI.]

[removed: Sales] [added: Additionally, sales] of new products or products with additional indications may not meet investor expectations.

In addition, in some markets, when a generic or biosimilar version of one of our products is commercialized, it [added: has in the past and] may [added: in the future] be automatically substituted for our product and significantly reduce our revenue in a short period of time.

The successful execution of our strategic and growth initiatives [removed: may depend] [added: depends] upon internal development projects, commercial initiatives and external opportunities, which may include the acquisition and in-licensing of products, [added: technologies, companies, the entry into strategic alliances and collaborations or our Fit for Growth program, as well as our ability to execute on strategic decisions and initiatives.]

Furthermore, we may not be able to achieve the full strategic and financial benefits expected to result from [removed: transactions,] [added: transactions] or [added: strategic decisions, such as] the [added: decision to retain the biosimilars business, or the] benefits may be delayed or not occur at all.

For example, we recently acquired Reata and [added: HI-Bio and] are in the process of integrating Reata [added: and HI-Bio] into our Company.

The ultimate success of our [removed: acquisition] [added: acquisitions] of Reata and [added: HI-Bio and] our ability to realize the anticipated benefits from the [removed: acquisition,] [added: acquisitions,] including [added: future performance of] the SKYCLARYS product and [added: further development of the felzartamab product and] anticipated synergies, depends on, among other things, how effective we are in integrating the [removed: Biogen and] [added: Biogen,] Reata [added: and HI-Bio] operations.

Governments may use a variety of cost-containment measures to control the cost of products, including price cuts, mandatory rebates, value-based pricing and reference pricing (i.e., referencing prices in other [removed: countries and using those reference prices to set a price).]

Drug prices are under significant scrutiny in the markets in which our products are prescribed; for example the IRA has certain provisions related to drug [removed: pricing.][added: pricing, including the ability for the U.S. government to set prices for certain drugs in Medicare.]

We depend on relationships with collaborators and other third-parties for revenue, and for the development, regulatory approval, commercialization and marketing of certain of our products and product candidates, which are outside of our full [removed: control.][added: control, and if these relationships fail, our business may be adversely affected.]

- the interests of our collaborators or third-parties may not always be aligned with our interests, and such parties may not [added: protect and enforce any intellectual property rights or] pursue regulatory approvals or market a product in the same manner or to the same extent [added: that we would, which could adversely affect our revenue, or may adopt tax strategies that could have an adverse effect on our business, results of operations or financial condition;]

- third-party relationships require the parties to cooperate, and failure to do so effectively could adversely affect product sales or the clinical development or regulatory approvals of product candidates under joint control, [removed: could result in termination of the research, development or commercialization of product candidates or could result in litigation or arbitration;]

For example, provisions of the PPACA have resulted in changes in the way health care is paid for by both governmental and private insurers, including increased rebates owed by manufacturers under the Medicaid Drug Rebate Program, annual fees and taxes on manufacturers of certain branded prescription drugs, the requirement that manufacturers participate in a discount program for certain outpatient drugs under Medicare Part D and [removed: the expansion of the number of hospitals eligible for discounts] under Section 340B of the Public Health Service [removed: Act.][added: Act and similar state legislation.]

[removed: These actions] [added: We face uncertainties regarding potential healthcare reforms, governmental policy] and [added: prioritization, and] the uncertainty about the future of the PPACA and healthcare laws may put downward pressure on pharmaceutical pricing and increase our regulatory burdens and operating costs.

Many countries have announced or implemented measures, and may in the future implement new or additional measures, to reduce health care costs to limit the overall level of government [added: expenditures.]

For example, a recently [removed: announced potential] [added: completed] acquisition of a contract development and manufacturing organization by a third [removed: party.][added: party may impact its operational, strategic or financial risk.]

If we encounter any [added: persistent] manufacturing or supply chain difficulties we may be unable to meet demand.

We are dependent on a third-party for the manufacture of our biosimilar products and such third-party may not perform its obligations in a timely and cost-effective manner or in compliance with applicable regulations and may be unable or unwilling to increase production capacity commensurate with demand for our existing or future biosimilar [removed: products;][added: products.]

- *Intellectual Property and Regulatory Challenges.* Biosimilar products may face extensive intellectual property clearances and infringement litigation, injunctions or regulatory challenges, which could prevent the commercial launch of a product or delay it for many years or result in imposition of monetary damages, penalties or other civil sanctions and damage our reputation; [added: and]

- *Failure to Gain Market and Patient Acceptance.* Market success of biosimilar products will be adversely affected if patients, physicians and/or payors do not accept biosimilar products as safe and efficacious products offering a more competitive price or other benefit over existing [removed: therapies; and][added: therapies.]

The number of competitors in a jurisdiction, the timing of approval and the ability to market biosimilar products successfully in a timely and cost-effective manner are additional factors that may impact our success in this business [removed: area.][added: area;]

Positive results in a clinical trial [added: have in the past and] may not [added: in the future] be replicated in subsequent or confirmatory trials.

Regulatory authorities [added: have in the past and] may [added: in the future] grant marketing approval that is more restricted than anticipated, including limiting indications to narrow patient populations and the imposition of safety monitoring, educational requirements, requiring confirmatory trials and risk evaluation and mitigation strategies.

Discovery of safety issues with our products could create product liability and could cause additional regulatory scrutiny and [added: requirements for additional labeling or safety monitoring, withdrawal of products from the market and/or the imposition of fines or criminal penalties.]

Restrictions on use or safety warnings that may be required to be included in the label of our products may significantly reduce expected revenue for those products and require significant expense and [added: divert] management time.

Breakdowns, invasions, corruptions, destructions and/or breaches, which [removed: impact] may [removed: include,] [added: include impacts such as,] but not limited to, comprising the capacity, reliability or security of our information systems or those of our business partners, including our cloud [removed: tech][added: technologies, and/or unauthorized access to our data and information could subject us to significant liability, negatively impact our business operations, and/or require replacement of technology and/or sizeable ransom payments.]

Recent developments in the threat landscape include use of [added: adversarial] AI [added: techniques] and machine learning, as well as an increased number of cyber extortion attacks, with higher financial ransom demand amounts and increasing sophistication and variety of ransomware techniques and methodology.

Regulators [removed: are imposing] [added: currently impose] new data privacy and security requirements, including [removed: new and greater] monetary fines for privacy violations.

[removed: New] U.S. data privacy and security laws, such as the CCPA, and others that may be passed, similarly introduce requirements with respect to personal information, and non-compliance with the CCPA may result in liability through private actions (subject to statutorily defined damages in the event of certain data breaches) and enforcement.

These third-parties are independent entities subject to their own unique [removed: operational] [added: operational, strategic] and financial risks that are outside of our control.

Our global bulk supply of these products and product candidates depends on the uninterrupted and efficient operation of these facilities, which could be adversely affected by equipment failures, labor or raw material shortages, geopolitical instability, public health epidemics, natural disasters, [added: adverse weather events,] power failures, cyber-attacks and many other factors.

- *Risks Relating to Compliance with current GMP (cGMP).* We and our third-party providers are [removed: generally] required to maintain compliance with cGMP and other stringent [removed: requirements] [added: requirements, as applicable,] and are subject to inspections by the FDA and other regulatory authorities to confirm compliance.

[removed: If microbial, viral or other contaminations are discovered] in our products or manufacturing facilities, we may need to close our manufacturing facilities for an extended period of time to investigate and remediate the contaminant.

Furthermore, factors such as geopolitical events, global health outbreaks, [added: adverse] weather events, labor or raw material [removed: shortages] [added: shortages, imposition of tariffs or trade restrictions] and other supply chain disruptions could result in difficulties and delays in manufacturing our products, which could have an adverse impact on our results in operations or result in product shortages.

[added: Such developments could increase our] manufacturing costs, cause us to lose revenue or market share as patients and physicians turn to competing therapeutics, diminish our profitability or damage our reputation.

Management, personnel and other organizational changes may disrupt our operations, and we may have difficulty retaining personnel or attracting and retaining qualified replacements on a timely basis for the management and other personnel who may leave the [removed: Company.][added: Company, which could disrupt our business and adversely affect our operations.]

LEQEMBI is in the early stages of commercial launch in the U.S. and certain international markets and SKYCLARYS is in the early stages of commercial launch in the U.S. and certain European markets.

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countries and using those reference prices to set a price).

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could result in termination of the research, development or commercialization of product candidates or could result in litigation or arbitration;

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For example, one of our contract manufacturers for IMRALDI and BENEPALI was acquired by a third party in December 2024, which may have an impact on our biosimilars business;

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The increasing use of AI-based software presents new risks and challenges and could adversely affect our business and reputation.

The use of AI-based software is increasingly being used in the biopharmaceutical industry, including by us, such as for research, marketing, manufacturing and commercialization, and we expect to use technology that uses AI in the future.

As with many developing technologies, AI-based software presents risks and challenges.

For example, algorithms may be flawed; data sets may be insufficient, of poor quality or contain biased information; and inappropriate or controversial data practices could impair results.

If the analyses that AI-based software assist in producing are deficient or inaccurate, we could be subjected to competitive harm, potential legal liability and brand or reputational harm.

The use of AI-based software may also result in unauthorized access of personal data or the intellectual property of third parties.

Since the use of AI is subject to new or evolving laws and regulations, compliance may impose operational costs and limit our ability to use AI-based software, and failure to comply may result in potential government actions, litigation, fines, penalties or adverse publicity.

For example, a recently completed acquisition of a contract development and manufacturing organization by a third party may impact its operational, strategic or financial risk.

If microbial, viral or other contaminations are discovered

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may have different product distribution methods, marketing programs or patient assistance programs from those we currently utilize or support.

Additionally, conditions and regulations governing the health care industry in the U.S. are subject to greater risk of change and uncertainty as a result of changes in legislative and regulatory priorities and personnel.

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at risk for a number of dangerous health consequences.

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impairment charges or additional depreciation when the expected useful lives of certain assets have been shortened due to the anticipated closing of facilities.

Upon a change in control, some of these provisions could trigger reduced milestone, profit or royalty

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Additionally, regulators have passed new environmental disclosure rules.

These new rules collectively will impose additional disclosure requirements relating to climate-related risks and emissions disclosures.

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technologies, companies, the entry into strategic alliances and collaborations or our Fit for Growth program, as well as our ability to execute on previously-announced initiatives such as the exploration of strategic options for our biosimilars business.

that we would, which could adversely affect our revenue, or may adopt tax strategies that could have an adverse effect on our business, results of operations or financial condition;

Some of these proposals could have significant effects on our business, including an executive order issued in September 2020 to test a “most favored nation” model for Part B and Part D drugs that tie reimbursement rates to international drug pricing metrics.

expenditures.

The decision to explore strategic options related to our biosimilars business could adversely affect our operations related to our biosimilars business.

requirements for additional labeling or safety monitoring, withdrawal of products from the market and/or the imposition of fines or criminal penalties.

nologies, and/or unauthorized access to our data and information could subject us to significant liability, negatively impact our business operations, and/or require replacement of technology and/or sizeable ransom payments.

Such developments could increase our

of a product or to report an alleged adverse event.

Additionally, the use of AI based software is increasingly being used in the biopharmaceutical industry.

withholding taxes, in the various places that we operate.

The new California laws, the Climate Corporate Data Accountability Act and the Climate-Related Financial Risk Act, each impose additional climate-related reporting requirements on large companies conducting business in the state of California.

For our discussion of the year ended December 31, [removed: 2022,] [added: 2023,] compared to the year ended December 31, [removed: 2021,] [added: 2022,] 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, [removed: 2022.][added: 2023.]

Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex [removed: diseases worldwide.][added: diseases.]

[removed: Through our 2023 acquisition of Reata we] [added: We] market the first and only drug approved in the U.S. and the E.U. for the treatment of [removed: Friedreich's Ataxia] [added: FA] in adults and adolescents aged 16 years and older.

We support our drug discovery and development efforts through internal research and development [removed: programs and] [added: programs,] external [removed: collaborations.][added: collaborations and acquisitions.]

Our marketed products include TECFIDERA, VUMERITY, AVONEX, [removed: PLEGRIDY, TYSABRI] [added: PLEGRIDY] and [removed: FAMPYRA] [added: TYSABRI] for the treatment of MS; SPINRAZA for the treatment of SMA; SKYCLARYS for the treatment of [removed: Friedreich's Ataxia;] [added: FA;] QALSODY for the treatment of ALS; and FUMADERM for the treatment of severe plaque psoriasis.

We [removed: also] have [removed: collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Sage on the commercialization of ZURZUVAE for the treatment of PPD and 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 [removed: including] [added: including:] BENEPALI, an etanercept biosimilar referencing [removed: ENBREL,] [added: ENBREL;] IMRALDI, an adalimumab biosimilar referencing [removed: HUMIRA, and] [added: HUMIRA;] FLIXABI, an infliximab biosimilar referencing [removed: REMICADE,] [added: REMICADE; and BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS,] in certain [removed: countries in Europe,] [added: international markets,] as well as [removed: BYOOVIZ,] [added: TOFIDENCE,] a [removed: ranibizumab] [added: tocilizumab] biosimilar referencing [removed: LUCENTIS,] [added: ACTEMRA,] in the U.S. and certain international markets.

To that end, we [removed: continually] [added: regularly] review our manufacturing capacity, capabilities, processes and facilities.

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

The second manufacturing [removed: suite] [added: suite, which was also licensed to operate by SWISSMEDIC,] became operational in [removed: January] [added: the first quarter of] 2024.

Solothurn has been approved for the manufacture of [removed: ADUHELM and LEQEMBI by the FDA.][added: LEQEMBI.]

We believe that the Solothurn facility will support our anticipated near to mid-term needs for the manufacturing of biologic [removed: assets, including the commercial launch of LEQEMBI.][added: assets.]

The plant represents a significant increase in our overall manufacturing [removed: capacity and is not yet being fully utilized, resulting in our recording of excess capacity charges.][added: capacity.]

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 [added: 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.]

Multiple TECFIDERA generic entrants are now in North America, Brazil and certain [removed: E.U.] [added: 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 [removed: decline in the future.][added: decline.]

For additional [removed: information,] [added: information on our acquisition of HI-Bio,] please read *Note [removed: 21, Litigation*,] [added: 2, Acquisitions*,] to our consolidated financial statements included in this report.

Factors such as global health outbreaks, adverse weather events, geopolitical events, [added: 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 our products.

[removed: Additionally, global] [added: Global] disputes and interruptions in international relationships, including tariffs, trade protection measures, import or export licensing requirements and the imposition of trade sanctions or similar [removed: restrictions by the U.S. or other governments,] [added: restrictions,] affect our ability to do business.

For example, tensions between [added: China and Taiwan and 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 mainland, [added: retaliatory tariffs imposed by China on U.S. imports,] as well as other business [removed: restrictions.][added: restrictions, with additional restrictive measures being proposed.]

Economic conditions remain vulnerable as markets continue to be impacted in part by elevated inflation, [removed: rising] [added: higher] interest rates, [added: adverse weather events,] global supply chain [removed: constraints] [added: uncertainties] and [removed: recent bank failures.][added: risks associated with geopolitical conflicts.]

The ongoing geopolitical tensions related to Russia's invasion of Ukraine and the [removed: recent] military conflict in the Middle East have resulted in global business disruptions and economic volatility.

[added: In addition, new government sanctions on the export of certain] manufacturing materials to Russia may delay or limit our ability to get new products approved.

Revenue generated from sales in Russia and Ukraine represent less than 2.0% of total revenue for the years ended December 31, [removed: 2023, 2022] [added: 2024, 2023] and [removed: 2021.][added: 2022.]

[removed: Revenue] [added: Additionally, revenue] generated from sales in the broader Middle East region represents less than 2.0% of total revenue for the years ended December 31, [removed: 2023, 2022] [added: 2024, 2023] and [removed: 2021.][added: 2022.]

The IRA did not result in any material adjustments to our income tax provision or other income tax balances as of December 31, [removed: 2023] [added: 2024] and [removed: 2022.][added: 2023.]

[removed: The IRA also establishes] [added: (ii)] drug inflationary rebate requirements to penalize manufacturers from raising the prices of Medicare covered single-source drugs and biologics beyond the inflation-adjusted [removed: rate.][added: rate, beginning in 2022 for Part D drugs and 2023 for Part B drugs;]

[removed: Further,] [added: (iii)] to incentivize biosimilar development, the IRA provides an 8.0% Medicare Part B add-on payment for qualifying biosimilar products for a five-year [removed: period.][added: period; and]

[removed: The] [added: We expect the] IRA's drug pricing controls and Medicare [added: Part D] redesign may have an adverse impact on our [removed: sales (particularly] [added: sales, particularly] for our products that are more substantially reliant on Medicare [removed: reimbursement), our business and our results of operations.][added: reimbursement.]

[removed: However, the] [added: The] degree of impact from this legislation on our business depends on a number of [added: forthcoming] implementation [removed: decisions.][added: actions by regulatory authorities, the full extent of the IRA's impacts on our sales and, in turn, our business, remains unclear.]

As described below under *Results of Operations*, our net income and diluted earnings per share attributable to Biogen Inc. for the year ended December 31, [removed: 2023,] [added: 2024,] compared to the year ended December 31, [removed: 2022,] [added: 2023,] reflects the following:

[removed: ][added: ]

[removed: ][added: ]

| PRODUCT [removed: REVENUE] [added: REVENUE, NET] | | | | | |

[removed: ][added: ]

- MS revenue decreased [removed: $768.3] [added: $312.1] million, or [removed: 14.1%][added: 6.7%]

- Rare disease revenue increased [removed: $9.5] [added: $185.1] million, or [removed: 0.5%][added: 10.3%]

- The decrease in MS product revenue was primarily due to a decrease in [removed: TECFIDERA demand as a result of multiple TECFIDERA generic entrants in North America, Brazil and certain E.U. countries, a decrease in] Interferon demand due to competition as patients transition to higher efficacy therapies and a decrease in [removed: U.S.] [added: global] TYSABRI revenue [removed: primarily] driven by increased [removed: competition and pricing pressure.][added: competition.]

[removed: - The increase in rare] [added: Rare] disease revenue [removed: was primarily due to revenue] [added: includes sales] from [removed: SKYCLARYS,] [added: SPINRAZA, QALSODY,] which [removed: we began recognizing] [added: became commercially available] in the [removed: fourth] [added: U.S. during the second] quarter of 2023 [added: and commercially available in the E.U. during the second quarter of 2024, and SKYCLARYS, which was obtained] as [removed: a result] [added: part] of our acquisition of Reata in September 2023.

[removed: ][added: ]

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 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.

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We are defending the validity of our EP 2 653 873 patent related to TECFIDERA and expiring in 2028 in opposition proceedings in the European Patent Office.

We are also engaged in litigation in Europe to defend and enforce national counterparts of our EP 2 653 873 patent, with mixed results.

TYSABRI

We expect the future sales of TYSABRI may be adversely affected by the entrance of this biosimilar.

ADVERSE WEATHER EVENTS

Adverse weather conditions, including hurricanes, earthquakes, wildfires and natural disaster damage, may affect our ability to do business.

We currently have operations in RTP, North Carolina, which were not impacted by recent hurricanes.

GLOBAL SUPPLY CHAIN DISRUPTIONS

Global supply chain disruptions, such as strikes, work stoppages, port congestion, port closures and other logistical problems, may affect our ability to do business.

For example, in 2024 major port strikes on the East and Gulf Coasts of the U.S. resulted in delayed cargo movement for several days.

As our primary shipping method for resources and finished goods is through air freight, the recent port strikes did not impact our business; however, we will continue to assess any future port disruptions and if necessary, work to secure alternative transportation.

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We, and the pharmaceutical industry, utilize China-based partners for certain raw materials, ingredients and components for our pharmaceutical products and their delivery devices.

Engaging alternative suppliers may involve seeking additional regulatory approvals and be costly in terms of time and resources needed.

For example, certain early processes related to our acquired SKYCLARYS product rely on a single supplier based in China.

We are continuing to evaluate SKYCLARYS' supply chain and prioritizing actions to mitigate risks associated with its manufacturing and our ability to supply patients.

The IRA also contains substantial drug pricing reforms that may have a significant impact on the pharmaceutical industry in the U.S. This includes the following:

(i) allowing CMS to negotiate prices for select high-cost Medicare Part D drugs (beginning in 2026) and Part B drugs (beginning in 2028) to reduce out-of-pocket prescription drug costs for beneficiaries, potentially resulting in higher contributions from plans and manufacturers;

(IV) Medicare Part D redesign which replaces the current coverage gap provisions and establishes a $2,000 cap for out-of-pocket costs for Medicare beneficiaries beginning in 2025, with manufacturers being responsible for up to 10.0% of costs up to the $2,000 cap and up to 20.0% after that cap is reached.

Manufacturers that qualify as either specified or specified small manufacturers will phase-in the new manufacturer liability for prescription drug costs over a 7-year period from 2025 to 2031 for certain Medicare Part D drugs dispensed to certain beneficiaries.

In April 2024 CMS informed us that we qualified for the specified manufacturer exception pertaining to the Medicare Part D redesign.

We anticipate the IRA Medicare Part D redesign will have a modest net unfavorable impact to our 2025 revenue, ranging from approximately $50.0 million to $100.0 million, concentrated in our SKYCLARYS and MS portfolio product revenue, approximately a third of which could be associated with SKYCLARYS.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

$159.7 million or 1.6%

$3.21 or 40.3%

$33.2 million or 0.5%

- The increase in rare disease product revenue in 2024 was primarily due to revenue from new product launches, including global SKYCLARYS revenue of $382.5 million, $72.2 million for ZURZUVAE and $32.4 million for QALSODY.

This was partially offset by a decrease in rest of world SPINRAZA revenue driven by the loss of an annual tender in Russia which resulted in an unfavorable impact of approximately $45.0 million.

The decrease was also impacted by the timing of SPINRAZA shipments and the unfavorable impact of foreign currency exchange.

$768.9 million or 9.0%

- Cost of sales decreased $223.0 million, or 8.8%

- R&D expense decreased $420.2 million, or 17.1%

- SG&A expense decreased $146.0 million, or 5.7%

- Amortization and impairment of acquired intangible assets increased $206.1 million, or 85.7%

- The decrease in R&D expense was primarily driven by approximately $197.0 million of equity-based compensation expense recognized in 2023 related to our Reata acquisition, cost-reduction measures realized in 2024 in connection with our portfolio prioritization initiatives and our Fit for Growth program, as well as higher spend on clinical trials and close out costs incurred during 2023, partially offset by approximately $48.5 million in SKYCLARYS amortization costs and approximately $42.5 million of equity-based compensation expense recognized in 2024 related to our HI-Bio acquisition.

We also have exclusive rights to commercialize TOFIDENCE, a tocilizumab biosimilar referencing ACTEMRA.

We continue to develop potential biosimilar product SB15, a proposed aflibercept biosimilar referencing EYLEA.

In February 2023 we announced that we are exploring strategic options for our biosimilars business.

[T](#ie5989ff7709d49d194ee19ecbcc140c3_10)[able of Contents](#ie5989ff7709d49d194ee19ecbcc140c3_10)

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.

Following a favorable March 2023 decision of the CJEU affirming TECFIDERA's right to regulatory data and marketing protection and the EC determination in May 2023 that TECFIDERA is entitled to an additional year of market protection for its pediatric indication, we believe that TECFIDERA is entitled to regulatory marketing protection in the E.U. until at least February 2, 2025, and are seeking to enforce this protection.

In December 2023, the EC revoked all centralized marketing authorizations for generic versions of TECFIDERA.

As of December 31, 2023, some of the TECFIDERA generics have not yet fully exited some E.U. markets and we expect removal of all generics from the market will take additional time.

We are closely monitoring this situation and working to enforce our legal right to market protection.

In addition, we will continue to enforce our EP 2 653 873 patent related to TECFIDERA, which expires in 2028.

During 2023 concerns arose with respect to the financial condition of certain banking institutions in the U.S., in particular those with exposure to certain types of depositors and large portfolios of investment securities.

In March 2023 two such banks were closed and taken over by the FDIC, which created significant market disruption.

While we did not have any direct exposure to these institutions, we do maintain our cash at financial institutions, often in balances that exceed the current FDIC insurance limits, and will continue to monitor our cash, cash equivalents and investments and take steps to identify any potential impact and minimize any disruptions on our business.

If other banks and financial institutions enter receivership or become insolvent in the future due to financial conditions affecting the banking system and financial markets, our ability to access our cash, cash equivalents and investments, including transferring funds, making payments or receiving funds, may be threatened and could have a material adverse effect on our business and financial condition.

In addition, new government sanctions on the export of certain

The IRA also contains substantial drug pricing reforms that may have a significant impact on the pharmaceutical industry in the U.S. This includes allowing CMS to negotiate a maximum fair price for certain high-priced single source Medicare drugs, as well as redesigning Medicare Part D to reduce out-of-pocket prescription drug costs for beneficiaries, potentially resulting in higher contributions from plans and manufacturers.

We will continue to assess as further information becomes available.

$337.8 million or 3.3%

$12.90 or 61.8%

$741.1 million or 9.3%

- Biosimilars revenue increased $18.9 million, or 2.5%

The increase was partially offset by a decrease in rest of world SPINRAZA revenue primarily due to the unfavorable impact of foreign currency exchange, increased competition, a decrease in pricing and the timing of shipments.

$1,957.2 million or 29.7%

- Cost of sales increased $255.1 million, or 11.2%

- R&D expense increased $230.9 million, or 10.3%

- SG&A expense increased $146.1 million, or 6.1%

- Restructuring expense increased $87.7 million, or 66.9%

- Other income decreased $423.7 million, net

- The increase in restructuring expense was primarily due to higher severance benefits associated with the 2023 cost savings initiatives as compared to 2022.

- The decrease in other income, net was primarily due to the pre-tax gain of $1.5 billion recorded in 2022 related to the sale of our equity interest in Samsung Bioepis, partially offset by a pre-tax charge of $900.0 million, plus settlement fees and expenses, related to a litigation settlement agreement

- Additionally, total cost and expense in 2022 was reduced by a pre-tax gain of approximately $503.7 million related to a sale of a building.

Net cash flow from operations includes $393.4 million of equity-based compensation expense related to our acquisition of Reata in September 2023.

The decrease was primarily due to consideration paid for our acquisition of Reata in September 2023.

In July 2023 the FDA granted traditional approval of LEQEMBI, an anti-amyloid antibody for the treatment of Alzheimer's disease, which was previously granted accelerated approval by the FDA in January 2023.

Following the FDA's traditional approval of LEQEMBI, CMS confirmed broader coverage of LEQEMBI.

Additionally, in March 2023 Eisai announced that the U.S. Veteran's Health Administration will be providing coverage of LEQEMBI to veterans living with early stages of Alzheimer's disease.

- In January 2024 we and Eisai announced that the SAG will convene at the request of the CHMP to discuss the MAA of lecanemab that is currently under review by the EMA.

The meeting of the SAG is expected to take place during the first quarter of 2024 and the EC decision for the MAA of lecanemab is expected during the first half of 2024.

- In December 2023 we and Eisai announced that LEQEMBI intravenous infusion was launched in Japan.

- In September 2023 the Japanese Ministry of Health, Labor and Welfare approved LEQEMBI in Japan.

This categorization did not have a material impact on our results of operations or financial position as of December 31, [removed: 2023,] [added: 2024,] and is not expected to have a material impact on our results of operations or financial position in the future.

[added: The devaluation resulted in a $16.0 million charge recorded] during the fourth quarter of 2023 in other (income) expense, net within our consolidated statements of income for the year ended December 31, 2023.

As of December 31, [removed: 2023] [added: 2024] and [removed: 2022,] [added: 2023,] a hypothetical adverse 10.0% movement in foreign currency exchange rates compared to the U.S. dollar across all maturities would result in a hypothetical decrease in the fair value of forward contracts of approximately [removed: $249.4] [added: $191.7] million and [removed: $293.7] [added: $249.4] million, respectively.

Our use of this methodology to quantify the market risk of such instruments is subject to assumptions and actual impact could be significantly [removed: different.]

We believe that our allowance for doubtful accounts was adequate as of December 31, [removed: 2023] [added: 2024] and [removed: 2022.][added: 2023.]

As of December 31, [removed: 2023] [added: 2024] and [removed: 2022,] [added: 2023,] a hypothetical adverse 10.0% movement would result in a hypothetical decrease in fair value of approximately [removed: $41.7] [added: $18.0] million and [removed: $79.1] [added: $41.7] million, respectively.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

different.

The devaluation resulted in a $16.0 million charge recorded

[T](#ie5989ff7709d49d194ee19ecbcc140c3_10)[able of Contents](#ie5989ff7709d49d194ee19ecbcc140c3_10)

INTEREST RATE RISK

Our investment portfolio includes cash equivalents and short-term investments.

The fair value of our marketable securities is subject to change as a result of potential changes in market interest rates.

The potential change in fair value for interest rate sensitive instruments has been assessed on a hypothetical 100 basis point adverse movement across all maturities.

As of December 31, 2022, we estimate that such hypothetical 100 basis point adverse movement would result in a hypothetical loss in fair value of approximately $11.7 million to our interest rate sensitive instruments.

The fair values of our investments were determined using third-party pricing services or other market observable data.

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

As of December 31, 2023, we have sold all of our marketable debt securities. For additional information on our acquisition of Reata, please read *Note 2, Acquisitions*, to our consolidated financial statements included in this report.

Biogen is a global biopharmaceutical company focused on discovering, developing and delivering innovative therapies for people living with serious and complex [removed: diseases worldwide.][added: diseases.]

[removed: Through our 2023 acquisition of Reata we] [added: We] market the first and only drug approved in the U.S. and the E.U. for the treatment of [removed: Friedreich's Ataxia] [added: FA] in adults and adolescents aged 16 years and older.

We support our drug discovery and development efforts through internal research and development [removed: programs and] [added: programs,] external [removed: collaborations.][added: collaborations and acquisitions.]

Our marketed products include TECFIDERA, VUMERITY, AVONEX, [removed: PLEGRIDY, TYSABRI] [added: PLEGRIDY] and [removed: FAMPYRA] [added: TYSABRI] for the treatment of MS; SPINRAZA for the treatment of SMA; SKYCLARYS for the treatment of [removed: Friedreich's Ataxia;] [added: FA;] QALSODY for the treatment of ALS; and FUMADERM for the treatment of severe plaque psoriasis.

We [removed: also] have [removed: collaborations with Eisai on the commercialization of LEQEMBI for the treatment of Alzheimer's disease and Sage on the commercialization of ZURZUVAE for the treatment of PPD and 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 [removed: including] [added: including:] BENEPALI, an etanercept biosimilar referencing [removed: ENBREL,] [added: ENBREL;] IMRALDI, an adalimumab biosimilar referencing [removed: HUMIRA, and] [added: HUMIRA;] FLIXABI, an infliximab biosimilar referencing [removed: REMICADE,] [added: REMICADE; and BYOOVIZ, a ranibizumab biosimilar referencing LUCENTIS,] in certain [removed: countries in Europe,] [added: international markets,] as well as [removed: BYOOVIZ,] [added: TOFIDENCE,] a [removed: ranibizumab] [added: tocilizumab] biosimilar referencing [removed: LUCENTIS,] [added: ACTEMRA,] in the U.S. and certain international markets.

The following is a summary of key developments affecting our business since the beginning of [removed: 2023.][added: 2024.]

Key developments related to LEQEMBI (lecanemab) in rest of world markets [removed: during 2023] consisted of the following:

- In [removed: January] [added: June] 2024 [added: we and Eisai announced] the [removed: NMPA approved] [added: launch of] LEQEMBI in China, [removed: with an expected launch date] [added: which had been approved by the NMPA] in [added: China in January] 2024.

- In [removed: September 2023] [added: December 2024] the Japanese Ministry of Health, Labor and Welfare approved [removed: LEQEMBI] [added: QALSODY] in Japan.

[removed: ZURZUVAE (zuranolone)][added: *zuranolone*]

[removed: In August 2023] [added: (3) Granted approval in] the [removed: FDA approved ZURZUVAE for adults with PPD,] [added: U.S. in August 2023,] pending DEA scheduling, which was completed in October [removed: 2023.][added: 2023, under the brand name ZURZUVAE.]

[added: Neuropsychiatry includes] ZURZUVAE for [removed: PPD] [added: PPD, which] became commercially available in the U.S. during the fourth quarter of 2023.

For additional information on our collaboration [removed: arrangement] [added: arrangements] with Sage, please read *Note 19, Collaborative and Other [removed: Relationships*,] [added: Relationships,*] to our consolidated financial statements included in this report.

For additional information on our acquisition of [removed: Reata,] [added: HI-Bio,] please read *Note 2, Acquisitions*, to our consolidated financial statements included in this report.

QALSODY [removed: (tofersen)]

[added: -] In [removed: April 2023] [added: May 2024] the [removed: FDA] [added: EC] approved QALSODY [added: in the E.U.] for the treatment of [removed: ALS in] adults [removed: who have] [added: with ALS associated with] a mutation in the SOD1 gene.

For additional information on our [removed: Fit for Growth program,] [added: acquisition of HI-Bio,] please read *Note [removed: 4, Restructuring*,] [added: 2, Acquisitions*,] to our consolidated financial statements included in this report.

[removed: - In September 2023 we announced the appointment of Jane] [added: | Jane] Grogan, [removed: Ph.D., as] [added: Ph.D. | | | | | |] Executive Vice President, Head of [removed: Research.][added: Research | | | | | | 58 | | | | | | 2023 | | |]

[removed: - In April 2023 we announced the appointment of Adam] [added: | Adam] Keeney, [removed: as] [added: Ph.D. | | | | | |] Executive Vice President, Head of Corporate [removed: Development.][added: Development | | | | | | 48 | | | | | | 2023 | | |]

[removed: - In June 2023 Susan Langer] [added: Minor, M.D.] joined our Board of Directors.

- In July [removed: 2023 we and] [added: 2024] Eisai announced the results of a detailed analysis of the Phase 3 CLARITY Alzheimer's disease study of LEQEMBI at the [removed: 2023] [added: 2024] AAIC conference.

[removed: Interim results from the Phase 4] [added: The reductions in biomarker complement previously reported] RESPOND study [removed: showed] [added: efficacy results showing] improved motor function in most participants treated with SPINRAZA after [removed: ZOLGENSMA.][added: gene therapy.]

SKYCLARYS [removed: (omaveloxolone)]

- In [removed: February] [added: September] 2024 [removed: the EC approved] SKYCLARYS [removed: in the E.U.] [added: was approved by SWISSMEDIC] for the treatment of FA in adults and adolescents aged 16 years and older.

In January 2024 we notified Acorda of our decision to terminate our collaboration and license agreement, effective January 1, [removed: 2025.][added: 2025, whereby Acorda regained global commercialization rights to FAMPYRA.]

The following graph shows our product [removed: revenue and] [added: revenue,] revenue from anti-CD20 therapeutic programs [added: and Alzheimer's collaboration revenue] for the years ended December 31, [removed: 2023, 2022] [added: 2024, 2023] and [removed: 2021.][added: 2022.]

[removed: ][added: ]

[removed: VUMERITY] [added: SKYCLARYS was approved and] became commercially available in the E.U. during the [removed: fourth] [added: first] quarter of [removed: 2021.][added: 2024.]

(2) Rare disease includes SPINRAZA, QALSODY, which became commercially available in the U.S. during the second quarter of [removed: 2023,] [added: 2023] and [added: commercially available in the E.U. during the second quarter of 2024, and] SKYCLARYS, which was obtained as part of our acquisition of Reata in September 2023.

[removed: BYOOVIZ] [added: (3) Biosimilars includes BENEPALI, IMRALDI, FLIXABI, BYOOVIZ, which] became commercially available in [added: certain international markets in 2023, and TOFIDENCE, which became commercially available in] the U.S. during the [removed: third] [added: second] quarter of [removed: 2022 and commercially available in certain international markets in 2023.][added: 2024.]

[removed: (4)] [added: (5)] Anti-CD20 therapeutic programs include RITUXAN, RITUXAN HYCELA, GAZYVA, OCREVUS and [removed: LUNSUMIO.][added: LUNSUMIO, which became commercially available in the U.S. during the first quarter of 2023.]

[removed: LUNSUMIO] [added: (6) Other includes FUMADERM, ADUHELM and ZURZUVAE, which] became commercially available in the U.S. during the [removed: first] [added: fourth] quarter of 2023.

Product sales for TECFIDERA, TYSABRI and SPINRAZA each accounted for more than 10.0% of our total revenue for the years ended December 31, [removed: 2023, 2022] [added: 2024, 2023] and [removed: 2021.][added: 2022.]

| [removed: ] [added: ] | | | | | | RMS in the U.S. RRMS in the E.U. | | | | | | None | | | | | | U.S. France Germany Italy Japan [removed: Spain] U.K. | | |

| [removed: ] [added: ] | | | | | | RMS in the U.S. RRMS in the E.U. | | | | | | Alkermes Pharma Ireland Limited, a subsidiary of Alkermes | | | | | | U.S. [added: France] Germany [removed: Israel] [added: Netherlands Spain] Switzerland [removed: U.K.] | | |

| [removed: ] [added: ] | | | | | | RMS | | | | | | None | | | | | | U.S. [added: Canada] France Germany Italy [removed: Japan] Spain | | |

| [removed: ] [added: ] | | | | | | RMS in the U.S. RRMS in the E.U. | | | | | | None | | | | | | U.S. France Germany Italy Spain U.K. | | |

| [removed: ] [added: ] | | | | | | RMS RRMS in the E.U. Crohn's disease in the U.S. | | | | | | None | | | | | | U.S. [added: Brazil] France Germany Italy [removed: Spain] U.K. | | |

For additional information on our collaboration arrangements with [removed: Alkermes and Acorda,] [added: Alkermes,] please read *Note 19, Collaborative and Other Relationships,* to our consolidated financial statements included in this report.

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 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.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

ACQUISITIONS AND DIVESTITURES

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.

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.

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.

Key developments related to LEQEMBI in the U.S. consisted of the following:

- In January 2025 the FDA approved LEQEMBI monthly IV maintenance dosing for the treatment of early Alzheimer's disease.

- In January 2025 the FDA accepted for review the BLA for LEQEMBI subcutaneous autoinjector for weekly maintenance dosing, with a PDUFA action date set for August 31, 2025.

- In July 2024 Eisai presented new clinical data from the CLARITY AD study open-label extension of LEQEMBI, demonstrating that three years of continuous LEQEMBI treatment reduced clinical decline, resulting in a clinically meaningful benefit for early Alzheimer's disease patients.

- In January 2025 we and Eisai announced an update regarding the ongoing regulatory review of the MAA for lecanemab in the E.U., which the CHMP of the EMA previously adopted a positive opinion on in November 2024.

The EC has asked the CHMP to consider information on the safety of lecanemab that became available after the adoption of the CHMP opinion in November 2024 and whether this may require an update of the opinion, and to consider whether the wording of the risk minimization measures in the opinion is clear enough to ensure correct implementation.

These will be discussed at the CHMP meeting in February 2025.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

- In December 2024 LEQEMBI was approved by the Federal Commission for the Protection Against Sanitary Risk in Mexico.

- In November 2024 we and Eisai announced the launch of LEQEMBI in South Korea, which had been approved by the Ministry of Food and Drug Safety in South Korea in May 2024.

- In October 2024 the Therapeutic Goods Administration of Australia issued a public statement about the initial decision not to register lecanemab.

In December 2024 Eisai submitted a request for reconsideration of this decision.

- In August 2024 LEQEMBI was approved by the Medicines and Healthcare products Regulatory Agency in Great Britain and by the Ministry of Health and Prevention in the United Arab Emirates.

- In July 2024 LEQEMBI was approved in Hong Kong and Israel.

UCB COLLABORATION

In September 2024 we and UCB announced positive topline data from the Phase 3 PHOENYCS GO study of dapirolizumab pegol, a novel Fc-free anti-CD40L drug candidate, in people living with moderate-to-severe SLE.

The Phase 3 study met the primary endpoint demonstrating clinical improvement in moderate-to-severe SLE with clinical improvements observed among key secondary endpoints.

Based on these results, UCB and Biogen initiated a second Phase 3 study in late 2024.

- In October 2024 we announced that Michael R.

McDonnell, Executive Vice President and Chief Financial Officer, plans to retire from Biogen on March 1, 2025.

Upon Mr. McDonnell's retirement, Robin C.

Kramer, currently Senior Vice President and Chief Accounting Officer at Biogen, will assume the role of Executive Vice President and Chief Financial Officer.

We also have exclusive rights to commercialize TOFIDENCE, a tocilizumab biosimilar referencing ACTEMRA.

We continue to develop potential biosimilar product SB15, a proposed aflibercept biosimilar referencing EYLEA.

In February 2023 we announced that we are exploring strategic options for our biosimilars business.

In July 2023 the FDA granted traditional approval of LEQEMBI, an anti-amyloid antibody for the treatment of Alzheimer's disease, which was previously granted accelerated approval by the FDA in January 2023.

Following the FDA's traditional approval of LEQEMBI, CMS confirmed broader coverage of LEQEMBI.

Additionally, in March 2023 Eisai announced that the U.S. Veteran's Health Administration will be providing coverage of LEQEMBI to veterans living with early stages of Alzheimer's disease.

- In January 2024 we and Eisai announced that the SAG will convene at the request of the CHMP to discuss the MAA of lecanemab that is currently under review by the EMA.

The meeting of the SAG is expected to take place during the first quarter of 2024 and the EC decision for the MAA of lecanemab is expected during the first half of 2024.

[T](#ie5989ff7709d49d194ee19ecbcc140c3_10)[able of Contents](#ie5989ff7709d49d194ee19ecbcc140c3_10)

- In December 2023 we and Eisai announced that LEQEMBI intravenous infusion was launched in Japan.

- In January 2023 the EMA accepted for review the MAA for lecanemab.

- In February 2023 the BLA for lecanemab was granted Priority Review by the NMPA of China.

- In May 2023 we and Eisai announced the submission of a MAA for lecanemab to the U.K. MHRA in Great Britain, which has been designated by the MHRA for the Innovative Licensing and Access Pathway.

Additionally, in May 2023 Health Canada accepted for review the NDS for lecanemab.

- In June 2023 we and Eisai announced the submission of a MAA for lecanemab to the Ministry of Food and Drug Safety in South Korea.

Upon approval, ZURZUVAE for PPD 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.

Additionally, the FDA issued a CRL for the NDA for zuranolone in the treatment of adults with MDD.

The CRL stated that the application did not provide substantial evidence of effectiveness to support the approval of zuranolone for the treatment of MDD and that an additional study or studies would be needed.

We and Sage are continuing to seek feedback from the FDA and evaluating next steps.

BUSINESS COMBINATIONS

REATA ACQUISITION

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 Friedreich's Ataxia in adults and adolescents aged 16 years and older, as well as other clinical and preclinical pipeline programs.

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.

OTHER KEY DEVELOPMENTS

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).

TECFIDERA

Following a favorable March 2023 decision of the CJEU affirming TECFIDERA's right to regulatory data and marketing protection and the EC determination in May 2023 that TECFIDERA is entitled to an additional year of market

protection for its pediatric indication, we believe that TECFIDERA is entitled to regulatory marketing protection in the E.U. until at least February 2, 2025, and are seeking to enforce this protection.

In December 2023, the EC revoked all centralized marketing authorizations for generic versions of TECFIDERA.

As of December 31, 2023, some of the TECFIDERA generics have not yet fully exited some E.U. markets and we expect removal of all generics from the market will take additional time.

We are closely monitoring this situation and working to enforce our legal right to market protection.

In addition, we will continue to enforce our EP 2 653 873 patent related to TECFIDERA, which expires in 2028.

CORPORATE MATTERS

FIT FOR GROWTH

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.

For a discussion of legal matters as of December 31, [removed: 2023,] [added: 2024,] please read *Note 21, Litigation,* to our consolidated financial statements included in this report, which is incorporated into this item by reference.

For the fiscal year ended December 31, [removed: 2023][added: 2024]

[removed: ][added: ]

The aggregate market value of the registrant’s common stock held by non-affiliates of the registrant (without admitting that any person whose shares are not included in such calculation is an affiliate) computed by reference to the price at which the common stock was last sold as of the last business day of the registrant’s most recently completed second fiscal quarter was [removed: $41,190,868,800.][added: $33,709,755,067.]

As of February [removed: 12, 2024,] [added: 11, 2025,] the registrant had [removed: 145,360,798] [added: 146,374,937] shares of common stock, $0.0005 par value, outstanding.

Portions of the definitive proxy statement for our [removed: 2024] [added: 2025] Annual Meeting of Stockholders are incorporated by reference into Part III of this report.

For the Year Ended December 31, [removed: 2023][added: 2024]

| [Item [removed: 1.](#ie5989ff7709d49d194ee19ecbcc140c3_25)] [added: 1.](#i8f04c147560c48a7bb5358179696a625_28)] | | | [removed: [Business](#ie5989ff7709d49d194ee19ecbcc140c3_25)] [added: [Business](#i8f04c147560c48a7bb5358179696a625_28)] | | | [removed: [1](#ie5989ff7709d49d194ee19ecbcc140c3_25)] [added: [1](#i8f04c147560c48a7bb5358179696a625_28)] | | |

| [Item [removed: 1A.](#ie5989ff7709d49d194ee19ecbcc140c3_70)] [added: 1A.](#i8f04c147560c48a7bb5358179696a625_73)] | | | [Risk [removed: Factors](#ie5989ff7709d49d194ee19ecbcc140c3_70)] [added: Factors](#i8f04c147560c48a7bb5358179696a625_73)] | | | [removed: [40](#ie5989ff7709d49d194ee19ecbcc140c3_70)] [added: [38](#i8f04c147560c48a7bb5358179696a625_73)] | | |

| [Item [removed: 1B.](#ie5989ff7709d49d194ee19ecbcc140c3_73)] [added: 1B.](#i8f04c147560c48a7bb5358179696a625_76)] | | | [Unresolved Staff [removed: Comments](#ie5989ff7709d49d194ee19ecbcc140c3_73)] [added: Comments](#i8f04c147560c48a7bb5358179696a625_76)] | | | [removed: [54](#ie5989ff7709d49d194ee19ecbcc140c3_73)] [added: [52](#i8f04c147560c48a7bb5358179696a625_76)] | | |

| [Item [removed: 1C.](#ie5989ff7709d49d194ee19ecbcc140c3_3122)] [added: 1C.](#i8f04c147560c48a7bb5358179696a625_79)] | | | [removed: [Cybersecurity](#ie5989ff7709d49d194ee19ecbcc140c3_3122)] [added: [Cybersecurity](#i8f04c147560c48a7bb5358179696a625_79)] | | | [removed: [54](#ie5989ff7709d49d194ee19ecbcc140c3_3122)] [added: [52](#i8f04c147560c48a7bb5358179696a625_79)] | | |

| [Item [removed: 2.](#ie5989ff7709d49d194ee19ecbcc140c3_76)] [added: 2.](#i8f04c147560c48a7bb5358179696a625_82)] | | | [removed: [Properties](#ie5989ff7709d49d194ee19ecbcc140c3_76)] [added: [Properties](#i8f04c147560c48a7bb5358179696a625_82)] | | | [removed: [55](#ie5989ff7709d49d194ee19ecbcc140c3_76)] [added: [54](#i8f04c147560c48a7bb5358179696a625_82)] | | |

| [Item [removed: 3.](#ie5989ff7709d49d194ee19ecbcc140c3_79)] [added: 3.](#i8f04c147560c48a7bb5358179696a625_85)] | | | [Legal [removed: Proceedings](#ie5989ff7709d49d194ee19ecbcc140c3_79)] [added: Proceedings](#i8f04c147560c48a7bb5358179696a625_85)] | | | [removed: [57](#ie5989ff7709d49d194ee19ecbcc140c3_79)] [added: [54](#i8f04c147560c48a7bb5358179696a625_85)] | | |

| [Item [removed: 4.](#ie5989ff7709d49d194ee19ecbcc140c3_82)] [added: 4.](#i8f04c147560c48a7bb5358179696a625_88)] | | | [Mine Safety [removed: Disclosures](#ie5989ff7709d49d194ee19ecbcc140c3_82)] [added: Disclosures](#i8f04c147560c48a7bb5358179696a625_88)] | | | [removed: [57](#ie5989ff7709d49d194ee19ecbcc140c3_82)] [added: [54](#i8f04c147560c48a7bb5358179696a625_88)] | | |

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| [Item [removed: 6.](#ie5989ff7709d49d194ee19ecbcc140c3_91)] [added: 6.](#i8f04c147560c48a7bb5358179696a625_97)] | | | [removed: [Reserved](#ie5989ff7709d49d194ee19ecbcc140c3_91)] [added: [Reserved](#i8f04c147560c48a7bb5358179696a625_97)] | | | [removed: [59](#ie5989ff7709d49d194ee19ecbcc140c3_91)] [added: [56](#i8f04c147560c48a7bb5358179696a625_97)] | | |

| [Item [removed: 7.](#ie5989ff7709d49d194ee19ecbcc140c3_94)] [added: 7.](#i8f04c147560c48a7bb5358179696a625_100)] | | | [Management’s Discussion and Analysis of Financial Condition and Results of [removed: Operations](#ie5989ff7709d49d194ee19ecbcc140c3_94)] [added: Operations](#i8f04c147560c48a7bb5358179696a625_100)] | | | [removed: [60](#ie5989ff7709d49d194ee19ecbcc140c3_94)] [added: [57](#i8f04c147560c48a7bb5358179696a625_100)] | | |

| [Item [removed: 7A.](#ie5989ff7709d49d194ee19ecbcc140c3_187)] [added: 7A.](#i8f04c147560c48a7bb5358179696a625_232)] | | | [Quantitative and Qualitative Disclosures About Market [removed: Risk](#ie5989ff7709d49d194ee19ecbcc140c3_187)] [added: Risk](#i8f04c147560c48a7bb5358179696a625_232)] | | | [removed: [91](#ie5989ff7709d49d194ee19ecbcc140c3_187)] [added: [87](#i8f04c147560c48a7bb5358179696a625_232)] | | |

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| [Item [removed: 9.](#ie5989ff7709d49d194ee19ecbcc140c3_193)] [added: 9.](#i8f04c147560c48a7bb5358179696a625_238)] | | | [Changes in and Disagreements with Accountants on Accounting and Financial [removed: Disclosure](#ie5989ff7709d49d194ee19ecbcc140c3_193)] [added: Disclosure](#i8f04c147560c48a7bb5358179696a625_238)] | | | [removed: [93](#ie5989ff7709d49d194ee19ecbcc140c3_193)] [added: [89](#i8f04c147560c48a7bb5358179696a625_238)] | | |

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| [Item [removed: 9B.](#ie5989ff7709d49d194ee19ecbcc140c3_199)] [added: 9B.](#i8f04c147560c48a7bb5358179696a625_244)] | | | [Other [removed: Information](#ie5989ff7709d49d194ee19ecbcc140c3_199)] [added: Information](#i8f04c147560c48a7bb5358179696a625_244)] | | | [removed: [94](#ie5989ff7709d49d194ee19ecbcc140c3_199)] [added: [90](#i8f04c147560c48a7bb5358179696a625_244)] | | |

| [Item [removed: 9C.](#ie5989ff7709d49d194ee19ecbcc140c3_202)] [added: 9C.](#i8f04c147560c48a7bb5358179696a625_250)] | | | [Disclosure Regarding Foreign Jurisdictions that Prevent [removed: Inspections](#ie5989ff7709d49d194ee19ecbcc140c3_202)] [added: Inspections](#i8f04c147560c48a7bb5358179696a625_250)] | | | [removed: [95](#ie5989ff7709d49d194ee19ecbcc140c3_202)] [added: [91](#i8f04c147560c48a7bb5358179696a625_250)] | | |

| [Item [removed: 10.](#ie5989ff7709d49d194ee19ecbcc140c3_208)] [added: 10.](#i8f04c147560c48a7bb5358179696a625_256)] | | | [Directors, Executive Officers and Corporate [removed: Governance](#ie5989ff7709d49d194ee19ecbcc140c3_208)] [added: Governance](#i8f04c147560c48a7bb5358179696a625_256)] | | | [removed: [96](#ie5989ff7709d49d194ee19ecbcc140c3_208)] [added: [92](#i8f04c147560c48a7bb5358179696a625_256)] | | |

| [Item [removed: 11.](#ie5989ff7709d49d194ee19ecbcc140c3_211)] [added: 11.](#i8f04c147560c48a7bb5358179696a625_259)] | | | [Executive [removed: Compensation](#ie5989ff7709d49d194ee19ecbcc140c3_211)] [added: Compensation](#i8f04c147560c48a7bb5358179696a625_259)] | | | [removed: [96](#ie5989ff7709d49d194ee19ecbcc140c3_211)] [added: [92](#i8f04c147560c48a7bb5358179696a625_259)] | | |

| [Item [removed: 12.](#ie5989ff7709d49d194ee19ecbcc140c3_214)] [added: 12.](#i8f04c147560c48a7bb5358179696a625_262)] | | | [Security Ownership of Certain Beneficial Owners and Management and Related Stockholder [removed: Matters](#ie5989ff7709d49d194ee19ecbcc140c3_214)] [added: Matters](#i8f04c147560c48a7bb5358179696a625_262)] | | | [removed: [96](#ie5989ff7709d49d194ee19ecbcc140c3_214)] [added: [92](#i8f04c147560c48a7bb5358179696a625_262)] | | |

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| [Item [removed: 15.](#ie5989ff7709d49d194ee19ecbcc140c3_226)] [added: 15.](#i8f04c147560c48a7bb5358179696a625_274)] | | | [Exhibits and Financial Statement [removed: Schedules](#ie5989ff7709d49d194ee19ecbcc140c3_226)] [added: Schedules](#i8f04c147560c48a7bb5358179696a625_274)] | | | [removed: [97](#ie5989ff7709d49d194ee19ecbcc140c3_226)] [added: [93](#i8f04c147560c48a7bb5358179696a625_274)] | | |

| [Item [removed: 16.](#ie5989ff7709d49d194ee19ecbcc140c3_229)] [added: 16.](#i8f04c147560c48a7bb5358179696a625_277)] | | | [Form 10-K [removed: Summary](#ie5989ff7709d49d194ee19ecbcc140c3_229)] [added: Summary](#i8f04c147560c48a7bb5358179696a625_277)] | | | [removed: [97](#ie5989ff7709d49d194ee19ecbcc140c3_229)] [added: [93](#i8f04c147560c48a7bb5358179696a625_277)] | | |

| [Consolidated Financial [removed: Statements](#ie5989ff7709d49d194ee19ecbcc140c3_238)] [added: Statements](#i8f04c147560c48a7bb5358179696a625_286)] | | | | | | F- [removed: [1](#ie5989ff7709d49d194ee19ecbcc140c3_238)] [added: [1](#i8f04c147560c48a7bb5358179696a625_286)] | | |

This report contains forward-looking statements that are being made pursuant to the provisions of the Private Securities Litigation Reform Act of 1995 (the [removed: Act)] [added: PSLRA)] with the intention of obtaining the benefits of the “Safe Harbor” provisions of the [removed: Act.][added: PSLRA.]

These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” [added: "assume,"] “believe,” [removed: “could,” "contemplate," "continue,"] [added: “contemplate,” “continue," "could,"] “estimate,” “expect,” “forecast,” [removed: "goal,"] [added: “goal,” “guidance,” “hope,”] “intend,” “may,” [added: “objective,”] “plan,” [removed: “potential,”] “possible,” [removed: "predict," "project", "should," "target,"] [added: "potential," “predict” “project,” “should,” “target,”] “will,” “would” or the negative of these words or other words and terms of similar meaning.

- the anticipated amount, timing and accounting of [removed: revenue;] contingent, milestone, royalty and other payments under licensing, collaboration, acquisition or divestiture agreements; tax positions and contingencies; collectability of receivables; pre-approval inventory; cost of sales; research and development costs; compensation and other selling, general and administrative expense; amortization of intangible assets; foreign currency exchange risk; estimated fair value of assets and liabilities; and impairment assessments;

- the potential impact of increased product competition in the [added: biopharmaceutical and healthcare industry, as well as any other] markets in which we compete, including increased competition from new originator therapies, generics, prodrugs and biosimilars of existing products and products approved under abbreviated regulatory pathways, including [removed: generic] [added: generic, prodrugs] or biosimilar versions of our [added: marketed] products or competing [removed: products;][added: products, including but not limited to increased competition from TECFIDERA generic entrants in the U.S. market;]

- patent terms, patent term extensions, patent office actions and expected availability and periods of regulatory [removed: exclusivity;][added: exclusivity, as well as our ability to adequately enforce existing patents, including our European patent related to TECFIDERA;]

- the [added: successful] execution of our strategic and growth initiatives, including [removed: the ultimate success of our acquisition of Reata] [added: acquisitions,] and our ability to realize the anticipated benefits from [removed: the acquisition,] [added: our acquisitions of Reata and HI-Bio,] including future performance of the SKYCLARYS product and [removed: anticipated synergies, as well as the exploration] [added: further development] of [removed: strategic options for our biosimilars business;][added: the felzartamab product and anticipated synergies;]

- the drivers for growing our business, including our plans and intention to commit resources relating to discovery, research and development programs and business development [removed: opportunities] [added: opportunities, including collaboration agreements,] as well as the potential benefits and results of, and the anticipated completion of, certain business development [removed: transactions] [added: transactions, reorganizations] and cost-reduction measures, including our Fit for Growth program;

- the expectations, development plans and anticipated timelines, including costs and timing of potential clinical trials, regulatory [removed: filings and approvals,] [added: filing approvals and/or discontinuation,] of our products, drug candidates and pipeline programs, including collaborations with [removed: third-parties,] [added: third-parties including but not limited to Eisai and Sage,] as well as the potential therapeutic scope of the development and commercialization of our and our collaborators’ pipeline [removed: products;][added: products, including ZURZUVAE;]

- the timing, outcome and impact of administrative, regulatory, legal and other [removed: proceedings] [added: proceedings, including those] related to our patents and other proprietary and intellectual property rights, tax audits, assessments and settlements, pricing matters, sales and promotional practices, product liability, investigations and other matters;

- our ability to finance our [added: present and future] operations and business initiatives and obtain funding for such [removed: activities;][added: activities on favorable terms;]

| [PART I](#i8f04c147560c48a7bb5358179696a625_25) | | | | | | | | |

| [PART II](#i8f04c147560c48a7bb5358179696a625_91) | | | | | | | | |

| [PART III](#i8f04c147560c48a7bb5358179696a625_253) | | | | | | | | |

| [PART IV](#i8f04c147560c48a7bb5358179696a625_271) | | | | | | | | |

| [Signatures](#i8f04c147560c48a7bb5358179696a625_283) | | | | | | [96](#i8f04c147560c48a7bb5358179696a625_283) | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

Given their forward-looking nature, these statements involve substantial risks and uncertainties and may be based on inaccurate assumptions.

This report includes, among others, forward-looking statements regarding:

- our expected financial and operating performance;

- our long-term strategy and supporting business plans, including our product pipeline;

- our expectations about continued growth through acquisitions and key collaborative relationships;

- our belief that our long-term competitive position depends upon our success in discovering and developing innovative, cost-effective products that serve unmet medical needs, along with our ability to manufacture products efficiently and to launch and market them effectively in a highly competitive environment;

- our ability to obtain and maintain adequate coverage, pricing and reimbursement from third-party payors;

- our expectations regarding certain legal and regulatory proceedings and investigations; and

- our belief that our existing funds, when combined with cash generated from operations and our access to additional financing resources, if needed, are sufficient to satisfy our operating, working capital, strategic alliance, milestone payment, capital expenditure and debt service requirements for the foreseeable future.

These forward-looking statements are based on management's current beliefs and assumptions and on information currently available to management.

Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part.

We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to be materially different from those stated or implied in this document, including, among others, factors relating to:

- our substantial dependence on the anticipated amount, timing and accounting of revenue from our products, including from the successful development of new products and approval of additional indications for our existing products, including but not limited to LEQEMBI and SKYCLARYS;

- expectations, plans and prospects relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products all of which is subject to governmental and regulatory oversight, and therefore subject to risks, including but not limited to those related to approvals, unfavorable or delayed reimbursements and coverage determinations, and changes in reimbursement policies or practices of payors and other third-parties;

- our ability to effectively implement our corporate strategy which includes significant investment in product and pipeline candidates, including but not limited to felzartamab and nusinersen;

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

- our ability to commercialize biosimilars, which is subject to risks such as our reliance on third-parties, competitive challenges, regulatory compliance, adequate supply, intellectual property and regulatory challenges and failure to gain market and patient acceptance;

- our ability to attract, retain and motivate qualified individuals for management and other employee positions in a highly competitive environment, including potential difficulty in retaining talent following acquisitions or following the discontinuation or underperformance of one or more marketed, pre-clinical or clinical programs;

- our incorporation of technologies using AI into some of our processes;

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

- changes in our effective tax rate and obligations in various jurisdictions in which we are subject to taxation; and

Risk Factors* and *Item 7.

The factors identified above should not be construed as an exhaustive list of factors that could affect our future results and should be read in conjunction with the other cautionary statements that are included in this Annual Report on Form 10-K.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| 2024 Omnibus Equity Plan | | | Biogen Inc. 2024 Omnibus Equity Plan | | |

| 2017 Omnibus Equity Plan | | | Biogen Inc. 2017 Omnibus Equity Plan | | |

| 2024 ESPP | | | Biogen Inc. 2024 Employee Stock Purchase Plan | | |

| 2015 ESPP | | | Biogen Inc. 2015 Employee Stock Purchase Plan | | |

| 2023 Term Loan | | | $1.5 billion term loan credit agreement | | |

| AMR | | | Antibody-Mediated Rejection | | |

| CISA | | | Cybersecurity and Infrastructure Security Agency | | |

| Directors Plan | | | Biogen Inc. 2015 Non-Employee Directors Equity Plan | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| District Court | | | U.S. District Court for the District of Massachusetts | | |

| [PART I](#ie5989ff7709d49d194ee19ecbcc140c3_22) | | | | | | | | |

| [PART II](#ie5989ff7709d49d194ee19ecbcc140c3_85) | | | | | | | | |

| [PART III](#ie5989ff7709d49d194ee19ecbcc140c3_205) | | | | | | | | |

| [PART IV](#ie5989ff7709d49d194ee19ecbcc140c3_223) | | | | | | | | |

| [Signatures](#ie5989ff7709d49d194ee19ecbcc140c3_235) | | | | | | [100](#ie5989ff7709d49d194ee19ecbcc140c3_235) | | |

[T](#ie5989ff7709d49d194ee19ecbcc140c3_10)[able of Contents](#ie5989ff7709d49d194ee19ecbcc140c3_10)

Reference is made in particular to forward-looking statements regarding:

- expectations, plans and prospects relating to product approvals, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products;

- our plans and investments in our portfolio as well as implementation of our corporate strategy;

| DE&I | | | Diversity, Equity and Inclusion | | |

| ERN | | | Employee Resource Network | | |

| ESG | | | Environmental, Social and Governance | | |

| Mylan Ireland | | | Mylan Ireland Ltd. | | |

Our [removed: Audit Committee of 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 [removed: Audit Committee] [added: Board of Directors] also receives [removed: regular] cybersecurity updates and education on a broad range of topics, including:

Risk Factors - A breakdown or breach of our [removed: technology] [added: information] systems could subject us to liability or interrupt the operation of our business*, included in this report.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

We do not believe that any risks from cybersecurity threats have materially affected or are reasonably likely to materially affect our business strategy, results of operations or financial condition during the period covered by this filing.

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Below is a summary of our [added: significant properties] owned and leased [removed: properties] as of December 31, [removed: 2023.][added: 2024.]

[added: |] U.S. [added: | | | | | | | | | | | | | | | | | | | | |]

In the fourth quarter of 2021 we began construction of a new gene [removed: therapy] [added: therapy, clinical packaging and other] manufacturing facility in RTP, North Carolina to support our gene therapy pipeline across multiple therapeutic areas.

[removed: - 42,000 square feet in] [added: |] Plano, [removed: Texas, which is comprised of office] [added: Texas | | | | | | 327,000 | | | | | | Office] and laboratory [removed: space and expires in 2024.][added: | | | | | | Leased - Expires 2038 | | |]

[removed: INTERNATIONAL][added: | International(1) | | | | | | | | | | | | | | | | | | | | |]

[added: (1)] We [added: also] lease office space in [removed: Baar, Switzerland, our] [added: other] international [removed: headquarters;] [added: regions including:] the U.K.; Germany; France; Japan; Canada and numerous other countries.

| | | | | | | | | | | | | | | | | | | | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

| Location | | | | | | Approximate Square Feet | | | | | | Use | | | | | | Owned/Leased | | |

| Cambridge, Massachusetts | | | | | | 263,000 | | | | | | Research laboratory and cogeneration plant | | | | | | Owned | | |

| Cambridge, Massachusetts | | | | | | 729,000 | | | | | | Corporate headquarters and laboratory | | | | | | Leased - Expires 2028 | | |

| Weston, Massachusetts | | | | | | 357,000 | | | | | | Office | | | | | | Leased - Expires 2025 | | |

| RTP, North Carolina | | | | | | 1,040,000 | | | | | | Office, laboratory, manufacturing, warehouse | | | | | | Owned | | |

| Durham, North Carolina | | | | | | 65,000 | | | | | | Warehouse | | | | | | Leased - Expires 2025 | | |

| | | | | | | | | | | | | | | | | | | | | |

| Solothurn, Switzerland | | | | | | 734,000 | | | | | | Manufacturing facility, warehouse and office | | | | | | Owned | | |

| Baar, Switzerland | | | | | | 81,800 | | | | | | International headquarters | | | | | | Leased - Expires 2028 | | |

We estimate the construction of this manufacturing facility will be completed during 2025.

We believe that our our existing properties, including both owned and leased sites, are adequate and suitable for the conduct of our business.

We believe our capital resources are sufficient to purchase, lease or construct any additional facilities required to meet our expected long-term growth needs.

MASSACHUSETTS

In Cambridge, Massachusetts we own approximately 263,000 square feet of real estate space, consisting of a building that houses a research laboratory and a cogeneration plant.

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In addition, we lease a total of approximately 1,165,000 square feet in Massachusetts, which is summarized as follows:

- 808,000 square feet in Cambridge, Massachusetts, which is comprised of offices for our corporate headquarters and other administrative and development functions and laboratories, of which 209,000 square feet is subleased by multiple companies for general office space, laboratories and manufacturing facilities; and

- 357,000 square feet of office space in Weston, Massachusetts, of which 174,000 square feet is subleased through the remaining term of our lease agreement.

Our lease expires in May 2025 and we do not intend on renewing the lease agreement.

Our Massachusetts lease agreements expire at various dates through the year 2028.

125 BROADWAY BUILDING SALE AND LEASEBACK

In September 2022 we completed the sale of our building and land parcel located at 125 Broadway.

In connection with this sale, we simultaneously leased back the building for a term of approximately 5.5 years.

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 our 125 Broadway sale and leaseback transaction, please read *Note 11, Property, Plant and Equipment* and *Note 12, Leases*, to our consolidated financial statements included in this report.

300 BINNEY STREET LEASE MODIFICATION

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

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

For additional information on our 300 Binney Street lease modification, please read *Note 12, Leases*, to our consolidated financial statements included in this report.

NORTH CAROLINA

In RTP, North Carolina we own approximately 1,040,000 square feet of real estate space, which is summarized as follows:

- 357,000 square feet of laboratory and office space;

- 206,000 square foot multi-purpose facility, including an ASO manufacturing suite and administrative space;

- 175,000 square feet related to a large-scale biologics manufacturing facility;

- 105,000 square feet related to a small-scale biologics manufacturing facility;

- 84,000 square feet of warehouse space and utilities;

- 70,000 square feet related to a parenteral fill-finish facility; and

- 43,000 square feet related to a large-scale purification facility.

In addition, we lease approximately 65,000 square feet of warehouse space in Durham, North Carolina.

Our North Carolina lease agreements expire at various dates through the year 2025.

As we continue to advance our research and development prioritization efforts, which includes refocusing our investment in gene therapy, we are evaluating several alternative uses for this facility.

TEXAS

As part of our acquisition of Reata in September 2023 we acquired leases totaling approximately 404,000 square feet of real estate space, which is summarized as follows:

- 327,000 square feet in Plano, Texas, which is comprised of office and laboratory space, with an initial lease term through the year 2038.

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

- 35,000 square feet in Irving, Texas, which is comprised of office and laboratory space and expires in 2024; and

For additional information on our acquisition of Reata, please read *Note 2, Acquisitions*, to our consolidated financial statements included in this report.

SWITZERLAND

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.

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

The second manufacturing suite became operational in January 2024.

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Our common stock trades on The Nasdaq Global Select Market under the symbol “BIIB.” As of February [removed: 12, 2024,] [added: 11, 2025,] there were approximately [removed: 420] [added: 392] shareholders of record of our common stock.

The following table summarizes our common stock repurchase activity during the fourth quarter of [removed: 2023:][added: 2024:]

| Period | | | [added: | | |] Total Number of Shares Purchased (#) | | | | | | Average Price Paid per Share ($) | | | | | | Total Number of Shares Purchased as Part of Publicly Announced Programs (#) | | | | | | Approximate Dollar Value of Shares That May Yet Be Purchased Under Our Programs ($ in millions) | | |

| October [removed: 2023] [added: 1, 2024 - October 31, 2024] | | | [added: | | |] — | | | | | | $ | — | | | | | — | | | | | | $ | 2,050.0 | |

| November [removed: 2023] [added: 1, 2024 - November 30, 2024] | | | [added: | | |] — | | | | | | $ | — | | | | | — | | | | | | $ | 2,050.0 | |

| December [removed: 2023] [added: 1, 2024 - December 31, 2024] | | | [added: | | |] — | | | | | | $ | — | | | | | — | | | | | | $ | 2,050.0 | |

| Total(1) | | | [added: | | |] — | | | | | | $ | — | | | | | | | | | | | | | |

(1) There were no share repurchases during the fourth quarter of [removed: 2023.][added: 2024.]

All [removed: share repurchases] [added: shares repurchased] under our 2020 Share Repurchase Program [removed: will be] [added: were] retired.

Under our 2020 Share Repurchase Program, we repurchased and retired approximately 3.6 million [removed: and 6.0 million] shares of our common stock at a cost of approximately $750.0 million [removed: and $1.8 billion] during the [removed: years] [added: year] ended December 31, [removed: 2022 and 2021, respectively.][added: 2022.]

There were no share repurchases of our common stock during the [removed: year] [added: years] ended December 31, [added: 2024 and] 2023.

Approximately $2.1 billion remained available under our 2020 Share Repurchase Program as of December 31, [removed: 2023.][added: 2024.]

While we have historically made discretionary share repurchases, we had no share repurchases of our common stock during the [removed: year] [added: years] ended December 31, [added: 2024 and] 2023.

The performance graph below assumes the investment of $100.00 on December 31, [removed: 2018,] [added: 2019,] in our common stock and each of the three indexes, with dividends being reinvested.

[removed: ][added: ]

| | | | | | | [removed: 2018] [added: 2019] | | | | | | [removed: 2019] [added: 2020] | | | | | | [removed: 2020] [added: 2021] | | | | | | [removed: 2021] [added: 2022] | | | | | | [removed: 2022] [added: 2023] | | | | | | [removed: 2023] [added: 2024] | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | |

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| Biogen Inc. | | | | | | $100.00 | | | | | | $82.52 | | | | | | $80.85 | | | | | | $93.31 | | | | | | $87.19 | | | | | | $51.52 | | |

| Nasdaq Pharmaceutical Index | | | | | | $100.00 | | | | | | $110.52 | | | | | | $137.47 | | | | | | $153.08 | | | | | | $159.01 | | | | | | $172.62 | | |

| S&P 500 Index | | | | | | $100.00 | | | | | | $118.40 | | | | | | $152.39 | | | | | | $124.79 | | | | | | $157.59 | | | | | | $197.02 | | |

| Nasdaq Biotechnology Index | | | | | | $100.00 | | | | | | $126.42 | | | | | | $126.45 | | | | | | $113.65 | | | | | | $118.87 | | | | | | $118.20 | | |

| | | | | | | | | | | | | | | | | | | | | | | | |

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| Biogen Inc. | | | | | | $100.00 | | | | | | $98.61 | | | | | | $81.37 | | | | | | $79.73 | | | | | | $92.01 | | | | | | $85.97 | | |

| Nasdaq Pharmaceutical Index | | | | | | $100.00 | | | | | | $114.51 | | | | | | $126.56 | | | | | | $157.42 | | | | | | $175.29 | | | | | | $182.08 | | |

| S&P 500 Index | | | | | | $100.00 | | | | | | $131.49 | | | | | | $155.68 | | | | | | $200.37 | | | | | | $164.08 | | | | | | $207.21 | | |

| Nasdaq Biotechnology Index | | | | | | $100.00 | | | | | | $125.11 | | | | | | $158.17 | | | | | | $158.20 | | | | | | $142.19 | | | | | | $148.72 | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

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The information required by this Item 8 is contained on pages F-1 through [removed: F-85] [added: F-83] of this report and is incorporated herein by reference.

We have carried out an evaluation, under the supervision and with the participation of our management, including our principal executive officer and principal financial officer, of the effectiveness of the design and operation of our disclosure controls and procedures (as defined in Rules 13a-15(e) or 15d-15(e) under the Securities Exchange Act of 1934, as amended), as of December 31, [removed: 2023.][added: 2024.]

There were no changes in our internal control over financial reporting during the quarter ended December 31, [removed: 2023,] [added: 2024,] that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

Our management assessed the effectiveness of our internal control over financial reporting as of December 31, [removed: 2023.][added: 2024.]

Based on our assessment, our management has concluded that, as of December 31, [removed: 2023,] [added: 2024,] our internal control over financial reporting is effective based on those criteria.

The effectiveness of our internal control over financial reporting as of December 31, [removed: 2023,] [added: 2024,] has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their attestation report, which is included herein.

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We excluded Reata from our assessment of internal control over financial reporting as of December 31, 2023, as Reata was acquired by our Company in a business combination during 2023.

The total assets and total revenue of Reata represents 1.0% and 0.6%, respectively, of the related consolidated financial statement amounts as of and for the year ended December 31, 2023.

During the fourth quarter of [removed: 2023] [added: 2024] our officers and directors took the following actions with respect to 10b5-1 trading arrangements:

| Stephen A. Sherwin, Director | | | | | | Adopt | | | | | | 11/7/2024 | | | | | | X | | | | | | — | | | | | | 8,760 | | | | | | 05/08/2025 | | |

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| Robin Kramer (Senior Vice President, Chief Accounting Officer) | | | | | | Adopt | | | | | | 11/13/2023 | | | | | | X | | | | | | — | | | | | | 1,500 | | | | | | 11/10/2025 | | |

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[added: Code of Business Conduct and Ethics:] The text of our code of business conduct, which includes the code of ethics that applies to our principal executive officer, principal financial officer, principal accounting officer or controller, and persons performing similar functions, is posted on our website, www.biogen.com, under the “*Corporate Governance*” subsection of the “*Investors*” section of the site.

The response to the remainder of this item is incorporated by reference from the discussion responsive thereto in the sections entitled “*Proposal 1 - Election of Directors,” “Corporate Governance”* and “*Miscellaneous - Stockholder Proposals*” contained in the proxy statement for our [removed: 2024] [added: 2025] annual meeting of stockholders.

Insider Trading Policy: We have adopted an insider trading policy governing the purchase, sale and/or other dispositions of our securities and those of public companies in which we do business with by our directors, executive officers, employees and temporary staff, that we believe is reasonably designed to promote compliance with insider trading laws, rules and regulations and applicable NASDAQ listing standards.

A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K.

The response to this item is incorporated by reference from the discussion responsive thereto in the sections entitled “*Executive Compensation Tables,*” *"Compensation Discussion and Analysis"* and *“Corporate Governance”* contained in the proxy statement for our [removed: 2024] [added: 2025] annual meeting of stockholders.

The response to this item is incorporated by reference from the discussion responsive thereto in the sections entitled *“Stock Ownership”* and *“Equity Compensation Plan Information”* contained in the proxy statement for our [removed: 2024] [added: 2025] annual meeting of stockholders.

The response to this item is incorporated by reference from the discussion responsive thereto in the sections entitled “*Certain Relationships and Related Person Transactions*” and *“Corporate Governance*” contained in the proxy statement for our [removed: 2024] [added: 2025] annual meeting of stockholders.

The response to this item is incorporated by reference from the discussion responsive thereto in the section entitled “*Proposal 2 - Ratification of the Selection of our Independent Registered Public Accounting Firm*” contained in the proxy statement for our [removed: 2024] [added: 2025] annual meeting of stockholders.

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

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| Notes to Consolidated Financial Statements | | | | | | [removed: F-9] [added: F-8] | | |

| Report of Independent Registered Public Accounting Firm (PCAOB ID 238) | | | | | | [removed: F-83] [added: F-81] | | |

The exhibits listed on the Exhibit Index beginning on page [removed: 98,] [added: 95,] which is incorporated herein by reference, are filed or furnished as part of this report or are incorporated into this report by reference.

| [removed: 3.4] [added: 3.5] | | | | | | [Fifth Amended and Restated [removed: Bylaws. Filed] [added: Bylaws](https://www.sec.gov/Archives/edgar/data/875045/000119312523293433/d850833dex31.htm) [of Biogen Inc.](https://www.sec.gov/Archives/edgar/data/875045/000119312523293433/d850833dex31.htm) [Filed] as Exhibit 3.1 to our Current Report on Form 8-K filed on December 12, 2023.](https://www.sec.gov/Archives/edgar/data/875045/000119312523293433/d850833dex31.htm) | | |

| 10.1 | | | | | | [Credit Agreement, dated as of [removed: January 28, 2020,] [added: August 12, 2024,] among Biogen Inc., Bank of America, N.A., as administrative agent, swing line lender and the L/C issuer, and the other lenders party thereto. Filed as Exhibit 10.1 to our Current Report on Form 8-K filed on [removed: February 3, 2020.](https://www.sec.gov/Archives/edgar/data/875045/000119312520022940/d854655dex101.htm)] [added: August 14, 2024.](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524200660/d867868d8k.htm)] | | |

| 10.2 | | | | | | [removed: [Amendment to Credit] [added: [Credit] Agreement, dated as of [removed: February 7,] [added: August 28,] 2023, [removed: by and] among Biogen Inc., [added: JPMorgan Chase] Bank [removed: of America, N.A.,] [added: N.S.,] as administrative [removed: agent, swing line lender and the L&C issuer,] [added: agent] and the other lenders party thereto. Filed as Exhibit [removed: 10.3] [added: 10.1] to our [removed: Annual] [added: Current] Report on Form [removed: 10-K for the year ended December 31, 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit103amendmenttocredi.htm)] [added: 8-K filed on September 1, 2023.](https://www.sec.gov/Archives/edgar/data/875045/000119312523227692/d540978dex101.htm)] | | |

| [removed: 10.4†] [added: 10.3†] | | | | | | [Second Amended and Restated Collaboration Agreement between Biogen Idec Inc. and Genentech, Inc., dated as of October 18, 2010. Filed as Exhibit 10.5 to our Annual Report on Form 10-K for the year ended December 31, 2010.](http://www.sec.gov/Archives/edgar/data/875045/000095012311009300/b83162exv10w5.htm) | | |

| [removed: 10.5†] [added: 10.4†] | | | | | | [Letter Agreement regarding GA101 financial terms between Biogen Idec Inc. and Genentech, Inc., dated October 18, 2010. Filed as Exhibit 10.6 to our Annual Report on Form 10-K for the year ended December 31, 2010.](http://www.sec.gov/Archives/edgar/data/875045/000095012311009300/b83162exv10w6.htm) | | |

| [removed: 10.6*] [added: 10.8*] | | | | | | [Biogen Inc. 2017 Omnibus Equity Plan. Filed as Appendix B to our Definitive Proxy Statement on Schedule 14A filed on April 26, 2017.](http://www.sec.gov/Archives/edgar/data/875045/000119312517139450/d43428ddef14a.htm#toc43428_63) | | |

| [removed: 10.7*] [added: 10.9*] | | | | | | [Form of restricted stock unit award agreement under the Biogen Inc. 2017 Omnibus Equity Plan. Filed as Exhibit 10.2 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504517000024/biib-2017630xexhibit102.htm) | | |

| [removed: 10.8*] [added: 10.10*] | | | | | | [Form of [removed: market] [added: performance] stock [removed: unit] [added: units] award agreement under the Biogen Inc. 2017 Omnibus Equity [removed: Plan.] [added: Plan (for grants commencing in July 2019).] Filed as Exhibit [removed: 10.3] [added: 10.2] to our Quarterly Report on Form 10-Q for the quarter ended June 30, [removed: 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504517000024/biib-2017630xexhibit103.htm)] [added: 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000029/biib-2019630xex102.htm)] | | |

| [removed: 10.9*] [added: 10.6] | | | | | | [Form of [removed: performance unit] [added: restricted stock] award agreement under the Biogen Inc. [removed: 2017] [added: 2024] Omnibus Equity Plan. Filed as Exhibit 10.4 to our Quarterly Report on Form 10-Q for the quarter ended June 30, [removed: 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504517000024/biib-2017630xexhibit104.htm)] [added: 2024.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit104-formofrsuawarda.htm)] | | |

| [removed: 10.10*] [added: 10.5] | | | | | | [Form of [removed: cash-settled] performance [removed: unit] [added: share] award agreement under the Biogen Inc. [removed: 2017] [added: 2024] Omnibus Equity [removed: Plan.] [added: P](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit103-formofpsuawarda.htm)[lan.] Filed as Exhibit [removed: 10.5] [added: 10.3] to our Quarterly Report on Form 10-Q for the quarter ended June 30, [removed: 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504517000024/biib-2017630xexhibit105.htm)] [added: 202](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit103-formofpsuawarda.htm)[4.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit103-formofpsuawarda.htm)] | | |

| 10.11* | | | | | | [Form of [removed: performance] [added: nonqualified] stock [removed: units] [added: option] award agreement [removed: (cash-settled)] under [removed: the] Biogen Inc. 2017 Omnibus Equity Plan. Filed as Exhibit [removed: 10.10] [added: 10.20] to our Annual Report on Form 10-K for the year ended December 31, [removed: 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504518000005/biib-20171231xex1010.htm)] [added: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit10ormofnonqualified.htm)] | | |

| 10.13* | | | | | | [removed: [Form of performance stock units award agreement under the Biogen] [added: [Biogen] Inc. [removed: 2017 Omnibus Equity Plan.] [added: 2019 Form of Performance-Based Management Incentive Plan, as amended.] Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended [removed: March 31, 2018.](http://www.sec.gov/Archives/edgar/data/875045/000087504518000010/biib-2018331xex101.htm)] [added: June 30, 2021.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000017/biib-2019331xex101.htm)] | | |

| [removed: 10.14*] [added: 10.7] | | | | | | [removed: [Form] [added: [F](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[orm] of [removed: performance] [added: non-employee dire](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[ctor restricted] stock [removed: units award] [added: u](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[ni](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[t awar](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[d] agreement [removed: (cash settled)] under the Biogen Inc. [removed: 2017 Omnibus Equity Plan.] [added: 2024 Omni](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[bus Equity](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm) [Plan.] Filed as Exhibit [removed: 10.2] [added: 10.5] to our Quarterly Report on Form [removed: 10-Q] [added: 10-](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)[Q] for the quarter ended [removed: March 31, 2018.](http://www.sec.gov/Archives/edgar/data/875045/000087504518000010/biib-2018331xex102.htm)] [added: June 30, 2024.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000025/exhibit105-formofrsuawarda.htm)] | | |

| [removed: 10.18*] [added: 10.26] | | | | | | [removed: [Form of nonqualified stock option award agreement under] [added: [Amended and Restated Collaboration Agreement, dated October 22, 2017, between] Biogen [added: MA] Inc. [removed: 2017 Omnibus Equity Plan.] [added: and Eisai Co., LTD.] Filed as Exhibit [removed: 10.20] [added: 10.45] to our Annual Report on Form 10-K for the year ended December 31, [removed: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit10ormofnonqualified.htm)] [added: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit1045amendedandresta.htm)] | | |

| [removed: 10.19*] [added: 10.24*] | | | | | | [removed: [Biogen Inc. 2006 Non-Employee Directors Equity Plan, as amended.] [added: [Letter regarding employment arrangement of Nicole Murphy dated January 28, 2022.] Filed as Exhibit [removed: 10.2] [added: 10.3] to our Quarterly Report on Form 10-Q for the quarter ended March 31, [removed: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504522000016/exhibit102biogeninc2006non.htm)] [added: 2023.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)] | | |

| [removed: 10.20*] [added: 10.12*] | | | | | | [Biogen [added: Idec] Inc. [removed: 2015 Employee Stock Purchase] [added: 2008 Performance-Based Management Incentive] Plan. Filed as Appendix [removed: A] [added: B] to our Definitive Proxy Statement on Schedule 14A filed on [removed: April 30, 2015.](http://www.sec.gov/Archives/edgar/data/875045/000119312515159387/d786327ddef14a.htm#toc786327_57)] [added: May 8, 2008.](http://www.sec.gov/Archives/edgar/data/875045/000095013508003542/b67068dfdefc14a.htm#152)] | | |

| [removed: 10.22*] [added: 10.17*] | | | | | | [removed: [Biogen Inc. 2019 Form] [added: [Annual Retainer Summary for Board] of [removed: Performance-Based Management Incentive Plan, as amended.] [added: Directors (effective January 1, 2020).] Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended [removed: June] [added: September] 30, [removed: 2021.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000017/biib-2019331xex101.htm)] [added: 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000041/biib-2019930xex101.htm)] | | |

| [removed: 10.24*] [added: 4.6+] | | | | | | [removed: [Biogen Idec Inc. Supplemental Savings Plan, as amended. Filed] [added: [Description of Securities.](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000087504524000009/biib-20231231.htm) [](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000087504524000009/biib-20231231.htm)[Filed] as Exhibit [removed: 10.23] [added: 4.6] to our Annual Report on [removed: Form 10-K] [added: Form](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000087504524000009/biib-20231231.htm) [10-K] for the year ended December 31, [removed: 2015.](http://www.sec.gov/Archives/edgar/data/875045/000087504516000042/biib-20151231xex1023.htm)] [added: 202](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000087504524000009/biib-20231231.htm)[3.](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000087504524000009/biib-20231231.htm)] | | |

| [removed: 10.26*] [added: 10.16*] | | | | | | [Biogen Inc. Executive Severance Policy - U.S. Executive Vice President, as amended effective July 13, 2020. Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended September 30, 2020.](https://www.sec.gov/Archives/edgar/data/875045/000087504520000036/exhibit101-severancepo.htm) | | |

| [removed: 10.28*] [added: 10.18*] | | | | | | [Form of indemnification agreement for directors and executive officers. Filed as Exhibit 10.1 to our Current Report on Form 8-K filed on June 7, 2011.](http://www.sec.gov/Archives/edgar/data/875045/000095012311057276/b86869exv10w1.htm) | | |

| [removed: 10.29*] [added: 10.19*] | | | | | | [Employment Agreement, dated November 10, 2022, by and between Biogen Inc. and Christopher A. Viehbacher. Filed as Exhibit 10.1 to our Current Report on Form 8-K filed on November 10, 2022.](https://www.sec.gov/Archives/edgar/data/875045/000119312522281950/d419645dex101.htm) | | |

| [removed: 10.30*] [added: 10.20*] | | | | | | [Letter regarding employment arrangement of Michael McDonnell dated July 16, 2020. Filed as Exhibit 10.2 to our Quarterly Report on Form 10-Q for the quarter ended September 30, 2020.](https://www.sec.gov/Archives/edgar/data/875045/000087504520000036/exhibit102-mcdonnellof.htm) | | |

| [removed: 10.31*] [added: 10.21*] | | | | | | [Letter regarding employment arrangement of Susan Alexander dated December 13, 2005. Filed as Exhibit 10.58 to our Annual Report on Form 10-K for the year ended December 31, 2009.](http://www.sec.gov/Archives/edgar/data/875045/000095012310010528/b77985exv10w58.htm) | | |

| [removed: 10.32*+] [added: 10.22*] | | | | | | [removed: [L](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm)[etter] [added: [Letter] amending employment [removed: arrangement](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm) [of] [added: arrangement of] Susan Alexander dated February 28, 2020.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm) [added: [](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm)[Filed as Exhibit 10.32](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm) [to our Annual Report on Form 10-K for the year ended December 3](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm)[1, 202](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm)[3.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1032-salexanderamen.htm)] | | |

| [removed: 10.33*+] [added: 10.23*] | | | | | | [removed: [L](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1033-rachidemployme.htm)[etter] [added: [Letter] regarding employment arrangement of Rachid Izzar dated [removed: August](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1033-rachidemployme.htm) [1,] [added: August 1,] 2019.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1033-rachidemployme.htm) [added: [](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1033-rachidemployme.htm)[Filed as Exhibit 10.33 to our Annual Report on Form 10-K for the year ended December 31, 2023.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1033-rachidemployme.htm)] | | |

| [removed: 10.36] [added: 10.27] | | | | | | [removed: [Amended] [added: [First Amendment to Amended] and Restated Collaboration Agreement, dated [removed: October 22, 2017,] [added: March 13, 2022,] between Biogen MA Inc. and Eisai Co., LTD. Filed as Exhibit [removed: 10.45] [added: 10.46] to our Annual Report on Form 10-K for the year ended December 31, [removed: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit1045amendedandresta.htm)] [added: 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit1046firstamendmentt.htm)] | | |

| 21+ | | | | | | [removed: [Subsidiaries.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/biib-20231231xex21.htm)] [added: [Subsidiaries.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/biib-20241231xex21.htm)] | | |

| 23+ | | | | | | [Consent of PricewaterhouseCoopers LLP, an Independent Registered Public Accounting [removed: Firm.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/biib-20231231xex23.htm)] [added: Firm.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/biib-20241231xex23.htm)] | | |

| 31.1+ | | | | | | [Certification of the Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of [removed: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/biib-20231231xex311.htm)] [added: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/biib-20241231xex311.htm)] | | |

| 31.2+ | | | | | | [Certification of the Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of [removed: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/biib-20231231xex312.htm)] [added: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/biib-20241231xex312.htm)] | | |

| 32.1++ | | | | | | [Certification of the Chief Executive Officer and the Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of [removed: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/biib-20231231xex321.htm)] [added: 2002.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/biib-20241231xex321.htm)] | | |

| [removed: 97.1+] [added: 97.1] | | | | | | [Policy relating to recovery of erroneously awarded compensation.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit971-clawbackpolicy.htm) [added: [](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit971-clawbackpolicy.htm)[Filed as Exhibit 97.1 to our Annual Report on Form 10-K for the year ended December 31, 2023.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit971-clawbackpolicy.htm)] | | |

| 101++ | | | | | | The following materials from Biogen Inc.’s Annual Report on Form 10-K for the year ended December 31, [removed: 2023,] [added: 2024,] formatted in iXBRL (Inline Extensible Business Reporting Language): (i) the Consolidated Statements of Income, (ii) the Consolidated Statements of Comprehensive Income, (iii) the Consolidated Balance Sheets, (iv) the Consolidated Statements of Cash Flow, (v) the Consolidated Statements of Equity and (vi) Notes to Consolidated Financial Statements. | | |

Date: February [removed: 13, 2024][added: 12, 2025]

| /S/ CHRISTOPHER A. VIEHBACHER | | | | | | Director and Chief Executive Officer (principal executive officer) | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

| /S/ MICHAEL R. MCDONNELL | | | | | | Executive Vice President and Chief Financial Officer (principal financial officer) | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

| /S/ ROBIN C. KRAMER | | | | | | Senior Vice President, Chief Accounting Officer (principal accounting officer) | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

| /S/ CAROLINE D. DORSA | | | | | | Director and Chair of the Board of Directors | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

| /S/ MARIA C. FREIRE | | | | | | Director | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

| /S/ WILLIAM A. HAWKINS | | | | | | Director | | | | | | February [removed: 13, 2024] [added: 12, 2025] | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| 3.4 | | | | | | [Certificate of Amendment of Biogen Inc.'s Amended and Restated Certificate of Incorporation, as amended. Filed as Exhibit 3.1 to our Current Report on Form 8-K filed on June 25, 2024.](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524167938/d840763d8k.htm) | | |

| 10.14+ | | | | | | [Voluntary Board of Directors Savings Plan.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/exhibit1014-voluntaryboard.htm) | | |

| 10.15+ | | | | | | [Biogen Inc. Supplemental Savings Plan.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/exhibit1015-supplementalsa.htm) | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| 10.25* | | | | | | [L](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[etter regarding employment arrangement of Robi](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[n Kramer dated October 28, 2024. Fil](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[ed as Exhi](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[b](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[i](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm)[t 10.1 to our Current Report on Form 8-K filed on October 30, 2024.](https://www.sec.gov/ix?doc=/Archives/edgar/data/0000875045/000119312524247628/d890797d8k.htm) | | |

| 19.1+ | | | | | | [Policy relating to insider trading.](https://www.sec.gov/Archives/edgar/data/875045/000087504525000009/exhibit191-insidertradinga.htm) | | |

| 104 | | | | | | Cover Page Interactive Data File (contained in Exhibit 101) | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| /S/ LLOYD B. MINOR | | | | | | Director | | | | | | February 12, 2025 | | |

| Lloyd B. Minor | | | | | | | | | | | | | | |

| /S/ SIR MENELAS PANGALOS | | | | | | Director | | | | | | February 12, 2025 | | |

| Sir Menelas Pangalos | | | | | | | | | | | | | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| Alzheimer's collaboration revenue | | | | | | 59.9 | | | | | | — | | | | | | — | | |

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

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| Net income attributable to Biogen Inc. | | | | | | $ | 1,632.2 | | | | | $ | 1,161.1 | | | | | $ | 3,046.9 | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| Goodwill | | | 6,478.9 | | | | | | 6,219.2 | | |

| | | | | | | | | | | | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

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

| Acquisition of HI-Bio, net of cash acquired | | | (1,074.8) | | | | | | — | | | | | | — | | |

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

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| Net income | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | 1,632.2 | | | | | | — | | | | | | — | | | | | | | | | | | | | | | | | | 1,632.2 | | |

| Other | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | (3.2) | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | | | | | | | | | | | | | (3.2) | | |

| Balance, December 31, 2024 | | | — | | | | | | $ | — | | | | | 169.5 | | | | | | $ | 0.1 | | | | | $ | 569.4 | | | | | $ | (136.2) | | | | | $ | 19,259.8 | | | | | (23.8) | | | | | | $ | (2,977.1) | | | | | | | | | | | | | | | | | $ | 16,716.0 | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| Balance, December 31, 2023 | | | — | | | | | | $ | — | | | | | 168.7 | | | | | | $ | 0.1 | | | | | $ | 302.5 | | | | | $ | (153.7) | | | | | $ | 17,627.6 | | | | | (23.8) | | | | | | $ | (2,977.1) | | | | | $ | 14,799.4 | | | | | $ | — | | | | | $ | 14,799.4 | |

[Table o](#i8f04c147560c48a7bb5358179696a625_10)[f](#i8f04c147560c48a7bb5358179696a625_10) [Contents](#i8f04c147560c48a7bb5358179696a625_10)

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | For the Year Ended December 31, 2022 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |

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

[T](#ie5989ff7709d49d194ee19ecbcc140c3_10)[able of Contents](#ie5989ff7709d49d194ee19ecbcc140c3_10)

| 4.6+ | | | | | | [Description of Securities.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit46-descriptionofsec.htm) | | |

| 10.3 | | | | | | [Credit Agreement, dated as of August 28, 2023, among Biogen Inc., JPMorgan Chase Bank N.S., as administrative agent and the other lenders party thereto. Filed as Exhibit 10.1 to our Current Report on Form 8-K filed on September 1, 2023.](https://www.sec.gov/Archives/edgar/data/875045/000119312523227692/d540978dex101.htm) | | |

| 10.12* | | | | | | [Form of performance stock units award agreement under the Biogen Inc. 2017 Omnibus Equity Plan. Filed as Exhibit 10.11 to our Annual Report on Form 10-K for the year ended December 31, 2017.](http://www.sec.gov/Archives/edgar/data/875045/000087504518000005/biib-20171231xex1011.htm) | | |

| 10.15* | | | | | | [Form of market stock unit award agreement under the Biogen Inc. 2017 Omnibus Equity Plan (for grants commencing in July 2019). Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000029/biib-2019630xex101.htm) | | |

| 10.16* | | | | | | [Form of performance stock units award agreement under the Biogen Inc. 2017 Omnibus Equity Plan (for grants commencing in July 2019). Filed as Exhibit 10.2 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000029/biib-2019630xex102.htm) | | |

| 10.17* | | | | | | [Form of performance stock units award agreement (cash settled) under the Biogen Inc. 2017 Omnibus Equity Plan (for grants commencing in July 2019). Filed as Exhibit 10.3 to our Quarterly Report on Form 10-Q for the quarter ended June 30, 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000029/biib-2019630xex103.htm) | | |

| 10.21* | | | | | | [Biogen Idec Inc. 2008 Performance-Based Management Incentive Plan. Filed as Appendix B to our Definitive Proxy Statement on Schedule 14A filed on May 8, 2008.](http://www.sec.gov/Archives/edgar/data/875045/000095013508003542/b67068dfdefc14a.htm#152) | | |

| 10.23* | | | | | | [Biogen Idec Inc. Voluntary Executive Supplemental Savings Plan, as amended and restated effective January 1, 2004. Filed as Exhibit 10.13 to our Annual Report on Form 10-K for the year ended December 31, 2003.](http://www.sec.gov/Archives/edgar/data/875045/000095013504001180/b48790biexv10w13.txt) | | |

| 10.25* | | | | | | [Biogen Idec Inc. Voluntary Board of Directors Savings Plan, as amended. Filed as Exhibit 10.24 to our Annual Report on Form 10-K for the year ended December 31, 2015.](http://www.sec.gov/Archives/edgar/data/875045/000087504516000042/biib-20151231xex1024.htm) | | |

| 10.27* | | | | | | [Annual Retainer Summary for Board of Directors (effective January 1, 2020). Filed as Exhibit 10.1 to our Quarterly Report on Form 10-Q for the quarter ended September 30, 2019.](http://www.sec.gov/Archives/edgar/data/875045/000087504519000041/biib-2019930xex101.htm) | | |

| 10.34* | | | | | | [L](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[etter regarding employment arrangement of Nicole Murphy dated January 28, 2022. Filed as Exhi](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[bit 10.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[3 to our Q](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[uarterly Report on Form 10-Q for the quarter ended Mar](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[ch 31, 20](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[2](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[3](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm)[.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000016/exhibit103-nmurphyofferlet.htm) | | |

| 10.35+ | | | | | | [J](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm)[VA Termination](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm) [Agreement](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm)[, by and among Biogen Therap](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm)[eutics](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm) [Inc.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm)[, Samsung BioLogics Co., Ltd. and Samsung Bioepis Co., Ltd, dated April 20, 2020.](https://www.sec.gov/Archives/edgar/data/875045/000087504524000009/exhibit1035-jvatermination.htm) | | |

| 10.37 | | | | | | [First Amendment to Amended and Restated Collaboration Agreement, dated March 13, 2022, between Biogen MA Inc. and Eisai Co., LTD. Filed as Exhibit 10.46 to our Annual Report on Form 10-K for the year ended December 31, 2022.](https://www.sec.gov/Archives/edgar/data/875045/000087504523000009/exhibit1046firstamendmentt.htm) | | |

| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |

BIOGEN INC. AND SUBSIDIARIES

| | | | | | | | | | | | | | | | | | | | | |

See accompanying notes to these consolidated financial statements.

(In millions)

| Marketable securities | | | — | | | | | | 705.7 | | |

| Total Biogen Inc. shareholders’ equity | | | 14,799.4 | | | | | | 13,397.9 | | |

| Noncontrolling interests | | | — | | | | | | (9.5) | | |

| Proceeds from divestiture of Hillerød, Denmark manufacturing operations | | | — | | | | | | — | | | | | | 28.1 | | |

CONSOLIDATED STATEMENTS OF EQUITY - (Continued)

| Balance, December 31, 2021 | | | — | | | | | | $ | — | | | | | 170.8 | | | | | | $ | 0.1 | | | | | $ | 68.2 | | | | | $ | (106.7) | | | | | $ | 13,911.7 | | | | | (23.8) | | | | | | $ | (2,977.1) | | | | | $ | 10,896.2 | | | | | $ | 63.5 | | | | | $ | 10,959.7 | |

| Balance, December 31, 2020 | | | — | | | | | | $ | — | | | | | 176.2 | | | | | | $ | 0.1 | | | | | $ | — | | | | | $ | (299.0) | | | | | $ | 13,976.3 | | | | | (23.8) | | | | | | $ | (2,977.1) | | | | | $ | 10,700.3 | | | | | $ | (14.2) | | | | | $ | 10,686.1 | |

| Net income | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | 1,556.1 | | | | | | — | | | | | | — | | | | | | 1,556.1 | | | | | | 171.5 | | | | | | 1,727.6 | | |

| Distribution to noncontrolling interest | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | (100.0) | | | | | | (100.0) | | |

| Capital contribution from noncontrolling interest | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | 5.6 | | | | | | 5.6 | | |

| Repurchase of common stock pursuant to the 2020 Share Repurchase Program, at cost | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | — | | | | | | (6.0) | | | | | | (1,800.0) | | | | | | (1,800.0) | | | | | | — | | | | | | (1,800.0) | | |

| Retirement of common stock pursuant to the 2020 Share Repurchase Program, at cost | | | — | | | | | | — | | | | | | (6.0) | | | | | | — | | | | | | (231.9) | | | | | | — | | | | | | (1,568.1) | | | | | | 6.0 | | | | | | 1,800.0 | | | | | | — | | | | | | — | | | | | | — | | |

We also have exclusive rights to commercialize TOFIDENCE, a tocilizumab biosimilar referencing ACTEMRA.

We continue to develop potential biosimilar product SB15, a proposed aflibercept biosimilar referencing EYLEA.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

disclosure of contingent assets and liabilities.

Our liability for Medicaid rebates consists of estimates for claims

Therefore, royalties received are recognized as the underlying sales occur.

The majority of our financial assets have been classified as Level 2.

We also

Expenses incurred by Genentech in the ongoing development of RITUXAN,