UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission file number: 0-19311 BIOGEN INC. (Exact name of registrant as specified in its charter) Delaware 33-0112644 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identi ...

Core Viewpoint - Biogen's stock is rising despite a significant decline in multiple sclerosis revenue and ongoing challenges within its drug portfolio [1] Group 1: Financial Performance - Biogen reported fourth-quarter adjusted earnings and revenue that exceeded analysts' expectations [1] Group 2: Market Reaction - Investors are focusing on the positive earnings report while overlooking the declining sales and poor performance of most of Biogen's drug portfolio in the fourth quarter [1]

Growth products up 6% year-over-year in the fourth quarter demonstrating continued strong commercial execution 1 Continued to deliver progress across key late-stage pipeline programs Biogen Inc. (Nasdaq: BIIB) today reported fourth quarter and full year 2025 financial results. Press Release Cambridge, Mass. – February 6, 2026 Biogen reports strong fourth quarter and full year 2025 results and provides full year 2026 financial guidance Fourth quarter 2025 total revenue $2.3 billion; GAAP diluted EPS $(0.33); ...

Group 1 - Biogen forecasts 2026 profit exceeding Wall Street estimates, driven by demand for newer medicines and its Alzheimer's treatment Leqembi [1] - The company faces competition as older multiple sclerosis drugs encounter pressure from cheaper alternatives [1]

Core Insights - Biogen Inc. is preparing for its quarterly earnings release on February 6, 2026, with analysts predicting an earnings per share (EPS) of $1.60 and revenue of approximately $2.2 billion [1][6] Group 1: Product Development and Research - The Phase 2/3 DEVOTE study results for nusinersen, published in Nature Medicine, highlight Biogen's commitment to spinal muscular atrophy (SMA) treatment, demonstrating safety and efficacy across a broad patient group [2] - This development is expected to enhance Biogen's product portfolio and mitigate declining sales in other segments [2] Group 2: Market Challenges and Opportunities - Biogen faces challenges in multiple sclerosis (MS) drug sales due to increasing competition from generics and biosimilars [3] - Despite these challenges, the company is optimistic about growth prospects with newer products such as Vumerity, Skyclarys, and Zurzuvae, along with positive traction for its Alzheimer's drug, Leqembi, in the U.S. market [3][6] Group 3: Financial Indicators - Biogen's financial indicators present a mixed outlook, with a price-to-earnings (P/E) ratio of 16.84 and a price-to-sales ratio of 2.72, reflecting market assessments of its earnings and revenue [4] - The enterprise value to sales ratio is 2.99, and the enterprise value to operating cash flow ratio is 12.16, indicating market valuation of its sales and cash flow [4] - The company maintains a debt-to-equity ratio of 0.36, suggesting a relatively low level of debt compared to equity, and a current ratio of 2.72, indicating strong capability to meet short-term liabilities [5]

Core Insights - Biogen announced the publication of results from the Phase 2/3 DEVOTE study in Nature Medicine, evaluating a high-dose regimen of nusinersen for spinal muscular atrophy (SMA) [1][2] - The high-dose regimen includes a loading dose of 50 mg/5 mL and a maintenance dose of 28 mg/5 mL, which is more rapid and higher than the previously approved 12 mg regimen [1][6] - The study demonstrated safety and effectiveness across a broad range of SMA patients, showing significant improvements in motor function and other health domains [2][3] Study Details - DEVOTE enrolled 139 participants of various ages and SMA types, with treatment-naïve infants showing statistically significant improvements in motor function compared to a matched sham group [2][3] - The pivotal cohort (Part B) reported a mean difference of 26.19 points in motor function (CHOP-INTEND) between the high-dose regimen and sham group (p<0.0001) [2] - In the open-label Part C, participants transitioning from the 12 mg regimen to the high-dose regimen experienced mean increases of 1.8 points on the Hammersmith Functional Motor Scale – Expanded (HFMSE) [3] Safety Profile - The safety profile of the high-dose regimen was consistent with the known safety profile of the 12 mg regimen, with common adverse events including pneumonia and respiratory failure [4] - In the Part B infantile-onset cohort, the most common adverse events (≥15% of participants) were pneumonia, respiratory failure, pyrexia, COVID-19, and upper respiratory tract infection [4] Regulatory Status - The high-dose regimen of nusinersen is approved in the European Union and Japan, and is currently under review by the U.S. FDA with a PDUFA action date of April 3, 2026 [5][7]

It's been an interesting start to the year, with plenty of geopolitical developments for investors to unpack. The market managed monthly wins in January, but as we get into February, it's not a bad idea to keep an eye on stocks that have had a tendency to underperform. For your convenience, Schaeffer's Senior Quantitative Analyst Rocky White compiled a list of the 25 worst stocks on the S&P 500 over the last decade. Biogen Inc (NASDAQ:BIIB) is one of the worst stocks on the list. Per White, BIIB averages a ...

Core Viewpoint - Biogen is set to report its fourth-quarter and full-year 2025 results on February 6, with expectations for sales of $2.21 billion and earnings per share of $1.60, following a previous quarter where earnings exceeded expectations by 23.65% [1][10]. Sales Performance - Sales of Biogen's multiple sclerosis (MS) drugs are anticipated to decline due to generic competition for Tecfidera and biosimilar competition for Tysabri, although new products may offset some of this decline [2]. - The Zacks Consensus Estimate for Tecfidera sales is $120 million, while Tysabri is estimated at $362 million, and Vumerity is expected to rise to $183 million due to increased demand [3]. - U.S. MS sales were better than expected in the first three quarters of 2025, driven by Vumerity, but a steeper decline is expected in the fourth quarter due to increased competition, particularly in Europe [4]. Drug-Specific Insights - Sales of Spinraza are projected to decline to $380 million due to lower demand, while Skyclarys is expected to show sequential growth supported by demand and geographic expansion [5]. - Zurzuvae is likely to continue rising in sales, benefiting from strong patient demand and an expanding prescriber base, with its approval in the EU contributing to growth [6][7]. - Alzheimer's collaboration revenues are expected to rise, driven by Biogen's share of net product revenues from Leqembi, which has shown sequential sales improvement in the U.S. [8][9]. Earnings Surprise and Stock Performance - Biogen has a history of beating earnings estimates, with a four-quarter average surprise of 14.02%, and its stock has increased by 25.9% over the past year, outperforming the industry average of 15.2% [12][13]. - The company's Earnings ESP is currently -2.49%, indicating that the model does not predict an earnings beat this time [15][16].

Core Insights - Biogen has received FDA Breakthrough Therapy designation for its investigational drug litifilimab (BIIB059) aimed at treating cutaneous lupus erythematosus (CLE) [1][5] Group 1: FDA Breakthrough Therapy Designation - The FDA's Breakthrough Therapy designation accelerates the development and review of drugs for serious conditions, granted when early clinical evidence indicates significant improvement over existing treatments [2] - This designation provides drugs with enhanced guidance and support from senior FDA management [2] Group 2: Clinical Evidence and Current Treatments - The FDA's decision was backed by evidence from the phase II LILAC study, which showed that litifilimab significantly reduced skin disease activity in CLE patients compared to placebo [3][5] - Current treatments for CLE, such as topical steroids and immunosuppressants, primarily manage symptoms without modifying disease progression [3] Group 3: Ongoing Studies and Future Prospects - Biogen is conducting a phase III AMETHYST study for litifilimab, with data expected in 2027, alongside two other studies for systemic lupus erythematosus (SLE) [7] - The company has additional late-stage candidates in its immunology pipeline, including dapirolizumab pegol for active SLE and felzartamab for multiple indications [8][9] Group 4: Strategic Partnerships - Biogen has entered a research agreement with Dayra Therapeutics to enhance its immunology pipeline with a new class of oral therapies, aiming to improve patient convenience and adherence [10][12]

Core Insights - The FDA has granted Breakthrough Therapy Designation to Biogen's litifilimab (BIIB059) for treating cutaneous lupus erythematosus (CLE), recognizing the urgent need for new therapies in this area [1][2][3] Company Overview - Biogen is a leading biotechnology company founded in 1978, focused on pioneering innovative science to deliver new medicines and create value for shareholders [10] - The company is advancing litifilimab as a first-in-class therapy targeting blood dendritic cell antigen 2 (BDCA2) for CLE, with ongoing clinical trials [3][5] Product Information - Litifilimab is a humanized IgG1 monoclonal antibody targeting BDCA2, currently under investigation for systemic lupus erythematosus (SLE) and CLE [5][6] - The drug has shown promise in reducing skin disease activity in CLE patients, as evidenced by results from the Phase 2 LILAC study [2][6] Clinical Development - The FDA's designation aims to expedite the development and review process for litifilimab, which is currently being evaluated in the AMETHYST Phase 3 study, with data readout expected in 2027 [3][6] - The current standard of care for CLE includes topical steroids, antimalarials, and immunosuppressants, but these do not alter disease progression [2][6] Industry Context - CLE is a chronic autoimmune skin disease that significantly impacts patients' quality of life, with symptoms including rash, pain, and potential irreversible skin damage [8][9] - The Lupus Research Alliance emphasizes the need for effective therapies that can alter the disease course, highlighting the importance of incorporating patient voices in drug development [4]