Biogen Inc. (BIIB.US) reported its fourth-quarter 2025 results and provided future performance guidance on February 6, before the U.S. market opened. The latest data shows that management's profit outlook for 2026 exceeds the average analyst expectation from Wall Street, indicating that significant cost-cutting measures are helping to cushion the impact of declining sales from its multiple sclerosis (MS) business.

The Cambridge, Massachusetts-based biotechnology company stated on Friday that it expects adjusted earnings per share for the year to be between $15.25 and $16.25, higher than the average analyst forecast. However, management anticipates total revenue for 2026 to decline by a mid-single-digit percentage, continuing the operational pressure for this company, which has long relied on its MS treatment business.

Biogen's total revenue for the fourth quarter was approximately $2.3 billion, a slight decrease of 7% year-over-year. Adjusted earnings per share were $1.99. Both figures significantly surpassed Wall Street's average expectations. Recent sales figures for Skyclarys, a drug for rare disease treatment, and Spinraza, used for the muscle-wasting disease spinal muscular atrophy, fell short of average analyst expectations. Spinraza's sales were affected by shipment timing schedules outside the United States.

Biogen's stock showed little change in pre-market trading. Over the past 12 months, its share price has surged by 30%. Overall, Biogen's total revenue continues to be dragged down by its mature MS product line, but its profitability has shown greater resilience, supported by "expense discipline and product mix."

For the full year 2025, total revenue was $9.891 billion, implying a 2% year-over-year increase. Non-GAAP adjusted earnings per share were $15.28, down 7% year-over-year. Both annual figures also exceeded Wall Street expectations.

Biogen's incremental growth and valuation flexibility primarily depend on the ramp-up efficiency of its "new drug portfolio," especially Leqembi. The company disclosed that combined revenue from LEQEMBI, SKYCLARYS, ZURZUVAE, and QALSODY approached $1 billion in 2025. However, Leqembi remains in a "slow-burn" phase: Q4 2025 sales were approximately $134 million, up from $121 million the previous quarter. Its sales growth is constrained by systemic bottlenecks such as limited neurologist resources and infusion capacity. The company continues to target an acceleration at some stage in 2026.

A key catalyst is the FDA's priority review for the Leqembi IQLIK subcutaneous initiation dosing regimen, with a PDUFA date set for May 24, 2026. If this significantly reduces administration friction and improves diagnosis/enrollment efficiency, Leqembi's growth curve is more likely to shift from "linear" to "accelerated."

Regarding its pipeline and mid-term strategy, Biogen is reshaping its risk profile by "reducing reliance solely on neuroscience." On one hand, it acquired Skyclarys through the 2023 Reata acquisition, strengthening its rare disease portfolio. On the other hand, it is shifting its business development and R&D focus more towards immunology.

Recent key milestones include: a high-dose regimen for Spinraza has been approved in Japan and the EU, with an FDA decision expected by April 3, 2026; litifilimab received FDA Breakthrough Therapy designation for cutaneous lupus erythematosus, with data readouts from two Phase III studies for systemic lupus erythematosus expected in Q4 2026.

Overall, 2026 appears more like a transitional year characterized by "MS decline, new drug ramp-up, and expense reset." Profit certainty is higher than revenue certainty, and the key to a stock re-rating lies in whether Leqembi and the immunology pipeline can use clearer sales traction/data to upgrade the "cost-control story" into a "growth story."

**Cost-Cutting and Betting on New Products Advance Simultaneously**

During the earnings call, CEO Chris Viehbacher, in an interview with analysts, stated that while pushing for growth from new products, Biogen has maintained "extremely strict discipline" on costs. Since taking over as CEO over three years ago, he has cut hundreds of jobs and repeatedly announced significant expense reduction measures, including removing some drugs from the development pipeline.

Under Viehbacher's leadership, Biogen has increasingly bet on growth from newer drugs—including the Alzheimer's treatment Leqembi, and rare disease treatments Skyclarys and Spinraza—to counter the ongoing decline of its MS treatments, as generic competition continues to erode related sales. The company does not expect this offset to materialize fully this year.

Following 2% total sales growth for the full previous year, the company expects a slight sales decline in 2026, primarily due to MS drugs losing exclusivity in Europe and facing new competition in the U.S., Viehbacher said.

Leqembi received full FDA approval in early 2023, but its rollout has been slow, hampered by healthcare system bottlenecks, including a shortage of neurologists and limited infusion capacity. Leqembi's total Q4 sales were approximately $134 million, roughly in line with analyst expectations and up from about $121 million the prior quarter.

"We expect to see an acceleration in its growth rate at some point in 2026," Viehbacher said regarding Leqembi sales.

Biogen and its Japanese partner Eisai Co. are seeking U.S. government approval in May for patients to begin Leqembi treatment via subcutaneous injection at home. This change could make the drug easier to use and differentiate it from a competitive Alzheimer's treatment developed by Eli Lilly & Co. Viehbacher also suggested that broader use of blood tests to diagnose Alzheimer's could help expand the eligible patient population of older adults.

Viehbacher has been trying to reshape the company to reduce its heavy reliance on the high-risk neuroscience field. His largest deal was the $7.3 billion acquisition of Reata Pharmaceuticals Inc. in 2023, which brought Skyclarys—the first approved treatment for the rare neurological disorder Friedreich's ataxia.

Recently, Biogen has focused on early-stage research collaborations and agreements in immunology, a field known for blockbuster drugs like AbbVie Inc.'s arthritis treatment Humira.

Regulators in Japan and Europe recently approved a higher-dose version of Spinraza, which Biogen says offers improved efficacy. A decision from U.S. regulators is expected in April.

The company is also awaiting data from several key trials later this year, including studies for an experimental Alzheimer's drug that works via a different mechanism than Leqembi, and for litifilimab in treating a form of lupus that disproportionately affects Black women. This disease causes the immune system to mistakenly attack healthy tissue, leading to symptoms like rashes and arthritis.