Biogen Inc. (NASDAQ: BIIB) delivered better-than-anticipated financial results for the fourth quarter of fiscal 2025, buoyed by substantial growth in its Alzheimer’s treatment and rare disease drug portfolios. The company posted an adjusted earnings per share (EPS) of $1.99, surpassing analyst expectations that had forecasted $1.59. Quarterly revenues reached $2.28 billion, outpacing the consensus estimate of $2.20 billion, though reflecting a 7% decrease compared to the prior year on both reported and constant currency bases.
On the drug performance front, Biogen’s growth products' revenue increased 19% year-over-year, a gain that effectively offset the declines recorded in certain Multiple Sclerosis (MS) therapies, excluding revenue from the MS drug Vumerity. Collaboration revenue related to the Alzheimer’s disease medication LEQEMBI reached $47 million, with Eisai, Biogen’s partner, reporting in-market sales escalating approximately 54% to about $134 million globally. Approximately $78 million of these sales were attributed to the United States, indicating continued uptake in that market.
Revenues from MS treatments totaled $917 million, down 14% year-over-year and by 15% on a constant currency basis. The MS drug Tysabri contributed $397.5 million in sales, marking a decline from $415.4 million in the prior year period. The rare disease segment registered a 4% decrease in revenue to $514.6 million, matching the percentage decline on a constant currency basis. In particular, Spinraza’s sales decreased to $356.2 million from $421.4 million one year prior. The decline in Spinraza sales for the quarter is linked to shipment timing effects outside the United States, with full-year revenue down marginally by 2% compared to fiscal 2024.
The acquisition of Reata Pharmaceuticals expanded Biogen’s pipeline, with Skyclarys, a treatment for Friedreich’s Ataxia, generating $133.4 million during the quarter, up from $102.2 million the previous year. Patient numbers globally on Skyclarys therapy increased by roughly 30% in 2025. U.S. sales contributed about $89 million for the quarter, driven by rising demand, while ex-U.S. sales were approximately $44 million, reflecting ongoing demand growth alongside a one-time adjustment for reimbursement.
Additionally, Zurzuvae, Biogen’s postpartum depression treatment, posted estimated fourth-quarter revenue of roughly $66 million, illustrating sustained demand growth. Vumerity sales grew by 3% year-over-year in the quarter, achieving $181.1 million.
Biogen’s President and CEO, Christopher Viehbacher, highlighted that the company's 2025 financial performance was underpinned by strong execution and a focus on financial discipline. He underscored revenue contributions nearing $1 billion from the combined products LEQEMBI, Skyclarys, Zurzuvae, and Qalsody, alongside pipeline advancements and resilience within Biogen’s MS franchise.
Looking forward to fiscal 2026, Biogen projects earnings per share in a range of $15.25 to $16.25, exceeding the consensus of $14.92 per share. The company anticipates revenues to decline by a mid-single-digit percentage relative to 2025. This decrease is primarily expected from continued declines in MS products excluding Vumerity, which could fall by a mid-teen percentage. The company also foresees ongoing low double-digit percentage declines in biosimilar revenues. However, growth product sales are expected to partially offset these declines.
Additional expected contributions include contract manufacturing revenues estimated at approximately $300 million for both the first and second halves of 2026.
Following the earnings release, Biogen’s stock rose 4.28% to $193.29, reaching a new 52-week high, signaling positive investor sentiment around the company’s growth trajectory and outlook.
On the drug performance front, Biogen’s growth products' revenue increased 19% year-over-year, a gain that effectively offset the declines recorded in certain Multiple Sclerosis (MS) therapies, excluding revenue from the MS drug Vumerity. Collaboration revenue related to the Alzheimer’s disease medication LEQEMBI reached $47 million, with Eisai, Biogen’s partner, reporting in-market sales escalating approximately 54% to about $134 million globally. Approximately $78 million of these sales were attributed to the United States, indicating continued uptake in that market.
Revenues from MS treatments totaled $917 million, down 14% year-over-year and by 15% on a constant currency basis. The MS drug Tysabri contributed $397.5 million in sales, marking a decline from $415.4 million in the prior year period. The rare disease segment registered a 4% decrease in revenue to $514.6 million, matching the percentage decline on a constant currency basis. In particular, Spinraza’s sales decreased to $356.2 million from $421.4 million one year prior. The decline in Spinraza sales for the quarter is linked to shipment timing effects outside the United States, with full-year revenue down marginally by 2% compared to fiscal 2024.
The acquisition of Reata Pharmaceuticals expanded Biogen’s pipeline, with Skyclarys, a treatment for Friedreich’s Ataxia, generating $133.4 million during the quarter, up from $102.2 million the previous year. Patient numbers globally on Skyclarys therapy increased by roughly 30% in 2025. U.S. sales contributed about $89 million for the quarter, driven by rising demand, while ex-U.S. sales were approximately $44 million, reflecting ongoing demand growth alongside a one-time adjustment for reimbursement.
Additionally, Zurzuvae, Biogen’s postpartum depression treatment, posted estimated fourth-quarter revenue of roughly $66 million, illustrating sustained demand growth. Vumerity sales grew by 3% year-over-year in the quarter, achieving $181.1 million.
Biogen’s President and CEO, Christopher Viehbacher, highlighted that the company's 2025 financial performance was underpinned by strong execution and a focus on financial discipline. He underscored revenue contributions nearing $1 billion from the combined products LEQEMBI, Skyclarys, Zurzuvae, and Qalsody, alongside pipeline advancements and resilience within Biogen’s MS franchise.
Looking forward to fiscal 2026, Biogen projects earnings per share in a range of $15.25 to $16.25, exceeding the consensus of $14.92 per share. The company anticipates revenues to decline by a mid-single-digit percentage relative to 2025. This decrease is primarily expected from continued declines in MS products excluding Vumerity, which could fall by a mid-teen percentage. The company also foresees ongoing low double-digit percentage declines in biosimilar revenues. However, growth product sales are expected to partially offset these declines.
Additional expected contributions include contract manufacturing revenues estimated at approximately $300 million for both the first and second halves of 2026.
Following the earnings release, Biogen’s stock rose 4.28% to $193.29, reaching a new 52-week high, signaling positive investor sentiment around the company’s growth trajectory and outlook.