What should I know about Biogen?
Biogen is a US biotechnology company based in Cambridge, Massachusetts, that specialises in treatments for neurological and neurodegenerative diseases such as multiple sclerosis, spinal muscular atrophy and Alzheimer's disease. In the second quarter of 2026 it reported total revenue of $2.7 billion, up 3% on a year earlier. Its "growth portfolio" of newer products passed $1 billion in the quarter. In May 2026 it completed its acquisition of Apellis, which added medicines for eye disease and a rare blood disorder.
What are Biogen's main drugs?
In the second quarter of 2026, Tysabri, for multiple sclerosis, made $451 million, Spinraza, for spinal muscular atrophy, $402 million, and Vumerity, another multiple sclerosis drug, $197 million. Leqembi, the Alzheimer's drug it sells with Eisai, had in-market revenue of $184 million (up 15%). Skyclarys, for Friedreich's ataxia, earned $168 million (up 29%) and the postpartum depression drug Zurzuvae $71 million. The acquired eye drug Syfovre made $162 million and Empaveli $46 million. Biogen expects mid-single-digit revenue growth in 2026.
What is Biogen currently developing?
Biogen expects Phase III data in 2026 and 2027 from programmes in lupus and in antibody-mediated rejection of transplanted organs, including litifilimab and felzartamab. A higher-dose version of Spinraza has exceeded its launch expectations for patient starts and switches. Biogen is also continuing to build the Leqembi franchise with Eisai and has said its aim is sustainable revenue growth. It expects full-year 2026 non-GAAP earnings of $12 to $13 per share.
Have there been any controversies involving Biogen?
Biogen's biggest controversy was Aduhelm, an Alzheimer's drug the FDA approved in 2021 on its accelerated pathway. Critics questioned whether its benefits outweighed its risks, and an 18-month congressional investigation concluded the approval process was "rife with irregularities". Medicare sharply limited coverage, which restricted sales. In January 2024 Biogen announced it would discontinue Aduhelm, saying the decision was not related to safety or efficacy and that it wanted to focus resources on Leqembi. It took a $60 million charge.
Is Biogen publicly traded, and how big is it?
Yes. Biogen trades on the Nasdaq under the ticker BIIB and is part of the S&P 500. Its market value was about $33 billion on 7 October 2026, up from about $22 billion at the end of 2024. In the second quarter of 2026 it reported total revenue of $2.7 billion and raised its 2026 outlook.