Biogen IncLegacy MS franchise and Spinraza face accelerating generic/biosimilar competition and rival drugs, driving sales decline.

Biogen's newer drugs Leqembi, Skyclarys, Qalsody and Zurzuvae are gaining traction but remain insufficient to offset the ongoing sales erosion of its multiple sclerosis franchise and Spinraza. The company expects MS product revenues excluding Vumerity to decline by a mid-teen percentage in 2026 versus 2025 due to accelerating generic competition for Tecfidera in Europe and biosimilar pressure on Tysabri. Spinraza sales are also falling amid competition from Novartis' Zolgensma and Roche and PTC Therapeutics' Evrysdi. Biogen's growth products generated $851 million in first-quarter sales, up 12% year over year, and the recent acquisition of Apellis Pharmaceuticals adds Empaveli and Syfovre to its portfolio. The company believes the subcutaneous autoinjector Leqembi Iqlik and blood-based diagnostics will drive Leqembi's growth from 2027 onward, but replacing lost revenues from Tecfidera, Tysabri and Spinraza will likely take time.
Biogen IncLegacy MS franchise and Spinraza face accelerating generic/biosimilar competition and rival drugs, driving sales decline.
Apellis Pharmaceuticals Inc
Novartis AG
PTC Therapeutics Inc
Supernus Pharmaceuticals Inc
Roche Holding AG