Biogen Marks One of the Year’s Largest Biotech Acquisitions with $5.6 Billion Apellis Pharmaceuticals Purchase
Biogen Inc. made a landmark announcement on March 31, 2026. The company has entered into a definitive agreement to acquire Apellis Pharmaceuticals for an estimated $5.6 billion in cash. This acquisition is one of the most significant biotechnology purchases of the year. Apellis shareholders are set to receive $41 per share upfront, representing a 140% premium to the company’s closing price on March 30.
This strategic acquisition significantly broadens Biogen’s portfolio in the fields of immunology and rare diseases, with a particular focus on nephrology and ophthalmology. Apellis is known for developing medicines that target the complement system and has two approved C3-targeted drugs on the market: EMPAVELI and SYFOVRE. Notably, SYFOVRE is the first-ever therapy for geographic atrophy, a leading cause of blindness.
In 2025, the combined net product revenues for EMPAVELI and SYFOVRE reached $689 million. Apellis anticipates that these products will continue to grow in the mid-to-high teens through at least 2028. The acquisition deal also includes contingent value rights that could provide Apellis shareholders with an additional $2 per share if SYFOVRE achieves $1.5 billion in annual global sales between 2027 and 2030. An additional $2 per share will be provided if it reaches $2 billion in sales.
Christopher Viehbacher, Biogen’s CEO, referred to the acquisition as a key part of the company’s “ongoing transformation” beyond neuroscience into broader therapeutic areas. The transaction is expected to be increasingly accretive to Biogen’s earnings per share starting in 2027 and is anticipated to close in the second quarter of 2026.
Source: Biogen News Release