Biogen has completed its acquisition of Apellis Pharmaceuticals, adding two commercial drugs and expanding its reach into nephrology in a deal the company says will strengthen earnings growth through the end of the decade.

The Cambridge, Massachusetts-based biotechnology company announced that Apellis is now a wholly owned subsidiary following the successful completion of a tender offer for the company’s outstanding shares. Biogen said approximately 82.4% of Apellis shares were tendered by shareholders before the offer expired late May 13.

Under the terms of the transaction, Apellis shareholders will receive $41 per share in cash plus a contingent value right worth up to an additional $4 per share tied to future sales milestones for SYFOVRE, Apellis’ treatment for geographic atrophy secondary to age-related macular degeneration (AMD).

The acquisition brings two marketed products into Biogen’s portfolio: SYFOVRE and EMPAVELI. Together, the therapies generated $689 million in net product revenue during 2025, according to the company. Biogen said the transaction is expected to become accretive to non-GAAP diluted earnings per share by 2027 and materially boost its long-term earnings growth trajectory. Updated financial guidance is expected alongside the company’s second-quarter earnings report in July.

The deal also provides Biogen with an established nephrology commercial and medical infrastructure that could support the future launch of felzartamab, its investigational therapy currently in Phase 3 testing for antibody-mediated rejection in kidney transplant patients. The first late-stage readout is anticipated in the first half of 2027.

Following the merger, Apellis shares have ceased trading on Nasdaq. The acquisition marks one of Biogen’s largest strategic moves in recent years as the company seeks to diversify beyond its traditional neuroscience franchise and strengthen its presence in rare disease and immunology markets.

Source: Biogen.