Biogen Acquires Apellis for $5.6 Billion, Expanding Immunology and Rare Disease Portfolio
核心洞察
Biogen announced the acquisition of Apellis Pharmaceuticals for $41 per share in cash, representing approximately $5.6 billion in upfront equity consideration, with additional contingent payments up to $4 per share based on SYFOVRE sales milestones.
The acquisition brings two FDA-approved complement-targeting therapies to Biogen's portfolio: EMPAVELI for rare kidney diseases and paroxysmal nocturnal hemoglobinuria (搜索), and SYFOVRE for geographic atrophy (搜索) secondary to age-related macular degeneration (搜索).
Combined 2025 net product revenue for both drugs reached $689 million, with expected growth rates in the mid-to-high teens through at least 2028, strengthening Biogen's expansion into nephrology and immunology markets.
Biogen Inc. announced Tuesday it has entered into a definitive agreement to acquire Apellis Pharmaceuticals Inc. for $41.00 per share in cash, representing approximately $5.6 billion in upfront equity consideration. The acquisition significantly expands Biogen's immunology and rare disease portfolio with two FDA-approved complement-targeting therapies that generated combined revenues of $689 million in 2025.
The transaction includes a contingent value right (CVR) structure that could provide Apellis shareholders with additional payments of up to $4 per share based on SYFOVRE's global net sales performance. Shareholders will receive $2 per share if SYFOVRE achieves $1.5 billion in annual global net sales between 2027-2030, an additional $2 per share if it reaches $2 billion in annual sales during the same period, or $4 per share if the $2 billion threshold is met in 2031.
Strategic Portfolio Enhancement
The acquisition brings two differentiated complement therapies to Biogen's growth portfolio. EMPAVELI (pegcetacoplan) is FDA-approved for three indications, including two rare kidney diseases - C3 glomerulopathy (搜索) (C3G) and primary immune-complex membranoproliferative glomerulonephritis (搜索) (IC-MPGN) - as well as paroxysmal nocturnal hemoglobinuria (搜索) (PNH). SYFOVRE (pegcetacoplan injection) is approved for geographic atrophy (搜索) secondary to age-related macular degeneration (搜索).
"The addition of Apellis expands our growth portfolio in immunology and rare disease with two approved, best-in-class medicines that complement our existing portfolio and bolsters our near-and long-term growth potential," said Christopher A. Viehbacher, Biogen's President and Chief Executive Officer.
Clinical Differentiation and Market Position
EMPAVELI demonstrated significant clinical efficacy in the Phase 3 VALIANT study, showing a 68% reduction in proteinuria, stabilization of kidney function, and substantial clearance of C3 (搜索) deposits compared to placebo in patients with C3G and primary IC-MPGN. The drug holds unique market positions as the only FDA-approved treatment for pediatric patients (12+ years) with C3G and the only approved treatment for patients with post-transplant C3G disease recurrence.
SYFOVRE's approval was based on positive results from the Phase 3 OAKS and DERBY studies, which demonstrated reduced geographic atrophy (搜索) lesion growth compared to sham treatment. The treatment showed increasing effects over time, with up to 36% reduction in lesion growth with monthly treatment in the DERBY study between months 18 and 24. Long-term data from the GALE open-label extension study showed SYFOVRE delayed GA lesion progression by approximately 1.5 years compared to sham treatment.
Financial Impact and Growth Projections
The combined 2025 net product revenue of $689 million for EMPAVELI and SYFOVRE is expected to grow at a rate in the mid-to-high teens at least through 2028. The transaction is projected to be increasingly accretive to Biogen's non-GAAP diluted earnings per share starting in 2027 and is expected to meaningfully increase Biogen's non-GAAP EPS compounded annual growth rate through the end of the decade.
Biogen plans to finance the acquisition through a combination of cash and borrowings and expects to fully de-lever by the end of 2027, maintaining financial flexibility for future investments.
Nephrology Expansion Strategy
The acquisition accelerates Biogen's entry into nephrology, with Apellis bringing established U.S. sales infrastructure and capabilities in this therapeutic area. This positions Biogen to strengthen commercial readiness for felzartamab, currently in Phase 3 studies for three kidney diseases with the first trial readout expected in the first half of 2027.
"With Biogen's extensive experience with immunology and rare disease, we believe this transaction will accelerate our impact and enable us to reach more patients," said Cedric Francois, M.D., Ph.D., co-founder and Chief Executive Officer of Apellis.
Transaction Timeline and Regulatory Process
The transaction, approved by both companies' boards of directors, is expected to close in the second quarter of 2026, subject to successful completion of the tender offer, customary closing conditions, and receipt of necessary regulatory approvals. Upon closing, Biogen expects a significant proportion of Apellis employees to join the company.
The acquisition represents an 86% premium to Apellis' 90-day volume-weighted average stock price and a 35% premium to its 52-week high stock price, reflecting the strategic value of the complement-targeting platform and commercial assets.