Biogen Finalizes $5.3B Acquisition of Apellis, Gains $689M Drugs
Biogen completed its $5.3 billion acquisition of Apellis Pharmaceuticals on May 14, acquiring two complement-targeting drugs that generated $689 million in net revenue in 2025. Shareholders received $41 per share plus CVRs worth up to $4 tied to SYFOVRE revenue milestones through 2031 for a potential $582 million payout.
1. Acquisition Completion
Biogen officially closed its $5.3 billion purchase of Apellis Pharmaceuticals when the tender offer expired at 12:01 a.m. Eastern on May 14. Holders of 82.4% of outstanding Apellis shares elected to tender, and the remaining shares were automatically exchanged, triggering delisting from the Nasdaq Global Select Market.
2. Payment Structure and CVRs
Each Apellis shareholder received $41 cash per share plus one nontransferable contingent value right (CVR) tied to annual SYFOVRE revenue benchmarks through 2031. If all milestones are achieved, Biogen estimates total CVR payouts could reach $582 million.
3. Portfolio Expansion and Financial Outlook
The deal brings SYFOVRE and EMPAVELI into Biogen’s portfolio, drugs that generated $689 million in net product revenue in 2025. Biogen expects the acquisition to be accretive to non-GAAP diluted EPS in 2027 and to boost its non-GAAP EPS compound annual growth rate through 2030.
4. Pipeline Infrastructure and Leadership
Apellis’ nephrology commercial infrastructure is slated to support felzartamab’s Phase 3 launch, with a readout in antibody-mediated kidney transplant rejection expected in the first half of 2027. Michael Dambach has been appointed sole director of the former Apellis board following closing.