Biogen to Acquire Apellis, Holds 14.2% Stake

On March 31, 2026, Biogen Inc. entered into a definitive merger agreement to acquire Apellis Pharmaceuticals, Inc. (APLS) for approximately $41.00 per share in cash, plus one contingent value right (CVR) per share. The CVRs could provide up to an additional $4.00 per share based on the achievement of specific sales milestones for SYFOVRE. Concurrently with the merger agreement, Biogen entered into a Tender and Support Agreement with certain Apellis directors, executive officers, and Morningside Venture Investments, Ltd. Under this agreement, these stockholders, who collectively hold approximately 14.2% of the outstanding shares (18,469,475 shares, including exercisable options), have agreed to tender their shares in the offer. Biogen filed this Schedule 13D to report beneficial ownership of these shares resulting solely from the support agreement. The transaction is expected to close in the second quarter of 2026, following which Apellis will become a wholly owned subsidiary of Biogen and will be delisted from public markets. Biogen plans to fund the acquisition using cash on hand and term loan proceeds.