Biogen Inc. (NasdaqGS:BIIB) entered into a definitive agreement to acquire Apellis Pharmaceuticals, Inc. (NasdaqGS:APLS) for $5.5 billion on March 31, 2026. Under the terms of the agreement, Biogen will commence a tender offer to acquire all of the outstanding shares of Apellis common stock for a price of $41 per share in cash representing an upfront equity consideration of approximately $5.6 billion and a contingent value right (CVR) per share entitling the holder to receive two payments of $2 per share each, payable upon achievement of certain thresholds related to global net sales of SYFOVRE. Biogen expects to finance the acquisition with a combination of cash and borrowings. Upon the successful completion of the tender offer, Biogen will acquire all remaining Apellis shares that are not tendered into the tender offer through a second-step merger at the same consideration.

The transaction, which was approved by the boards of directors of both companies, is subject to successful completion of the tender offer, customary closing conditions, and the receipt of necessary regulatory approvals. The transaction is expected to close in the second quarter of 2026. This transaction is expected to strengthen Biogen?s revenue and EPS growth potential and is expected to be increasingly accretive to Biogen?s Non-GAAP diluted EPS starting in 2027.

Lazard acted as sole financial advisor for Biogen Inc. Cravath, Swaine & Moore LLP and Arnold & Porter acted as legal advisors to Biogen. Evercore acted as sole financial advisor and Wachtell, Lipton, Rosen & Katz and WilmerHale acted as legal advisors to Apellis.