7 Trillion Won Rare Disease M&A: Biogen Makes Another Bold Move

On March 31, major shareholders of Apellis Pharmaceuticals, Inc. (APLS) entered into a tender and support agreement with a subsidiary of Biogen Inc. (BIIB), under which they agreed to tender all of their common shares into Biogen’s proposed tender offer, vote in favor of the merger proposal and oppose any competing acquisition bids.

These shareholders—including Morningside Venture Investments and certain insiders—also agreed to grant their voting rights to Biogen and accept restrictions on share transfers, thereby reinforcing Biogen’s planned acquisition of Apellis under the concurrently executed merger agreement.

On the same day, Biogen agreed to acquire Apellis for $41 in cash per share plus a contingent value right of up to $4, implying a total transaction value of approximately $5.6 billion (roughly KRW 7.5 trillion).

Biogen’s subsidiary has since filed a preliminary tender offer statement with the U.S. Securities and Exchange Commission and is preparing to launch a tender offer to purchase all remaining Apellis shares.

Apellis is a U.S. biotechnology company that develops complement C3–targeting therapies and markets treatments for geographic atrophy, a form of macular degeneration, and for the rare blood disorder paroxysmal nocturnal hemoglobinuria.

Biogen is a major biopharmaceutical company with strengths in neuroscience, including Alzheimer’s disease, and has been actively pursuing mergers and acquisitions to expand its rare disease and immunology portfolio.