Biogen's Acquisition Boosted by Major Shareholders of Rare Disease Treatment Developer

Apellis Pharmaceuticals, Inc. (APLS) has agreed, as of March 31, under a tender-and-support agreement with Biogen Inc. (BIIB), its subsidiaries, major shareholder Morningside Venture Investments and certain insiders, to tender all of their shares in Biogen’s buyout offer. Under the agreement, they will vote in favor of the proposed merger, oppose any competing acquisition proposals, grant Biogen proxy voting rights on specified matters, and—aside from limited exceptions—restrict transfers of their shares to facilitate closing the transaction. The agreement covers roughly 14% of Apellis’s outstanding shares, bolstering the certainty of the tender offer.

Earlier, Biogen announced an agreement to acquire 100% of Apellis’s outstanding shares for $41 per share in cash, plus up to $4 per share in contingent value rights tied to sales milestones for its ophthalmology therapy Syfovre. The total deal is valued at approximately $5.6 billion (around KRW 7 trillion), reflecting Biogen’s move to strengthen its rare disease and immunology portfolio based on combined annual revenues of about $689 million from Apellis’s Empaveli and Syfovre.

Apellis is a biotech company that develops and commercializes therapies targeting the complement C3 pathway, including Empaveli for hematologic and rare kidney disorders and Syfovre for geographic atrophy, an advanced stage of macular degeneration. Global pharma companies have increasingly pursued strategic transactions to acquire revenue-generating biotechs, aiming to offset slowing blockbuster drug sales and expand into rare and immunological disease areas.