Biogen Tender Offer for Apellis at $41.00/Share

Biogen will acquire Apellis Pharmaceuticals through a tender offer by Aspen Purchaser Sub, a wholly owned indirect subsidiary of Biogen. The offer seeks to purchase all outstanding Apellis common shares for $41.00 per share in cash, net to the seller, without interest and subject to tax withholding.

The consideration also includes one contractual, non-transferable contingent value right per share, representing contingent cash payments of up to an aggregate of $4.00 upon achievement of specified milestones. The Schedule TO references an Agreement and Plan of Merger dated March 31, 2026.