Biogen $BIIB completed its acquisition of Apellis Pharmaceuticals on Thursday, adding two marketed drugs to its portfolio in a deal valued at about $5.3 billion, the company said.
Each Apellis shareholder received $41.00 per share in cash along with a single non-transferable contingent value right as part of the deal's payment structure. The CVRs could pay out as much as $4.00 apiece, according to Investing.com, with payouts tied to whether SYFOVRE clears specific annual revenue benchmarks at any point through 2031. Biogen estimates it would need to pay up to $582 million in total if all milestones are met.
When the tender offer window closed at 12:01 a.m. Eastern Time on May 14, holders of roughly 82.4% of Apellis' outstanding shares had submitted their stock. Shares not tendered were automatically exchanged for the same cash-and-CVR consideration. The merger simultaneously delisted Apellis stock from the Nasdaq $NDAQ Global Select Market, with trading having been suspended as of May 13.
The acquisition adds two complement-targeting drugs to Biogen's portfolio: SYFOVRE, approved in the U.S. and Australia for geographic atrophy secondary to age-related macular degeneration, and EMPAVELI, approved in the U.S. for C3 glomerulopathy, primary immune-complex membranoproliferative glomerulonephritis, and paroxysmal nocturnal hemoglobinuria. Together, the two drugs generated $689 million in net product revenue in 2025, the company said.
Biogen said the deal accelerates its expansion into nephrology and will be accretive to its non-GAAP diluted earnings per share in 2027. The company also said it expects the acquisition to increase its non-GAAP EPS compound annual growth rate through the end of the decade. Updated financial guidance will accompany Biogen's second-quarter earnings report in July.
Apellis also brings nephrology commercial and medical infrastructure that Biogen said will support the launch readiness for felzartamab, a drug candidate with a first Phase 3 readout in antibody-mediated rejection in kidney transplant patients expected in the first half of 2027.
Michael Dambach, who had served as a director of Biogen's acquisition subsidiary, was installed as Apellis' sole director after the entire prior board stepped down upon closing.