Apellis stockholders will also receive a nontransferable CVR for each Apellis share held, entitling the holder to receive two payments of USD 2 per share each, contingent on certain annual global net sales thresholds being met for SYFOVRE.

Two commercialized differentiated immunology and rare disease medicines

The addition of Apellis is expected to enhance Biogen’s short- and long-term revenue growth profile by adding two commercialized differentiated immunology and rare disease medicines to its growth portfolio, it states. EMPAVELI and SYFOVRE add immediate sales revenue to Biogen, having achieved combined net sales of USD 689 million in 2025, which is expected to grow at a rate in the mid-to-high teens at least through 2028.

Sobi retains commercial rights to EMPAVELI (Aspaveli in the EU) outside the US

EMPAVELI is FDA-approved in rare immune-mediated kidney diseases (C3G and primary IC-MPGN) and in PNH and SYFOVRE is FDA-approved in geographic atrophy secondary to age related macular degeneration, an immune-mediated retinal disease. Apellis brings an established US sales infrastructure and capabilities, including in nephrology, that Biogen believes will accelerate and strengthen Biogen’s commercial readiness for felzartamab, which is currently in Phase 3 studies for three kidney diseases with the first trial readout expected in the first half of 2027. Upon closing, Biogen expects a significant proportion of Apellis employees to join the company. Biogen will continue to work with Sobi, which retains commercial rights to EMPAVELI (Aspaveli in the EU) outside the U.S.

“Consistent with our strategy, this acquisition immediately advances Biogen’s ongoing transformation. The addition of Apellis expands our growth portfolio in immunology and rare disease with two approved, best-in-class medicines that complement our existing portfolio and bolsters our near-and long-term growth potential,” says Christopher A. Viehbacher, Biogen’s President and Chief Executive Officer. “We look forward to welcoming Apellis employees to Biogen. We believe our combined capabilities and experience will allow us to maximize the potential of SYFOVRE and EMPAVELI, while Apellis’ talent, expertise and field capabilities will further strengthen Biogen, deepening the foundation for our growing nephrology franchise with felzartamab and serving many more patients with immune-mediated retinal disease.”