Biogen announced on Mar. 31 that it will acquire Apellis Pharmaceuticals for $5.6 billion, gaining two approved medicines in kidney and eye diseases, as well as the expertise of a biotech already active in the nephrology sector.
The deal is seen as an effort by Biogen to diversify its portfolio and strengthen its presence in the kidney disease market, particularly ahead of the potential launch of felzartamab, a CD38 targeting antibody currently in Phase 3 trials for multiple kidney conditions. Analysts say this acquisition gives Biogen access to revenue-generating assets and a commercial team experienced in nephrology.
Felzartamab is being tested for immunoglobulin A nephropathy (IgAN), primary membranous nephropathy (PMN), and antibody-mediated rejection (AMR), with key trial results expected starting in 2027. Meanwhile, Apellis’ Empaveli is already approved for three other kidney diseases, providing Biogen with immediate access to prescribers and patients within this therapeutic area.
"We just think that if the clinical trials work out for felzartamab as we hope, that we will have a running start into the launch, and we could actually potentially achieve peak sales faster than we would if we were just doing on this on our own," CEO Chris Viehbacher said during a conference call.
Alisha Alaimo, president and head of North America at Biogen, explained that hiring specialized talent in nephrology can be challenging due to competition. "Hiring in nephrology is actually not so easy. It’s a competitive space," Alaimo said. Instead of recruiting new staff from scratch for felzartamab's future launch, Biogen plans to retain much of Apellis' existing commercial team.
The acquisition also includes Syfovre, which treats geographic atrophy secondary to age-related macular degeneration—another competitive field with established rivals. Together Empaveli and Syfovre generated $689 million in revenue during 2025 according to company figures; both drugs are projected to continue growing through at least 2028 when more products from Biogen's pipeline are expected to reach market.
Viehbacher acknowledged concerns about the premium paid but emphasized thorough due diligence: "We’ve looked at a whole range of companies...we believe that this was the best opportunity that really fits strategically with Biogen and where our pipeline is taking us."
