Biogen has announced an agreement to acquire Apellis Pharmaceuticals for approximately $5.6 billion, a move that will add two approved medicines and expand the company’s presence in kidney and eye diseases. The transaction includes access to Apellis’ commercial capabilities and is expected to support the future launch of Biogen’s investigational kidney disease therapy, felzartamab.
Under the terms of the deal, Biogen will pay $41 per share in cash and provide a contingent value right of up to $4 per share tied to specific sales milestones for Apellis’ products. The acquisition is anticipated to close in the second quarter. Apellis shareholders will receive the additional payments if certain global net sales benchmarks are met.
The acquisition brings two marketed products into Biogen’s portfolio: Empaveli and Syfovre. Empaveli is approved for multiple kidney-related conditions, including complement 3 glomerulopathy and primary immune complex membranoproliferative glomerulonephritis, as well as paroxysmal nocturnal hemoglobinuria. Syfovre is approved for geographic atrophy secondary to age-related macular degeneration. Combined, the two products generated $689 million in revenue in 2025 and are projected to continue growing through at least 2028.
Biogen executives indicated that the deal aligns with the company’s strategy to diversify beyond its existing focus areas while avoiding high levels of late-stage development risk. CEO Chris Viehbacher said the company sought assets with established or near-term commercial potential rather than taking on significant Phase 3 uncertainty. He also noted that pricing discipline and balance sheet considerations were key factors in evaluating acquisition targets.
“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 this on our own,” said Chris Viehbacher.
Felzartamab, a CD38-targeting antibody, is currently in Phase 3 trials across three kidney disease indications: immunoglobulin A nephropathy, primary membranous nephropathy, and antibody-mediated rejection. Initial trial readouts are expected beginning in 2027. The addition of Apellis’ nephrology-focused commercial infrastructure is expected to provide Biogen with access to prescribers and operational expertise in the kidney disease space ahead of a potential launch.
Biogen also expects to retain a significant portion of Apellis’ workforce, which includes approximately 740 employees. The company highlighted the importance of Apellis’ existing team, particularly in nephrology, where hiring experienced professionals can be challenging. Apellis’ commercial organization includes around 350 employees, which Biogen intends to integrate into its operations.
In addition to internal perspectives, analysts noted both advantages and concerns associated with the transaction. Some highlighted the immediate revenue contribution and reduced clinical risk from marketed products, while others pointed to competitive pressures in both kidney and ophthalmology markets and questioned the valuation. Apellis is projected to reach approximately $1.5 billion in revenue by 2030, implying a multiple of around 3.5 times that estimate based on the purchase price.
Biogen stated that it does not anticipate regulatory challenges, as there is no overlap in approved indications between the two companies’ products. The company will also continue collaborating with Apellis’ partner, Sobi, for the commercialization of Empaveli outside the United States.
The acquisition follows Biogen’s broader effort to address declining revenue from its multiple sclerosis franchise and to build new growth drivers. While the company reported a 2% increase in total revenue to $9.9 billion in 2025, it has forecast a decline in 2026. Executives indicated that contributions from its late-stage pipeline are not expected until around 2028, making near-term revenue sources a priority.
By adding Apellis’ products and capabilities, Biogen aims to strengthen its commercial position and prepare for upcoming product launches later in the decade.
Biogen Expands Portfolio with Apellis Acquisition
Biogen has announced a major strategic move as Biogen plans to acquire Apellis Pharmaceuticals for $5.6 billion. This acquisition positions Biogen to significantly strengthen its presence in kidney and eye disease therapeutics. By integrating Apellis’ innovative complement inhibition technology, Biogen aims to diversify its pipeline and accelerate growth in high-demand treatment areas.
