Biogen has announced the acquisition of Apellis Pharmaceuticals for approximately $5.6 billion, marking one of the largest deals under CEO Chris Viehbacher's tenure. According to reports from Reuters, the deal was announced on Tuesday and is part of Biogen's strategy to diversify beyond its slowing multiple sclerosis franchise. The acquisition provides Biogen with a promising kidney disease drug to broaden its rare-disease portfolio amid efforts to reset the business after initial uptake of its Alzheimer's treatment, Leqembi, fell short of expectations. As reported by Trader Edge, CEO Christopher Viehbacher described the acquisition as consistent with the company's ongoing transformation, stating that the addition of Apellis expands their growth portfolio in immunology and rare disease with two approved, best-in-class medicines that complement their existing portfolio.
Under the terms of the deal, expected to close in the second quarter of 2026, Apellis shareholders will receive $41 per share in cash, representing a premium of about 140% to the stock's last close. According to Trader Edge, Apellis stock surged over 136% in pre-market trading on Tuesday, while Biogen fell roughly 7% on the news. The two drugs generated combined revenue of about $689 million last year and are expected to grow in the mid-to-high-teens rate at least through 2028, according to the companies. Shareholders may also receive additional $2 per share payments if SYFOVRE achieves certain sales milestones, with the maximum potential payout reaching $45 per share if all milestones are met. The deal is expected to be increasingly accretive to non-GAAP diluted earnings per share starting in 2027, significantly boosting Biogen's long-term growth profile as the company leverages Apellis' commercial infrastructure.
According to Reuters, Apellis's Empaveli is approved for two rare kidney diseases as well as a rare blood disorder, while its Syfovre is approved to treat geographic atrophy, an advanced eye condition that is a leading cause of blindness worldwide. The acquisition gives Biogen access to these two best-in-class medicines that complement their existing portfolio. Syfovre is the first and only FDA-approved therapy for geographic atrophy (GA) secondary to age-related macular degeneration (AMD), while Empaveli was approved in 2025 as the first treatment for C3 glomerulopathy (C3G) or primary immune complex membranoproliferative glomerulonephritis (IC-MPGN) in patients aged 12 years and older. CEO Chris Viehbacher told Reuters that the acquisition gives a foothold in kidney disease, providing a commercial base with nephrologists that could support future launches, including late-stage kidney drug felzartamab.
As reported by Reuters, Biogen said it expects to finance the acquisition with a combination of cash and borrowings and plans to fully deleverage by the end of 2027. The acquisition is Biogen's latest move to reposition itself away from its legacy MS business toward higher-growth rare disease treatments. The company added that it plans to update the full-year 2026 guidance when it reports its first-quarter (Q1) earnings. The success of Biogen's strategy will depend on several factors, including smooth integration of Apellis' sales team and product portfolio, regulatory and market acceptance of SYFOVRE, and Biogen's ability to maintain financial flexibility while funding the acquisition. Analysts broadly agreed that Apellis is a strong strategic fit, providing needed near-term growth for Biogen, though some raised concerns about the premium paid.
