Biogen has forged a $5.6bn deal to acquire immunology and rare disease specialist Apellis Pharmaceuticals – marking another M&A milestone in a flurry of pharma deal activity at the end of Q1.
As per the agreement, Biogen will pay $41 per share in cash at closing, a near 140% premium on the company’s 30 March closing stock price, to absorb a vast proportion of Apellis’ employee base and its portfolio of medicines.
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This includes geographic atrophy (GA) therapy, Syfovre (pegcetacoplan) and the US commercial rights to kidney disease therapy, Empaveli (pegcetacoplan), which pulled in a combined revenue of $689m in 2025. Biogen expects the drugs to continue on a mid-to-high teens upward trajectory until at least 2028.
Analyst consensus forecasts from GlobalData, parent company of Pharmaceutical Technology, currently predict that Syfovre and Empaveli will pull in $1bn and $747m in 2031, respectively.
According to Biogen’s CEO, Christopher Viehbacher, the Apellis buyout will also provide Biogen with the expertise and field capabilities to support commercialisation efforts for its late-stage kidney disease candidate, felzartamab. The Massachusetts-based pharma is currently evaluating the anti-CD38 therapy in primary membranous nephropathy (PMN), late antibody-mediated rejection (AMR) and immunoglobulin A nephropathy (IgAN).
Biogen expects this acquisition deal to close in Q2 2026.
Investor feelings mixed on Biogen-Apellis deal
In a 31 March statement, Viehbacher noted that the Apellis acquisition would “immediately advance Biogen’s ongoing transformation” by expanding its growth portfolio and boosting its near- and long-term prospects.
Despite Biogen’s enthusiasm towards this deal, investors do not seem to share this sentiment, as Biogen’s stock value dropped by over 4% from $187.57 at market close on 30 March to $179.46 at opening on 31 March, after the news debuted.
According to William Blair analysts, Wall Street will likely debate on the price paid for Apellis, but the buyout has the potential to add $1.54bn in sales to Biogen’s top line by 2030.
The analysts added that Biogen’s Apellis deal could help offset the near-term decline of Biogen’s MS franchise, while providing prospects for longer-term growth.
The M&A madness continues
Biogen’s Apellis acquisition marks a continuation of the M&A rush the pharma sector has observed at the end of Q1, which saw several big pharma players like Novartis, MSD and Eli Lilly making multi-billion dollar bids to restock and diversify their pipelines.
Companies are particularly eager to ink deals as a significant patent cliff looms over the industry. Currently, a report from GlobalData, parent company of Pharmaceutical Technology, estimates that only 4% of global drug sales will be protected by patents in 2030 – a stark decrease from the 12% rate seen in 2022.
Another report from GlobalData expects the enhanced entry of generic and biosimilar medicines to wipe out $230bn in sales within the US market between 2025 and 2030.
Alongside dealmaking activity, companies are also revamping their best-selling drugs with new and improved formulations in preparation for their patent expiries, as evidenced by the debut of subcutaneous cancer drugs like MSD’s Keytruda Qlex (pembrolizumab) and Johnson & Johnson’s Darzalex Faspro (daratumumab and hyaluronidase).
