CAMBRIDGE, Massachusetts, May 14, 2026, 10:21 (EDT)
- Biogen has finalized its acquisition of Apellis Pharmaceuticals, which is now a wholly owned subsidiary.
- Apellis investors are getting $41 per share in cash, along with a contingent value right linked to future Syfovre sales.
- Biogen picks up Syfovre and Empaveli with this deal—both drugs on the market, together pulling in $689 million in net product revenue for 2025.
Biogen wrapped up its takeover of Apellis Pharmaceuticals on Thursday, bringing an end to Apellis’ time as an independent Nasdaq-listed biotech. With the Waltham, Massachusetts firm now a wholly owned Biogen subsidiary, Apellis shares stopped trading on Nasdaq following completion of the tender offer and merger.
With the deal complete, Biogen suddenly has a pair of commercial assets—Syfovre and Empaveli—beyond its traditional neurology lineup. The company reported combined net product revenue of $689 million from the two drugs in 2025, and said it plans to revise its financial outlook when second-quarter results drop in July.
The tender offer wrapped up shortly after 11:59 p.m. Eastern on May 13, with around 105.7 million Apellis shares validly tendered and still in, according to a filing. That’s about 82.4% of the company’s outstanding shares at the cutoff.
Holders will receive $41 per share in cash, along with a non-transferable contingent value right—known as a CVR—that could mean more cash if certain sales milestones are reached. According to the filing, the deal values the cash component of the offer and merger at roughly $5.3 billion. That figure doesn’t include fees or any additional payments from the CVRs.
Biogen secured $2 billion in unsecured term loans to finance the deal, dividing the sum evenly between a $1 billion 364-day tranche and another $1 billion two-year tranche. The company tapped the entire facility on May 13, its filing shows.
Biogen stock slid 2.98% to $198.43 on the Nasdaq, as of a print just after 10:05 a.m. EDT. Apellis, on the other hand, was last seen at $41.03 before trading was halted, market data show.
Biogen’s interest in Apellis gets a clear rationale from the latest quarterly numbers. For the three months ended March 31, Apellis posted $268.3 million in total revenue and net income of $18.7 million, reversing a loss from the same period last year. U.S. product sales hit $192.0 million, with Syfovre pulling in $150.7 million and Empaveli contributing $41.3 million.
Syfovre is aimed at geographic atrophy—advanced age-related macular degeneration threatening central vision. Empaveli, on the other hand, targets rare complement system diseases such as C3 glomerulopathy and primary immune-complex membranoproliferative glomerulonephritis. Both are kidney conditions that can progress to kidney failure.
When Biogen announced the deal, CEO Christopher Viehbacher told Reuters the company sees “a lot of value” in Apellis’ kidney franchise. BMO Capital’s Evan Seigerman described the move as one that could “meaningfully change how investors think about near-term revenue growth” for Biogen. Reuters
Rivals are circling. In the eye disease space, Syfovre is up against Astellas’ Izervay. This week, Astellas pointed to new data showing Izervay slowed geographic atrophy progression—and for some, extended the period patients could keep their driver’s licenses. Over in rare kidney disease, Novartis’ Fabhalta is making moves too. On May 1, Novartis Canada announced Health Canada has cleared the oral treatment for adults with C3G, citing its ability to reduce proteinuria—high levels of protein in the urine. Astellas Global
But there’s a catch—investors only get paid on the CVR if Syfovre achieves annual global net sales of $1.5 billion and $2 billion in certain years. Biogen, in its filing, is blunt: there’s no guarantee those targets will be reached. Safety is another shadow. Syfovre comes with warnings, including instances of retinal vasculitis or retinal vascular occlusion—both serious eye conditions that can lead to major vision loss. SEC
For Biogen, it’s no longer about closing deals—the real challenge now is execution. The company pointed to Apellis’ nephrology commercial setup as a potential boost for felzartamab, Biogen’s kidney drug in development. The first Phase 3 data for felzartamab is targeted for the first half of 2027.
