Pharma BD Deal Intelligence
Outcome grade pending — assessed 5 years post-close.
Full analysis, sources & comparables →Biogen has agreed to spend at least $5.6 billion to diversify its lineup of immune system-regulating drugs through an acquisition of fellow Massachusetts-based…
For Biogen, the Apellis deal marks CEO Chris Viehbacher's largest bet yet to rebuild growth after Spinraza erosion and slower-than-expected Leqembi uptake. The…
Biogen hiked its offer for Apellis Pharmaceuticals multiple times before the two companies agreed to terms on a $5.6 billion acquisition last month. The…
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Biogen agreed (Mar 31, 2026) to acquire Apellis for $41/share (~$5.6B equity) plus a CVR of up to $4/share tied to Syfovre global net sales 2027-2031, structured as a tender offer plus back-end merger. The deal CLOSED on May 14, 2026: the tender offer expired May 13 with ~82.4% of shares tendered, the merger completed under Delaware law, and Apellis shares ceased trading on Nasdaq, making Apellis a wholly owned subsidiary of Biogen. The deal adds Empaveli (pegcetacoplan) and Syfovre (pegcetacoplan intravitreal) - $689M combined 2025 net product revenue - to Biogen's portfolio, anchoring an immunology/nephrology growth platform. Financed with cash + debt; Biogen expects accretion to non-GAAP EPS in 2027 and to de-lever by end of 2027.
| Deal | Year | Value | Outcome |
|---|---|---|---|
| Biogen Inc. / Apellis Pharmaceuticals, Inc. (this deal) | 2026 | $5.6B | — |
| Biogen Inc. / Reata Pharmaceuticals | 2023 | $7.3B | 73 |
| Biogen Inc. / Human Immunology Biosciences | 2024 | $1.1B | 68 |
| Biogen Inc. / RayThera Inc. | 2026 | $1.0B | 52 |
| Biogen Inc. / Bristol-Myers Squibb Company | 2017 | $710M | 15 |
| Biogen Inc. / Nightstar Therapeutics | 2019 | $800M | — |
| Biogen Inc. / TJ Biopharma Co., Ltd. | 2026 | $850M | — |
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More: 2026 deals · Biogen Inc. deals · Nephrology deals