Biogen moves on Apellis Pharma for USD 5.6b to strengthen complement immunology portfolio

Biogen Inc. has [entered into a definitive agreement](https://www.globenewswire.com/news-release/2026/03/31/3265288/0/en/Biogen-to-Acquire-Apellis-Enhancing-the-Company-s-Growth-Portfolio-in-Immunology-and-Rare-Disease-Bolstering-Growth-Outlook-and-Accelerating-Expansion-into-Nephrology.html) to acquire Massachusetts-based Apellis Pharmaceuticals, Inc. (NASDAQ: APLS) for USD 41.00 per share in cash, representing an upfront equity consideration of approximately USD 5.6 billion, plus contingent value rights tied to Syfovre net sales milestones. The transaction consolidates two FDA-approved complement component 3 (C3) inhibitors into Biogen's immunology and rare disease portfolio while providing an established US nephrology sales infrastructure and capabilities that Biogen believes will help support felzartamab, its Phase III kidney disease asset with a first readout expected in the first half of 2027. ### Pegcetacoplan and the C3 complement inhibition platform Both commercial assets acquired in this transaction — Syfovre (pegcetacoplan injection, intravitreal) and Empaveli (pegcetacoplan, subcutaneous) — share the same active molecule and mechanism of action. Pegcetacoplan is a pegylated cyclic peptide that selectively binds complement component C3, the central convergence node of all three complement activation pathways: classical, lectin, and alternative. By inhibiting C3 upstream, the therapy provides broad suppression of complement-mediated tissue injury without targeting a single downstream effector, which distinguishes it from C5-targeting agents that leave proximal complement activity intact. Syfovre became the first therapy to gain an[ FDA approval for geographic atrophy (GA) ](https://app.allsci.com/article/ASC-PB-0000200111324-1.0-1731073926)secondary to age-related macular degeneration in February 2023. In the Phase III OAKS and DERBY studies, intravitreal pegcetacoplan reduced GA lesion growth rate versus sham at 24 months, with the monthly dosing arm of DERBY demonstrating up to a 36% reduction in lesion growth between months 18 and 24. Five-year data from the GALE open-label extension study, presented in November 2025, indicated that Syfovre delayed GA lesion progression by approximately 1.5 years in patients with nonsubfoveal GA relative to sham or projected sham. Apellis has completed a clinical trial for a [prefilled syringe formulation](https://app.allsci.com/clinical-trial/ASC-CT-0000001053856-1.0-1760425651) and plans to submit an FDA application in the first half of 2026. Biogen acquires full global rights to Syfovre. Empaveli holds FDA approval across three indications: paroxysmal nocturnal hemoglobinuria (PNH) in adults; C3 glomerulopathy (C3G) in patients aged 12 years and older; and primary immune-complex membranoproliferative glomerulonephritis (IC-MPGN) in patients aged 12 years and older. In the Phase III VALIANT study, Empaveli produced a 68% reduction in proteinuria, stabilized kidney function, and achieved substantial clearance of C3 deposits by biopsy in patients with C3G and primary IC-MPGN, including those with post-transplant C3G disease recurrence. Empaveli is the only FDA-approved treatment for pediatric patients aged 12 and older with C3G, the only approved therapy for post-transplant C3G recurrence, and the first approved treatment for both adult and pediatric populations in primary IC-MPGN. Ex-US commercialization rights for systemic pegcetacoplan are retained by Sobi under a pre-existing collaboration agreement; Biogen confirmed it will continue that relationship post-close. ### Deal terms The transaction is structured as a tender offer at USD 41.00 per share in cash, representing an 86% premium to the 90-day volume-weighted average stock price and a 35% premium to the 52-week high. Each Apellis shareholder receives one non-transferable CVR per share. The CVR entitles holders to USD 2.00 per share if Syfovre achieves USD 1.5 billion in annual global net sales in any calendar year from 2027 through 2030, and an additional USD 2.00 per share if Syfovre achieves USD 2.0 billion in annual global net sales in that same window. If neither threshold is met during 2027 to 2030 but Syfovre achieves USD 2.0 billion in global net sales in calendar year 2031, a single payment of USD 4.00 per share becomes payable. Biogen intends to finance the acquisition through a combination of cash and borrowings and expects to fully de-lever by the end of 2027. The transaction, approved by both boards, is subject to tender offer completion, customary regulatory approvals, and standard closing conditions, with closing expected in the second quarter of 2026. ### Strategic outlook The commercial rationale centers on the combined 2025 net product revenue of USD 689 million generated by Syfovre and Empaveli, which Biogen projects will grow at a mid-to-high teens rate at least through 2028. Beyond the revenue profile, the acquisition transfers Apellis's established US nephrology commercial infrastructure — including field-based capabilities and specialist relationships built during the C3G and IC-MPGN launches — directly into Biogen's organizational structure. Biogen has stated this infrastructure will strengthen its commercial readiness for felzartamab, which is currently in [Phase III studies](https://app.allsci.com/clinical-trial/ASC-CT-0000000071148-1.0-1745763661) across three kidney diseases. The alignment between Apellis's nephrology footprint and Biogen's pipeline timing represents the clearest operational synergy disclosed in the announcement. For R&D leads tracking complement biology, the acquisition positions Biogen among the few large-cap biopharma companies with approved C3-targeting assets spanning multiple specialties. --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/biogen-acquires-apellis-pharmaceuticals-for-usd)