Biogen Acquires Apellis for $5.6B, Boosting Rare Disease Portfolio

Biogen is significantly expanding its footprint in immunology and rare disease therapeutics through a definitive agreement to acquire Apellis Pharmaceuticals for approximately $5.6 billion in cash. This strategic move injects two commercially successful treatments into Biogen's pipeline, aiming to accelerate near- and long-term revenue growth and bolster its presence in nephrology.

The acquisition brings EMPAVELI, a treatment for rare kidney diseases and paroxysmal nocturnal hemoglobinuria, and SYFOVRE, the first approved therapy for geographic atrophy (an advanced form of age-related macular degeneration), under the Biogen umbrella. These therapies collectively generated $689 million in net product revenue in the past fiscal year and are projected to experience mid-to-high teens growth through at least 2028. This influx of revenue-generating assets aligns with Biogen's strategy to integrate de-risked, commercial-stage products ahead of its internal pipeline advancements.

Beyond the immediate revenue contribution, Biogen anticipates leveraging Apellis' established commercial infrastructure and specialized expertise. This synergy is expected to expedite Biogen's entry into the nephrology market and support the future development and launch of felzartamab, a Phase 3 kidney disease candidate currently in Biogen's pipeline. The integration is designed to deepen Biogen's foundation in kidney disease treatment and expand its reach in immune-mediated retinal diseases.

Financially, the transaction is structured to be increasingly accretive to Biogen's non-GAAP diluted earnings per share, beginning in 2027. The company projects a meaningful boost to its compounded annual growth rate in EPS through the end of the decade. To finance the acquisition, Biogen plans to utilize a combination of existing cash reserves and new borrowings, with a commitment to fully deleverage its balance sheet by the end of 2027. The deal also includes contingent value rights, offering Apellis shareholders potential additional payments tied to specific global net sales milestones for SYFOVRE between 2027 and 2031.

The acquisition is anticipated to conclude in the second quarter of 2026, pending the satisfaction of customary closing conditions and regulatory approvals. This move underscores Biogen's commitment to strategic acquisitions that enhance its therapeutic portfolio with proven commercial assets, complementing its robust internal research and development efforts. The integration of Apellis' team and assets is expected to unlock significant value and expand patient access to critical therapies.

Christopher A. Viehbacher, President and Chief Executive Officer of Biogen, highlighted the strategic alignment, stating, "The addition of Apellis expands our growth portfolio in immunology and rare disease with two approved, best-in-class medicines that complement our existing portfolio and bolsters our near- and long-term growth potential." Similarly, Cedric Francois, M.D., Ph.D., Co-Founder and Chief Executive Officer of Apellis Pharmaceuticals, expressed confidence in the transaction's ability to accelerate impact, noting, "With Biogen’s extensive experience with immunology and rare disease, we believe this transaction will accelerate our impact and enable us to reach more patients."