Sanofi, Regeneron Expand Immunology Alliance in Deal Worth Up to $8 Billion

Sanofi and Regeneron Pharmaceuticals announced an expansion of their two-decade immunology partnership on Thursday, a deal that could pay the U.S. drugmaker up to $8 billion and adds four next-generation drug candidates to their joint pipeline. Under the agreement, Tarrytown, N.Y.-based Regeneron will receive $1 billion upfront and up to $7 billion in development, regulatory and commercial milestone payments. The companies will equally share costs and future profits, while their existing Dupixent profit-sharing terms remain unchanged. The new framework also settles 2024 litigation between the partners. Sanofi shares rose as much as 3.7% before paring gains; Regeneron opened 1.1% higher and later slipped. Dupixent, their flagship asthma and eczema treatment, faces patent expiration in the early 2030s, spurring both sides to refresh the alliance. Regeneron holds final say on development decisions, Sanofi on commercialization.