French pharmaceutical leader Sanofi and U.S. biotechnology company Regeneron Pharmaceuticals have entered into an expanded licensing and collaboration agreement valued at up to $8 billion, building upon their long-standing commercial success with the blockbuster biologic Dupixent. Under the terms of the agreement, the two companies will jointly develop and commercialize four late-stage and clinic-ready antibody candidates targeting Type 2 inflammation, with Sanofi providing an upfront payment of $1 billion and committing up to $7 billion tied to development and regulatory milestones. Both companies will share development and commercialization expenditures equally and split net global profits on a 50:50 basis.
The multi-asset pipeline covers four Regeneron-invented biologics, led by an interleukin-13 (IL-13) inhibitor designated as REGN20423, which is currently undergoing Phase 1 clinical evaluation for atopic dermatitis. The remaining three candidates—an IL-4xIL-13 bispecific antibody, an interleukin-4 (IL-4) inhibitor, and an interleukin-4 receptor alpha (IL-4Rα) inhibitor—are all scheduled to enter clinical studies next year. Concurrently, Regeneron has secured rights to evaluate Sanofi’s investigational bispecific antibody, lunsekimig, in combination with REGN20423. Lunsekimig targets thymic stromal lymphopoietin (TSLP), an upstream driver of allergic diseases and severe asthma, with the combination option exercisable upon completion of Phase 3 studies in chronic obstructive pulmonary disease (COPD).
The major investment represents a deliberate strategic move under Sanofi Chief Executive Officer Belén Garijo to ignite the company’s R&D engine, replenish its late-stage pipeline, and secure a therapeutic successor to Dupixent amid mounting investor scrutiny. By combining Regeneron’s proprietary antibody discovery platforms with Sanofi’s global commercial reach, the expanded alliance aims to accelerate the delivery of next-generation biologic therapies to patients suffering from severe respiratory and dermatological disorders.
Written by: Pragna Biswas
Graphics by: Pramit Hazra
