French healthcare company Sanofi S.A. (Euronext Paris:SAN) (Nasdaq:SNY) and US biotechnology company Regeneron Pharmaceuticals Inc (Nasdaq:REGN) said on Thursday that they have expanded their more than 20-year antibody collaboration to include four long-acting antibodies targeting interleukin-13 (IL-13), IL-4xIL-13 bispecific, interleukin-4 (IL-4) and interleukin-4 receptor alpha (IL-4Rα).

The programmes include REGN20423, a Phase 1 IL-13 monoclonal antibody for atopic dermatitis. The other three antibodies are expected to enter clinical studies in 2027.

Regeneron will receive USD1bn upfront from Sanofi, with potential development, regulatory and commercial milestone payments of up to an additional USD7bn.

The companies will share development and commercialisation costs and split future profits from the new programmes equally worldwide, with Regeneron leading research and development and Sanofi leading global commercial activities.

Regeneron will also have an option to add Sanofi's investigational lunsekimig, a bispecific Nanobody VHH therapy targeting TSLP and IL-13, following completion of its Phase 3 studies in chronic obstructive pulmonary disease.

The expanded alliance builds on the companies' collaboration around Dupixent, which is currently used by more than 1.5 million people across nine indications.

Sanofi and Regeneron also said they have settled their prior collaboration-related litigation.