Sanofi and Regeneron Pharmaceuticals have expanded their longstanding antibody collaboration to include four next-generation, long-acting antibodies targeting pathways involved in type 2 inflammation and immune-mediated diseases.

The agreement builds on more than two decades of collaboration between the companies, which has resulted in the development of Dupixent (dupilumab). More than 1.5 million people are currently receiving Dupixent across nine indications, making it one of the most widely used antibody medicines globally.

Under the expanded agreement, Sanofi and Regeneron will jointly develop and commercialise four Regeneron-invented antibodies targeting interleukin-13 (IL-13), IL-4xIL-13, interleukin-4 (IL-4) and interleukin-4 receptor alpha (IL-4Ra).

The IL-13 antibody REGN20423 is currently being evaluated in a Phase 1 clinical study for atopic dermatitis, while the other three antibody programmes are expected to enter clinical studies in 2027.

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

Under the financial terms, Regeneron will receive an upfront payment of USD 1 billion from Sanofi and could receive up to an additional USD 7 billion in development, regulatory and commercial milestone payments. The companies will share development and commercialisation costs and split future global profits from the new programmes equally.

Regeneron will lead research and development activities, while Sanofi will lead global commercialisation efforts. The existing profit-sharing arrangement for Dupixent will remain unchanged.

The companies have also settled their prior collaboration-related litigation.

The expanded agreement builds on the companies’ existing work in type 2 inflammation. Dupixent is a fully human monoclonal antibody that inhibits signalling through the IL-4 and IL-13 pathways and is approved in more than 60 countries for multiple indications, including certain patients with atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyps, eosinophilic esophagitis, prurigo nodularis, chronic spontaneous urticaria and chronic obstructive pulmonary disease.

Sanofi and Regeneron continue to evaluate dupilumab across additional diseases driven by type 2 inflammation and other allergic processes. The potential uses under investigation have not been fully evaluated by regulatory authorities.