Regeneron Pharmaceuticals and Sanofi are expanding their more than 20-year antibody partnership, adding four next-generation, long-acting antibodies to the alliance behind Dupixent, one of the world’s most widely used antibody medicines.

 

Under the expanded agreement, Regeneron will receive $1 billion upfront from Sanofi, with up to $7 billion more available through development, regulatory and commercial milestones.

 

The companies will jointly develop and commercialize four Regeneron-invented antibodies targeting IL-13, IL-4xIL-13, IL-4 and IL-4Rα, broadening a collaboration that has already helped establish Dupixent as a leading treatment for diseases driven by type 2 inflammation.

 

“The Regeneron-Sanofi alliance has been one of the most productive in biopharma history. This agreement builds on that foundation to bring the next generation of immunology medicines to patients even faster,” said Leonard S. Schleifer, Board co-Chair, President and Chief Executive Officer of Regeneron. 

 

“By expanding our alliance, we are positioning promising new long-acting antibodies for the kind of rapid, global impact that our shared work on Dupixent has already achieved.”

 

One of the four programs, IL-13 antibody REGN20423, is already being tested in a Phase 1 clinical trial for atopic dermatitis. The other three antibodies are expected to enter clinical studies in 2027.

 

The deal also gives Regeneron an option to bring Sanofi’s lunsekimig into the collaboration after completion of its Phase 3 trials for chronic obstructive pulmonary disease. Lunsekimig is an investigational bispecific Nanobody VHH therapy targeting TSLP and IL-13.

 

“This is a deliberate first step in igniting Sanofi’s innovation engine. Our longstanding Alliance with Regeneron has transformed the treatment landscape for millions of patients living with diseases driven by type 2 inflammation and created one of the world's leading immunology businesses,” said Belén Garijo, Chief Executive Officer of Sanofi. 

 

“By deepening our collaboration, we will make rapid progress in creating the next generation of meaningful therapies for patients with immune-mediated diseases, while contributing to Sanofi’s long-term future.”

 

The companies will split development and commercialization costs for the new programs and share future profits 50:50 globally. Regeneron will lead research and development, while Sanofi will oversee global commercial efforts.

 

The existing profit-sharing arrangement for Dupixent will remain unchanged.

 

The expanded deal builds on a collaboration that dates to 2003. More than 1.5 million people across nine indications are currently receiving Dupixent, according to the companies.

 

“The companies’ clinical and commercial alliance dates to 2003 and has resulted in multiple approved medicines to date, including Dupixent which has redefined the standard of care for people with type 2 inflammatory diseases and is now one of the most widely used antibodies for any disease, with over 1.5 million active patients worldwide,” said George D. Yancopoulos, Board co-Chair, President and Chief Scientific Officer at Regeneron, and a principal inventor of Dupixent. 

 

“By combining Regeneron’s world-class scientific discovery and antibody development expertise with Sanofi’s global capabilities and reach, we hope to once again deliver the next wave of innovation in immunology.”