Sanofi Expands Collaboration with Regeneron to Four New Antibodies
The two groups are adding several long-acting antibodies to their long-standing collaboration, built around Dupixent. The agreement provides for an initial payment of one billion dollars from Sanofi to Regeneron and ends a previous dispute between the partners.
Four New Antibodies Co-Developed and Co-Commercialized
Sanofi and Regeneron Pharmaceuticals announced on October 1, 2026 the expansion of their collaboration in the field of antibodies, integrating several next-generation long-acting antibodies. The expanded license and collaboration agreement covers four new antibodies invented by Regeneron, targeting interleukin-13 (IL-13), the bispecific IL-4xIL-13, interleukin-4 (IL-4) and interleukin-4 receptor alpha (IL-4Rα).
The anti-IL-13 antibody REGN20423 is currently under phase 1 clinical study in atopic dermatitis, with the three other antibodies expected to enter clinical studies in 2027. Regeneron will also have an option to include in the collaboration Sanofi's lunsekimig, in phase 2/3, an experimental bispecific therapy targeting TSLP and IL-13, an option exercisable upon completion of its phase 3 studies in chronic obstructive pulmonary disease.
The collaboration between the two companies dates back to 2003 and has led to several approved medicines, including Dupixent (dupilumab), currently administered to more than 1.5 million patients across nine indications.
An Initial Payment of One Billion Dollars and Milestones Up to 7 Billion
Under the terms of the agreement, Regeneron will receive an initial payment of one billion dollars from Sanofi, with potential milestone payments linked to development, regulatory approvals and commercialization, reaching up to 7 billion dollars additional.
The two companies will share the costs of development and commercialization of the new programs and will split equally (50/50) future profits from these potential products on a global scale. Regeneron will lead research and development activities, while Sanofi will lead global commercial efforts.
The existing profit-sharing agreement concerning Dupixent remains unchanged.
End of Previous Dispute Between the Two Partners
The two companies indicated that they have resolved their previous dispute related to the collaboration. Belén Garijo, Chief Executive Officer of Sanofi, presented the operation as "a deliberate first step to restart Sanofi's innovation engine".
For his part, Leonard S. Schleifer, President and Chief Executive Officer of Regeneron, described an agreement intended to "bring the next generation of immunological medicines to patients even faster".
