REGN: Material agreement · Financial results · Other company developments

Item 1.01. Entry into a Material Definitive Agreement. On October 1, 2026, Regeneron Pharmaceuticals, Inc., a New York corporation (“ Regeneron ” or the “ Company ”), Sanofi Biotechnology SAS, a société par actions simplifée organized under the laws of France (“ Sanofi Biotechnology ”), and Sanofi, a société anonyme organized under the laws of France (“ Sanofi Parent ” and, with Sanofi Biotechnology, “ Sanofi ”), entered into the Sixth Amendment to the Amended and Restated License and Collaboration Agreement (the “ Sixth Amendment ”), which amends the Amended and Restated License and Collaboration Agreement, dated as of November 10, 2009 (as amended), by and between the Company, Sanofi Biotechnology (as successor in interest to Aventis Pharmaceuticals Inc.), and Sanofi Parent (the “ Antibody LCA ”). Pursuant to the Sixth Amendment, the parties have agreed to co-develop and co-commercialize four new long-acting, Regeneron-invented antibodies: (i) an antibody targeting interleukin-13 (“ IL-13 ”), (ii) an antibody targeting interleukin-4 (“ IL-4 ”), (iii) an antibody targeting IL-4 receptor alpha (IL-4Rα), and (iv) a bispecific antibody targeting IL-4xIL-13 (each, a “ New Licensed Product ” and, collectively, the “ New Licensed Products ”). Regeneron will also have the option, on an asset-by-asset basis after completion of certain ongoing clinical trials, to include in the collaboration Sanofi’s Phase 2/3 asset lunsekimig, an investigational bispecific Nanobody ® VHH therapy targeting thymic stromal lymphopoietin (TSLP) and IL-13, and another Sanofi early development product. In the event Regeneron exercises this option for any such product, it will reimburse Sanofi for certain development costs related to such product. Pursuant to the Sixth Amendment, Sanofi will make an