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 upfront payment to Regeneron of $1.0 billion. In addition, the Sixth Amendment provides that Regeneron will be entitled to receive up to an additional $7.0 billion of payments in the aggregate upon the achievement of certain development, regulatory, and commercial milestones with respect to the New Licensed Products. Global profits realized on the sale of New Licensed Products will be shared equally between Regeneron and Sanofi, as calculated under the Antibody LCA.

Pursuant to the Sixth Amendment, the parties have agreed on an initial global development plan for the IL-13 asset and are to agree on an initial global development plan for each of the other New Licensed Products. All development costs incurred with respect to all licensed products under the Antibody LCA, including the New Licensed Products, will be shared equally by the parties. In addition, development costs in excess of a budget cap for all New Licensed Products will be the responsibility of Regeneron, subject to certain rights to recoup such excess costs in future years. Regeneron will be the lead development party and the lead regulatory party prior to the filing of an application for marketing approval for each New Licensed Product. Regeneron will remain the lead regulatory party for applications for marketing approval and further commercialization in the United States, and Sanofi will be the lead regulatory party for applications for marketing approval and further commercialization outside the United States. Sanofi will be the lead party with respect to the commercialization of the New Licensed Products.

The foregoing description of the Sixth Amendment is qualified in its entirety by reference to the full text of the Sixth Amendment, a copy of which will be filed with the U.S. Securities and Exchange Commission as an exhibit to the Quarterly Report on Form 10-Q to be filed by the Company for the quarterly period ended September 30, 2026.

Regeneron currently expects that its financial results calculated in accordance with U.S. generally accepted accounting principles ("GAAP") and its non-GAAP financial results for the third quarter 2026 will include an acquired in-process research and development ("IPR&D") charge of approximately $22 million on a pre-tax basis. The acquired IPR&D charge is expected to negatively impact each of GAAP and non-GAAP net income per diluted share for the third quarter 2026 by approximately $0.18.

Acquired IPR&D charges may include IPR&D acquired in connection with asset acquisitions as well as up-front, opt-in, and development milestone payments and premiums paid on equity securities related to collaboration and licensing agreements. Regeneron does not forecast such acquired IPR&D charges due to the uncertainty of the future occurrence, magnitude, and timing of these transactions in any given period.

Regeneron's results for the third quarter 2026 have not been finalized and are subject to Regeneron's financial statement closing procedures. There can be no assurance that actual results will not differ from the preliminary (unaudited) estimates described herein.

The information included in this Item 2.02 shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, nor shall such information be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing.