Sanofi Regeneron Investor Agreement

The slides and management discussion will be available on the Regeneron website: www.regeneron.com on the Investor Relations presentation page at the time of the presentation. TARRYTOWN, N.Y.–Regeneron Pharmaceuticals, Inc. (Nasdaq: REGN) and sanofi-aventis (Euronext: SAN and NYSE: SNY) announced today that they have entered into a comprehensive strategic cooperation agreement to detect, develop and commercialize fully human therapeutic antibodies® of Regenerons owner VelociSuite. About Regeneron Pharmaceuticals, Inc.Regeneron is a leading scientific biopharmaceutical company based in Tarrytown, New York, that detects, invents, develops, manufactures and markets drugs to treat serious diseases. Regeneron markets drugs for eye disease, colon cancer and a rare inflammatory disease and has candidates for development in other areas with unmet medical needs, including high cholesterol, oncology, rheumatoid arthritis, asthma and atopic dermatitis. For more information about the company, visit www.regeneron.com. Regeneron Forward-Looking States and Use of Digital Media This press release contains forward-looking statements that involve risks and uncertainties regarding the future events and future performance of Regeneron Pharmaceuticals, Inc. («Regeneron» or «the Company»), and actual events or results may differ materially from such forward-looking statements. Words such as «anticipate,» «expect,» «plan,» «believe,» «seek,» «appreciate,» variations in these words and similar expressions are intended to identify these forward-looking statements, although not all forward-looking statements contain these identifying words.

These statements relate to, and these risks and uncertainties include, among other things, the effects of SARS-CoV-2 (the virus, which caused the COVID 19 pandemic) is Regeneron`s company and its employees, its employees, suppliers and other third parties on which Regeneron relies, Regeneron`s ability and collaborators to pursue research and clinical programs, Regeneron`s ability to manage its supply chain, the net sale of products marketed by Regeneron and/or its employees (all «Regeneron products»), and the global economy; The nature, timing and possible therapeutic and successful applications of Regeneron`s Products and Regeneron products and current or scheduled research and clinical programs, including and without restriction Dupixent® (dupilumab); the probability, timing and extent of possible administrative approval and commercial introduction of Regeneron products and new indications for Regeneron products, such as dupilumab for the treatment of pediatric asthma, pediatic atopic dermatitis, eosinophilic esophagitis, chronic obstructive pulmonary disease, inflatable pemphigoid, prurigo nodularis, chronic uncertainty about market acceptance and commercial success of Regeneron products and products, as well as the impact of studies (whether regeneron or others, and on mandate or voluntary) on the commercial success of Regeneron`s products and products; unforeseen safety issues resulting from the administration of Regeneron products (such as Dupixent) and product candidates in patients, including serious complications or adverse events related to the use of Regeneron products and product candidates in clinical trials; regulatory and administrative authorities` provisions that may delay or limit Regeneron`s ability to develop or market Regeneron`s products and products; regulatory obligations and ongoing oversight affecting Regeneron`s products, research programs and clinical programs and business programs, including those related to patient privacy; availability and reimbursement level of Regeneron (z.B. Dupixent) products from third-party payers, including private health and insurance programs, health care organizations, pharmacy management companies and government programs such as Medicare and Medicaid; findings of hedging and reimbursement by these payers and the new policies and procedures adopted by these