The European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP) has adopted a positive opinion for avalglucosidase alfa, a long-term enzyme replacement therapy for the treatment of people with Pompe disease. The CHMP positive opinion and recommended indication reflect the robust data from avalglucosidase alfa?s clinical development program. While Sanofi is pleased with the CHMP?s recognition of the clinically meaningful improvements demonstrated in the avalglucosidase alfa development program, the CHMP considered that avalglucosidase alfa does not qualify as a New Active Substance (NAS). As a result, Sanofi will be requesting a re-examination of the CHMP opinion in relation to the NAS conclusion. The positive opinion is based on data from the Phase 3 COMET study, which found that avalglucosidase alfa showed clinically meaningful improvements in respiratory function and movement endurance measures in people with late-onset Pompe disease. About?avalglucosidase alfa Avalglucosidase alfa is an enzyme replacement therapy designed to target the mannose-6-phosphate (M6P) receptor, the underlying disease mechanism in Pompe disease. With approximately 15-fold increase in M6P content compared to the current standard of care, avalglucosidase alfa aims to help improve cellular enzyme uptake and enhance glycogen clearance in target tissues. The CHMP positive opinion for avalglucosidase alfa follows the EMA?s acceptance of Sanofi?s MAA at the end of 2020. Avalglucosidase alfa is also currently undergoing review in other countries including the U.S., U.K. and Japan. The U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy, Fast Track and Priority Review designations to avalglucosidase alfa and the target FDA action date under the Prescription Drug User Fee Act is anticipated to be August 18, 2021. Avalglucosidase alfa has been granted Promising Innovative Medicine designation in the U.K. The safety and efficacy of avalglucosidase alfa have not been fully evaluated by any regulatory authority worldwide. About Sanofi Sanofi is dedicated to supporting people through their health challenges. We are a global biopharmaceutical company focused on human health. We prevent illness with vaccines, provide innovative treatments to fight pain and ease suffering. We stand by the few who suffer from rare diseases and the millions with long-term chronic conditions. With more than 100,000 people in 100 countries, Sanofi is transforming scientific innovation into healthcare solutions around the globe. Media Relations Contact Sally Bain +1 (781) 264-1091 Sally.Bain@sanofi.com Investor Relations Contacts Paris Eva Schaefer-Jansen Arnaud Delepine Nathalie Pham Investor Relations Contacts North America Felix Lauscher Fara Berkowitz Suzanne Greco Tel.: +33 (0)1 53 77 45 45 investor.relations@sanofi.com https://www.sanofi.com/en/investors/contact Sanofi Forward-Looking Statements

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions and expectations with respect to future financial results, events, operations, services, product development and potential, and statements regarding future performance. Forward-looking statements are generally identified by the words ?expects?, ?anticipates?, ?believes?, ?intends?, ?estimates?, ?plans? and similar expressions. Although Sanofi?s management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of Sanofi, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward-looking information and statements. These risks and uncertainties include among other things, the uncertainties inherent in research and development, future clinical data and analysis, including post marketing, decisions by regulatory authorities, such as the FDA or the EMA, regarding whether and when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labelling and other matters that could affect the availability or commercial potential of such product candidates, the fact that product candidates if approved may not be commercially successful, the future approval and commercial success of therapeutic alternatives, Sanofi?s ability to benefit from external growth opportunities, to complete related transactions and/or obtain regulatory clearances, risks associated with intellectual property and any related pending or future litigation and the? ultimate outcome of such litigation,? trends in exchange rates and prevailing interest rates, volatile economic and market conditions, cost containment initiatives and subsequent changes thereto, and the impact that COVID-19 will have on us, our customers, suppliers, vendors, and other business partners, and the financial condition of any one of them, as well as on our employees and on the global economy as a whole. Any material effect of COVID-19 on any of the foregoing could also adversely impact us. This situation is changing rapidly and additional impacts may arise of which we are not currently aware and may exacerbate other previously identified risks. The risks and uncertainties also include the uncertainties discussed or identified in the public filings with the SEC and the AMF made by Sanofi, including those listed under ?Risk Factors? and ?Cautionary Statement Regarding Forward-Looking Statements? in Sanofi?s annual report on Form 20-F for the year ended December 31, 2020. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.