[caption id="attachment_9277" align="aligncenter" width="747"] Press Release[/caption]

• Prioritize key growth drivers ? Dupixent^??(dupilumab) and vaccines
• Accelerate R&D focus on six potentially transformative medicines
• Improve operating efficiencies to fund growth and expand business operating income margin¹
• Align to support new strategy with three core businesses and a standalone Consumer Healthcare unit

PARIS ? DECEMBER 9, 2019?? At Sanofi?s Capital Markets Day tomorrow with the financial community, the company will provide details of a new strategic framework with four key priorities to drive innovation and growth. Sanofi will also discuss the alignment of the organization to support this new strategy.

Sanofi Chief Executive Officer Paul Hudson and Executive Committee members will provide a detailed overview of the company?s strategy based on four main priorities ? focusing the portfolio, leading with science, accelerating efficiency, and reinventing how the company works. ?Our new strategy positions Sanofi to achieve breakthroughs with our most promising medicines, addressing significant patient needs. We will anchor our efforts in leading-edge science with clearer priorities and a focus on delivering results,??said Hudson.??Sanofi gained leadership and changed the practice of medicine in diabetes and cardiovascular diseases. We are now preparing for our next cycle, with a new round of innovative solutions for patients. I?m confident we will achieve long-term growth and value for shareholders while turning innovation into transformative medicines for patients.?

Focus on growth

• Dupixent^??(dupilumab)²?? Sanofi expects to deliver strong growth for Dupixent with the ambition of achieving more than ?10 billion in peak sales driven by its unique mechanism of action targeting the type 2 inflammation pathway.
• Vaccines?? Vaccines are expected to deliver a mid-to-high single-digit net sales CAGR from 2018 to 2025, through differentiated products, market expansion and new launches.
• Pipeline?? The company has identified and prioritized six potentially transformative therapies.

Additional core drivers include treatments for oncology, hematology, rare diseases, neurology, and Sanofi?s strong presence in China.

Lead with innovation

Sanofi has six potentially practice changing therapies in areas of high unmet patient need. These investigational therapies are listed as follows in order of planned submission timing:

• Fitusiran?is an RNAi therapeutic in development for the treatment of hemophilia A and B with or without inhibitors with the potential to provide once-monthly dosing convenience.
• BIVV001³?is a factor VIII therapy designed to extend protection from bleeds with prophylaxis dosing of once weekly for people with hemophilia A that seek to enjoy a normalized lifestyle.
• Venglustat?is an oral therapy in development for several rare diseases in the category of lysosomal storage disorders (Gaucher type 3, Fabry, Tay-Sachs disease, etc.), and also showing promise for more common disorders including autosomal dominant polycystic kidney disease and some sub-types of Parkinson?s disease.
• SERD (?859)?is a selective estrogen receptor degrader which aims to be the new standard of care in hormone-receptor-positive breast cancer.
• Nirsevimab⁴?is a potentially cost-effective prevention against respiratory syncytial virus, with initial focus on protecting infants.
• BTKi (?168)⁵?is an oral medicine for multiple sclerosis with potential to be the first disease-modifying therapy to address inflammation and disability drivers in the brain.

The company also announced plans to acquire Synthorx, Inc. which will bolster its immuno-oncology (IO) pipeline with both a proprietary IO platform synergistic with Sanofi?s existing therapeutics platforms, and a lead IO candidate (THOR-707) being explored across multiple solid tumor types both alone and in combination with immune checkpoint inhibitors and other future IO combinations. Additional details can be found here:?https://www.sanofi.com/en/media-room/press-releases

Sanofi plans to hold a R&D Day in 2020 to provide a detailed review of its R&D portfolio of candidate medicines, strategy, and specifically productivity.

Accelerate efficiency

Sanofi expects to expand its business operating income (BOI) margin¹? to 30% by 2022, with an ambition for its BOI margin to exceed 32% by 2025. The company is also announcing efficiency initiatives that are expected to generate ?2 billion savings by 2022. These savings will fund investment in its key growth drivers and accelerate priority pipeline projects as well as support the expansion of the BOI margin.

The efficiency savings are expected to result primarily from limiting spend on de-prioritized businesses, from smart spending (procurement) initiatives and from operational excellence in manufacturing and organizational productivity. Regarding de-prioritized businesses, Sanofi is announcing a discontinuation of research in diabetes and cardiovascular (DCV) and will not pursue plans to launch efpeglenatide⁶. The company will also optimize the commercial model for DCV and rheumatoid arthritis, including right-sizing the resources deployed behind Praluent^??(alirocumab)^2?and Kevzara^??(sarilumab)².

Reinventing how we work

Sanofi will be structured with three core global business units to support the company?s strategy⁷???Specialty Care?(immunology, rare diseases, rare blood disorders, neurology and oncology),?Vaccines, and?General Medicines?(diabetes, cardiovascular, and established products).?Consumer Healthcare?will be a standalone business unit with integrated R&D and manufacturing functions.

Hudson explained,??Our objective?for the Consumer Healthcare business is to unlock value and entrepreneurial energy by growing faster than the market over the mid term. We believe the new standalone structure, coupled with plans to accelerate the over-the-counter switches for Cialis^??and Tamiflu^?, will position the business well to accomplish this ambition.?

Focused capital allocation

Sanofi expects to increase its annual Free Cash Flow by approximately 50% by 2022 compared with an adjusted base of ?4.1bn in 2018.⁸

Sanofi continues its focused and disciplined capital allocation policy. It expects to deploy cash generated from its three core GBUs as well as the standalone CHC business with the following order of preference:

1. Organic investment
2. Business Development and M&A activities, focusing on bolt-on, value-enhancing opportunities to drive scientific and commercial leadership in core therapeutic areas
3. Growing the annual dividend
4. Anti-dilutive share buybacks

Additionally, Sanofi has the potential to raise capital through asset disposals, including streamlining ?tail? brands in its Established Products business, and by monetizing its stake after the expiry of the lock-up under the amended and restated investor agreement with Regeneron.

R&D update

Consult Appendix 1 for full overview of Sanofi?s R&D pipeline

Regulatory update

Regulatory updates since October 31, 2019 include the following:

• In November, the FDA approved a supplemental Biologics License Application for?Fluzone^??High-Dose Quadrivalent (Influenza Vaccine)?for use in adults 65 years of age and older.

As of November 2019, the R&D pipeline contained 84 projects, including 37 new molecular entities in clinical development (or that have been submitted to the regulatory authorities). 35 projects are in phase 3 or have been submitted to the regulatory authorities for approval.

Portfolio update

Phase 3:

• In December, positive results from the pivotal Phase 3 trial in patients with cold agglutinin disease (a type of anemia) for?sutimlimab,?a humanized, monoclonal antibody designed to directly target the classical complement pathway (C1s), will be presented at the Late-Breaking Abstracts Session of the 61^st?Annual Meeting of the American Society of Hematology in Orlando, Florida.? Results from this trial will be submitted to regulatory authorities, starting with the U.S. Food and Drug Administration (FDA) in the near future
• In December, a Phase 3 study evaluating the extended pharmacology, once-weekly, Factor VIII replacement?BIVV001?in patients with hemophilia A was initiated.
• In November, positive results from the Phase 3 trial for?Toujeo^??in children and adolescents with type 1 diabetes were presented at the International Society of Pediatrics and Adolescent Diabetes 45^th?Annual Conference in Boston.
• In November, plans to initiate Phase 3 studies in?dupilumab?in additional Type 2 inflammatory diseases were announced, including studies in prurigo nodularis, bullous pemphigoid, chronic spontaneous urticaria and allergic bronchopulmonary aspergillosis.

Phase 2:

• In December, additional analysis of the ongoing Phase 2 open-label extension study of?fitusiran, an RNA interference therapeutic targeting antithrombin (AT) for patients with hemophilia A and B with and without inhibitors, was shared at the 61^st?Annual Meeting of the American Society of Hematology in Orlando, Florida.
• Proof of concept was achieved for?SAR439859,?a selective estrogen receptor degrader (SERD), as a monotherapy in third-line metastatic breast cancer.? A pivotal study evaluating SAR439859 as a monotherapy in second and third-line metastatic breast cancer was initiated.
• Phase 2 results for?SAR440340, Anti-IL33 in collaboration with Regeneron, in chronic obstructive pulmonary disease (COPD) demonstrated reduced exacerbations in the overall study population, but the results were not statistically significant.? Sanofi and Regeneron are evaluating a potential path forward in this indication.

Phase 1:

• Proof of concept was achieved for?sutimlimab?in patients with immune thrombocytopenic purpura (ITP) without adequate response to two or more prior therapies.? These results will be presented at the 61^st?Annual Meeting of the American Society of Hematology in Orlando, Florida. ITP represents the second indication investigated for sutimlimab, an antibody molecule that could have broad utility for several complement-mediated diseases where autoantibodies attack host tissues.

Collaboration ??In November, Sanofi and Aetion announced an enterprise-wide collaboration that will integrate Sanofi?s real-world data platform, DARWIN, with the Aetion Evidence Platform? to advance more efficient use of real-world evidence.

About Sanofi Capital Markets Day

Sanofi will host a Capital Markets Day in its offices in Cambridge, Massachusetts, U.S., on December 10, 2019, which will start at 9:00 am EST (2:00pm CET). The meeting will be a live webcast and can be accessed along with full copies of the presentations via the Investors Relations section of Sanofi corporate website:?www.sanofi.com/investors. A replay will be available shortly after the live webcast.

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. Sanofi, Empowering Life

Media Relations Contacts Quentin Vivant Tel.: +33 (0)1 53 77 46 46 mr@sanofi.com Ashleigh Koss Tel: +908 205 2572 Ashleigh.Koss@sanofi.com	Investor Relations Contact George Grofik Tel.: +33 (0)1 53 77 45 45 ir@sanofi.com
?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 absence of guarantee that the product candidates if approved will 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 conditions, the impact of cost containment initiatives and subsequent changes thereto, the average number of shares outstanding as well as those 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, 2018. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements. Additional Information and Where to Find It Regarding?Synthorx The tender offer for the outstanding shares of [Synthorx] common stock?(?[Synthorx]?) referenced in this communication has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a solicitation of an offer to sell shares of [Synthorx], nor is it a substitute for the tender offer materials that Sanofi and its acquisition subsidiary will file with the U.S. Securities and Exchange Commission (the ?SEC?) upon commencement of the tender offer. At the time the tender offer is commenced, Sanofi and its acquisition subsidiary will file tender offer materials on Schedule TO, and thereafter [Synthorx] will file a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC with respect to the tender offer. THE TENDER OFFER MATERIALS (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND CERTAIN OTHER TENDER OFFER DOCUMENTS) AND THE SOLICITATION/RECOMMENDATION STATEMENT WILL CONTAIN IMPORTANT INFORMATION. HOLDERS OF SHARES OF [Bento] ARE URGED TO READ THESE DOCUMENTS WHEN THEY BECOME AVAILABLE (AS EACH MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO TIME) BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION THAT [SYNTHORX] STOCKHOLDERS SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SHARES. The Offer to Purchase, the related Letter of Transmittal and certain other tender offer documents, as well as the Solicitation/Recommendation Statement, will be made available to all holders of shares of [SYNTHORX] at no expense to them. The tender offer materials and the Solicitation/Recommendation Statement will be made available for free at the SEC?s web site at?www.sec.gov. Additional copies may be obtained for free by contacting Sanofi at?ir@sanofi.com?or on Sanofi?s website at?https://en.sanofi.com/investors.

¹?See Appendix 3 for definition ²?Partnered with Regeneron ³?Partnered with SOBI⁴?Partnered with AstraZeneca ⁵?Partnered with Principia ⁶?Sanofi commits to complete ongoing studies ? Sanofi will look for a partner to take over and commercialize efpeglenatide ⁷?Subject to completion of the appropriate social processes ⁸?See Appendix 4 for definition Appendices List of Appendices

Appendix 1	R&D Pipeline
Appendix 2	Expected R&D milestones
Appendix 3 Appendix 4	Business Operating Income definition Free Cash Flow definition