Exhibit 99.1

		Press Release Source: Sanofi (EURONEXT: SAN) (NASDAQ: SNY)

FDA accepts for priority review Dupixent^® (dupilumab) for children aged 6 to 11 years with moderate-to-severe atopic dermatitis

PARIS and TARRYTOWN, NY – January 28, 2020 - The U.S. Food and Drug Administration (FDA) has accepted for Priority Review the supplemental Biologics License Application (sBLA) for Dupixent^® (dupilumab) as an add-on maintenance treatment for children aged 6 to 11 years with moderate-to-severe atopic dermatitis whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable. The target action date for the FDA decision is May 26, 2020.

Despite standard-of-care therapy, many young children with moderate-to-severe atopic dermatitis continue to experience uncontrolled, persistent symptoms. These children live with intense, persistent itching, skin lesions and skin dryness, cracking, redness or darkness, crusting and oozing. Beyond the physical symptoms, moderate-to-severe atopic dermatitis can have a significant impact on health-related quality of life for children, as well as placing a burden on their families.

The sBLA is supported by data that includes pivotal Phase 3 results on the efficacy and safety of Dupixent combined with topical corticosteroids (TCS) in children with severe atopic dermatitis. In the trial, children treated with Dupixent and TCS experienced significantly improved measures of overall disease severity, skin clearing, itching and health-related quality of life, compared to TCS alone. Adverse events that were more commonly observed with Dupixent included conjunctivitis, nasopharyngitis and injection site reactions, which is consistent with the previously documented safety profile of Dupixent in older populations. Detailed results from this trial will be presented at an upcoming medical congress.

In 2016, the FDA granted Breakthrough Therapy designation to review Dupixent for the treatment of severe atopic dermatitis in children 6 months to 11 years of age not well controlled on topical prescription medications.

Dupixent is a fully human monoclonal antibody that inhibits the signaling of the interleukin-4 (IL-4) and interleukin-13 (IL-13) proteins. Data from Dupixent clinical trials have shown that IL-4 and IL-13 are key drivers of the type 2 inflammation that plays a major role in atopic dermatitis, asthma and chronic rhinosinusitis with nasal polyposis (CRSwNP).

About Dupixent

Dupixent is approved in the U.S. to treat patients aged 12 years and older with moderate-to-severe atopic dermatitis that is not well controlled with prescription therapies used on the skin (topical), or who cannot use topical therapies; for use with other asthma medicines for the maintenance treatment of moderate-to-severe eosinophilic or oral steroid dependent asthma in patients aged 12 years and older whose asthma is not controlled with their current asthma medicines; and for use with other medicines to treat CRSwNP in adults whose disease is not controlled.

Outside of the U.S., Dupixent is approved for specific patients with moderate-to-severe atopic dermatitis and certain patients with asthma in a number of other countries around the world, including the EU and Japan. Dupixent is also approved in the EU to treat certain adults with severe CRSwNP.

Dupilumab Development Program

To date, there have been 11 pivotal studies involving more than 9,000 patients across various chronic type 2 inflammatory diseases.

In addition to the currently approved indications, Sanofi and Regeneron are also studying dupilumab in a broad range of clinical development programs for diseases driven by allergic and other type 2 inflammation, including pediatric asthma (6 to 11 years of age, Phase 3), pediatric atopic dermatitis (6 months to 5 years of age, Phase 2/3), eosinophilic esophagitis (Phase 3), chronic obstructive pulmonary disease (Phase 3) and food and environmental allergies (Phase 2). Dupilumab is also being studied in combination with SAR440340 (REGN3500), which targets IL-33. These potential uses are investigational and the safety and efficacy have not been evaluated by any regulatory authority. Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement.

About Regeneron

Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents life-transforming medicines for people with serious diseases. Founded and led for over 30 years by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to seven FDA-approved treatments and numerous product candidates in development, all of which were homegrown in our laboratories. Our medicines and pipeline are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, infectious diseases, pain and rare diseases.

Regeneron is accelerating and improving the traditional drug development process through our proprietary VelociSuite^® technologies, such as VelocImmune^®, which uses a unique genetically-humanized mouse to produce optimized fully-human antibodies and bispecific antibodies, and through ambitious research initiatives such as the Regeneron Genetics Center, which is conducting one of the largest genetics sequencing efforts in the world.

For additional information about the company, please visit www.regeneron.com or follow @Regeneron on Twitter.

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 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 regarding the marketing and other potential of the product, or regarding potential future revenues from the product. 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, unexpected regulatory actions or delays, or government regulation generally, that could affect the availability or commercial potential of the product, the absence of guarantee that the product will be commercially successful, the uncertainties inherent in research and development, including future clinical data and analysis of existing clinical data relating to the product, including post marketing, unexpected safety, quality or manufacturing issues, competition in general, risks associated with intellectual property and any related future litigation and the ultimate outcome of such litigation, and volatile economic conditions, as well as those risks 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.

Regeneron Forward-Looking Statements and Use of Digital Media

This press release includes forward-looking statements that involve risks and uncertainties relating to future events and the future performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the “Company”), and actual events or results may differ materially from these forward-looking statements. Words such as “anticipate,” “expect,” “intend,” “plan,” “believe,” “seek,” “estimate,” variations of such words, and similar expressions are intended to identify such forward-looking statements, although not all forward-looking statements contain these identifying words. These statements concern, and these risks and uncertainties include, among others, the nature, timing, and possible success and therapeutic applications of Regeneron’s products, product candidates, and research and clinical programs now underway or planned, including without limitation Dupixent^® (dupilumab); the likelihood, timing, and scope of possible regulatory approval and commercial launch of Regeneron’s late-stage product candidates and new indications for marketed products, such as dupilumab for the treatment of pediatric atopic dermatitis, pediatric asthma, eosinophilic esophagitis, chronic obstructive pulmonary disease, food and environmental allergies, and other potential indications (as well as in combination with REGN3500); unforeseen safety issues resulting from the administration of products and product candidates (such as dupilumab) in patients, including serious complications or side effects in connection with the use of Regeneron’s product candidates in clinical trials; ongoing regulatory obligations and oversight impacting Regeneron’s marketed products (such as Dupixent), research and clinical programs, and business, including those relating to patient privacy; determinations by regulatory and administrative governmental authorities which may delay or restrict Regeneron’s ability to continue to develop or commercialize Regeneron’s products and product candidates, including without

limitation dupilumab; the availability and extent of reimbursement of the Company’s products (such as Dupixent) from third-party payers, including private payer healthcare and insurance programs, health maintenance organizations, pharmacy benefit management companies, and government programs such as Medicare and Medicaid; coverage and reimbursement determinations by such payers and new policies and procedures adopted by such payers; uncertainty of market acceptance and commercial success of Regeneron’s products and product candidates (such as Dupixent) and the impact of studies (whether conducted by Regeneron or others and whether mandated or voluntary) on the commercial success of any such products and product candidates; competing drugs and product candidates that may be superior to Regeneron’s products and product candidates; the extent to which the results from the research and development programs conducted by Regeneron or its collaborators may be replicated in other studies and lead to therapeutic applications; the ability of Regeneron to manufacture and manage supply chains for multiple products and product candidates; the ability of Regeneron’s collaborators, suppliers, or other third parties (as applicable) to perform manufacturing, filling, finishing, packaging, labeling, distribution, and other steps related to Regeneron’s products and product candidates; unanticipated expenses; the costs of developing, producing, and selling products; the ability of Regeneron to meet any of its financial projections or guidance and changes to the assumptions underlying those projections or guidance; the potential for any license or collaboration agreement, including Regeneron’s agreements with Sanofi, Bayer, and Teva Pharmaceutical Industries Ltd. (or their respective affiliated companies, as applicable), to be cancelled or terminated without any further product success; and risks associated with intellectual property of other parties and pending or future litigation relating thereto (including without limitation the patent litigation and other related proceedings relating to Dupixent and Praluent^® (alirocumab)), other litigation and other proceedings and government investigations relating to the Company and/or its operations, the ultimate outcome of any such proceedings and investigations, and the impact any of the foregoing may have on Regeneron’s business, prospects, operating results, and financial condition. A more complete description of these and other material risks can be found in Regeneron’s filings with the U.S. Securities and Exchange Commission, including its Form 10-K for the year ended December 31, 2018 and its Form 10-Q for the quarterly period ended September 30, 2019. Any forward-looking statements are made based on management’s current beliefs and judgment, and the reader is cautioned not to rely on any forward-looking statements made by Regeneron. Regeneron does not undertake any obligation to update publicly any forward-looking statement, including without limitation any financial projection or guidance, whether as a result of new information, future events, or otherwise.

Regeneron uses its media and investor relations website and social media outlets to publish important information about the Company, including information that may be deemed material to investors. Financial and other information about Regeneron is routinely posted and is accessible on Regeneron’s media and investor relations website (http://newsroom.regeneron.com) and its Twitter feed (http://twitter.com/regeneron).

Exhibit 99.2

		Press Release Source: Sanofi (EURONEXT: SAN) (NASDAQ: SNY)

Positive topline results demonstrated by olipudase alfa, first and only investigational therapy in late-stage development for acid sphingomyelinase deficiency

PARIS – January 30, 2020 – Olipudase alfa, an investigational recombinant human acid sphingomyelinase, demonstrated positive results in two separate clinical trials evaluating olipudase alfa for the treatment of acid sphingomyelinase deficiency (ASMD) in adult and pediatric patients. Olipudase alfa is the first and only investigational enzyme replacement therapy in late-stage development for the treatment of ASMD. No treatments are currently approved for ASMD.

“These significant results for olipudase alfa mark a major scientific advancement for ASMD and an important step toward providing a potential therapy for adult and pediatric patients who currently have no approved treatment options for this devastating disease,” said John Reed, M.D., Ph.D., Global Head of Research and Development at Sanofi. “We look forward to engaging with regulatory authorities to bring this potential new treatment to patients.”

Trial in Adult Patients with ASMD (ASCEND)

The randomized Phase 2/3 trial enrolled 36 adult patients with ASMD across 24 centers in 16 countries. Patients received either placebo or olipudase alfa intravenous infusion every two weeks at a dose of up to 3mg/kg administered every two weeks over 52 weeks.ⁱ

The trial contained two independent primary efficacy endpoints to address separate critical manifestations of ASMD, progressive lung disease and enlarged spleen, which are prominent clinical features in patients with ASMD. The study protocol defines the trial outcome as positive if one of the independent primary endpoints was met.

The first independent primary endpoint measuring improvement in lung function, using the percent predicted diffusing capacity of carbon monoxide (DLco), was met; therefore, ASCEND is declared positive. The relative improvement from baseline to week 52 was 22% for the olipudase alfa arm compared with 3% for the placebo arm. The difference between the two treatment arms (19%) was statistically significant (p=0.0004).

The other independent primary endpoint measuring the effect of olipudase alfa on spleen size, assessed as percent change from baseline in multiples of normal (MN) of spleen volume, was met per the study protocol. In the olipudase alfa arm, spleen volume was reduced by 39.5%, compared with a 0.5% increase in the placebo arm. The difference between the two treatment arms (40%) was statistically significant (p<0.0001).

For the U.S., the spleen volume endpoint was further combined with a patient-reported outcome (PRO) measurement of symptoms associated with enlarged spleen called Splenomegaly Related Score (SRS). Compared to baseline, the SRS was reduced by 8.0 points in the olipudase alfa arm and 9.3 points in the placebo arm (p=0.70); therefore, this combination endpoint was not met.

“These are important data in a disease with no approved treatments available currently,” said Melissa Wasserstein, MD, Chief, Division of Pediatric Genetic Medicine, Children’s Hospital at Montefiore; Professor of Pediatrics and Genetics, Albert Einstein College of Medicine; and an investigator in the ASCEND trial. “Treatment with olipudase alfa showed clinically meaningful improvement in pulmonary function and reduction in spleen size, critical manifestations of this progressive disease. Both of these findings are consistent across the clinical studies with olipudase alfa. The absence of an effect on SRS in this trial requires exploration, in light of the significant reduction in spleen size.”

Over the 52-week period, all patients in both the placebo and olipudase alfa arms experienced at least one adverse event. The number of events was lower in the olipudase alfa arm (242 events) compared with the placebo arm (267 events). Severe adverse events were less frequent in the olipudase alfa arm (3 events) compared with the placebo arm (13 events). There were five serious adverse events in the olipudase alfa arm and 11 in the placebo arm, none of which were treatment related. There were no adverse events that led to treatment discontinuation or study withdrawal. The most common adverse events (as defined by percentages of events greater than or equal to 2% and number of patients greater than or equal to two in all olipudase alfa treated patients; occurring with higher percentages in olipudase alfa patients compared to placebo patients) seen in this trial were headache, nasopharyngitis, upper respiratory tract infection, cough, and arthralgia.

Trial in Pediatric Patients with ASMD (ASCEND-Peds)

The single arm, open label Phase 2 trial enrolled 20 pediatric patients (birth to <18 years) with ASMD in six countries. Children with rapidly progressive neurological disease were excluded. The primary objective of the trial was to evaluate the safety and tolerability of olipudase alfa at a dose of up to 3mg/kg administered intravenously every two weeks for 64 weeks.ⁱⁱ

Over the 64-week treatment period, all patients experienced at least one adverse event. These events were mostly mild and moderate, with one patient experiencing a severe and serious (see below) anaphylactic reaction that was considered related to olipudase

alfa. Five treatment-related serious adverse events were observed in three patients: two cases of transient, asymptomatic alanine aminotransferase (ALT) increase in one patient, one case each of urticaria and rash in one patient, and one anaphylactic reaction in one patient. No patients had to permanently discontinue treatment due to an adverse event. The most common adverse events (as defined by percentages of events greater than or equal to 2% and number of patients greater than or equal to two in all olipudase alfa treated patients) seen in this trial were pyrexia, cough, vomiting, nasopharyngitis, diarrhea, headache, upper respiratory tract infection, contusion, abdominal pain, nasal congestion, rash, urticaria, scratch, and epistaxis.

The study also explored secondary endpoints of progressive lung disease and enlarged spleen. After one year of treatment (52 weeks), the percent predicted DLco increased by a mean of 33% in nine patients who were able to perform the test at baseline (children over the age of five were assessed if they were able to perform the test). Additionally, at 52 weeks, the spleen volumes decreased by 49% as assessed by mean MN (individual patient decreases ranged from 23% to 61%).

Results from these trials will be submitted to future medical meetings and will form the basis of global regulatory submissions expected to begin the second half of 2021.

About ASMD

Traditionally referred to as Niemann-Pick Disease (NPD) Type A and Type B, ASMD is a rare, progressive and potentially life-threatening lysosomal storage disorder that results from a deficient activity of the enzyme acid sphingomyelinase (ASM), which is found in special compartments within cells called lysosomes and is required to breakdown lipids called sphingomyelin. If ASM is absent or not functioning as it should, sphingomyelin cannot be metabolized properly and accumulates within cells, eventually causing cell death and the malfunction of major organ systems. The deficiency of the lysosomal enzyme ASM is due to mutations in the sphingomyelin phosphodiesterase 1 gene (SMPD1). The estimated prevalence of ASMD is approximately 2,000 patients in the U.S., Europe and Japan.

ASMD represents a spectrum of disease caused by the same enzymatic deficiency, with two types that may represent opposite ends of a continuum sometimes referred to as NPD Type A and Type B. NPD Type A is a rapidly progressive neurological form of the disease resulting in death in early childhood due to central nervous system complications. NPD Type B is a serious and potentially life-threatening disease that predominantly, but not only, impacts the lungs, liver, spleen and heart. NPD Type A/B represents an intermediate form that includes varying degrees of neurologic involvement. Another type of NPD is NPD Type C, which is unrelated to ASMD.

About Olipudase alfa

Olipudase alfa is an investigational enzyme replacement therapy designed to replace deficient or defective ASM, allowing for the breakdown of sphingomyelin. Olipudase alfa is currently being investigated to treat ASMD Type A/B and B. Olipudase alfa has not

been studied in NPD Type A patients. Olipudase alfa is an investigational agent and the safety and efficacy have not been evaluated by the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), or any other regulatory authority.

The FDA has granted Breakthrough Therapy designation to olipudase alfa. This designation is intended to expedite the development and review of drugs intended to treat serious or life-threatening diseases and conditions. The criteria for granting Breakthrough Therapy designation include preliminary clinical evidence indicating that the molecule may demonstrate substantial improvement over available therapies on a clinically significant endpoint.

The EMA has awarded PRIority MEdicines, also known as PRIME, designation to olipudase alfa. This designation is designed to aid and expedite the regulatory process for investigational medicines that may offer a major therapeutic advantage over existing treatments, or benefit patients without treatment options.

Olipudase alfa was awarded the SAKIGAKE designation in Japan. SAKIGAKE is intended to promote research and development in Japan for innovative new medical products that satisfy certain criteria, such as the severity of the intended indication.

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 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 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..