Positive Dupixent® (dupilumab) Phase 3 results in adults and adolescents with eosinophilic esophagitis published in the New England Journal of Medicine Dupixent 300 mg weekly showed significant histological disease remission and improvement in symptoms of the disease compared to placeboImprovements were sustained for up to one year in patients aged 12 years and older with eosinophilic esophagitis (EoE)Dupixent is the first and only targeted medicine indicated in the U.S. to treat EoE patients aged 12 and older weighing at least 40 kg Paris and Tarrytown, N.Y. DECEMBER 21, 2022 The New England Journal of Medicine has published results from a positive Phase 3 trial showing adults and adolescents treated with Dupixent® (dupilumab) 300 mg weekly experienced significant improvements in signs and symptoms of eosinophilic esophagitis (EoE), which were sustained for up to one year. EoE is a chronic, progressive inflammatory disease that damages the esophagus and prevents it from working properly. These data formed the basis for the U.S. Food and Drug Administration (FDA) approval of Dupixent in May 2022, making it the first and only medicine indicated to treat patients with EoE aged 12 years and older, weighing at least 40 kg. These Phase 3 data have been submitted to the European Medicines Agency (EMA) to support regulatory approval for adults and adolescents with EoE. The EMA’s Committee for Medicinal Products for Human Use recently adopted a positive opinion recommending approval with a final decision expected in the coming months. Evan S. Dellon, M.D., M.P.H.Professor of Gastroenterology and Hepatology at the University of North Carolina School of Medicine “The publication of these Phase 3 results in the New England Journal of Medicine reinforces the impact of the clinical trial data. These data showed dupilumab 300 mg weekly substantially decreased patient symptoms of difficulty swallowing, and led to histological disease remission and improvements in the endoscopic appearance of the esophagus, as compared to placebo. These data also underscore the role of inhibiting the IL-4 and IL-13 pathways in eosinophilic esophagitis with dupilumab, adding to our growing knowledge of this poorly understood disease.” As published, patients received Dupixent 300 mg either weekly or every two weeks in the Phase 3 trial. Patients receiving Dupixent weekly experienced improvement in the ability to swallow and achieved histological disease remission. Additionally, these patients experienced improved anatomic, cellular, molecular and health-related quality of life measures, with improvements in signs and symptoms of EoE sustained for up to one year. Patients treated with Dupixent every two weeks experienced histological disease remission but did not experience improvement in the ability to swallow. The current FDA-approved dosage for Dupixent as a treatment for children and adults aged 12 years and older with EoE, weighing at least 40 kg, is 300 mg weekly. The safety results were generally consistent with the known safety profile of Dupixent in its approved indications. Adverse events (≥5%) that were more commonly observed with Dupixent included injection site reactions, nasopharyngitis and rash. About Eosinophilic Esophagitis EoE is a chronic, progressive inflammatory disease that damages the esophagus and prevents it from working properly. The results seen with Dupixent in adults and adolescents with EoE demonstrate that interleukin-4 (IL-4) and interleukin-13 (IL-13) are key and central drivers of the type 2 inflammation underlying this disease. For people with EoE, swallowing even small amounts of food can be a painful and worrisome choking experience. They are often left to contend with the frustration and anxiety of a constantly evolving list of foods to avoid, a poor quality of life and a higher risk of depression. In cases where EoE causes the esophagus to narrow, forced and potentially painful dilation (physical expansion) of the esophagus may be needed. In severe cases, a feeding tube may be the only option to ensure proper caloric intake and adequate nutrition. Of the approximately 209,000 patients aged 12 years and older living with EoE in the U.S. who are currently treated with therapies not specifically approved for the disease, about 42,000 continue to experience symptoms despite multiple treatments. About the Dupixent Eosinophilic Esophagitis Trial The Phase 3 randomized, double-blind, placebo-controlled trial evaluated the efficacy and safety of Dupixent in patients aged 12 years and older with EoE in three parts. Part A enrolled 81 patients and evaluated Dupixent 300 mg weekly for 24 weeks. Part B enrolled 240 patients and evaluated Dupixent 300 mg weekly and every two weeks for 24 weeks. Parts A and B were designed similarly and consisted of separate patient groups. All patients in Parts A and B had an option to participate in Part C for an additional 28 weeks, for up to 52 weeks of Dupixent treatment. Part C enrolled 77 patients from Part A. At 24 weeks, the co-primary endpoints in Parts A and B assessed patient-reported measures of difficulty swallowing and esophageal inflammation. The secondary endpoints included assessments of histopathologic measures of the severity and extent of additional histological measures in the esophagus, and other measures. In Part C, all primary and secondary endpoints assessed in Parts A and B were assessed as secondary endpoints at 52 weeks. About Dupixent Dupixent is a fully human monoclonal antibody that inhibits the signaling of the IL-4 and IL-13 pathways and is not an immunosuppressant. The Dupixent development program has shown significant clinical benefit and a decrease in type 2 inflammation in Phase 3 trials, establishing that IL-4 and IL-13 are key and central drivers of the type 2 inflammation that plays a major role in multiple related and often co-morbid diseases. These diseases include approved indications for Dupixent such as asthma, atopic dermatitis, chronic rhinosinusitis with nasal polyposis (CRSwNP), EoE and prurigo nodularis (PN). Dupixent has received regulatory approvals in one or more countries around the world for use in certain patients with atopic dermatitis, asthma, CRSwNP, EoE or PN in different age populations. Dupixent is currently approved across these indications in the U.S. and for one or more of these indications in more than 60 countries, including in the European Union and Japan. More than 500,000 patients have been treated with Dupixent globally. Dupilumab Development Program Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement. To date, dupilumab has been studied across more than 60 clinical trials involving more than 10,000 patients with various chronic diseases driven in part by type 2 inflammation. In addition to the currently approved indications, Sanofi and Regeneron are studying dupilumab in a broad range of diseases driven by type 2 inflammation or other allergic processes in Phase 3 trials, including pediatric EoE, hand and foot atopic dermatitis, chronic inducible urticaria-cold, chronic spontaneous urticaria, chronic pruritis of unknown origin, chronic obstructive pulmonary disease with evidence of type 2 inflammation, chronic rhinosinusitis without nasal polyposis, allergic fungal rhinosinusitis, allergic bronchopulmonary aspergillosis and bullous pemphigoid. These potential uses of dupilumab are currently under clinical investigation, and the safety and efficacy in these conditions have not been fully evaluated by any regulatory authority. About Regeneron Regeneron is a leading biotechnology company that invents, develops and commercializes life-transforming medicines for people with serious diseases. Founded and led for nearly 35 years by physician-scientists, our unique ability to repeatedly and consistently translate science into medicine has led to nine FDA-approved treatments and numerous product candidates in development, almost 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, pain, hematologic conditions, infectious diseases and rare diseases. Regeneron is accelerating and improving the traditional drug development process through our proprietary VelociSuite® technologies, such as VelocImmune®, which uses unique genetically humanized mice 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 more information, please visit www.Regeneron.com or follow @Regeneron on Twitter. About SanofiWe are an innovative global healthcare company, driven by one purpose: we chase the miracles of science to improve people’s lives. Our team, across some 100 countries, is dedicated to transforming the practice of medicine by working to turn the impossible into the possible. We provide potentially life-changing treatment options and life-saving vaccine protection to millions of people globally, while putting sustainability and social responsibility at the center of our ambitions. Sanofi is listed on EURONEXT: SAN and NASDAQ: SNY. 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