FDA accepts Dupixent® (dupilumab) for Priority Review in patients aged 12 years and older with eosinophilic esophagitis

• If approved, Dupixent would be the first medicine available in the U.S. indicated to treat eosinophilic esophagitis
• There are approximately 160,000 patients in the U.S. living with eosinophilic esophagitis who are currently treated, of whom approximately 48,000 have failed multiple treatments

Paris and Tarrytown, N.Y., April 4, 2022. The U.S. Food and Drug Administration (FDA) has accepted for Priority Review the supplemental Biologics License Application (sBLA) for Dupixent^® (dupilumab) 300 mg weekly to treat adult and pediatric patients aged 12 years and older with eosinophilic esophagitis (EoE), a chronic and progressive type 2 inflammatory disease that damages the esophagus and impairs the ability to swallow. The target action date for the FDA decision on this investigational use is August 3, 2022.

The sBLA is supported by data from two Phase 3 trials evaluating the efficacy and safety of Dupixent 300 mg weekly in patients aged 12 years and older with EoE (Part A and Part B), and data from an active long-term extension trial. Dupixent 300 mg weekly significantly improved the signs and symptoms of EoE at 24 weeks compared to placebo, including the ability to swallow and reduction in eosinophil count in the esophagus. The safety results of these trials were generally consistent with the known safety profile of Dupixent in its approved indications. The most common adverse event observed with Dupixent, in Part A and Part B, was injection site reactions.

In September 2020, the U.S. FDA granted Breakthrough Therapy designation to Dupixent for the treatment of patients aged 12 years and older with EoE. Dupixent was also granted Orphan Drug designation for the potential treatment of EoE in 2017. Priority review is granted to therapies that have the potential to provide significant improvements in the treatment, diagnosis or prevention of serious conditions. Regulatory filings around the world are also planned in 2022. The potential use of Dupixent in EoE is currently under clinical development, and the safety and efficacy have not been fully evaluated by any regulatory authority.

About Eosinophilic Esophagitis (EoE)

EoE is a chronic, progressive type 2 inflammatory disease that damages the esophagus and prevents it from working properly. For people with EoE, swallowing the smallest amount of food can be a painful and worrisome choking experience. Those with EoE live with anxiety and frustration from having a constantly evolving list of foods to avoid. This disease can also cause narrowing of the esophagus and dilation (physical expansion) of the esophagus may be needed, which is often painful. In severe cases, a feeding tube is the only option to ensure proper caloric intake and adequate nutrition. People with EoE may have poor quality of life and are more likely to experience depression than people without EoE. There are approximately 160,000 patients in the U.S. living with EoE who are currently treated, of whom approximately 48,000 have failed multiple treatments.

About Dupixent

Dupixent is a fully human monoclonal antibody that inhibits the signaling of the interleukin-4 (IL-4) and interleukin-13 (IL-13) pathways and is not an immunosuppressant. IL-4 and IL-13 are key and central drivers of the type 2 inflammation that plays a major role in atopic dermatitis, asthma and chronic rhinosinusitis with nasal polyposis (CRSwNP).

In the U.S., Dupixent is approved in patients aged 6 years and older with uncontrolled moderate-to-severe atopic dermatitis; as an add-on maintenance treatment of patients aged 6 years and older with moderate-to-severe asthma characterized by an eosinophilic phenotype or with oral corticosteroid-dependent asthma; and for use with other medicines for the maintenance treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP) in adults whose disease is not controlled.

Dupixent is also approved in Europe, Japan and other countries around the world for use in specific patients with moderate-to-severe atopic dermatitis and certain patients with asthma or CRSwNP in different age populations. Dupixent is approved in one or more of these indications in more than 60 countries around the world, and more than 400,000 patients have been treated 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, including eosinophilic esophagitis (Phase 3), pediatric atopic dermatitis (6 months to 5 years of age, Phase 3), chronic rhinosinusitis without nasal polyposis (Phase 3), chronic obstructive pulmonary disease with evidence of type 2 inflammation (Phase 3), prurigo nodularis (Phase 3), chronic spontaneous urticaria (Phase 3), bullous pemphigoid (Phase 3), chronic inducible urticaria-cold (Phase 3), allergic fungal rhinosinusitis (Phase 3), allergic bronchopulmonary aspergillosis (Phase 3) and peanut allergy (Phase 2). 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 (NASDAQ: REGN) is a leading biotechnology company that invents 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 additional information about the company, please visit www.regeneron.com or follow @Regeneron on Twitter.