Regeneron Pharmaceuticals, Inc. and Sanofi announced 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.