Dupilumab (Dupixent) jointly developed by Sanofi and Regeneron has been approved by the FDA to treat Eosinophilic esophagitis in adults and children aged 12 and above who weigh at least 40 kg (88 lb), making it the first drug to be approved for the indication.

Dupilumab blocks interleukin-4 and -13 receptors, inhibiting part of the inflammatory cascade and lowering esophageal inflammation caused by eosinophil accumulation.

Dupilumab was formerly approved for certain patients with moderate-to-severe atopic dermatitis, some kinds of moderate-to-severe asthma, and poorly managed chronic rhinosinusitis with nasal polyposis.

The FDAs approval was based on a placebo-controlled parallel-group trial which was conducted in distinct groups of patients (Part A and Part B) for two 24-week treatment periods. Subjects were administered either placebo or 300 mg of Dupilumab weekly. 

A predetermined level of reduced eosinophils was achieved among 60% of patients who received Dupilumab in Part A compared to 5% in patients receiving placebo. An average improvement of 22 points on the Dysphagia Symptom Questionnaire (DSQ) score was observed in Dupilumab-treated patients, while placebo receiving patients showed a 10-point improvement. Similarly, in Part B, a pre-determined level of reduced eosinophils was observed in 59% of patients in the Dupilumab group compared to 6% in the placebo group, while DSQ scores showed an improvement of 24 points in the Dupilumab group against 14 points for the placebo.

Common side effects included reactions at the injection site, infections of the upper respiratory tract, pain in joints and herpes viral infections. Contraindications were reported among patients who were hypersensitivity to Dupilumab or any of its inactive ingredients. Hence, warnings and precautions regarding the same were included.