In May, the U.S. Food and Drug Administration approved dupilumab (Dupixent) as a treatment for eosinophilic esophagitis (EoE) in adults and pediatric patients 12 years and older weighing at least 40 kilograms (which is about 88 pounds). Today’s action marks the first FDA approval of a treatment for EoE. Dupilumab, originally approved by the FDA in 2017, is a monoclonal antibody that acts to inhibit part of the inflammatory pathway.
Dupilumab’s efficacy and safety in EoE was studied in a randomized, double-blind, parallel-group, multicenter, placebo-controlled trial that included two 24-week treatment periods (Part A and Part B) that were conducted independently in separate groups of patients. Patients in both parts received either a placebo or 300 milligrams of dupilumab every week. The two primary measurements of efficacy were the proportion of patients who achieved a certain level of reduced eosinophils in the esophagus at week 24 (determined by assessing esophageal tissue under a microscope) and change in the patient-reported Dysphagia Symptom Questionnaire (DSQ) score from baseline to week 24.
Sixty percent of the 42 Part A patients who received dupilumab achieved the predetermined level of reduced eosinophils in the esophagus compared to 5% of the 39 patients who received a placebo. Part A patients in who received dupilumab experienced an average improvement of 22 points in their DSQ score compared to 10 points in patients who received a placebo. In Part B, 59% of the 80 patients who received dupilumab achieved the predetermined level of reduced eosinophils in the esophagus compared to 6% of the 79 patients who received a placebo; Part B patients who received dupilumab had an average 24-point improvement in their DSQ score compared to 14 points for placebo patients.