FDA approves dupilumab as first Treatment for Eosinophilic Esophagitis

Dupilumab (Dupixent, Regeneron Pharmaceuticals, Inc.) is first drug in the U.S. specifically indicated for the treatment of eosinophilic esophagitis.

The U.S. Food and Drug Administration has approved Dupixent (dupilumab) to treat 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.

"As researchers and clinicians have gained knowledge about eosinophilic esophagitis in recent years, more cases of the disorder have been recognized and diagnosed in the U.S.," said Jessica Lee, M.D., director of the Division of Gastroenterology in the FDA's Center for Drug Evaluation and Research. "Today's approval will fulfill an important unmet need for the increasing number of patients with eosinophilic esophagitis."

EoE is a chronic inflammatory disorder in which eosinophils, a type of white blood cell, are found in the tissue of the esophagus. In adults and adolescent patients with EoE, common symptoms include difficulty swallowing, difficulty eating, and food getting stuck in the esophagus. Dupixent is a monoclonal antibody that acts to inhibit part of the inflammatory pathway.

The efficacy and safety of Dupixent 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. In Part A and Part B, patients received either placebo or 300 milligrams of Dupixent 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, as determined by assessing patients' esophageal tissue under a microscope, and the change in the patient-reported Dysphagia Symptom Questionnaire (DSQ) score from baseline to week 24. The DSQ is a questionnaire designed to measure difficulty swallowing associated with EoE, with total scores ranging from 0 to 84; higher DSQ scores indicate worse symptoms.

In Part A of the trial, 60% of the 42 patients who received Dupixent achieved the pre-determined level of reduced eosinophils in the esophagus compared to 5% of the 39 patients who received a placebo. Patients in Part A who received Dupixent experienced an average improvement of 22 points in their DSQ score compared to 10 points in patients who received placebo.

In Part B, 59% of the 80 patients who received Dupixent achieved the pre-determined level of reduced eosinophils in the esophagus compared to 6% of the 79 patients who received a placebo. Patients in Part B who received Dupixent experienced an average improvement of 24 points in their DSQ score compared to 14 points in patients who received placebo. Assessments incorporating the perspectives from patients with EoE supported that the DSQ score improvement in patients who received Dupixent in the clinical trial was representative of clinically meaningful improvement in dysphagia.

The most common side effects associated with Dupixent include injection site reactions, upper respiratory tract infections, joint pain, and herpes viral infections.

Dupixent is contraindicated in patients with known hypersensitivity to dupilumab or any of its inactive ingredients. Dupixent carries warnings and precautions, including ones addressing potential development of allergic reactions, conjunctivitis, keratitis, or joint pain; use in patients with certain parasitic infections; and use in conjunction with live vaccinations.

Dupixent received priority review and breakthrough therapy designations for this indication.

Dupixent was originally approved in 2017. It is approved for the treatment of moderate-to-severe atopic dermatitis in adult and pediatric patients aged 6 and older whose disease is not adequately controlled by topical prescription therapies or when those therapies are not advisable. Dupixent is also approved as an add-on maintenance treatment of adults and pediatric patients aged 6 and older with certain types of moderate-to-severe asthma, as well as an add-on maintenance treatment in adults with inadequately controlled chronic rhinosinusitis with nasal polyposis.