FDA Approves Dupilumab as First Therapy for Eosinophilic Esophagitis

Eosinophilic esophagitis is a chronic inflammatory disorder in which eosinophils, a type of white blood cell, proliferate in the esophagus, causing difficulties with eating and swallowing.

The FDA Friday approved dupilumab (Dupixent), a biologic, to treat eosinophilic esophagitis (EoE) in adults and children 12 years and older.

It is the first therapy approved specifically for EoE.

EoE was unknown a few decades ago; the chronic inflammatory disorder creates difficulty swallowing, difficulty eating, choking, and food getting stuck in the esophagus.

The monoclonal antibody acts on type 2 inflammation that drives the disease and causes eosinophils, a type of white blood cell, to flourish in the tissue of the esophagus, causing inflammation.

The approval, for patients weighing at least 40 kilograms, or about 88 pounds, was granted to Sanofi and Regeneron about 2 months earlier than expected, and comes at the end of National Eosinophil Awareness Week.

"We have waited a long time for an FDA-approved treatment option for eosinophilic esophagitis–an underdiagnosed and misunderstood disease of the esophagus that can make it extremely challenging and uncomfortable to eat and swallow," said Mary Jo Strobel, Executive Director at the American Partnership for Eosinophilic Disorders (APFED), in a statement provided by the drug companies. "Before today, there were no approved treatments specifically for eosinophilic esophagitis, resulting in many people needing to maintain a strict diet and live in constant fear of food getting stuck in their throat. We welcome therapeutic options that can provide much-needed relief for these patients."

“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 US,” said Jessica Lee, MD, 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.”

The efficacy and safety of dupilumab in EoE was studied in a randomized, double-blind, parallel-group, multicenter, placebo-controlled trial, that included 2 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 dupilumab every week.

The 2 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 dupilumab 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 dupilumab 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 dupilumab 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 dupilumab experienced an average improvement of 24 points in their DSQ score compared to 14 points in patients who received placebo.

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

Dupilumab is also approved to treat atopic dermatitis, moderate to severe asthma or chronic rhinosinusitis with nasal polyposis.