Dupilumab (Dupixent) became the first drug approved to treat eosinophilic esophagitis in adults and pediatric patients ages 12 and older weighing at least 40 kg (~88 lb), the FDA announced. Eosinophilic esophagitis is a chronic, progressive disease in which the esophagus becomes inflamed due to a buildup of eosinophils, creating difficulty swallowing and eating. Dupilumab is a monoclonal antibody that acts to inhibit part of the inflammatory pathway, blocking interleukin-4 and -13 receptors. "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.," Jessica Lee, MD, director of the division of gastroenterology in the FDA's Center for Drug Evaluation and Research, said in a statement. "Today's approval will fulfill an important unmet need for the increasing number of patients with eosinophilic esophagitis," she added.
The FDA's greenlight expands the indication for dupilumab, which is also approved for moderate-to-severe atopic dermatitis in certain adult and pediatric patients, some types of moderate-to-severe asthma, and poorly controlled chronic rhinosinusitis with nasal polyposis. The FDA's decision was based on a parallel-group placebo-controlled trial that included two 24-week treatment periods -- Part A and Part B -- conducted independently in separate groups of patients. In both parts of the trial, participants received placebo or 300 mg of dupilumab weekly. Primary efficacy measurements were the proportion of patients who achieved a certain level of reduced eosinophils in the esophagus at week 24 and the change in Dysphagia Symptom Questionnaire (DSQ) score from baseline to week 24. The DSQ measures difficulty swallowing associated with eosinophilic esophagitis; total scores range from 0 to 84, with higher scores indicating worse symptoms.
In Part A, 60% of patients who received dupilumab achieved the pre-determined level of reduced eosinophils, compared with 5% in the placebo group. Dupilumab-treated patients reported an average improvement of 22 points on the DSQ, compared with a 10-point improvement in the placebo group. In Part B, 59% of patients who received dupilumab reached the pre-determined level of reduced eosinophils compared with 6% of the placebo group. Patients who received dupilumab reported an average improvement of 24 points in DSQ scores versus 14 points for placebo. Patient perspectives supported that DSQ scores with dupilumab represented clinically meaningful improvement in dysphagia.
The most common side effects associated with dupilumab include injection site reactions, upper respiratory tract infections, joint pain, and herpes viral infections, the FDA said. The drug is contraindicated for patients with known hypersensitivity to dupilumab or any of its inactive ingredients. Dupilumab carries warnings and precautions about the potential development of allergic reactions, conjunctivitis, keratitis, or joint pain; use in patients with certain parasitic infections; and use in conjunction with live vaccinations, the agency added.
Dupilumab is being jointly developed by Sanofi and Regeneron under a global collaboration agreement. It has been studied in 60 clinical trials involving more than 10,000 patients with various chronic diseases driven in part by type 2 inflammation.
Dr. Katherine Bloom of Allergy & Asthma Care comments: "Eosinophilic esophagitis has become a very common cause of symptoms in both pediatric and adult patients, often leading to chronic discomfort and dramatic dietary limitations. Swallowed corticosteroid formulations originally developed for asthma, acid suppressant medications, and food elimination diets have been the mainstay of treatment, but this is the first therapy specifically approved for EoE, and offers the opportunity for relief to a large number of patients who have not been controlled on current treatment protocols. It is the first in what is likely to be a number of biologic medications geared toward controlling the underlying inflammation involved in this disorder."
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