Dupilumab (Dupixent) has been approved to treat eosinophilic esophagitis in adults and children ages 12 years and older who weigh at least 40 kilograms. This is the first drug approved for this disease. The drug was previously approved to treat moderate to severe atopic dermatitis in adults and children ages six years and older; as an adjunct maintenance treatment for moderate to severe asthma in patients ages six years and older; and to treat chronic rhinosinusitis with nasal polyposis.

Eosinophilic esophagitis is a chronic allergic reaction to food or environmental allergens that inflames the esophagus, causing it to narrow and develop rings or abscesses. The esophagus does not normally contain eosinophils, so their presence is considered pathological. The exact etiology of the disease is unknown. Symptoms of eosinophilic esophagitis vary, but can include trouble swallowing (dysphagia), chest pain or heartburn, abdominal pain, vomiting, and food stuck in the throat due to narrowing (this is a medical emergency).

Although it has similar symptoms to those of gastroesophageal reflux disease (GERD), eosinophilic esophagitis will not respond to treatment with proton pump inhibitors.

Dupilumab, an interleukin-4 receptor [alpha] antagonist, is a monoclonal antibody and immune globulin G4 inhibitor that inhibits the signaling of the interleukin-4 and interleukin-13 pathways, part of the inflammatory pathway responsible for the inflammation of eosinophilic esophagitis; it is not an immunosuppressant.

The efficacy and safety of dupilumab in eosinophilic esophagitis was determined in a single, randomized, double-blind, placebo-controlled, parallel-group, multicenter trial. The trial included two 24-week treatment periods (part A and part B) in which patients received 300 mg of dupilumab or placebo weekly. A total of 81 subjects (61 adults and 20 children) were in part A and 159 subjects (107 adults and 52 children) were in part B. All enrolled patients had elevated eosinophil counts following treatment with a proton pump inhibitor. All patients also provided subjective confirmation of dysphagia symptoms, as measured by the Dysphagia Symptom Questionnaire (DSQ). There were two primary efficacy end points for dupilumab after 24 weeks: the proportion of subjects achieving histological remission and the absolute change in self-reported DSQ score (improved symptoms) from baseline.

Approximately 60% of part A patients on dupilumab achieved the desired level of eosinophil reduction compared with just over 5% of those on placebo. Part A patients on dupilumab also reported vastly improved eosinophilic esophagitis symptoms compared with those receiving placebo. The outcome measures were similar for those in part B, with nearly 59% of patients who received dupilumab having fewer eosinophils in the esophagus compared with just over 6% of those receiving placebo. The subjective scores indicating symptom improvement in part B were also lower in those receiving dupilumab than in those receiving placebo.

Warnings and precautions for this clinical indication of dupilumab are similar to those for previously approved uses and include potential hypersensitivity reactions, conjunctivitis, keratitis, or joint pain; the need to treat helminth infections before starting dupilumab; and the need to avoid live vaccines while receiving dupilumab. The most common adverse effects associated with dupilumab treatment for eosinophilic esophagitis include injection site reactions, eosinophilia, upper respiratory tract infections, joint pain, and herpes viral infections.

Nurses should teach patients or their families how to give dupilumab subcutaneously using the prefilled pen or syringe. The drug should reach room temperature prior to injection. Nurses should also educate patients on the potential adverse effects of dupilumab. Women of childbearing age should be cautioned that the effects of dupilumab on pregnancy are unknown. If a woman becomes pregnant while receiving dupilumab, she can participate in a pregnancy exposure registry by calling 877-311-8972 or going to https://mothertobaby.org/ongoing-study/dupixent.

For complete prescribing information for dupilumab, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2022/761055s040lbl.pdf.