Dupilumab, a monoclonal antibody previously indicated for the treatment of atopic dermatitis and asthma, has been recently approved by the United States (US) Food and Drug Administration (FDA) for treating eosinophilic esophagitis (EoE), a chronic, inflammatory disease in which the build-up of a type of white blood cells called eosinophils in the esophagus leads to dysphagia and other severe symptoms in patients.^1,2 The approval was based on the positive results of the phase 3 LIBERTY EoE TREET trial, which demonstrated significant improvements in disease symptoms in adult and adolescent EoE patients treated with dupilumab vs. placebo.²

EoE is a T-helper type 2 (Th2) immune-mediated disease, where eosinophils build up in the esophagus, causing damage and preventing esophagus from functioning properly.^2,3 EoE has become increasingly prevalent worldwide, with 1 in 2,500 individuals in the western countries, and is now recognized as the primary cause of dysphagia in the adult population.^3,4 However, many patients fail to respond to the standard therapies of dietary elimination, proton pump inhibitors (PPIs) and steroids.⁴

The phase 3 LIBERTY EoE TREET study, involving 42 and 39 patients treated with dupilumab and placebo, respectively, showed positive effects of dupilumab in patients aged 12 years and older with EoE after 24 weeks of treatment.⁵ Based on the dysphagia symptom questionnaire (DSQ), dupilumab reduced the disease symptoms by 69%, but only by 32% with placebo (p=0.0002).⁵ Furthermore, with the baseline DSQ score of approximately 34 points, patients experienced a 21.92 point improvement with dupilumab compared with a 9.60 point improvement with placebo, on a 0-84 scale (p=0.0004).⁵ As another co-primary endpoint, with the mean baseline peak level of esophageal eosinophil count of 89 eos/hpf, about 60% of patients who received dupilumab achieved a normal level (≤6eos/hpf) vs. 5% of patients who received placebo (p<0.0001).⁵ Dupilumab also showed a significant improvement in abnormal endoscopic findings vs. placebo (p<0.0001).⁵

Another part of the study, which recruited a higher number of patients (n=159), confirmed the efficacy of dupilumab relative to placebo in adult and adolescent patients with EoE after 24 weeks of treatment.⁶ The DSQ data indicated a 64% reduction in disease symptoms from baseline, compared with 41% for placebo (p=0.0008).⁶ With the baseline DSQ score of approximately 38 and 36 points for patients receiving dupilumab and placebo, respectively, the former had a 23.78 point improvement vs. 13.86 point improvement in the placebo group (p<0.0001).⁶ In addition, with the similar mean baseline peak level of eosinophils for patients receiving dupilumab and placebo, nearly 10 times as many patients treated with dupilumab achieved significant histological remission vs. those receiving placebo (59% vs. 6%, p<0.0001).⁶

With regard to safety, adverse events (AEs) were found to be consistent with the known safety profile of dupilumab.⁶ The overall rate of AEs for dupilumab (300mg weekly) was 84%, while the most common AEs (≥5%) associated with dupilumab included injection site reactions, fever, sinusitis, coronavirus disease 2019 (COVID19) and hypertension.⁶

Overall, dupilumab is a novel EoE treatment option. It has been demonstrated in the clinical trials to be safe and more effective, compared with placebo for the EoE management in adult and pediatric patients aged 12 and older, and weigh at least 40kg.