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Sanofi and Regeneron Announce Positive Phase 2 Study Results for Dupilumab in Patients With Active Moderate-to-Severe Eosinophilic Esophagitis

Sanofi and Regeneron Pharmaceuticals, Inc. today announced positive results from a Phase 2 investigational study of dupilumab in adults with active moderate-to-severe eosinophilic esophagitis. The study showed that patients who received dupilumab weekly reported a significant improvement in the ability to swallow versus placebo. The results of this study were presented at the World Congress of Gastroenterology (WCOG) held in partnership with The American College of Gastroenterology Annual Scientific Meeting (ACG 2017) in Orlando, Florida.
Eosinophilic esophagitis is a chronic, allergic inflammatory disease that damages the esophagus and prevents it from working properly, leading to difficulties swallowing and food impaction.[1] Food allergies are the main cause of eosinophilic esophagitis in a large number of patients. Corresponding with the increase in incidence of allergic diseases in the overall population, eosinophilic esophagitis is rapidly increasing in incidence.
The primary endpoint of the study was the change from baseline to week 10 in the Straumann Dysphagia Instrument (SDI) score, a patient-reported measure of swallowing difficulty on a 0-9 point scale, with 9 indicating more severe symptoms. A total of 47 patients were randomized into two treatment groups in this 12-week treatment study and both groups had a mean baseline SDI score of 6.4. Patients received dupilumab 300 mg weekly following a 600 mg loading dose or placebo.  At week 10, patients who received 300 mg weekly reported a significant improvement in the ability to swallow with a 3 point reduction in their SDI score (45 percent improvement) compared to 1.3 (19 percent improvement) for those patients who received placebo (p=0.0304).
Secondary endpoints of the study included measures of the impact of dupilumab on endoscopic and histopathologic measures of disease severity, as well as symptoms. The results include:
  • The mean change in the Eosinophilic Esophagitis Endoscopic Reference Score (EoE-EREFS) was significantly reduced by 1.9 from baseline (48 percent improvement) in patients who received dupilumab weekly compared to 0.3 (7 percent improvement) for those who received placebo at 12 weeks (p=0.0006). EoE-EREFS is a visual measure of disease severity (inflammation and fibrosis in the esophagus) on a 0-8 point scale, with 8 indicating more severe disease. The mean baseline score for the dupilumab group was 3.9 and for the placebo group was 4.3.
  • The mean percent change in overall peak intraepithelial eosinophil count from baseline to 12 weeks was significantly reduced by 93 percent from baseline in patients who received dupilumab weekly compared to an increase of 14 percent in those who received placebo (p<0.0001).
  • The mean percent change in a composite measure of symptoms and quality of life, as measured by Eosinophilic Esophagitis Symptom Activity Index (EEsAI), was numerically improved (although not statistically significant) by 35 percent in patients who received dupilumab weekly compared to an 11 percent improvement for those who received placebo at 10 weeks (p=0.085).
Clinical manifestations of eosinophilic esophagitis in adults include difficulty swallowing and food impaction, which are consequences of pathological structural changes to the esophagus. Natural history studies have demonstrated an association between duration of untreated disease and the development of these esophageal changes,” said Ikuo Hirano, M.D., Professor of Medicine, Northwestern University Feinberg School of Medicine.  “Currently, there are no FDA-approved therapies for eosinophilic esophagitis. In this study, dupilumab, a monoclonal antibody targeting IL-4 and IL-13, significantly improved patients’ ability to swallow, inflammation of the esophagus, and endoscopic signs of the disease. These positive Phase 2 results support further clinical development of dupilumab for patients with eosinophilic esophagitis.” 
There were no new significant safety concerns in this trial. Higher rates of injection site reactions were observed on Dupilumab versus placebo.
Clinical and preclinical research indicates that the IL-4/IL-13 pathway may have an important role in allergic or Type 2 inflammation. Dupilumab, an antibody that inhibits IL-4/13 signaling, has been approved in the U.S. and EU for moderate-to-severe atopic dermatitis and has demonstrated clinical activity in two other investigational areas under study (asthma and nasal polyps).
Eosinophilic esophagitis is a chronic disease characterized by high levels of eosinophils in the esophagus.   The results of investigational IL-5 blocking studies in eosinophilic esophagitis suggest that eosinophils may act as a biomarker of broader allergic or Type 2 inflammation in the esophagus, but that eosinophils may not be solely responsible for disease activity. In the study presented today, the observed symptomatic and anatomic improvements associated with dupilumab, together with this reduction of eosinophils, suggest that dupilumab may have the potential to reverse multiple aspects of Type 2 inflammation in eosinophilic esophagitis.
Current treatment options for people with moderate-to-severe eosinophilic esophagitis are limited to diet modification, corticosteroids or surgery. The disease can affect patient’s health-related quality of life, including altered eating behaviors and pain when swallowing. People with active, moderate-to-severe eosinophilic esophagitis live with the risk of complete blockage or injury to their esophagus because of food impaction, and emergency care is often required for severe obstructions.
Dupilumab recently received Orphan Drug Designation from the FDA for the potential treatment of eosinophilic esophagitis. This status is given to investigational medicines being developed for the treatment of rare diseases or conditions that affect fewer than 200,000 people in the United States.
The potential use of dupilumab in eosinophilic esophagitis is currently under clinical development and the safety and efficacy have not been fully evaluated by any regulatory authority.