The efficacy and safety of EOHILIA 2 mg twice daily were evaluated in two multicenter, randomized, double-blind, parallel-group, placebo-controlled 12-week studies (Study 1 [NCT02605837] and Study 2 [NCT01642212]). Eligible subjects in Study 1 and Study 2 had esophageal inflammation defined as ≥15 eosinophils/high-power field (hpf) from at least 2 levels of the esophagus at baseline following a treatment course of a proton pump inhibitor (PPI) either prior to or during screening and at least 4 days of dysphagia as measured by the Dysphagia Symptom Questionnaire (DSQ) over a 2-week period prior to randomization. Concomitant use of stable doses of inhaled or intranasal steroids (for conditions other than EoE), PPIs, H2-receptor antagonists, antacids, antihistamines or anti-leukotrienes, and maintenance immunotherapy was allowed. In Study 1, subjects were enrolled after maintaining a stable diet for at least 3 months prior to screening and were instructed to maintain a stable diet throughout the study. Subjects were excluded if they were on a full liquid or 6-food elimination diet. In Study 2, subjects were instructed to maintain a stable diet throughout the study. In Study 1 and Study 2, subjects were instructed to not eat or drink for 30 minutes after taking the drug and then to rinse their mouth with water and spit out the contents without swallowing prior to resuming normal oral intake.

A total of 318 subjects (277 adults and 41 pediatric subjects) were randomized and received at least one dose of study drug (EOHILIA or placebo) in Study 1. The mean age of the study population was 34 years (range 11 to 56 years). Sixty percent of subjects were male, 95% were White, and 3% were Hispanic or Latino. Over 80% of the subjects were on concomitant PPI. The mean (SD) DSQ combined scores at baseline were 30.3 (13.9) and 30.4 (13.1) in the EOHILIA and placebo groups, respectively.

A total of 92 subjects (58 adults and 34 pediatric subjects) were randomized and received at least one dose of study drug (EOHILIA or placebo) in Study 2. The mean age of the study population was 22 years (range 11 to 42 years). Sixty-eight percent of subjects were male, 95% were White, and 1% were Hispanic or Latino. Over 65% of the subjects were on concomitant PPI. The mean (SD) DSQ combined scores at baseline were 30.7 (16.0) and 29.0 (13.5) in the EOHILIA and placebo groups, respectively.

Study 1 and Study 2 evaluated efficacy endpoints of histologic remission (defined as a peak eosinophil count of ≤6/hpf across all available esophageal levels) and the absolute change from baseline in subject-reported DSQ combined score after 12 weeks of treatment.

Efficacy results for Study 1 and Study 2 are presented in Table 2.

During the last 2 weeks of the 12-week treatment periods in Study 1 and Study 2, a greater proportion of subjects randomized to EOHILIA experienced no dysphagia or only experienced dysphagia that “got better or cleared up on its own” compared to placebo, as measured by the subject-reported DSQ.

Additional Study

After completing Study 1, 48 subjects from the EOHILIA 2 mg treatment arm entered a double-blind randomized withdrawal extension study. These subjects received EOHILIA 2 mg twice daily or placebo for up to an additional 36 weeks. Treatment with EOHILIA did not demonstrate a statistically significant difference compared to subjects re-randomized to placebo for prespecified efficacy endpoints based on eosinophil count and/or clinical symptoms measured by the DSQ at Week 36.