A140 DUPILUMAB IMPROVED HISTOLOGY, CLINICAL SYMPTOMS, AND ENDOSCOPIC FEATURES IN ADULTS AND ADOLESCENTS WITH EOSINOPHILIC ESOPHAGITIS THROUGH 52 WEEKS REGARDLESS OF BASELINE DISEASE DURATION: POST-HOC SUBGROUP ANALYSIS OF THE PHASE 3 LIBERTY EOE TREE

Abstract Background Limited literature is available on EoE disease duration and response to therapy. Dupilumab is approved for EoE in patients aged ≥12 years, weighing ≥40 kg, in the EU, and in patients aged ≥1 year, weighing ≥15 kg, in the USA and Canada. Aims To assess the long-term efficacy of dupilumab in patients with EoE stratified by baseline disease duration. Methods In Part B of LIBERTY EoE TREET (NCT03633617), patients received 24 weeks of dupilumab 300 mg or placebo weekly (qw). Eligible patients who completed Part B received dupilumab through 52 weeks (Part C). Co-primary endpoints were the proportion achieving peak esophageal intraepithelial eosinophil count (PEC) ≤6 eosinophils/high-power field (eos/hpf) and absolute change in Dysphagia Symptom Questionnaire (DSQ) total score. Secondary endpoints included proportion achieving PEC <15 eos/hpf, percent change in PEC, and mean change in Endoscopic Reference Score (EREFS) total score and Histologic Scoring System (HSS) grade/stage scores. Data were stratified by baseline disease duration defined as time since diagnosis (≤5 years, >5-≤10 years, >10 years). Results At Part B baseline in the dupilumab and placebo groups, respectively, 43 and 48 patients had EoE for ≤5 years, 22 and 13 patients had EoE for >5-≤10 years, and 15 and 18 patients had EoE for >10 years. At Week 24, PEC ≤6 eos/hpf and DSQ total score favored dupilumab over placebo, regardless of disease duration. Dupilumab also improved percent change in PEC and change in EREFS and HSS grade/stage scores across all disease duration subgroups vs placebo (Table). At Week 52, improvements were maintained in patients who received continued dupilumab; patients who switched from placebo to dupilumab at Week 24 also showed improvement in all outcomes. Overall safety was consistent with the known dupilumab safety profile. Conclusions These results show that dupilumab 300 mg qw is an effective long-term treatment for patients with EoE, including a subset of patients with longstanding disease potentially inadequately addressed by alternative therapies. Funding Agencies Research sponsored by Sanofi and Regeneron Pharmaceuticals Inc.