PC3003: Baseline Demographics and Disease Characteristics of Adolescent and Adult Patients with Eosinophilic Esophagitis from Part B of the 3-part, Randomized, Placebo-controlled, Phase 3 TREET Study

Background: Eosinophilic esophagitis (EoE) is a chronic, type 2 immune-mediated disease predominantly diagnosed in White young adult males, and increasingly in other racial groups. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4/interleukin-13, key and central drivers of type 2 inflammation. In Parts A/B of the 3-part, double-blind, placebo-controlled, phase 3 LIBERTY EoE TREET study (NCT03633617), weekly dupilumab 300mg vs placebo demonstrated significant, clinically meaningful improvements in symptomatic and histologic aspects of the disease in adolescents/adults with EoE up to 24 weeks, and was generally well tolerated. Part B also assessed dupilumab 300mg every 2 weeks. In patients from Part A who continued to Part C, efficacy was sustained to Week 52. Here we present baseline demographic and disease characteristics of adolescent/adult patients with EoE in Part B.

Methods: Part B enrolled adolescents/adults EoE patients with EoE evidenced by peak eosinophil (eos) count of ≥15/high powered field (hpf) in ≥2/3 esophageal regions, who were unresponsive to 8-week treatment with high-dose proton-pump-inhibitors; had no other causes of esophageal eosinophilia; had history of ≥2 episodes of dysphagia/week over 4 weeks; ≥4 episodes of dysphagia in the two weeks prior to baseline, with ≥2 requiring intervention; and Dysphagia Symptom Questionnaire (DSQ) score ≥10.

Results: 79 adolescents (mean age 15.0) and 161 adults (mean age 34.6) were enrolled in Part B (Table). The majority of patients were male (adolescent/adult:72.2/59.6%), White (81.0/95.0%), and had a mean BMI of 22.7/27.1, mean duration of EoE of 5.5/5.6 years, and mean age of onset of 10.2/29.7 years. Over two thirds of patients had used swallowed topical corticosteroids (STCs), and 51.9/47.8% either inadequately responded to or were intolerant and/or had contraindications to using STCs. 6.3/49.7% of adolescent/adult patients had prior esophageal dilations, with a mean (SD) of 2.8 (4.0)/2.2 (2.7) dilations; and 54.4/28.6% were on dietary elimination therapy at screening. Most adolescent/adult patients had type 2 inflammatory comorbidities (91.1/88.1%), including allergic rhinitis (70.9/58.1%), food allergy (67.1/46.9%), asthma (50.6/31.3%), and atopic dermatitis (29.1/15.6%). Mean (SD) baseline scores for adolescent/adult patients were: DSQ, 36.2 (12.1)/36.9 (10.8); EoE-endoscopic reference score (EREFS), 6.2 (3.0)/7.7 (3.1); EoE-histology scoring system (HSS) grade, 1.3 (0.4)/1.3 (0.4); EoE-HSS stage, 1.3 (0.4)/1.2 (0.3). Mean (SD) baseline peak esophageal eosinophil counts for adolescent/adult patients were 80.6 (44.3)/90.3 (46.3) eos/hpf, median (Q1–Q3) levels of peripheral eos were 0.5 (0.3–0.6)/0.4 (0.3–0.5) Giga/L, and median serum total IgE levels were 235.0 (102.0–586.0)/112.0 (42.3–237.0) IU/mL

Conclusion: Baseline characteristics of patients enrolled in Part B of the phase 3 LIBERTY EoE TREET reveal a symptomatic, severely inflamed, and previously difficult-to-treat population of adolescent and adult patients. Baseline characteristics were similar between adolescents and adults although fewer adolescent patients had prior dilations.