S995 Efficacy of Monthly Dupilumab in Eosinophilic Esophagitis: A Retrospective Chart Review of Patients Under 1 Year of Age or Less Than 15 Kg

Introduction: Eosinophilic esophagitis (EoE) is a chronic inflammatory disease increasingly prevalent in young children, and management remains challenging as standard therapies are often insufficient to achieve remission. Dupilumab, a monoclonal antibody targeting Interleukin (IL)-4 and IL-13 initially used for asthma and atopic dermatitis, was approved by the U.S. Food and Drug Administration for EoE refractory to standard therapy, in 2022 for patients ≥12 years, and in 2024 for children ≥1 year and ≥15 kg. We conducted a retrospective chart review to explore the impact of dupilumab on EoE outcomes in patients <1 year or <15 kg who received this therapy for concurrent atopic dermatitis. Methods: We conducted a retrospective single-center chart review at the University of South Florida pediatric specialty clinics to identify individuals diagnosed with EoE (International Classification of Diseases-10 K20.0) at less than 1 year of age or less than 15 kg, and prescribed dupilumab (1 dose every 4 weeks). Patients were included in the analysis if they had upper endoscopy (EGD) pre- and 3 to 6 months post-dupilumab initiation. Student’s t test and Chi-squared test were used (significance P < 0.05), and a patient-level plot was created to visualize individual changes in peak eosinophils along the esophageal mucosa. Results: We identified 15 patients with EoE <1 year or <15 kg on dupilumab between 2021-2025. Five were excluded due to missing follow-up EGD. Among the 10 included, 60% were male, 60% identified as White, and 80% as non-Hispanic or Latino. Mean age at dupilumab initiation was 27.8 ± 13.3 months and mean weight 12.3 ± 2.7 kg. There was a significant reduction in the mean eosinophils per high-power field (hpf) in the distal esophagus (47.8 ± 39.1 vs 4.9 ± 8.0; P = 0.009) and mean peak eosinophils (64.1 ± 63.1 vs 5.7 ± 8.8; P = 0.006). However, the Eosinophilic Esophagitis Endoscopic Reference score remained unchanged. Before dupilumab, 70% (N = 7) were on dietary therapy for EoE. At follow-up, 57% of those patients (N = 4) had liberalized their diet, and 100% (N = 10) had a documented increase in their oral intake. Additionally, 70% had failed prior proton pump inhibitors and swallowed steroids. Conclusion: Monthly dupilumab may safely and effectively induce histologic remission and improve food intake in infants and small children with EoE. Further research is needed to optimize treatment for patients with early-onset EoE and poor growth currently ineligible for dupilumab.