S4214 Novel Strategy for Deep Remission in EoE: Combining Dupilumab With Palatable Elemental Diet

Introduction: Eosinophilic esophagitis (EoE) can involve all layers of the esophagus and, if left undertreated, may lead to progressive fibrosis and stricture formation. Effective therapies include proton pump inhibitors (PPIs), topical steroids, dupilumab, and elemental diets. We present a case of PPI-refractory EoE with partial response to dupilumab who showed clinical and objective improvement following a course of a palatable elemental diet. Case Description/Methods: In 2023, esophagogastroduodenoscopy (EGD) showed active EoE with Eosinophilic Esophagitis Endoscopic Reference Score (EREFS) of 1-2-2-1-0 with biopsies showing up to 40 eosinophils/hpf. Dupilumab 300 mg weekly was initiated, and PPI was discontinued. Dysphagia partially improved and a repeat EGD 3 months post-dupilumab showed improved EREFS of 1-0-0-0-0 and no eosinophils on biopsies. However, EndoFLIP™ showed repetitive antegrade contractions but lack distensibility of the lower esophageal sphincter (60cc balloon, pressure 55 mmHg, diameter 9 mm and distensibility index of 2.0) suggestive of ongoing mural inflammation. EGD in 2024 showed similar findings with continued mild dysphagia. In 2025, the patient underwent 2-week course of exclusive palatable elemental diet to treat IMO, resulting in improvement in bloating and bowel habits, with a drop in exhaled methane from 58 to 17 ppm Remarkably, the patient also experienced complete resolution of dysphagia. Follow-up EGD demonstrated complete mucosal healing (EREFS 0) and normalization of esophageal distensibility (70cc balloon: pressure 45 mmHg, diameter 15 mm, distensibility index 4.0). At 3-month follow-up, the patient remained asymptomatic. Discussion: This case highlights the utility of EndoFLIP™ in guiding the management of EoE and underscores the potential of elemental diets to induce deep remission in patients with incomplete response to dupilumab.