Sang Hee Choi, MD1, Jeffrey Nguyen, MD2, Gordon Liss, MD3, Quan Nhu, MD, PhD4 1Scripps Green Hospital, San Diego, CA; 2Scripps Green Hospital, La Jolla, CA; 3Scripps Clinic, Oceanside, CA; 4Scripps Clinic & Scripps Research Institute, La Jolla, CA Introduction: Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but are associated with immune-related adverse events (irAEs). ICI-induced eosinophilic esophagitis (EoE) is a rare irAE. Data on managing ICI-induced EoE, particularly with dupilumab, are lacking. We present a case of ICI-induced EoE in a patient on non-EoE dosing of dupilumab, an IL-4Rα antagonist, who achieved clinical, endoscopic, and histologic remission following sustained ICI discontinuation.
Case Description/
Methods: A 66-year-old female with a history of metastatic melanoma, status post nivolumab/ipilimumab initiation followed by maintenance nivolumab, and GERD on famotidine, presented with abnormal esophageal activity on PET/CT. She had recently completed 26 ICI cycles 3 months prior. PET/CT showed moderately increased metabolic activity in the distal esophagus. Notably, ICI course was complicated by dermatitis and pruritis, managed with dupilumab 300 mg once every 2 weeks (q2w). Dupilumab was initiated for skin irAE, starting 1 year before ICI completion and continuing until 10 months post-ICI completion.
In retrospect, 3 months after being on q2w dupilumab for skin irAE, she developed mild dysphagia to solids, despite GERD being controlled with famotidine. EGD performed for nausea and vomiting at 10 months on q2w dupilumab showed a normal esophagus; no esophageal biopsies were taken at that time. Five months later, for the abnormal esophageal PET/CT activity at 3 months post-ICI completion and a 1-year history of dysphagia, EGD revealed esophageal edema, furrows, and exudates; biopsies showed 40 eosinophils per high-power field (eos/hpf), consistent with EoE.
Off ICI, she continued non-EoE q2w dupilumab for both skin irAE and EoE, along with famotidine for GERD. A 6-month repeat EGD at 10 months post-ICI completion showed a normal esophagus with a resolution of EoE features and histologic remission at 0-1 eos/hpf. She discontinued dupilumab subsequently but remained in clinical remission; a surveillance EGD is pending. Discussion: While studies have shown that dupilumab improves EoE histologically, even at non-EoE dosing, concurrent use of q2w dupilumab did not prevent ICI-induced EoE pathology in this case. This patient achieved clinical, endoscopic, and histologic remission only after increased time away from ICI discontinuation, suggesting that non-EoE dupilumab dosing alone may be insufficient for preventing ICI-induced EoE. Further research is needed to guide the prevention and management of ICI-induced EoE.
Disclosures: Sang Hee Choi indicated no relevant financial relationships. Jeffrey Nguyen indicated no relevant financial relationships. Gordon Liss indicated no relevant financial relationships. Quan Nhu: Regeneron – Advisory Committee/Board Member, Consultant, Speakers Bureau. Sanofi – Advisory Committee/Board Member, Speakers Bureau. Takeda – Advisory Committee/Board Member, Speakers Bureau.
Sang Hee Choi, MD1, Jeffrey Nguyen, MD2, Gordon Liss, MD3, Quan Nhu, MD, PhD4. P0747 - Development of Immune Checkpoint Inhibitor-Induced Eosinophilic Esophagitis (EoE) in a Patient on Non-EoE Dupilumab Dosing, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.
