404. REAL-WORLD TREATMENT PATTERN OF EOSINOPHILIC ESOPHAGITIS IN JAPAN

Abstract Background Eosinophilic esophagitis (EoE) is characterized by eosinophilic infiltration in the esophageal epithelium that causes esophageal dysfunction-related symptoms. The treatment for EoE includes acid suppressants (proton pump inhibitors (PPIs) or potassium competitive acid blocker (P-CAB)), topical corticosteroid (TCS), and diet therapy. In addition, biologics (i.e. dupilumab) have been recently approved for EoE in the US. However, the appropriate initial and maintenance therapy for EoE have not been established yet. Therefore, the aim of the study was to investigate the treatment pattern of EoE and its association with fibrostenosis in Japan. Methods We investigated prescription pattern for EoE analyzing an employer-based health insurance claim database from 2005 to 2022. EoE cases were identified based on the International Classification of Diseases-tenth Revision code, K20.0. The initial treatment of interest for EoE included PPIs, P-CAB, and TCS (swallowed inhaled CS). The initial treatment for EoE was defined as these drugs prescribed within two months from the index date of EoE diagnosis. The discontinuation rates of initial PPIs or P-CAB were analyzed using Kaplan-Meier method. The discontinuation of treatment was defined as no treatment following within 90 days from the prescription of the previous treatment. Results Overall, 984 EoE patients (45 years old [38-52], male 747 [75.9%]) were ultimately analyzed. Most of the initial treatment for EoE was acid suppressants (PPIs [323 54.9%], P-CAB [241, 41%]), followed by TCS (13, 2.2%) and combination therapy of PPIs or P-CAB and TCS (11, 1.9%). PPIs or P-CAB discontinued in approximately 50% and 70% of the cases at approximately 150 days and 720 days respectively from the start of the initial therapy. The switching to the second-line therapy from the initial PPIs or P-CAB rarely happened. During the observation period, no EoE patients developed esophageal stenosis. Conclusion PPIs or P-CAB were most prescribed as the initial treatment for EoE in Japan. In addition, more than half of EoE patients discontinued such initial therapy within 2 years without fibrostenotic complication. These findings indicate that EoE that can respond to initial acid suppressants therapy does not necessarily require the maintenance therapy to prevent esophageal fibrostenosis.