Abstract. Background:. Erosive esophagitis (EE) is a gastroesophageal reflux disease characterized by mucosal breaks in the esophagus. Proton pump inhibitors are widely used as maintenance therapy for EE, but many patients still relapse. In this trial, we evaluated the noninferiority of vonoprazan vs. lansoprazole as maintenance therapy in patients with healed EE. Methods:. We performed a double-blind, double-dummy, multicenter, phase 3 clinical trial among non-Japanese Asian adults with endoscopically confirmed healed EE from April 2015 to February 2019. Patients from China, South Korea, and Malaysia were randomized to vonoprazan 10 mg or 20 mg once daily or lansoprazole 15 mg once daily for 24 weeks. The primary endpoint was endoscopically confirmed EE recurrence rate over 24 weeks with a noninferiority margin of 10% using a two-sided 95% confidence interval (CI). Treatment-emergent adverse events (TEAEs) were recorded. Results:. Among 703 patients, EE recurrence was observed in 24/181 (13.3%) and 21/171 (12.3%) patients receiving vonoprazan 10 mg or 20 mg, respectively, and 47/184 (25.5%) patients receiving lansoprazole (differences: –12.3% [95% CI, –20.3% to –4.3%] and –13.3% [95% CI, –21.3% to –5.3%], respectively), meeting the primary endpoint of noninferiority to lansoprazole in preventing EE recurrence at 24 weeks. Evidence of superiority (upper bound of 95% CI