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 <0%) was also observed. At 12 weeks, endoscopically confirmed EE recurrence was observed in 5/18, 2/20, and 7/20 of patients receiving vonoprazan 10 mg, vonoprazan 20 mg, and lansoprazole, respectively. TEAEs were experienced by 66.8% (157/235), 69.0% (156/226), and 65.3% (158/242) of patients receiving vonoprazan 10 mg, vonoprazan 20 mg, and lansoprazole, respectively. The most common TEAE was upper respiratory tract infection in 12.8% (30/235) and 12.8% (29/226) patients in vonoprazan 10 mg and 20 mg groups, respectively and 8.7% (21/242) patients in lansoprazole group.

CONCLUSION: Vonoprazan maintenance therapy was well-tolerated and noninferior to lansoprazole for preventing EE recurrence in Asian patients with healed EE.