Rationale and design of the VISION study: a randomized, open-label study to evaluate the long-term safety of vonoprazan as maintenance treatment in patients with erosive esophagitis

Erosive esophagitis (EE) occurs when the epithelial mucosa is damaged due to gastric acid reflux, and the incidence of this disease is increasing in Japan due to changes in diet and lifestyle. The condition can be treated using proton pump inhibitors (PPIs) that act by irreversibly blocking the H+,K+-ATPase responsible for acid secretion. Vonoprazan is a K+ competitive channel inhibitor, which reversibly and potently inhibits gastric acid secretion. However, long-term data on vonoprazan use are limited. The aim of the VISION trial is to investigate the long-term efficacy and safety of vonoprazan in comparison with the PPI lansoprazole. This randomized, multicenter, 5-year, open-label study has a planned recruitment of 195 participants (2:1 allocation vonoprazan:lansoprazole) from 33 sites in Japan. The study comprises an 8-week "healing" phase (vonoprazan 20 mg or lansoprazole 30 mg p.o.) and a 260-week "maintenance" phase (vonoprazan 10 mg or lansoprazole 15 mg). Safety populations in both phases are defined as participants who receive at least one dose of the study or control drug in the healing and maintenance phases, respectively. The full analysis set in both phases is defined as participants who are randomized and receive at least one dose of the study or control drug in the healing and maintenance phases, respectively. The primary endpoint of the study is the histopathological evaluation of gastric mucosa for the presence of neoplastic alteration of gastric mucosal epithelial cells. Secondary efficacy endpoints include endoscopic EE recurrence rate and EE healing rate, and secondary safety endpoints include incidence of adverse events (coded using MedDRA terminology) and endoscopic evaluation of malignant changes in the gastric mucosa. Patient recruitment started in March 2016 and is now complete. The estimated study completion date is February 2022.