Efficacy and Safety of Vonoprazan Compared to Lansoprazole in Participants With Erosive Esophagitis

Inclusion criteria

• . The participant is ≥18 years of age at the time of informed consent signing.
• . In the opinion of the investigator or subinvestigators, the participant is capable of understanding and complying with protocol requirements.
• . The participant signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures. The participant is informed of the full nature and purpose of the study, including possible risks and side-effects. The participant has the ability to cooperate with the investigator. Ample time and opportunity should be given to read and understand verbal and/or written instructions.
• . The participant is found to have endoscopically confirmed EE of LA Classification Grades A to D during the Screening Period (Visit 1) as assessed by a central adjudicator. The target number of participants with LA classification Grade C or D will be approximately 30% of the total number of participants (300 total). Enrollment of EE participants with Grade A or B will end when the number of participants with Grade A or B EE is approximately 700 or 70% of the total planned number of participants. Given the invasive nature of an endoscopy, any endoscopic confirmation performed in a routine clinical setting before signing the informed consent will be acceptable to use for the purpose of fulfilling the screening requirement if all of the following apply: (1) appropriate endoscopy pictures were taken; (2) appropriate gastric biopsy samples were taken; (3) the endoscopy pictures can be sent to the central adjudicator via the adjudication systems; and (4) all screening procedures (including the completion of adjudication) AND randomization can be completed within a 7-day period after the date of the endoscopy.
• . A female participant of childbearing potential who is or may be sexually active with a nonsterilized male partner agrees to routinely use adequate contraception from the signing of informed consent until 4 weeks after the last dose of study drug.