The trial was amended to extend the length of the trial in order to meet FDA requirements for the post-approval assessment of cardiovascular (CV) safety. The trial now contains 2 time intervals: Period 1 and Period 2. Period 1 refers to the time interval up to this recent protocol amendment and Period 2, the time interval from this protocol amendment until the end of the study. Participants in Period 1 will be re-consented and continue into Period 2. If required, additional participants will be enrolled in Period 2. Stage 1 refers to the prefiling United States Food and Drug Administration (US FDA) requirement to rule out a 80% increased CV risk. Stage 2 refers to the US FDA post-marketing requirement to rule out a 30% increased CV risk. The Stage 1 assessment of CV risk occurred during Period 1 and was based on a meta-analysis of major adverse CV events (MACE) and unstable angina across the omarigliptin Phase 2/Phase 3 program. The Stage 2 assessment will be based on MACE in P018 alone including CV events from both Period 1 and Period 2.