Trelagliptin is a long acting dipeptidyl peptidase-4 (DPP-4) inhibitor that is being developed for the treatment of type 2 diabetes (T2D). Two Phase II clinical studies have been completed with Efficacy and Safety of SYR-472 in Subjects With Type 2 Diabetes Mellitus. Phase III clinical studies with trelagliptin in Japan to evaluate its safety and efficacy in a once-weekly oral treatment regimen. Currently, all available DPP-4 inhibitors are dosed once-daily. A once-weekly treatment, such as trelagliptin, would provide patients with a convenient treatment alternative and has the potential to improve treatment compliance.