A Study in China Evaluating the Safety and Efficacy of Adding Sitagliptin to Stable Therapy With Insulin With or Without Metformin in Participants With Type 2 Diabetes Mellitus (T2DM) (MK-0431-254)

A study to compare safety and efficacy of sitagliptin and placebo therapy when added to stable insulin alone or in combination with metformin in participants with type 2 diabetes mellitus (T2DM). The primary hypothesis of this study is that after 24 weeks, the addition of sitagliptin compared with placebo provides greater reduction in hemoglobin A1C (HbA1C) in T2DM participants on insulin alone or in combination with metformin.