A Randomized, Placebo Controlled, Repeat Dose, Double Blind (Sponsor Unblind) Study Investigating Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of GSK2330672 Administered With Metformin to Type 2 Diabetes Patients

This study is being conducted to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of GSK2330672 compared to sitagliptin when administered with metformin for 14 days to subjects with type 2 diabetes mellitus (T2DM). Approximately 72 male and female subjects aged 30-64 years with T2DM and currently taking metformin will be recruited for this study. Eligible subjects will begin a run-in period of 13-15 days to stabilize on metformin 850 milligram (mg) twice a day (BID). Subjects will then be randomized to GSK2330672 10 mg, 20 mg, 30 mg, 90 mg, matching placebo or open-label sitagliptin 50 mg for 14 days BID. Subjects will return for a follow-up visit 7-10 days after discharge.