A Study of the Safety and Efficacy of Glimepiride, Gliclazide, Repaglinide or Acarbose When Added to Sitagliptin + Metformin Combination Therapy in Chinese Participants With Diabetes (MK-0431-313)

Participants coming on study will be stabilized to a standardized metformin dose: this may take about 10 weeks, and then combination therapy with metformin + sitagliptin will begin during Phase 1 (Week 0 through Week 20). If a participant has already been on a stabilized metformin dose, they will start immediately on combination therapy with metformin + sitagliptin for 20 weeks (Phase 1).

In Phase 2, participants who have failed to achieve adequate glycemic control (A1c ≥ 7% and ≤ 10% at Week 16 and fasting finger stick glucose ≥130 mg/dL and ≤280 mg/dL at Week 20) will be randomized to receive add-on therapy with glimepiride, repaglinide, acarbose, or gliclazide for 24 weeks (Week 20 through Week 44).

Inclusion criteria

• Has Type 2 Diabetes Mellitus;
• Agrees to use an effective method of contraception or must not otherwise be at risk of becoming pregnant (female participants).

Exclusion criteria

• Has a history of type 1 diabetes mellitus or a history of ketoacidosis;
• Has been treated with insulin, a dipeptidyl peptidase 4 (DPP-4) inhibitor, a Glucagon-like peptide-1 (GLP-1) mimetic or analogue before;
• Is on a weight loss program (not in maintenance phase), has started a weight loss medication, or has undergone bariatric surgery within 12 months;
• Has undergone a surgical procedure within 4 weeks;
• Has had new or worsening signs or symptoms of coronary heart disease or congestive heart failure within past 3 months, or has acute coronary syndrome, coronary artery intervention, or stroke or transient ischemic neurological disorder;
• Has a medical history of active liver disease, including chronic active hepatitis B or C, primary biliary cirrhosis, or symptomatic gallbladder disease;
• Has poorly controlled hypertension;
• Has severe peripheral vascular disease;
• Has human immunodeficiency virus (HIV);
• Has had a clinically important hematological disorder;
• Routinely consumes >2 alcoholic drinks per day or >14 alcoholic drinks per week, or engages in binge drinking;
• Has a history of intolerance or hypersensitivity or any contraindication to study medications (including sitagliptin, metformin, glimepiride, repaglinide, acarbose or gliclazide) based upon the Chinese label;
• Is on or likely to require treatment with ≥2 consecutive weeks or repeated courses of pharmacologic doses of corticosteroids (other than inhaled, nasal, or topical corticosteroids);
• Is pregnant or breast feeding or is expecting to conceive or donate eggs during the study, including 14 days following the last dose of study drug (female participants).