A Study to Evaluate the Safety and Efficacy of Sitagliptin 100 mg in Participants With Type 2 Diabetes Mellitus Who Have Inadequate Glycemic Control (MK-0431-229)

A Phase III, Randomized, Clinical Trial to Evaluate the Safety and Efficacy of the Addition of Sitagliptin in Patients With Type 2 Diabetes Mellitus Who Have Inadequate Glycemic Control on a Sulfonylurea in Combination With Metformin

This study will evaluate whether the addition of Sitagliptin treatment provides a greater decrease in A1C levels compared to placebo in participants with inadequate glycemic control on sulfonylurea and metformin combination therapy.

Inclusion Criteria:

• Type 2 diabetes mellitus
• Hemoglobin A1C of ≥7.5% and ≤10.5%
• Currently taking a stable dose of metformin (at least 1500 mg/day) and either glimepiride (at least 2 mg/day) or gliclazide (at least 50% of maximum registered dose) for at least 10 weeks prior to study start
• Male, or a female who is highly unlikely to conceive

Exclusion Criteria:

• Type 1 diabetes mellitus or ketoacidosis
• Taking a dipeptidyl peptidase-4 (DPP-4) inhibitor (such as sitagliptin) or a glucagon-like peptide-1 (GLP-1) mimetic (such as exenatide or liraglutide) or required insulin therapy within 12 weeks prior to study start
• On a weight loss program not in the maintenance phase or on a weight loss medication
• History of liver disease, heart failure, heart disease, stroke, high blood pressure, blood disorders, or cancer
• HIV positive
• Pregnant