Sitagliptin (MK-0431) vs. Placebo in Patients With Inadequate Glycemic Control on Metformin With Pioglitazone (MK-0431-128)

A Phase III Randomized, Placebo-Controlled Clinical Trial to Study the Safety and Efficacy of the Addition of Sitagliptin (MK-0431) in Patients With Type 2 Diabetes Mellitus Who Have Inadequate Glycemic Control on Combination Therapy With Metformin and Pioglitazone

This study will examine the safety and efficacy of the addition of sitagliptin (MK-0431) compared to placebo in patients with type 2 diabetes mellitus with inadequate glycemic control who are taking pioglitazone and metformin.

Inclusion Criteria:

• has type 2 diabetes and is at least 18 years of age and no older than 78 years of age
• is male or is a female who is unlikely to conceive children
• is on stable doses of a peroxisome proliferator-activated receptor gamma agonist and metformin OR metformin and a sulfonylurea agent

Exclusion Criteria:

• has type 1 diabetes
• has taken a dipeptidyl peptidase (DPP-4) inhibitor or a glucagon-like peptide-1 (GLP-1) analogue
• is on a weight loss program that is not in the maintenance phase or has started a weight loss medication within 8 weeks of screening
• has had surgery within 30 days of screening or has major surgery planned during the study
• is on or is likely to require treatment with corticosteroids for more than 2 weeks
• has a history of active liver disease, including hepatitis B or C, cirrhosis, or gallbladder disease
• is human immunodeficiency virus (HIV) positive
• has congestive heart failure, or has had new or worsening symptoms of coronary heart disease within 3 months prior to screening
• has had acute coronary syndrome, coronary artery intervention, or stroke within 3 months of screening
• has severe active peripheral vascular disease
• has a history of cancer or blood disorder
• is pregnant or breast feeding