Clinical Trial to Evaluate the Safety and Efficacy of the Addition of Sitagliptin in Participants With Type 2 Diabetes Mellitus Receiving Acarbose Monotherapy (MK-0431-130)

A Phase III, Multicenter, Randomized, Placebo-Controlled, Double-Blind 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 Diet/Exercise Therapy and Acarbose Monotherapy

This study will evaluate whether the addition of sitagliptin reduces hemoglobin A1C (A1C) more than the addition of placebo for participants with type 2 diabetes mellitus (T2DM) on a steady dose of acarbose. The primary hypothesis is that the addition of sitagliptin 100 mg once daily (q.d.) reduces A1C more than the addition of placebo in participants with T2DM with inadequate glycemic control on acarbose monotherapy.

The study includes an 8-week antihyperglycemic agent (AHA) wash-off period* (which includes a 2-week single-blind placebo run-in period) followed by a 24-week double-blind treatment period. All participants will receive open-label acarbose at a minimum dose of 50 mg three times daily (t.i.d.) during the run-in and treatment periods.

*: Wash-off only applicable to patients who were on acarbose and another AHA.

Inclusion Criteria:

• has T2DM and is on acarbose alone at a stable dose of at least 50 mg t.i.d.(three times a day) for at least 10 weeks or on acarbose at a stable dose of at least 50 mg t.i.d. (three times a day) for at least 10 weeks in combination with another antihyperglycemic agent (AHA)
• is at least 18 years of age (for participants in India: between 18 and 65 years of age)
• male or female who is unlikely to conceive (not of reproductive potential, or agrees to remain abstinent or use [or have partner use] acceptable birth control if of reproductive potential)

Exclusion Criteria:

• has a history of type 1 diabetes mellitus
• use of thiazolidinedione (TZD), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, or insulin
• has the following cardiovascular disorders: acute coronary syndrome; new or worsening symptoms of coronary heart disease; coronary artery intervention; stroke or transient ischemic neurological disorder
• has liver or kidney disease
• has cancer or any clinically significant disease or disorder as judged by the Investigator