Conditions: Type 2 Diabetes Mellitus
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 313
Healthy volunteers: no

Brief summary:
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.

Detailed description:

Arms:
arm 1: Sitagliptin 100 mg tablet orally once daily for 26 weeks. arm 2: Placebo to sitagliptin orally once daily for 26 weeks.

Interventions: intervention 1: Sitagliptin intervention 2: Comparator: Placebo intervention 3: Pioglitazone intervention 4: Metformin intervention 5: Glipizide
Intervention descriptions: intervention 1: Sitagliptin 100 mg tablet orally once daily for 26 weeks. intervention 2: Placebo to sitagliptin 100 mg tablet orally once daily for 26 weeks. intervention 3: Participants taking 30 mg or more pioglitazone oral tablet(s) daily at screening in combination with metformin will enter a 4-week dose-stable period followed by a 2-week single-blind run-in and a 26-week treatment period. Participants taking 4 mg or more rosiglitazone oral tablet(s) daily at screening in combination with metformin were to be switched to a corresponding dose of pioglitazone prior to starting a 4-week dose-stable period. Participants who are taking less than 30 mg/day or no pioglitazone at screening will be titrated to a stable dose of at least 30 mg pioglitazone once daily over a maximum of 4 weeks followed by a dose-stable period of 10 weeks, a 2-week single-blind placebo run-in, and a 26-week treatment period. Total treatment with pioglitazone will be up to 42 weeks. intervention 4: Participants taking 1500 mg or more metformin oral tablet(s) and at least 30 mg pioglitazone or 4 mg rosiglitazone daily at screening will enter a 4-week dose-stable period followed by a 2-week single-blind placebo run-in, and a 26-week treatment period. Participants who are taking less than 1500 mg/day metformin at screening will be titrated to a stable dose of at least 1500 mg metformin once daily over a maximum of 4 weeks followed by a dose-stable period of 10 weeks, a 2-week single-blind placebo run-in, and a 26-week treatment period. Total treatment with metformin will be up to 42 weeks. intervention 5: Participants not meeting specific glycemic controls during the 26-week treatment period will use glipizide oral tablets as rescue therapy. In countries where glipizide is not available, participants will receive a sulfonylurea marketed in that country.

Protocol document: