Study: NCT00885352

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Sitagliptin
Description: Sitagliptin 100 mg tablet orally once daily for 26 weeks.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Comparator: Placebo
Description: Placebo to sitagliptin 100 mg tablet orally once daily for 26 weeks.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Pioglitazone
Description: 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 type: DRUG
Group type: EXPERIMENTAL
Intervention: Pioglitazone
Description: 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 type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Metformin
Description: 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 type: DRUG
Group type: EXPERIMENTAL
Intervention: Metformin
Description: 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 type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Glipizide
Description: 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.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Glipizide
Description: 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.