A Study of Different Doses of Sitagliptin (MK-0431) in Participants With Type 2 Diabetes Mellitus (MK-0431-014)

Patients whose FPG \>240 mg/dL from Week 16 or HbA1C \>8.5% from Week 25 up to (not including) Week 52 could receive rescue antihyperglycemic therapy with pioglitazone, and remain in the extension study (Extension 1). Participants were eligible for rescue with pioglitazone 30 mg (or rosiglitazone in countries where pioglitazone was not licensed) if they met the following criteria: from Week 16 and during the second extension: FPG consistently \>240 mg/dL (repeated and confirmed within 3 to 7 days); from Week 52 up to (not including) Week 70: HbA1C \>8%; from Week 70 up to (not including) Visit 21/Week 106: HbA1C \>7.5% (Extension 2). Participants placed on rescue therapy with pioglitazone (rosiglitazone where pioglitazone is not available) in the first or second extensions were not eligible for enrollment in the third extension. Rescue therapy was not available in the third extension.