30-Week Extension to an Initial Combination Study (24 Weeks in Duration) of Sitagliptin With Pioglitazone (0431-064)

Patients will receive combination therapy with blinded sitagliptin 100 mg q.d. (q.d. = once daily) and open-label pioglitazone 45 mg q.d. during the up to 30 week extension study. Sitagliptin 100 mg q.d. and pioglitazone 45 mg q.d. will be administered as oral tablets.

Patients will receive placebo to match sitagliptin 100 mg q.d. (blinded) and open-label pioglitazone 45 mg q.d. during the up to 30 week extension study. The placebo to match sitagliptin 100 mg q.d. (blinded) and open-label pioglitazone 45 mg q.d. will be administered as oral tablets.

Patients not meeting specific glycemic goals during the 30-week extension study will receive open-label metformin at a dose determined by the investigator.