Study: NCT01485614

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Sitagliptin
Description: Sitagliptin 100 mg tablet administered orally once daily

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Sitagliptin
Description: Sitagliptin 100 mg tablet administered orally once daily

Intervention type: DRUG
Group type: ACTIVE_COMPARATOR
Intervention: Metformin
Description: Metformin 500 mg tablets administered orally starting at 500 mg/day and uptitrated by 500 mg every week to a final dose of 1000 mg twice daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Metformin
Description: Metformin 500 mg tablets administered orally starting at 500 mg/day and uptitrated by 500 mg every week to a final dose of 1000 mg twice daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo to sitagliptin
Description: Matching placebo to sitagliptin 100 mg tablet administered orally once daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo to sitagliptin
Description: Matching placebo to sitagliptin 100 mg tablet administered orally once daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo to metformin
Description: Matching placebo to metformin 500 mg tablets, 2 tablets administered orally twice daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Placebo to metformin
Description: Matching placebo to metformin 500 mg tablets, 2 tablets administered orally twice daily

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Placebo to metformin
Description: Matching placebo to metformin 500 mg tablets, 2 tablets administered orally twice daily

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Glycemic Rescue 1
Description: Participants in the sitagliptin arm who require glycemic rescue will receive metformin during Weeks 0-20 and Weeks 20-54. Participants in the placebo arm who require glycemic rescue will receive metformin during Weeks 0-20. Participants in the placebo arm who have switched to metformin during Weeks 20-54 and require glycemic rescue will receive sitagliptin.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Glycemic Rescue 1
Description: Participants in the sitagliptin arm who require glycemic rescue will receive metformin during Weeks 0-20 and Weeks 20-54. Participants in the placebo arm who require glycemic rescue will receive metformin during Weeks 0-20. Participants in the placebo arm who have switched to metformin during Weeks 20-54 and require glycemic rescue will receive sitagliptin.

Intervention type: BIOLOGICAL
Group type: PLACEBO_COMPARATOR
Intervention: Glycemic Rescue 2
Description: Participants who require glycemic rescue after Glycemic Rescue 1 will receive open-label insulin. Participants on background insulin therapy will have the dose of their background insulin up-titrated.

Intervention type: BIOLOGICAL
Group type: EXPERIMENTAL
Intervention: Glycemic Rescue 2
Description: Participants who require glycemic rescue after Glycemic Rescue 1 will receive open-label insulin. Participants on background insulin therapy will have the dose of their background insulin up-titrated.