Conditions: Diabetes
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 768
Healthy volunteers: no

Brief summary:
The purpose of this trial is to understand if adding saxagliptin to a sulfonylurea is safe and works better than increasing the amount of sulfonylurea a patient takes

Detailed description:
All subjects will participate in a lead-in period, and qualifying subjects will continue into a short-term randomized treatment period. Subjects who complete the short-term period will be eligible to enter the long term extension period. Also, subjects in the short-term period who have an elevated blood sugar that requires additional medication for blood sugar control (defined as rescue) will be eligible to enter the long-term treatment extension period where they will receive metformin.Rescue treatment with metformin is also available during the long-term extension period for subjects who meet glycemic criteria.

Arms:
arm 1: Metformin 500-2500 mg (as needed) arm 2: Metformin 500-2500 mg (as needed) arm 3: Metformin 500-2500 mg (as needed)

Interventions: intervention 1: Saxagliptin intervention 2: Saxagliptin intervention 3: Glyburide intervention 4: Placebo intervention 5: Glyburide intervention 6: Metformin
Intervention descriptions: intervention 1: Tablets, Oral, 2.5 mg, Daily AM, (24 weeks short-term \[ST\], 12 months long-term \[LT\]) intervention 2: Tablets, Oral, 5 mg, Daily AM (24 weeks ST, 12 months LT). intervention 3: Capsules, Oral, OL, 7.5 mg, Daily, AM (24 weeks ST, 12 months LT) intervention 4: Tablets, Oral, 0 mg, Daily AM/PM, (24 weeks ST, 12 months LT) intervention 5: Capsules, Oral, DB Glyburide, 2.5 mg titrated to 7.5 mg + 7.5 mg OL, Daily AM/PM (24 weeks ST, 12 months LT) intervention 6: Tablets, Oral, OL, 500 - 2500 mg, 1 or 2 times per day (12 months LT)

Protocol document: