3. Stable dose of sitagliptin (100 mg/day) and metformin (≥1500 mg/day) either co-administered or as a FDC, and a sulfonylurea for ≥12 weeks OR stable dose of metformin (≥1500 mg/day) and a sulfonylurea administered as a FDC and sitagliptin (100 mg/day) with A1C between 7.0% and 10.0%, inclusive.