In Phase 2, participants who have failed to achieve adequate glycemic control (A1c ≥ 7% and ≤ 10% at Week 16 and fasting finger stick glucose ≥130 mg/dL and ≤280 mg/dL at Week 20) will be randomized to receive add-on therapy with glimepiride, repaglinide, acarbose, or gliclazide for 24 weeks (Week 20 through Week 44).