- Patients with Type 2 Diabetes currently treated with diet and exercise and on metformin at a stable dose ≥1500 mg/day for at least 12 weeks. However, patients on metformin at a dose <1500 mg/day at the time of enrollment (stable dose for at least 12 weeks before enrollment) may be eligible for screening if documentation of lack of tolerance of a metformin dose ≥1500 mg/day can be provided.