- HbA1c ≥ 6.5% and ≤ 10.0% for monotherapy cohorts (study drug only) or HbA1c ≥ 7.5% and ≤ 10.0% for combination cohorts (study drug and on a stable regimen of metformin monotherapy that includes a morning dose for ≥ 8 weeks prior to first dose of study drug).