 This is a 24 week study comparing the efficacy of four dose levels of INT131 besylate with pioglitazone HCl in patients with type 2 diabetes. Eligible patients will be men and women of non-childbearing potential or using dual barrier methods of contraception between 30 and 75 years of age who are minimally responsive to treatment with sulfonylurea monotherapy or sulfonylurea plus metformin combination therapy. 