Inclusion Criteria:

• Has type 2 diabetes mellitus and were either receiving no current treatment or currently treated with a sulfonylurea, metformin, or a combination of a sulfonylurea and metformin but experiencing inadequate glycemic control. Subjects qualified as receiving no current treatment if 1 of the following conditions applied:

  • Subject was newly diagnosed (ie, had not received any treatment).
  • Subject was treated with diet and exercise alone for the 3 months prior to Screening
  • Subject had received <7 continuous days of any antidiabetic therapy within the 3 months prior to Screening.
  • Subject had a diagnosis of type 2 diabetes mellitus based on current American Diabetes Association criteria: fasting plasma glucose ≥126 mg/dL, oral glucose tolerance test at 2 hours after administration of the glucose load must have been ≥200 mg/dL, or symptoms of diabetes plus casual plasma glucose ≥200 mg/dL.
• Body mass index ≥23 kg/m2 and ≤40 kg/m2.
• Fasting C-peptide concentration ≥0.8 ng/mL.
• Glycosylated hemoglobin concentration between 6.8% and 11.0%.
• Fasting plasma glucose >126 mg/dL at Screening.

• No treatment within the 3 months prior to Screening with any other agents known to have effects on glucose (other than as described above, a sulfonylurea, metformin, or a combination of a sulfonylurea and metformin in subjects on antidiabetics), including but not limited to the following:

  • Other antidiabetic agents
  • Investigational antidiabetic agents
  • Niacin
  • Regular use of systemic glucocorticoids.
  • No treatment within the 3 months prior to Screening with weight-loss drugs
  • If taking other non-excluded medications, must have been on a stable dose of medication for at least 4 weeks.
• Diastolic blood pressure ≤110 mm Hg and a systolic pressure of ≤180 mm Hg.
• Female subjects could neither be pregnant (confirmed by laboratory testing) nor lactating, and if of childbearing potential must have been practicing adequate contraception.
• Able and willing to monitor their own blood glucose concentrations with a home glucose monitor.
• No major illness or debility that in the investigator's opinion prohibited the subject from completing the study.
• Hemoglobin ≥12 g/dL for males and ≥10 g/dL for females.
• Hepatic transaminase ≤2 x upper limit of normal.

Exclusion Criteria:

• History of cancer, other than squamous cell or basal cell carcinoma of the skin, that had not been in full remission for at least 1 year prior to Screening.
• History of proteinuria >1000 mg/day on a 12- or 24-hour urine collection OR a urine albumin/creatinine ratio >1000 μg/mg at Screening. If elevated, the subject was to be rescreened within 1 week.
• Serum creatinine ≥2.0 mg/dL.
• History of proliferative diabetic retinopathy OR any history of laser-treated retinopathy.
• History of treated peripheral or autonomic neuropathy.
• History of systolic dysfunction congestive heart failure.
• History of myocardial infarction within 1 year prior to Screening.
• History of ulcerative colitis or Crohn's disease.
• History of infection with hepatitis B, hepatitis C, or human immunodeficiency virus.
• History of a psychiatric disorder that would affect the subject's ability to participate in the study.
• History of anaphylactic reaction(s) to any drug.
• History of angioedema.
• History of alcohol or substance abuse within the last 2 years.
• History of any surgery that could potentially affect the absorption of the study drug.
• Receipt of any investigational drug within the preceding 30 days or a history of receipt of an investigational antidiabetic drug within the preceding 90 days.