To define the relative efficacy, safety and tolerability profiles of oral daily MBX-2982 at three different daily doses vs. placebo and sitagliptin 100 mg when administered for up to 4 weeks in patients that are treatment-naive or taking a single anti-diabetic medication (non-TZD, non-injectable).

Approximately 100 patients will be randomized in this study, 20 to each of of the three MBX-2982 treatment groups, 20 to placebo, and 20 to the sitagliptin group. Patients will be taking 3 tablets and 1 capsule daily. This sample size provides the minimum number expected to ensure a power of at least 80% to detect a 20% decrease in the weighted mean glucose level associated with an extended mixed meal tolerance test (with 2 standardized meals) relative to placebo after 4 weeks of daily treatment with MBX-2982, assuming a drop-out rate of 20% and a common SD of 25%.

Inclusion Criteria:

• History of type 2 diabetes of at least 3 months duration
• Treatment-naïve (not on any anti-diabetic medication) or treated with a single anti-diabetic agent (excluding insulin, exenatide or other GLP-1 analogs, pioglitazone or rosiglitazone)
• HbA1c 7.0-8.5% (inclusive) at screening
• BMI ≥ 26 kg/m2 for patients recruited from U.S or Georgia or ≥ 22 kg/m2 for patients recruited from India

Exclusion Criteria:

• Any history of type 1 diabetes or diabetic ketoacidosis
• History of major upper GI surgery
• Evidence or history of clinically significant GI illness including dyspepsia, PUD, nausea, diarrhea, malabsorption, etc.
• History of outpatient insulin use within last 1 year (insulin use while hospitalized is acceptable)
• Weight loss > 10 pounds (4.5 kg) in the 3 months prior to screening visit or use of weight loss medications (prescription or OTC) within 30 days of screening