The purpose of this study is to evaluate the safety, pharmacokinetics and pharmacodynamics of TA-7284 orally administered once daily for 15 days (1 day followed by a 1 day washout period and then 14 consecutive days). Dose escalation design is utilized in this study, and dose escalation of TA-7284 will be starting with 25 mg (step 1). Subsequent doses of 100 mg (step 2), 200 mg (step 3) and 400 mg (step 4) are planned after review of the tolerance and PK of the previous step.

Inclusion Criteria:

• Clinically stable Type 2 Diabetes Mellitus
• Females without childbearing potential
• Body mass index (BMI) >= 18.5 kg/m2 and <= 39.9 kg/m2
• Hemoglobin A1c levels >= 6.5% and <= 10%
• Fasting blood glucose levels >= 140 mg/dL and <= 270 mg/dL
• Systolic blood pressure >= 95 mmHg and <= 160 mmHg, and diastolic blood pressure >= 50 mmHg and <= 100 mmHg, and pulse rate >= 50 bpm
• Patients who have not been administered anti-diabetic medication within 2 weeks Prior to dosing
• Medicines if necessary for Hypertension or Dyslipidemia should be administered with stable dosage at least 3 months
• Treatment with diet and exercise should be unchanged for more than 3 months

Exclusion Criteria:

• Type 1 Diabetes Mellitus or Secondary Diabetic Mellitus
• History of diabetic complications which need treatment
• Treatment with insulin, thiazolidinediones, thiazide diuretics、beta blockers or systemic steroids within 3 months prior to informed consent
• Serum creatinine > upper limit of the normal range
• Patients with significant complications

19 days