An Efficacy, Safety, and Tolerability Study for TA-7284 in Patients With Type 2 Diabetes

Inclusion Criteria: * Aged from 20 to 80 years inclusive on the day of informed consent; * Patients who was diagnosed with type 2 diabetes mellitus at least 3 months before the start of the run-in period; * Patients with HbA1c of ≥6.5% and ≤9.5% (according to the Japan Diabetic Society \[JDS\] criteria) on the start day of the run-in period; Exclusion Criteria: * Type I diabetes mellitus, diabetes mellitus resulting from pancreatic disorder, or secondary diabetes mellitus (acromegaly, Cushing's syndrome, etc.); * Past or current history of severe diabetic complications (proliferative diabetic retinopathy, stage III or later stage overt nephropathy, diabetic ketoacidosis, or serious diabetic neuropathy); * Fasting blood glucose of \>270 mg/dL on the start day of the run-in period or at Week 2 of the run-in period; * eGFR of \<60 mL/min/1.73 m2 on the start day of the run-in period; * Systolic blood pressure of ≥160 mmHg or diastolic blood pressure of ≥100 mmHg on the start or end day of the run-in period; * History of myocardial infarction, unstable angina, or cerebrovascular disorder within 3 months before the start of the run-in period; * Concurrent serious (e.g., requiring inpatient hospitalization or surgical intervention) renal or hepatic disease; * Past or current history of malignant tumor; however, this criterion shall not apply to those who have been free of relapse for at least 5 years even with a history of malignant tumor. * Past or current history of drug hypersensitivity such as shock and anaphylactoid symptoms; * Pregnant women, lactating mothers, or women of childbearing potential; * Any condition that subjects are assessed to be ineligible by the investigator (sub investigator).