The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of multiple ascending doses of DSP-8658 in patients with Type 2 diabetes mellitus and healthy adults.

Inclusion Criteria: Diabetic subjects

• Age ≥ 18 and ≤ 65 years
• Body Mass Index ≤45
• Drug naive type 2 diabetes or type 2 diabetes previously treated with an oral antidiabetic drug

Inclusion Criteria: Healthy subjects

• Age ≥ 18 and ≤ 65 years
• Body Mass Index ≥ 18 and ≤ 29
• Good health as determined by medical history, ECG, clinical chemistry, hematology, urinalysis, virology, and a physical examination.

Exclusion Criteria: Diabetic subjects

• Have a current or expected requirement for any antidiabetic or lipid-lowering drug

Exclusion Criteria: Healthy subjects

• Have, or have had a history of clinically significant neurological, urological, gastrointestinal, renal, hepatic, cardiovascular, psychological, pulmonary, metabolic, endocrine, hematological, or other major disorders including cancer