Long-term Safety Study of MP-513 as Monotherapy or in Combination With Sulfonylurea in Japanese Type 2 Diabetic Patients

Inclusion Criteria: * In case of combination therapy with Sulfonylurea, patients who has been receiving a stable dose and regimen of sulfonylurea for diabetes over 12 weeks before administration of investigational drug * Patients who are under dietary management and taking therapeutic exercise for diabetes over 12 weeks before administration of investigational drug * HbA1c criteria: * monotherapy: 6.9% - 10.5% * combination therapy with Sulfonylurea: 7.4 - 10.5% * Patients who were not administered diabetes therapeutic drugs prohibited for concomitant use within 12 weeks before administration of investigational drug. Exclusion Criteria: * Patients with type 1 diabetes, diabetes mellitus caused by pancreas impairment, or secondary diabetes (Cushing disease, acromegaly, etc) * Patients who are accepting treatments of arrhythmias * Patients with serious diabetic complications * Patients who are the excessive alcohol addicts * Patients with severe hepatic disorder or severe renal disorder * Patients who are pregnant, lactating, and probably pregnant patients, and patients who can not agree to contraception