This study is a multicenter, double-blind, active-controlled, randomized, parallel clinical trial to evaluate the efficacy and safety of DA-2811 when added to ongoing BT-1 and BT-2 combination therapy in patients with type 2 diabetes who have inadequate glycemic control

Inclusion Criteria:

1. Patients with type II diabetes mellitus aged 19 years or older
2. Patients with fasting plasma glucose≤270mg/dL at the screening visit
3. Patients with 18.5kg/m^2≤BMI≤40kg/m^2 at the screening visit
4. Patients who have signed an informed consent themselves after receiving detailed explanation about the clinical study

Exclusion Criteria:

1. Patients with type 1 diabetes, secondary diabetes, gestational diabetes, diabetic coma or -pre-coma, metabolic acidosis including lactic acidosis and diabetic ketoacidosis
2. Patients with a medical history of New York Heart Association(NYHA) class III~IV heart failure or with congestive heart failure, acute and unstable heart failure
3. Patients with severe infectious disease or severe traumatic systemic disorders
4. Patients with hypopituitarism or adrenal insufficiency, pulmonary infarction, severe pulmonary dysfunction and other hypoxemia
5. Patients with galactose intolerance, lapp lactase deficiency, glucosegalactose malabsorption