This trial is designed to show the effect of treatment with TT223 or placebo on blood glucose control after 12 weeks of treatment with a 6 month follow-up. TT223 is administered by injection once daily to patients currently treated with Metformin and/or Thiazolidinedione.

Inclusion Criteria:

• Type 2 Diabetes for at least 6 months
• Treated with metformin and/or thiazolidinediones with stable dose for at least 3 months
• BMI of 21-45 kg/m2, inclusive
• HbA1c level of 7.50 - 10.00%, inclusive
• If a female of childbearing potential, willing to utilize contraception from Screening through 4 weeks after the last dose of study drug

Exclusion Criteria:

• Treatment with insulin, sulfonylurea, DPP-4 inhibitors, Symlin® and/or GLP-1 analogues ≤ 3 months prior to the Screening
• Severe hypoglycemia ≤ 60 days prior to the Screening visit or currently diagnosed with having hypoglycemia unawareness
• History of peptic ulcer(s) and/or gastrointestinal bleeding/perforation
• Previous gastric surgery, including gastric bypass, or has gastric bypass/other major surgery planned to occur during the 10 month trial
• Myocardial infarction within the last 2 years, current congestive heart failure with NYHA class 2 or greater, or chronic atrial fibrillation
• Current clinically significant and/or chronic illness
• Takes regular courses of non-steroidal anti-inflammatory drugs (NSAIDS). If these medications are discontinued upon starting Screening procedures and are not planned to be regularly used during the trial, the patient will be allowed to enter the Study
• Use of systemic corticosteroids (oral, suppository, injected). Use of inhaled or topical corticosteroids is permitted