The purpose of this study is to compare the safety and effect of TTP054 versus placebo on glucose control in patients with type 2 diabetes.

Inclusion Criteria:

• Diagnosis of type 2 diabetes mellitus
• On a stable (for the last 3 months) regimen of either metformin alone or metformin in combination with one additional acceptable oral antidiabetic (OAD) agent
• HbA1c: Metformin only: 7.0 - 11.0%; Metformin + acceptable OAD agent: 6.5 - 9.5%

Exclusion Criteria:

• History or evidence of significant diabetic complications
• History of heart attack, stroke or congestive heart failure
• Severe, uncontrolled hypertension
• Frequent hypoglycemia
• Women of child-bearing potential