This trial is a multi-center, randomized, double-blind, placebo-controlled parallel group, Phase 2 study in subjects with Type 2 diabetes mellitus on a stable dose of metformin to evaluate the safety and efficacy of TTP273 versus placebo glucose control and body weight following administration for 3 months.

Inclusion Criteria:

• The subject has a 6 month diagnosis of Type 2 diabetes mellitus prior to screening and meets the American Diabetes Association (ADA) guidelines for Type 2 diabetes mellitus.
• On a stable regimen of metformin monotherapy equivalent to at least 1000 mg/day for the last 3 months prior to screening.
• Males. Females of non-childbearing potential.
• Generally stable health without a history of major surgery or significant injuries within the last year and without an active infection.

Exclusion Criteria:

• Diagnosis of Type 1 diabetes mellitus, maturity-onset diabetes of the young, insulin-requiring Type 2 Diabetes, other unusual or rare forms of diabetes mellitus, or history of diabetic ketoacidosis.
• Participation in a clinical trial and receipt of an investigational product within 30 days.
• Participation in any formal weight loss program, or fluctuation of > 5% in body weight, or having received medications approved for weight loss within 3 months prior to screening or contemplating such therapy during the trial.
• Previous surgical treatment of obesity.
• Have a history of hypoglycemic episode requiring glucose, glucagon, or orange juice administered by someone other than the patient within 6 months prior to screening.
• Use of other diabetic agents except metformin within 3 months prior to Screening.
• History of pancreatitis.
• Blood donation of approximately 1 pint (500 mL) within 8 weeks prior to screening.
• History of hemolytic anemia, chronic transfusion requirement or other condition rendering HbA1c results unreliable.
• History of MEN-2 or family history of medullary thyroid cancer.
• History or presence of clinically significant disease (other than Type 2 diabetes mellitus).