Primary objective:

To evaluate the safety and tolerability of single and multiple ascending doses of PB1023 administered as a subcutaneous (SC) injection in adult subjects with T2DM.

Secondary objectives:

1. To characterize the pharmacokinetic profile of PB1023 after single and multiple ascending doses of PB1023.
2. To assess the pharmacodynamic response of various single and multiple doses of PB1023 (daily fasting plasma glucose, and serial glucose, c-peptide and insulin levels in response to a liquid Mixed Meal Tolerance Test (MMTT).

Inclusion Criteria:

• Males or post menopausal or surgically sterile females age 18-75 years of age inclusive.
• Diagnosed with T2DM for > or = 6 months with HbA1c > or = 6.0% but < or = 9.0% while taking stable doses of one oral antihyperglycemic agent but < or = 8.5% when taking two oral antihyperglycemic agents for up to a maximum of 3 months prior to screening.
• Fasting Plasma glucose between 115 mg/dL and 269 mg/dL.
• Fasting C-peptide of > or = 0.8 ng/mL.
• BMI < or = 40 kg/m2.
• Otherwise stable health except for T2DM.

Exclusion Criteria:

• Currently taking a non-oral antihyperglycemic agent.
• Have taken a PPARg agonist within 90 days of screening.
• Known allergy to an approved or investigational GLP-1 receptor analog/agonist.
• Unstable cardiovascular disease as defined in clinical protocol.
• History, symptoms or signs of pancreatitis or severe gastrointestinal disease.
• Personal or family history of medullary thyroid tumors history of Multiple Endocrine Neoplasia Syndrome Type 2.
• Poor glucose control as defined in clinical protocol.
• Clinically significant renal and/or hepatic dysfunction as defined in clinical protocol.
• Absolute requirement for corticosteroids or received systemic steroids within 90 days prior to PB1023 administration.
• Pregnant or lactating females.
• Known history or active alcohol or drug abuse within 12 months prior to screening.
• Positive for HIV, Hepatitis B surface antigen or Hepatitis C antibodies.
• Participating in any other study within 30 days prior to screening.
• Other medical or psychiatric condition which in the opinion of the investigator would place the subject at increased risk.