Safety and Efficacy of PB-119 in Subjects With Type 2 Diabetes and Not Well-controlled by Metformin Monotherapy

This is a phase 3 multicenter, randomized, double-blind, placebo-controlled, parallel dose cohort study to evaluate the efficacy and safety of PB-119 to patients with T2DM not well-controlled by metformin monotherapy. Patients will be assessed for eligibility over a 2 week screening period prior to a 4-week run-in period,a 24-week double-blind treatment period and a 28-week open-label treatment period. The eligible patients will be randomized to PB-119 or placebo cohort at a 1:1 ratio for the first 24-week. Patients in PB-119 group will subsequently be given active drug and patients in placebo group will take placebo, all patients in two groups will remain metformin background therapy. In the 28-week open-label period, all patients will be administered active drugs. After that, there will be a 4-week follow-up period; All randomized patients will be taken blood samples for the pharmacokinetic (PK) analysis.

Inclusion criteria

• Male or female, aged 18~75 years old;
• T2DM and treated with Metformin ≥ 1500mg/day or maximum tolerated dose(≥1000mg,<1500mg) constantly for at least 8 consecutive weeks;
• 7.5% ≤ HbA1c ≤ 10.0% at screening;
• 18.5 kg/m2 < BMI < 40.0 kg/m2 at screening;

Exclusion criteria

• Any anti-diabetic therapy other than Metformin within 8 weeks before screening；
• T1DM;
• Received insulin therapy more than 14 days within 1 year before screening;
• Female who is pregnant, breast-feeding;
• Any disorder which in the investigator's opinion might jeopardise subject's safety or compliance with the protocol;
• History of acute diabetic complications, such as diabetic ketoacidosis or hyperglycemic hyperosmolar status within 6 months before screening；
• History or presence of pancreatitis (acute or chronic);
• Presence or history of malignant neoplasms within the past 5 years prior to the day of screening