A study on the safety, efficacy, pharmacokinetics and pharmacodynamics of Supaglutide dosing weekly and bi-weekly in patients with type 2 diabetes mellitus.

Inclusion Criteria:

1. Have diagnosed with type 2 diabetes for at least 3 months before enrollment.
2. Have diet and exercise intervention only (for part A and part B) or been treated with stable dose of metformin as monotherapy for at least 3 months (for part B only)
3. Have HbA1c ≥7.0% and ≤10.0% as assessed by the central laboratory.
4. Have a body mass index (BMI) of 20-40 kilograms per square meter (kg/m^2).

Exclusion Criteria:

1. Type 1 diabetes (T1D).
2. Evidences of fasting C-peptide levels<0.81 ng/mL.
3. History of trauma, infection or surgery within a month;
4. History of blood donation, blood transfusion or losing more than 450 ml blood within 3 months.
5. History of the severe cardiovascular conditions, gastrointestinal diseases, blood system diseases, pancreatitis, or malignant tumors.
6. Evidence of abnormal thyroid function within 6 months before screening.
7. Positive test results in HBsAg, HCVAB, HIVAB or TPAB.
8. History of serious mental illness.
9. History of drug or alcohol abuse.
10. History of a transplanted organ, acquired or congenital immune system diseases.
11. Allergy to active ingredients or excipients of the test drug.
12. Evidence of abnormal result of laboratory examination according to the judgment of researchers.
13. Participated in any interventional medical, surgical, or pharmaceutical study within 3 months prior to entry into the study.
14. Previously completed or withdrawn from this study after providing informed consent.