Evaluate the efficacy of GZR33 Injection and Insulin Degludec Injection (Tresiba®) in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Oral Antidiabetic Drugs.

This study will be conducted to evaluate the efficacy of once-daily GZR33 Injection and once-daily Insulin Degludec Injection (Tresiba®) in Patients with Type 2 Diabetes Mellitus Inadequately Controlled with Oral Antidiabetic Drugs.

Inclusion Criteria:

1. Subjects sign the Informed Consent Form (ICF) before the study, fully understand the contents, process and possible adverse reactions of the study, and are able to follow the contraindications and restrictions specified in this protocol.
2. Male or female, aged ≥18 years at the time of informed consent..
3. Body mass index (BMI) ≥18.5 and ≤35.0 kg/m2 at screening.
4. According to the diagnostic criteria and classification of diabetes mellitus issued by the World Health Organization (WHO) in 1999, and the supplementary diagnostic criteria recommended by WHO for diagnosis with Hemoglobin A1c (HbA1c) (2011), the time to diagnose T2DM is ≥ 180 days at screening.
5. Stable treatment with oral antidiabetic drugs for ≥ 90 days prior to screening.

Exclusion Criteria:

1. History of hypersensitivity to ≥ 2 drugs with distinct mechanisms of action, or known hypersensitivity, allergic reactions, or intolerance to the investigational medicinal products or their excipients (glycerol, phenol, metacresol, zinc acetate dihydrate, sodium chloride, hydrochloric acid, sodium hydroxide).
2. Female subjects who are pregnant, lactating at screening, or planning a pregnancy during the trial period.
3. Confirmed or suspected type 1 diabetes mellitus or specific types of diabetes due to other causes (monogenic diabetes syndrome, cystic fibrosis-related diabetes, pancreatitis-induced diabetes, drug- or chemical-induced diabetes, etc.) prior to screening.
4. Presence of any diseases that may affect HbA1c testing at screening, such as hemolytic anemia, aplastic anemia, hemoglobinopathy, etc., and in the investigator's judgment unsuitable for participation; or blood donation, blood loss > 400 mL, or blood transfusion within 90 days prior to screening.
5. History of severe cardiovascular and cerebrovascular diseases within 180 days prior to screening.
6. Significant hepatic or renal dysfunction or active infectious diseases at screening.
7. Lifestyle (diet, exercise, work circadian rhythm, etc.) expected to change significantly during the trial and affect glycemic control; irregular three-meal intake (e.g., habitual skipping of breakfast); or unwillingness to comply with relevant lifestyle restrictions during the trial.
8. Any other conditions that, in the investigator's judgment, may compromise subject safety or interfere with trial conduct, progress, or outcome.