This multicenter, randomized, double-Blind, parallel-group, placebo-controlled phase III trial is to evaluate the efficacy and safety of UBT251 Injection in patients with Type 2 Diabetes Mellitus with inadequate glycemic control on diet and exercise alone

Inclusion Criteria:

1. Aged 18-75 years (inclusive) at the time of signing the informed consent form (ICF), regardless of gender;
2. Diagnosed with type 2 diabetes mellitus (T2DM) for at least 3 months in accordance with the 2019 World Health Organization (WHO) criteria;
3. Managed solely through diet and exercise intervention (without the use of any glucose-lowering medications) for at least 3 months prior to screening;
4. Glycated hemoglobin (HbA1c) level ≥7.5% and ≤10.5% at screening;
5. Body mass index (BMI) ≥23.0 kg/m² at screening, and stable body weight (change <5%, which may be based on the participant's self-report) within 3 months prior to screening;
6. Trial participants (including their partners) have no plan for pregnancy from screening to 6 months after trial completion, and are willing to comply with the contraceptive measures specified in the trial, and have no plan for sperm or egg donation within 6 months after trial completion;
7. Have been fully informed about this study and voluntarily sign a written informed consent form.

Exclusion Criteria:

1. Known history of hypersensitivity to this study drug, its drug product excipients, or other similar active drugs;
2. History of medication use within 3 months prior to screening that meets any of the following conditions:

1) Use of any glucose-lowering medications, including glucagon-like peptide-1 (GLP-1) analogues, oral antidiabetic drugs (OADs) (including but not limited to metformin, sulfonylureas, dipeptidyl peptidase-4 (DPP-4) inhibitors, alpha-glucosidase inhibitors, thiazolidinediones, glinides, sodium-glucose cotransporter 2 (SGLT-2) inhibitors), insulin (except for short-term use ≤14 days for acute conditions, such as perioperative or inpatient use), traditional Chinese medicines, or health supplements with glucose-lowering effects; 2) Use of medications that may affect glucose metabolism, such as systemic glucocorticoids, growth hormone, etc. (except for cumulative use <7 days with the last dose administered more than 7 half-lives prior to the first day of screening); 3) Use of weight-loss medications (including but not limited to orlistat, liraglutide, or other similar prescription or over-the-counter medications for weight loss); 3.History or evidence of any of the following diseases:

1. Diagnosis of other types of diabetes: such as type 1 diabetes mellitus (T1DM), other specific types of diabetes (e.g., genetic defects in beta-cell function, genetic defects in insulin action, diseases of the exocrine pancreas, etc.);
2. History of acute or chronic pancreatitis, or pancreatic surgery;
3. History of symptomatic gallbladder disease within 1 year before screening (excluding trial participants who have undergone cholecystectomy [completed at least 3 months before screening] without long-term complications), or abdominal ultrasound at screening indicating large gallstones (diameter ≥2 cm), gallbladder polyps (diameter ≥1 cm), or other gallbladder lesions that the study physician determines may affect trial participant safety;
4. Personal or family history (within first-degree relatives, i.e., parents, children, or siblings) of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN2);
5. History of hematological disorders that may affect HbA1c test results or increase the risk to trial participants (e.g., aplastic anemia, myelodysplastic syndromes, etc.), or any diseases causing hemolysis or erythrocyte instability (e.g., sickle cell disease, thalassemia, etc.);
6. History of moderate to severe depression or severe psychiatric disorders (including but not limited to suicidal ideation or attempt, schizophrenia, bipolar disorder, etc.);
7. History of clinically significant cardiovascular or cerebrovascular disease within 6 months before screening
8. Severe retinal or macular disease (including but not limited to proliferative retinopathy, macular edema, retinal detachment, etc.) at screening or in the past, requiring urgent treatment as determined by the study physician;
9. Severe hypoglycemia (hypoglycemia accompanied by severe cognitive impairment requiring assistance from others to recover) or recurrent symptomatic hypoglycemia (≥2 episodes in 6 months) within 6 months prior to screening;
10. History of acute metabolic complications of diabetes (including but not limited to diabetic ketoacidosis [DKA], hyperosmolar hyperglycemic state [HHS] requiring hospitalization, hyperosmolar coma, lactic acidosis, etc.) or diabetic foot within 6 months prior to screening;
11. History of malignancy; 4.Blood loss ≥400 mL (including trauma, blood draw, blood donation) within 3 months before screening, or receipt of blood or blood component transfusion; 5.Lactating women or pregnant women;