To assess the efficacy and safety of THDBH120 injection compared with placebo in weight reduction in overweight or obese subjects after 26 weeks of treatment.

Inclusion Criteria:

• Male or female patients 18 to 75 years of age, inclusive;
• Have a BMI ≥ 28 kg/m² or 24 ≤BMI< 28.0 kg/m² with at least 1 weight-related comorbidity at screening: prediabetes, hypertension, metabolic-associated fatty liver disease, dyslipidemia, weight-bearing joint pain, or obstructive sleep apnea syndrome;
• Diet and exercise control for at least 3 months before screening visit, and less than 5% self-reported change within the last 3 months.

Exclusion Criteria:

• History of diabetes;
• History of obesity attributable to endocrine diseases, monogenic mutations, or drug-induced causes, such as hypothalamic obesity, pituitary obesity, hypothyroid obesity, Cushing's syndrome, insulinoma, acromegaly, or hypogonadism; or weight gain resulting from increased non-fat mass (e.g., edema);
• Presence of uncontrolled hypertension at screening: systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥100 mmHg;
• A 12-lead electrocardiogram (ECG) shows any of the following at screening: heart rate <50 bpm or >100 bpm; QTcF prolongation (QT interval corrected by Fridericia's formula: QTc = QT/RR^0.33; >450 ms for males, >470 ms for females); PR interval >200 ms; presence of long QT syndrome; second- or third-degree atrioventricular block; left bundle branch block; complete right bundle branch block; Wolff-Parkinson-White syndrome; or any other condition that, in the opinion of the investigator, makes the subject unsuitable for participation in the clinical trial.