A Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of PB-718 Injection in Chinese Obese Subjects.

Inclusion Criteria: 1. Chinese male or female subjects aged 18-60 years (both inclusive). 2. Body weight ≥70 kg(male) or 60 kg(female), and body mass index (BMI) ≥28.0 kg/m2 at screening. 3. Weight change \<5% in the past 3 months before screening. Exclusion Criteria: 1. FPG ≥7.0mmol/L or glycosylated hemoglobin (HbA1c) ≥6.5% or diagnosed diabetes 2. FPG \<3.9 mmol/L at screening and/or a history of hypoglycemia. 3. History of Cushing's syndrome, polycystic ovaries, or other hereditary endocrine disorders, or obesity caused by secondary factors such as cortisol hormones. 4. Abnormal Thyroid-Stimulating Hormone(TSH), free triiodothyronine(FT3), Free thyroxine(FT4) or diagnosed thyroid dysfunction 5. History of multiple endocrine neoplasia syndrome type 2 (MEN-2) or medullary thyroid carcinoma (MTC). 6. Diagnosed cardiovascular and cerebrovascular diseases with obvious clinical significance within 6 months before screening 7. Systolic blood pressure \> 160 mmHg and/or diastolic blood pressure \> 100 mmHg at screening or randomization. 8. PR intervals \> 210 msec and/or QRS wave group time limit \> 120 msec and/or Corrected QT interval using Fridericia's formula（QTcF）\> 450 msec at screening or randomization. 9. Serum amylase or lipase \> 3× upper limit of normal (ULN) at screening or before randomization, or previously diagnosed acute/chronic pancreatitis. 10. Low density lipoprotein cholesterol(LDL-C) ≥4.40 mmol/L or triglyceride (TG) ≥5.65 mmol/L. 11. Use of any approved or unapproved drugs or products that have an effect on body weight within 3 months prior to screening 12. History of bariatric surgery for weight loss 1 year before screening.