BGM1812 Injection for Overweight or Obesity

Inclusion Criteria: * Capable of understanding the written informed consent document; willingly provides valid, signed written informed consent; willing and able to comply with the schedule, requirements and restrictions of the study. * Body mass index (BMI) meeting one of the following requirements: 1. Between ≥ 30.0 kg/m2 and ≤ 40.0 kg/m2 (obese) (for Cohort 3-6); OR 2. Between ≥ 27.0 kg/m2 and \< 30.0 kg/m2 (overweight) with at least 1 of the following: One or more symptoms of prediabetes (impaired fasting plasma glucose and/or abnormal glucose tolerance), grade 1 hypertension, simple fatty liver or dyslipidemia (For Cohort 3- 6); OR 3. Between ≥ 23.0 kg/m2 and \< 27.0 kg/m2 healthy subjects (for Cohort 1 and Cohort 2) * Have a stable body weight (\<5% self-reported change during the previous 12 weeks) before screening Exclusion Criteria: * Have allergic predisposition (allergic to 3 or more foods or drugs), or are allergic to amylin agonist-based therapeutic agents or suffer from severe allergic diseases (asthma, urticaria, eczematous dermatitis). * Known type I/II diabetes. * Has underwent gastric bariatric surgery in the past, or has had liposuction or fat removal within 1 year before screening, or plan to have bariatric surgery, liposuction or abdominal fat removal during the study period or other surgery that would obviously affect the body weight. * History of acute or chronic pancreatitis or pancreatic injury. * Has any other conditions or disorders deemed unsuitable for including in the study, in the opinion of the Investigator.