A Phase I Study of Single and Multiple Doses of HS-20136-2 Injection in Healthy or Obese Participants

Inclusion Criteria: 1. Aged between 18 and 55 years (inclusive) at screening, male or female. 2. Participants must fully understand the study content, procedures, and potential adverse reactions, and voluntarily sign the informed consent form (ICF) prior to any study-related procedures. 3. Agree to use effective contraceptive measures and refrain from sperm or egg donation from the time of signing the ICF until 4 months after the last dose. 4. Agree to abstain from alcohol, smoking, and food or beverages containing xanthine or caffeine (including chocolate, tea, coffee, cola, etc.), and refrain from strenuous exercise from 48 hours prior to dosing until discharge from the study site. 5. Self-reported body weight fluctuation of ≤ 5.0% within 12 weeks prior to screening through diet and exercise control alone. 6. Willing and able to maintain a stable diet and exercise lifestyle throughout the study period. 7. SAD cohort: body weight ≥ 50 kg, BMI 19.0-28.0 kg/m² (inclusive). MAD cohort: BMI 28.0-40.0 kg/m² (inclusive). Exclusion Criteria: 1. History of cardiovascular, respiratory, hepatic, renal, gastrointestinal, psychiatric, neurological, hematological, immunological, or metabolic disorders (e.g., recurrent hypoglycemia of unknown cause) that, in the investigator's opinion, would make the participant unsuitable for participation in this study. 2. Clinically significant abnormalities in vital signs, physical examination, laboratory tests, or 12-lead electrocardiogram (ECG) at screening, as judged by the investigator. 3. Presence of diseases that, in the investigator's judgment, may significantly affect drug or nutrient absorption, including clinically significant gastrointestinal disorders (e.g., active inflammatory bowel disease) or symptoms of gastrointestinal disturbance; or any condition that may affect drug absorption, such as subtotal or total gastrectomy, sleeve gastrectomy, gastric bypass surgery, or resection of any intestinal segment. 4. Diagnosis of chronic pancreatitis or history of idiopathic acute pancreatitis, or serum amylase or lipase above the upper limit of normal (ULN) at screening. Participants with a history of acute pancreatitis due to cholelithiasis may be enrolled if they have undergone cholecystectomy. 5. History of acute cholecystitis, or presence of symptomatic/stone-related cholelithiasis requiring treatment on prior or screening ultrasound (except for participants who have undergone cholecystectomy and are deemed eligible by the investigator). 6. Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN-2), or screening calcitonin level ≥ 50 ng/L. 7. Participation in any other clinical trial of a drug or medical device within 3 months prior to screening (excluding those who did not receive the investigational product or device). 8. History of diabetes mellitus (type 1, type 2, or rare forms of diabetes). 9. Presence of endocrine disorders or history thereof that may significantly affect body weight (e.g., Cushing's syndrome, hypothyroidism, or hyperthyroidism; except for hypothyroidism managed with a stable thyroid hormone replacement regimen for at least 6 months), or obesity due to single-gene mutations or hereditary obesity syndromes. 10. Use of any medication or treatment known to cause significant weight gain or weight loss within 3 months prior to screening. 11. Any other condition that, in the investigator's opinion, would make the participant unsuitable for enrollment in this study.