A Study of SYH2082 Injection in Healthy Participants

• SYH2082 Injection (Drug): A subcutaneous injection in the abdomen of the corresponding dose of SYH2082 Injection according to the assigned dose cohort.
• Placebo (Drug): A subcutaneous injection in the abdomen of the corresponding dose of Placebo according to the assigned dose cohort.

Primary outcomes

• Number of participants with treatment-related adverse events as accessed by CTCAE v6.0 [Screening period up to day 57]

Secondary outcomes

• Maximum plasma concentration (Cmax) [Pre-dose at day 1 to day 57]
• Area under the concentration-time curve from time 0 to the last measurable time point (AUClast) [Pre-dose at day 1 to day 57]
• Area under the concentration time curve from time 0 to infinity (AUCinf) [Pre-dose at day 1 to day 57]
• Percent of AUC extrapolated to infinity (AUC_Extrap) [Pre-dose at day 1 to day 57]
• Time to maximum concentration (Tmax) [Pre-dose at day 1 to day 57]
• Elimination half-life (t1/2) [Pre-dose at day 1 to day 57]
• Apparent volume of distribution (Vz/F) [Pre-dose at day 1 to day 57]
• Apparent clearance (CL/F) [Pre-dose at day 1 to day 57]
• Anti-SYH2082 antibodies (ADA) [Pre-dose at day 1 to day 57]
• Mean change in plasma glucose from baseline [Baseline up to Day 57]
• Mean change in insulin from baseline [Baseline up to Day 57]
• Mean change in C-peptide from baseline [Baseline up to Day 57]
• Mean change in glucagon from baseline [Baseline up to Day 57]
• Mean change in HbA1c from baseline [Baseline up to Day 57]
• Change in body weight from baseline [Baseline up to Day 57]
• Change in waist circumference from baseline [Baseline up to Day 57]
• Mean change in Total Cholesterol(TC) from baseline [Baseline up to Day 57]
• Mean change in Triglycerides(TG) from baseline [Baseline up to Day 57]
• Mean change in Low-Density Lipoprotein Cholesterol(LDLC) from baseline [Baseline up to Day 57]
• Mean change in High-Density Lipoprotein Cholesterol(HDLC) from baseline [Baseline up to Day 57]
• Change in blood pressure from baseline [Baseline up to Day 57]
• Change in Visceral Fat from baseline via Bioelectrical Impedance Analysis (BIA) [Baseline up to Day 57]
• Change in Body Fat from baseline via Bioelectrical Impedance Analysis (BIA) [Baseline up to Day 57]
• Change in Skeletal Muscle from baseline via Bioelectrical Impedance Analysis (BIA) [Baseline up to Day 57]
• Corrected QT(QTc) interval [Pre-dose at day 1 to day 8]: Baseline- and placebo-corrected QTcF (ΔΔQTcF)

Sex: All, ages: 18 Years to 55 Years, accepts healthy volunteers

Inclusion Criteria:

* Fully understands the content, procedures, and possible adverse reactions of the study, and voluntarily signs the ICF before the study;
* At screening, age 18-55 years (inclusive, at the time of signing the ICF), male or female;
* At screening, body weight ≥50 kg for males and ≥45 kg for females; body mass index (BMI) between 19.0 and 35.0 kg/m2 (inclusive);
* Body weight change ≤5% within 3 months prior to screening (including the screening period);
* From the time of signing the ICF until 6 months after the last dose, the participant (including their partner) has no plans for childbirth and agrees to use highly effective contraceptive measures;

Exclusion Criteria:

* Known or suspected allergy to glucagon-like peptide-1 (GLP-1) or Glucose dependent insulinotropic polypeptide (GIP) receptor agonists or any component of the investigational product; or has an allergic constitution (allergic to multiple drugs and foods);
* Abnormal results in vital signs, physical examination, laboratory tests, chest X-ray, ultrasound and ECG that are judged by the investigator to be clinically significant within the screening period. Specifically, the following conditions are not excluded: 1)Systolic blood pressure (SBP) < 160 mmHg, diastolic blood pressure (DBP) < 100 mmHg;2)Fasting TG ≤ 3.42 mmol/L, fasting TC ≤ 7.75 mmol/L(with abnormal HDL-C regardless of LDL-C status); 3)Alanine aminotransferase (ALT) < 2 × ULN, aspartate aminotransferase (AST) < 2 × ULN, gamma-glutamyl transferase (GGT) < 2.5 × ULN, and total bilirubin (TBIL) < 1.5 × ULN.4) Blood uric acid <480 μmol/L and never accompanied by physiological abnormalities (gout, etc.); 5) Ultrasound shows fatty liver and excludes causes
* Meet any of the following at screening: (1) HbA1c > upper limit of normal, or fasting blood glucose ≤ 3.9 mmol/L or ≥ 6.1 mmol/L; (2) Calcitonin ≥ 50 ng/L; (3) eGFR < 90 mL/min/1.73m 2; (4) TSH exceeds the normal reference range; 4) Patients with prolonged QT/QTc interval at screening (QTcF > 450 ms), or have a history of risk factors for torsades de pointes (such as family history of heart failure/cardiomyopathy or long QT syndrome), or are taking concomitant medications that prolong the QT/QTc interval;
* Those who are positive for any of hepatitis B surface antigen, hepatitis C virus antibody, human immunodeficiency virus antibody, and Treponema pallidum antibody;
* History or presence of major cardiovascular, respiratory, digestive, urinary, hematological, endocrine, immune or nervous system diseases;
* Subjects with severe trauma or major surgery within 6 months prior to screening, or planned to undergo surgery during the trial;
* Patients with thyroid nodules diagnosed as C-TIRADS category 3 or above in the past or during the screening period;
* Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2, or history of pancreatitis or acute or chronic gallbladder disease;
* Those with a history of malignant tumors, mental illness, depression, anxiety, or epilepsy;
* History of clinical gastric emptying abnormalities (such as gastric outlet obstruction), severe chronic gastrointestinal diseases (such as inflammatory bowel disease, active ulcer);
* Previous gastrointestinal surgery leading to malabsorption, or long-term use of drugs that have a direct effect on gastrointestinal motility. e.g., bariatric surgery or procedures (e.g., gastric banding), or use of GLP-1 or GIP receptor agonists or drugs or products that, in the opinion of the investigator, may cause weight change and affect weight assessment within 3 months prior to screening.
* Those who have symptoms such as dermatitis or skin abnormalities at and around the administration site;
* Use of any prescription drugs, over-the-counter drugs, or Chinese herbal medicines within 2 weeks before screening, or less than 5 half-lives since the last dose of the above-mentioned drugs;
* Use of drugs that may affect glucose metabolism (e.g., systemic steroids, non-selective beta-blockers, monoamine oxidase inhibitors) within 1 month before screening, or less than 5 half-lives since the last dose of the above-mentioned drugs (whichever is longer);