Inclusion Criteria:
1. Male or female individuals aged between 18 and 65 years old (inclusive of 18 and 65 years old), as determined by the date of signing the informed consent form.
2. Weight ≥ 70 kg (for males) or ≥ 60 kg (for females), with a BMI ranging from 27.0 to 35.0 kg/m2.
3. Resting heart rate ≥ 55 beats per minute and ≤ 90 beats per minute (results of 12-lead electrocardiogram before randomization).
4. Self-reported or documented weight change before the screening period of 12 weeks was less than 5.0%, and the participant can maintain their original diet and lifestyle during the trial period.
5. Participants must have no pregnancy plans from the time of signing the informed consent form until 4 months after the last dose of the investigational drug.
Exclusion Criteria:
1. Individuals with a known allergy to GLP - 1 receptor agonist drugs or the excipient components of MWN109 injection, or those with severe allergic diseases or a severe allergic constitution at the time of screening.
2. Used GLP-1 receptor agonists or similar drugs targeting the same site, drugs that affect body weight, or weight-loss drugs within 12 weeks before screening.
3. Laboratory abnormalities: HbA1c ≥ 6.5%, or fasting blood glucose ≥ 7.0 mmol/L, or 2-hour blood glucose in the OGTT≥ 11.1 mmol/L (participants with fasting blood glucose between 6.1 and 6.9 mmol/L at the time of screening need to undergo the OGTT), ALT or AST ≥ 2.5ULN, or total serum bilirubin ≥ 1.5ULN. Serum amylase or serum lipase ≥ 1.5ULN. eGFR\< 60 mL/min/1.73 m². Serum calcitonin level ≥ 35 ng/L (pg/mL). TSH\> 6.0 mIU/L or \< 0.4 mIU/L. Triglycerides ≥ 5.64 mmol/L (500 mg/dL). HGB\< 110 g/L (for males) or \< 100 g/L (for females).
4. ECG shows second- or third-degree atrioventricular block, long QT syndrome (QTcF \> 470 ms for females or \> 450 ms for males), pre-excitation syndrome, or other ECG abnormalities that the investigator deems require drug intervention.
5. Participants with a history or evidence of any of the following diseases: obesity secondary to other diseases or drug use; previously or currently diagnosed with type 1 or type 2 diabetes at the time of screening; previously or currently diagnosed with acute or chronic pancreatitis, or pancreatic injury at the time of screening; previous diagnosis of medullary thyroid carcinoma (MTC), multiple endocrine neoplasia type 2A or 2B, or with a relevant family history; previously undergone gastric weight-loss surgery, or planning to undergo weight-loss surgery, liposuction, or abdominal fat-reduction surgery during the study, which can significantly affect body weight; a history of past or current depression, other severe mental illnesses, or a history of suicidal tendencies or behaviors; diagnosed with a malignant tumor within 5 years before screening (except for cured carcinoma in situ), or with a potential malignant tumor as evaluated at the time of screening; a history of any of the following heart diseases within 6 months before screening; suffered from hemorrhagic or ischemic stroke within 6 months before screening and deemed ineligible to participate in this clinical trial by the investigator; experienced severe hypoglycemia or recurrent (≥ 2 times within 6 months) symptomatic hypoglycemia within 6 months before screening; participants with uncontrolled hypertension (systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 100 mmHg at the time of screening) after treatment, or those with untreated blood pressure reaching the above-mentioned criteria at the time of screening; abnormal thyroid function that cannot be controlled with a stable drug dosage at the time of screening, or abnormal thyroid function test results with clinical significance that require initiation of treatment at the time of screening; abdominal ultrasound at the time of screening indicates symptomatic gallbladder polyps or other gallbladder diseases that require treatment, or gallbladder diseases with symptoms that the investigator deems require treatment; clinically significant gastric emptying abnormalities, gastric reflux disease, active gastrointestinal diseases, etc., present at the time of screening.
