Phase 1 Clinical Study of MWN105 Injection in Participants With Overweight or Obesity

Inclusion Criteria: 1. Participants should be aged 18 to 50 years (inclusive, based on the date of signing the informed consent form) and be male or female, non-diabetic, overweight or obese individuals from China. 2. Obese individuals: BMI ≥ 28.0 kg/m²; overweight individuals: 24.0 kg/m² ≤ BMI \< 28.0 kg/m², with or without the following: i. Complications including prediabetes (impaired fasting glucose and/or impaired glucose tolerance), hypertension, metabolic dysfunction-associated steatotic liver disease, or dyslipidemia; ii. Weight-bearing joint pain; iii. Breathing difficulties caused by obesity or obstructive sleep apnea syndrome. 3. Female participants must have no plans for pregnancy or egg donation from 14 days before the first administration until 4 months after the last administration, and must voluntarily use effective contraception. Male participants must have no plans for sperm donation from the first administration until 4 months after the last administration and must voluntarily use effective contraception to prevent partner pregnancy. Exclusion Criteria: 1. Individuals with a history of severe drug allergy, concurrent severe allergic diseases, or a severe allergic constitution. 2. Individuals with a history or evidence of any of the following: * Secondary or drug-induced obesity. * Type 1 or type 2 diabetes. * Acute or chronic pancreatitis or pancreatic injury. * Medullary thyroid carcinoma, MEN type 2A or 2B, or a related family history. * Prior gastric weight-loss surgery, or liposuction/fat removal surgery within one year before screening. * Plans to undergo weight-loss surgery, liposuction, or abdominal fat removal surgery during the study period that would significantly affect body weight. * History of depression or other serious mental illness, or history of suicidal ideation or behavior. * History of malignant tumors. * History of any of the following heart diseases within 6 months before screening: decompensated heart failure, unstable angina pectoris, myocardial infarction, coronary artery bypass grafting, or coronary stent implantation; history of hemorrhagic or ischemic stroke within 6 months before screening, who were assessed by the investigator as unsuitable for the trial. * Severe or recurrent symptomatic hypoglycemia within 6 months before screening. * Untreated hypertension at screening that is not stabilized by treatment (systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 100 mmHg), or hypertension reaching these levels despite treatment at the time of screening. * History of other severe endocrine system diseases affecting glucose metabolism. * History of digestive system diseases that may increase participant risk, such as acute or chronic cholecystitis; symptomatic or treated cholelithiasis or gallbladder polyps at the time of screening; history of chronic gastrointestinal diseases; gastrointestinal surgery within 12 weeks before screening, who were assessed by the investigator as unsuitable for the trial. * A history of infectious diseases, severe trauma, or major surgery within 4 weeks before screening, who were assessed by the investigator as unsuitable for the trial. 3. Use of any of the following medications or treatments: * Use of GLP-1 receptor agonists or drugs targeting the same target within 12 weeks prior to screening. * Use of systemic glucocorticoids within 12 weeks prior to screening. * Use of tricyclic antidepressants, psychiatric medications, or sedative drugs that significantly affect body weight within 12 weeks prior to screening. * Use of prescription drugs for weight control within 12 weeks prior to screening. * Use of over-the-counter drugs, health supplements, herbal preparations, or meal replacement products for weight control, appetite reduction, or as an alternative to diet within 12 weeks prior to screening, if used for a long-term period (continuous for ≥4 weeks or cumulative for ≥6 weeks). * Use of acupuncture, physical therapy, or other non-drug treatments for weight loss within 12 weeks prior to screening. * Regular use of drugs for gastrointestinal motility or drugs for irritable bowel syndrome, or use of any dosage of laxatives, within 4 weeks prior to screening.