A Clinical Trial of TQF6422 Injection in Overweight or Obese Healthy Subjects.

Inclusion criteria

• Chinese male or female trial participants aged ≥18 years (inclusive) and ≤55 years (inclusive).
• Participant body weight ≥50 kg, with body-mass index (BMI) of 24-40 kg/m² (end-points included).
• At screening, the following findings shall be within normal limits, or deemed clinically insignificant by the Investigator despite being abnormal and not meeting exclusion criteria: vital signs, physical examination, 12-lead electrocardiogram (ECG), chest X-ray, abdominal ultrasound, and clinical laboratory tests (including but not limited to hematology, urinalysis, serum biochemistry, coagulation function, serological virology, and thyroid function).
• Negative human immunodeficiency virus antibody (HIV-Ab) test.
• For female participants:

• Non-childbearing potential: including surgical sterilization performed at least 6 weeks prior to screening visit (documented tubal ligation, hysterectomy, or bilateral oophorectomy), or post-menopausal status for ≥12 months prior to screening visit (confirmed by follicle-stimulating hormone (FSH) level ≥40 IU/L); OR
• Child-bearing potential: must be non-pregnant and non-lactating, and must agree to use effective (at least one highly-effective) non-pharmacological contraceptive measures from 14 days before screening, throughout the study period, and for 6 months after study drug administration. Serum pregnancy test shall be negative with human chorionic gonadotropin (hCG) <5 mIU/mL at screening and baseline (D-1). Participants shall not donate ova during this period.
• Male participants with female partners of child-bearing potential must agree to use effective (at least one highly-effective) non-pharmacological contraceptive measures from 14 days before screening, throughout the study period, and for 6 months after study drug administration. Male participants shall not donate sperm during this period.
• Voluntarily provide written informed consent prior to trial participation, with full understanding of trial content, procedures and potential adverse reactions; able to communicate adequately with the Investigator, and understand and comply with all study-related requirements.

Exclusion criteria

Participants meeting any of the following criteria will be excluded from enrollment:

• Presence of clinically-significant ongoing disease, or history of chronic/severe disease, including but not limited to circulatory, lymphatic, respiratory, endocrine, urinary, digestive, nervous, psychiatric, or infectious diseases, malignant neoplasms, severe trauma; or other conditions judged by the Investigator to be exclusionary or likely to confound interpretation of trial results.
• History of second-degree or higher cardiac conduction block, or PR interval >220 ms; risk factors or history of torsades de pointes ventricular tachycardia, including but not limited to unexplained syncope, long-QT syndrome, heart failure; OR any abnormal 12-lead ECG at screening judged by the Investigator to increase risks associated with study participation.
• History of gastrointestinal surgery causing malabsorption (except for endoscopic resections such as gastric polypectomy), or long-term use of medications directly affecting gastrointestinal motility.
• Use within 3 months prior to screening, or ongoing use of medications known to significantly affect body weight (regardless of therapeutic indication), including: GLP-1R agonists, GLP-1R/GIPR agonists, GLP-1R/GCGR agonists, systemic corticosteroids (intravenous, oral or intra-articular), metformin, sodium-glucose cotransporter-2 (SGLT-2) inhibitors, thiazolidinediones (TZDs), tricyclic antidepressants, psychotropic or sedative agents (e.g., imipramine, amitriptyline, mirtazapine, paroxetine, phenelzine, chlorpromazine, thioridazine, clozapine, olanzapine, valproic acid and its derivatives, lithium salts).
• Known comorbid diseases affecting the skeletal-muscle system (e.g., myasthenia gravis, muscular dystrophy); or use of any medications or supplements known to affect muscle anabolism/catabolism within 3 months prior to screening.
• Sunburn, scar tissue, tattoos covering >25 % of total body surface area, open ulcers or branding at screening, judged by the Investigator to interfere with interpretation of cutaneous adverse reactions.
• Clinically-significant infection at screening, including but not limited to upper respiratory tract infection, lower respiratory tract infection, herpes simplex, herpes zoster, requiring antibiotic or antiviral therapy.
• Receipt of live-virus vaccine within 4 weeks prior to randomization, or planned live-virus vaccination during the study.
• Surgical procedure performed within 4 weeks prior to randomization, or planned surgery during the study.
• Blood transfusion, blood loss or blood donation exceeding 400 mL within 3 months prior to screening (excluding physiological menstrual blood loss in female subjects), and/or platelet donation within 2 weeks prior to study drug administration.
• Use of any prescription, over-the-counter, or herbal medicines within 4 weeks prior to randomization (if 5-half-lives of the relevant drug exceed 14 days, the 5-half-life period shall apply).
• History of needle-phobia or venipuncture-related vasovagal syncope, difficult-to-access venipuncture, or intolerance to venous puncture.
• Known hypersensitivity to any component of TQF6422 injection, or prior history of severe allergic reactions (including any food or drug allergy).
• History of substance abuse within 3 months prior to screening, or positive urine drug screen.
• Cigarette smoking >10 cigarettes per day, or equivalent nicotine-containing product use within 3 months prior to screening; or inability to abstain from all tobacco-containing products during the study.
• Chronic alcohol abuse, or alcohol intake exceeding 14 units per week within 3 months prior to screening (1 unit = 360 mL beer, or 45 mL 40 %-proof spirit, or 150 mL wine); or inability to refrain from alcohol during the study; or positive alcohol breath test.
• Habitual excessive intake of caffeine-containing beverages or food within 4 weeks prior to randomization (e.g., coffee, tea, milk-tea, chocolate, cola, energy drinks). Daily caffeine intake shall not exceed 6 units. 1 caffeine-unit = 1 cup coffee (177.4 mL) = 2 cans cola (354.9 mL) = 1 cup tea (354.9 mL) = ½ can energy drink = 85 g chocolate.
• Consumption of grapefruit, Seville-orange or their juices within 7 days prior to first-dose, or inability to discontinue consumption of grapefruit, Seville-orange or their juices during the study.
• Special-dietary requirements that prevent adherence to standard-diet instructions.
• Participation in any investigational drug or medical-device clinical trial within 3 months prior to screening, or planned participation in another clinical trial during this study.
• Body-weight change >5 % within 3 months prior to screening.
• Positive hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV-Ab), or treponema pallidum antibody (TP-Ab).
• Meeting any of the following clinical laboratory criteria at screening:

• Alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) >1.0×ULN, and/or total bilirubin (TBIL) >1.2×ULN;
• Estimated glomerular filtration rate (eGFR) calculated by CKD-EPI formula <90 mL/min/1.73 m²;
• Serum creatine kinase (CK) >1.2×ULN;
• Serum amylase or lipase >1.0×ULN.
• Any other condition or factor judged by the Investigator rendering the subject unsuitable for study participation.