A Phase I, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Single Ascending Doses of SIM0811 Injection in Healthy Chinese Adult Participants

Exclusion criteria

• . History of drug allergy, or specific allergies (asthma, urticaria, eczema, etc.), or allergic constitution (e.g., allergy to two or more drugs, foods, pollen), or known allergy or significant intolerance to the investigational product or any of its components.
• . Presence of clinically significant history of cardiovascular, respiratory, endocrine, urinary, digestive, hematological, neurological, skin, malignant tumor, infectious diseases, psychiatric disorders (e.g., seizures), metabolic abnormalities/dysfunction, etc.
• . Screening physical examination, vital signs, laboratory tests, or other examination results judged by the clinician as abnormal with clinical significance (confirmed upon repeat assessment); OR presence of the following abnormal laboratory indicators: Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), total bilirubin, direct bilirubin, creatinine above the upper limit of normal (ULN); platelet count below the lower limit of normal (LLN); hyperkalemia, hypokalemia, hypercalcemia, or hypocalcemia judged by the investigator as abnormal and clinically significant; PT prolongation \> ULN + 3s, TT prolongation \> ULN + 3s, APTT prolongation \> ULN + 10s, INR \> 1.2, FIB \< 1.5 g/L or \> 4.0 g/L, D-Dimer above ULN.
• . Screening ECG findings judged as abnormal with clinical significance. Resting heart rate not within the range of 50 to 100 beats per minute (exclusive of boundaries). QTcF interval \> 470 ms (QTcF = QT/(RR)\^0.33) or PR interval outside the range of 120 to 220 ms.
• . Risk factors for Torsades de Pointes, or family history (first-degree relatives - biological parents, siblings, or children) of short QT syndrome, long QT syndrome, unexplained sudden death at a young age (≤40 years), drowning, or sudden infant death syndrome.
• . Positive screening results for Hepatitis B surface antigen (HBsAg), Hepatitis C virus (HCV) antibody, Treponema pallidum specific antibody, or Human Immunodeficiency Virus (HIV) antibody.
• . Average daily alcohol consumption exceeding 2 units in the 2 years prior to screening, or weekly alcohol consumption \>14 units (1 unit alcohol ≈ 360 ml beer or 45 ml 40% spirits or 150 ml wine); consumption of any alcohol-containing product within 24 hours prior to investigational product administration; or inability to stop alcohol consumption during the trial; or positive alcohol breath test.
• . Average daily cigarette consumption \>5 in the 2 years prior to screening, or inability to stop using any tobacco products during the trial.