Study of QLC7401 in the Treatment of Primary Hypercholesterolemia or Mixed Hyperlipidemia With Elevated LDL Cholesterol

Inclusion Criteria: * Male or female participants aged ≥18 years of age. * Serum LDL-C ≥1.8mmol/L for ASCVD participants or ≥2.6mmol/L for other participants at screening. * Fasting TG \<400mg/dL (\<4.5mmol/L) at screening. * Stable lipid-lowering therapy for ≥4 weeks at randomization. * Understand the study procedures and methods, volunteer to participate in the study, and sign the informed consent. Exclusion Criteria: * Having the following diseases or treatment history: (1) cardiac function as defined by the New York Heart Association (NYHA) grade II-IV at screening or randomization or latest detected LVEF\<30%; (2) CVD events within 3 months; (3) uncontrolled severe hypertension; (4) previous diagnosis of familial hypercholesterolemia; (5) have known allergic reaction to experimental drug, or have severe allergic reaction to other drugs; (6) inadequate organ functions or malignancy history; (7) prior exposure to other RNA inhibitors within 2 years. * Any of the laboratory indicators met the following criteria at screening or at randomization: (1) ALT or AST exceeding 2 times the upper limit of normal (ULN), or total bilirubin exceeding 1.5 times ULN; (2) creatine kinase (CK) exceeding 3 times ULN; (3) TSH is less than the lower limit or normal (LLN) or exceeds 1.5 times ULN. * General conditions: (1) male or female participants who do not agree to use high-efficiency contraceptives during the trial and for 6 months after the last dosing; (2) women who are pregnant or lactating. * The investigator determines that the participants have poor compliance or have any factors that may prevent them from participating in the study.