QLC7401 in Participants With Heterozygous Familial Hypercholesterolemia (HeFH)

Inclusion Criteria: * Aged 18-80 years (inclusive) * Participants diagnosed with heterozygous familial hypercholesterolemia by Dutch Lipid Clinic * Network criteria or genetic testing; * Serum low density lipoprotein cholesterol ≥2.6 millimoles (mmol)/liter (L) at screening. * Fasting triglyceride \<4.5 mmol/L at screening. * Participants on lipid-lowering therapies should be on a stable dose for ≥4 weeks before screening with no planned medication or dose change during study participation. * Estimated glomerular filtration Rate (eGFR) \>30 mL/min/1.73 m². * Willing to provide informed consent. Exclusion Criteria: * New York Heart Association (NYHA) class III or IV heart failure. * Uncontrolled cardiac arrhythmia. * Cardiovascular Diseases within 3 months. * Uncontrolled hypertension. * Poorly controlled type 2 diabetes. * Significant liver or kidney disease. * Pregnancy or lactation. * Other conditions deemed unsuitable by investigator.