This is a single-center, randomized, double-blind, placebo-controlled, single HST101 SC dose cohort study to evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics in Healthy Chinese Participants with Elevated LDL-C Levels.

The planned 30 study participants will be assigned to low- or high-dose 2 cohorts and 15 participants in each cohort will be randomized to either the HST101 group or the matching dose placebo group and will be administered in subsequent or in-parallel manner. Cohort 1: 15 study participants will receive the low dose of HST101 or placebo at a corresponding dose. Cohort 2: additional 15 study participants will receive the high dose of HST101 or placebo at a corresponding dose.

Inclusion Criteria:

• Men and women who are ≥18 and ≤55 years of age with elevated LDL-C Levels;
• LDL-C ≥ 2.6 mmol/L (100 mg/dL) and ≤ 4.9 mmol/L (190 mg/dL) and TG ≤ 2.83 mmol/L (250 mg/dL) who are not on a lipid-lowering therapy 30 days prior to screening;
• Body mass index (BMI) ≥18 and≤28 kg/m2

Exclusion Criteria:

• Positive blood screen for HIV antibody, Treponema pallidum antibody, HBsAg or HCV antibody;
• Clinically significant liver function test abnormalities at screening, such as AST or ALT > 2 × ULN, total bilirubin > 1.5 × ULN, or ALP > 2 × ULN based on normal values;
• CK > 3 × ULN at the screening visit, it can be retested if considered to be related to exercise;
• History of prescription drug abuse, illicit drug use or alcohol abuse;
• Use of any prescription drug, herbal and compound decoction, vitamins, minerals, and OTC drugs and nutritional supplements that alter lipid metabolism within 14 days prior to Check-in and planned use of the above drugs throughout the study;
• Prior treatment with PCSK9 inhibitors, including mAbs, siRNA products, or any Adnectin products;
• History of allergy to protein-based biologics including, but not limited to, mAbs and vaccine;
• Less than 30 days or less than 5 half-lives (drug) since the end of participation in another clinical trial (drug or device), whichever is longer;
• Use of any other biologics within 3 months prior to investigational product administration;
• Any other significant clinical diseases or psychological diseases that the investigator considers to be inappropriate for participation in this study.