A Dose-exploration Study of EDP167 in HoFH

Inclusion Criteria:

1. Age ≥18 years old, male or female, and weight ≥40 kg.

2. Genetic diagnosis or clinical diagnosis of HoFH.

3. Fasting serum LDL-C ≥2.6 mmol/L.

4. Follow a daily low-fat diet during the study.

5. Receiving stable and tolerable lipid-lowering treatment or other drugs for chronicdiseases treatments for certain periods before the study, and maintain the stabletreatments throughout the study.

6. Women of childbearing potential (WOCBP) must have a negative serum pregnancy test atscreening and a negative pregnancy test prior to receiving EDP167 at baseline.

7. Agree to use contraceptive measures that comply with regulations and the protocolrequirements during the study, and until 6 months after the last dose.

8. Understand the study procedures, voluntarily participate, and sign the informedconsent form.

Exclusion Criteria:

1. Allergic to the drug in this study, its components or similar drugs.

2. Used any antisense oligonucleotide (ASO) or small interfering nucleic acid (siRNA)drugs within 12 months prior to randomization.

3. Received treatment targeting ANGPTL3 or Apolipoprotein C3 (ApoC3), or haveparticipated in other clinical trials within 6 months or 5 half-life (whicheverlonger) prior to screening.

4. Received health supplements or other medications that have been used forlipid-lowering purposes within 4 weeks prior to screening.

5. Received Lipoprotein apheresis within 8 weeks prior to screening.

6. A weight change of >10% within 4 weeks prior to randomization, or planning toundergo weight-loss surgery or weight intervention treatment during the studyperiod.

7. Starting a new diet plan or having significant differences from the previous dietwithin 4 weeks prior to randomization.

8. Presence of diseases that would affect lipid or lipoprotein levels, such asnephrotic syndrome, severe liver diseases, Cushing's syndrome, hypothyroidism orhyperthyroidism, etc., which are poorly controlled, and in the opinion of theInvestigator will interfere with the accurate assessment of the study results.

9. Had New York Heart Association (NYHA) grade III-IV heart failure within 12 monthsprior to randomization, or acute coronary syndrome or stroke within 6 months priorto randomization.

10. Performed coronary intervention within 6 months prior to randomization, or plan toperform coronary intervention during the study.

11. Have a history of major surgery within 3 months prior to screening, or plan toundergo major surgery during the study.

12. History of malignancy, unless considered cured by adequate treatment with noevidence of recurrence for ≥3 years prior to the first dose of EDP167; excludingadequately treated basal cell or squamous cell carcinoma of the skin, carcinoma insitu of the cervix, carcinoma in situ of the breast, or incidental histologicalfindings of prostate cancer (TNM stage T1a or T1b).

13. Clinical evidence of active infections or other major or poorly controlled seriousdiseases, any other conditions that in the opinion of the Investigator may interferewith the study results or put the subjects at excessive risk.

14. Have a history of current existence of alcohol or drug abuse per evaluation of theinvestigator.

15. Uncontrolled hypertension at screening (blood pressure >160/100 mmHg).

16. Subjects with any of the following laboratory abnormalities at screening: a) fastingserum TG≥5.6 mmol/L; b) Glycosylated hemoglobin A1C (HbA1c)>8.5%; c) alanineaminotransferase (ALT) or aspartate aminotransferase (AST) or gamma-glutamyltranspeptidase (GGT)>1.5×ULN (Upper Limit Of Normal), total bilirubin (TBIL)>2×ULN;d) prothrombin time (PT) or activated partial thromboplastin time (APTT) orInternational Normalized Ratio (INR) clinically significant abnormal; e) Hepatitis Bsurface antigen (HBsAg) or antibody to hepatitis C virus (HCVAb) or humanimmunodeficiency virus (HIV) positive; f) estimated glomerular filtration rate (eGFR)<30 mL/min/1.73m2.

17. Donated or lost blood ≥400 mL within 3 months prior to screening.

18. Women who are pregnant, breastfeeding or planning for pregnancy.

19. Other conditions that the Investigator would consider the subject is not suitable toparticipate in this study.