CS-121 APOC3 Base Editing in Severe Hypertriglyceridemia

Inclusion Criteria: * Male or female participants aged 18 years ≤ age \< 65 years. * The serum triglyceride levels of the participants failed to be effectively controlled under the standard treatment regimen (or the medication that is available and tolerable as recommended by clinical practice) and were defined as having at least 3 records of different fasting triglyceride levels ≥ 5.65 mmol/L (500 mg/dL) within 2 years.. * The screening period should include at least two different days with a TG level of ≥ 5.65 mmol/L (500 mg/dL), with an interval of at least 7 days. * Able to sign informed consent and comply with the requirements and restrictions specified in the informed consent form and the protocol. * Female participants must meet one of the following: be not of childbearing potential (e.g., documented hysterectomy, bilateral salpingectomy/sterilization, or ≥1 year postmenopausal); or, if of childbearing potential, have a negative pregnancy test at screening and be willing to use strict and effective contraception (e.g., abstinence, pharmacologic, or barrier methods) during the study. Male participants with reproductive potential must agree to use strict and effective contraception (e.g., abstinence, pharmacologic, or barrier methods) throughout the entire post-dose observation period; males without reproductive potential must provide supporting medical history (e.g., post-vasectomy). Exclusion Criteria: * Currently participating in other interventional clinical studi…