A Study to Evaluate SGB-3403 in Healthy Volunteers and Subjects With Elevated Low-Density Lipoprotein Cholesterol (LDL-C)

Inclusion Criteria in SAD: * Male and female subjects aged 18 to 55 years are included. * Body mass index between 19 and 32 kg/m2, inclusive. * Physical examination, vital signs, 12-lead electrocardiogram, and laboratory tests will be normal or slightly abnormal but not clinically significant according to the Investigator's judgment. * Willing to comply with the protocol required visit schedule and visit requirements and provide written informed consent. Exclusion Criteria in SAD: * An underlying known disease or surgical or medical condition that, in the opinion of the Investigator, might interfere with the interpretation of the clinical study results. * The positive result of hepatitis B surface antigen (HBsAg), hepatitis C virus antibody (HCV Ab), human immunodeficiency virus (HIV) antibody, or syphilis at screening. * Alanine aminotransferase (ALT), total bilirubin (TBIL), aspartate aminotransferase (AST), alkaline phosphatase (ALP), or gamma-glutamyl transferase (GGT) \> 1.5 × ULN (upper limit of normal). * Serum creatinine exceeds the upper limit of normal at screening. * History of multiple drug allergies or allergic reactions to an oligonucleotide or N acetylgalactosamine (GalNAc). * History of intolerance to subcutaneous (SC) injection or relevant abdominal scarring (surgical, burns, etc.) * Received an investigational agent within 28 days or 5 half-lives (whichever is longer) before the first dose of the study drug or are in another clinical study, received INCLI…