The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of single doses of RN0361 in Adult healthy subjects and Adult Hypertriglyceridemic Subjects.

Phase I：

Inclusion Criteria:

• Willing to provide written informed consent before any study-specific procedures.
• Comply with the study requirements and restrictions as listed in the Informed Consent Form and the protocol.
• Fasting serum triglyceride levels > 80 mg/dL and fasting LDL-C ≥70 mg/dL at screening
• Female participants must either be nonchildbearing or, if of childbearing potential, not pregnant, not breastfeeding, and using effective contraception. Male participants must use condoms and ensure their partners use contraception if they are of childbearing potential.
• Participants must avoid sperm or egg donation during the study

Exclusion Criteria:

• History or presence of any serious or uncontrolled disease
• clinically significant health concerns
• Recent vaccination with live vaccines, except for influenza, or plans to receive such during the study.
• Positive tests for alcohol or drugs of abuse at screening.
• History of multiple drug allergies or allergic reactions to specific components used in the study.

Phase II:

Inclusion Criteria:

• Willing to provide written informed consent before any study-specific procedures.
• Comply with the study requirements and restrictions as listed in the Informed Consent Form and the protocol.
• Fasting serum triglyceride levels ≥ 300 mg/dL at screening
• Female participants must either be nonchildbearing or, if of childbearing potential, not pregnant, not breastfeeding, and using effective contraception. Male participants must use condoms and ensure their partners use contraception if they are of childbearing potential.

Exclusion Criteria:

• History or presence of any serious or uncontrolled disease
• Active pancreatitis within 12 weeks prior to Day 1
• Uncontrolled hypertension (sitting blood pressure) >160/100 mm Hg
• Uncontrolled diabetes
• Symptomatic heart failure (NYHA II-IV)
• Positive serologic test of HBV, HCV, or HIV
• Alcohol or drugs abuse
• History of multiple drug allergies or history of allergic reaction to an oligonucleotide or GalNAc.
• History of intolerance to SC injection or relevant abdominal scarring (surgical, burns, etc)
• History of malignancy within the last 2 years prior to the date of consent

Note: Additional inclusion/exclusion ceiteria may apply, per protocol.