A Study of Olezarsen (ISIS 678354) in Participants With Hypertriglyceridemia and Atherosclerotic Cardiovascular Disease, or With Severe Hypertriglyceridemia

Inclusion Criteria:

• Participants must fall into 1 of the following groups (a or b): a. Hypertriglyceridemia with fasting TG ≥200 mg/dL (2.26 millimoles per liter [mmol/L]) and <500 mg/dL (5.65 mmol/L) with either

• Clinical diagnosis of atherosclerotic cardiovascular disease (ASCVD) or

• At increased risk for ASCVD b. Severe hypertriglyceridemia with fasting TG ≥500 mg/dL (5.65 mmol/L)

• Participants should be on standard of care (SOC) lipid-lowering medications perlocal guidelines. Lipid-lowering medications should be optimized and stabilized forat least 4 weeks prior to Screening to minimize changes in these medications duringthe study.

Exclusion Criteria:

• Hemoglobin A1c (HbA1c) ≥ 9.5% at Screening

• Alanine aminotransferase or aspartate aminotransferase > 3.0 × upper limit of normal

• Total bilirubin > 1.5 upper limit of normal unless due to Gilbert's syndrome

• Estimated GFR < 30 mL/min/1.73 m^2

NOTE: Other Inclusion/Exclusion criteria may apply.