Long-Term Safety and Efficacy of Plozasiran in Adults With Hypertriglyceridemia

This is an open-label study to be conducted in adults with hypertriglyceridemia (HTG) and severe hypertriglyceridemia (SHTG). Each participant must have completed all required visits per protocol in the parent study AROAPOC3-2003 (USA and Canada participants only; NCT# 05413135), AROAPOC3-3001(Canada and Japan participants only; NCT05089084), AROAPOC3-3003 (NCT06347003), AROAPOC3-3004 (NCT06347016) or AROAPOC3-3009 (Argentina, Italy, South Africa, and Spain; NCT06347133). Subjects who previously met all eligibility requirements for AROAPOC3-3003 or AROAPOC3-3004 and were not permitted to proceed to randomization per the Sponsor's direction in order to prevent excessive over-enrollment may also be enrolled in this trial. The subjects must meet all other applicable eligibility criteria prior to enrollment and have an HbA1c results of \<=10% within 30 days prior to Day 1. Subjects entering this OLE from AROAPOC3-2003 must meet the following additional criteria to be considered for enrollment in addition to applicable eligibility criteria: 1. HbA1c ≤10% within 30 days prior to Day 1 2. Completed AROAPOC3-2001 prior to entry into AROAPOC3-2003 AND fulfill either (c) or (d) 3. Baseline fasting TG level of ≥500 mg/dL and prior history of acute pancreatitis at the time of enrollment into AROAPOC3-2001 4. Baseline fasting TG level of ≥1000 mg/dL at the time of enrollment into AROAPOC3-2001 All eligible participants will receive plozasiran administered subcutaneously (SC) approximately every 3 months for 24 months. Participants will be counseled to remain on the specified low-fat diet throughout the study in accordance with local standard of care.