This is an open-label extension of the parent studies AROAPOC3-2001 and AROAPOC3-2002. Adult participants with dyslipidemia who completed the blinded 12-month period from either parent study and continued to meet eligibility criteria had the option to be enrolled into this study. Eligible enrolled participants initially received open-label ARO-APOC3 every three or six months at the assigned dose level of the parent study until a final dose of 25 mg was selected, at which point all participants transitioned to the selected dosing regimen of 25 mg every 3 months.

Inclusion Criteria:

• Adults who are nonpregnant, nonlactating and do not plan to become pregnant during the study
• Able and willing to provide written informed consent
• Completed the 48-week study treatment period in the parent study

Exclusion Criteria:

• Subject was permanently discontinued from ARO-APOC3 in the parent study due to elevated glycated hemoglobin (HbA1c), aspartate aminotransferase (AST) or alanine aminotransferase (ALT)
• Any new condition or worsening of existing condition or any other situation that would make the subject unsuitable for enrollment, could interfere with the subject participating in or completing the study, would make it difficult to comply with protocol requirements or put the subject at additional safety risk
• Unwilling to limit alcohol consumption to within moderate limits for the duration of the study