The purpose of AROANG3-2001 is to evaluate the efficacy and safety of ARO-ANG3 in participants with mixed dyslipidemia. Participants will initially receive 2 subcutaneous injections of ARO-ANG3 or placebo. Participants who complete the double-blind treatment period may opt to continue in an open-label extension during which they will receive up to 8 doses of ARO-ANG3.