Arrowhead Pharmaceuticals Inc. announced that it has dosed the first patients in the PALISADE study, a Phase 3 clinical study to evaluate the efficacy and safety of ARO-APOC3 in adults with familial chylomicronemia syndrome (FCS). ARO-APOC3 is the company's investigational RNA interference (RNAi) therapeutic that is designed to inhibit the production of apolipoprotein C3 (APOC3), a key regulator of triglyceride metabolism. ARO-APOC3 is currently being investigated in multiple clinical studies, including the Phase 3 PALISADE study in patients with FCS, the Phase 2b SHASTA-2 study in patients with severe hypertriglyceridemia (SHTG), and the Phase 2b MUIR study in patients with mixed dyslipidemia.

PALISADE (NCT05089084) is a global, placebo-controlled Phase 3 study to evaluate the efficacy and safety of ARO-APOC3 in adult participants with FCS. Approximately 60 participants who have met all protocol eligibility criteria during screening will be randomized in a double-blinded fashion to receive ARO-APOC3, or matching placebo, administered subcutaneously once every 3 months. Participants will be randomly assigned 2:1:2:1 to the dose cohorts (ARO-APOC3 25 mg, volume-matched placebo, ARO-APOC3 50 mg, and volume-matched placebo, respectively).

The study will enroll participants with fasting triglycerides greater than or equal to 10 mmol/L (greater than or equal to 880 mg/dL) that are refractory to standard lipid-lowering therapy and a diagnosis of FCS as defined in the inclusion criteria. The duration of the study is approximately 56 weeks from screening to the month 12 end-of-study examination. After month 12, participants will be eligible to continue in an open-label extension study.

All participants in the placebo group who opt to continue will switch to active drug during the extension study. The primary objective of the study is to evaluate the change from baseline in triglycerides between each ARO-APOC3 dose and pooled placebo at month 10.