Efficacy and safety of olezarsen in lowering apolipoprotein C-III and triglycerides in healthy Japanese Americans

Background: Olezarsen is a GalNAc₃-conjugated, hepatic-targeted antisense oligonucleotide that lowers apolipoprotein C-III (apoC-III) and triglyceride levels. The efficacy and safety of olezarsen has not previously been studied in ethnically diverse American populations. The aim of this study is to assess the effect of olezarsen in healthy Japanese Americans.

Methods: A randomized, placebo-controlled, double-blind phase 1 study was performed in 28 healthy Japanese American participants treated with olezarsen in single-ascending doses (SAD; 30, 60, 90 mg) or multiple doses (MD; 60 mg every 4 weeks for 4 doses). The primary, secondary, and exploratory objectives were safety and tolerability, pharmacokinetics, and effects of olezarsen on fasting serum triglycerides and apoC-III, respectively.

Results: There were 20 participants (16 active:4 placebo) in the SAD part of the study, and 8 participants (6 active:2 placebo) in the MD part of the study. For the primary endpoint, no serious adverse events or clinically relevant laboratory abnormalities were reported. The majority of olezarsen plasma exposure occurred within 24 h post-dose. In the SAD cohorts at Day 15 the percentage reduction in apoC-III/TG was - 39.4%/ - 17.8%, - 60.8%/ - 52.7%, and - 68.1%/ - 39.2% in the 30, 60 and 90 mg doses, respectively, vs 2.3%/44.5% increases in placebo. In the MD cohort, at Day 92 the percentage reduction in apoC-III/TG was - 81.6/ - 73.8% vs - 17.2/ - 40.8% reduction in placebo. Favorable changes were also present in VLDL-C, apoB and HDL-C.

Conclusions: Single- and multiple-dose administration of olezarsen was safe, was well tolerated, and significantly reduced apoC-III and triglyceride levels in healthy Japanese Americans.