Olezarsen, a liver-directed APOC3 ASO therapy for hypertriglyceridemia

Apolipoprotein (apo)C-III, a key regulator of plasma triglyceride (TG) levels, is a prime candidate for the treatment of hypertriglyceridemia (HTG), prevention of acute pancreatitis, and reduction of future atherosclerotic cardiovascular disease (ASCVD) events.

We discuss the role of apoC-III as a therapeutic target for HTG, describe the pharmacodynamics, pharmacokinetics, and metabolism of olezarsen, as well as report on the findings of recent clinical trials with this liver-directed APOC3 antisense oligonucleotide (ASO).

Olezarsen, a GalNac-conjugated ASO targeting apoC-III, can reduce TG levels by ~ 50% in patients with extreme HTG due to familial chylomicronemia syndrome, as well as in patients with moderate HTG. Attention is now focused on whether olezarsen reduces ASCVD risk in patients with moderate and severe HTG. While olezarsen does cause elevations in liver enzymes, these changes are not clinically meaningful, and are not associated with thrombocytopenia, an issue with its predecessor, volanesorsen. The need for 4-weekly administration puts olezarsen at a disadvantage to competing injectables. Results from the CORE, CORE2, and ESSENCE phase III clinical trials in patients with severe HTG, expected in the second half of 2025, will help determine the requirement for a larger cardiovascular outcomes trial.