The evaluation of plozasiran for the treatment of familial chylomicronemia syndrome.

INTRODUCTION: Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder marked by severe hypertriglyceridemia and characteristic clinical manifestations, particularly acute pancreatitis. Conventional triglyceride-lowering therapy is largely ineffective. Apolipoprotein (apo) C-III has emerged as a key therapeutic target to lower triglycerides in FCS.

AREAS COVERED: This review compares FCS with more common multifactorial chylomicronemia. We searched PubMed for all English language literature focusing on the search terms 'chylomicronemia,' 'hypertriglyceridemia,' 'APOC3 inhibition,' 'plozasiran,' 'olezarsen,' and 'volanesorsen.' We outline traditional management strategies and their limited role in FCS and explore non-traditional therapies including orlistat, lomitapide, inhibitors of angiopoietin like protein 3 (ANGPTL3), and analogues of fibroblast growth factor 21 (FGF21). The primary focus is on RNA-based gene silencing therapeutics that target apo C-III, particularly the small interfering RNA plozasiran and the allele specific oligonucleotides volanesorsen and olezarsen, highlighting key differences in efficacy and tolerability.

EXPERT OPINION: In a phase 3 trial of plozasiran, at 10 months, median placebo-adjusted reductions in apo C-III were approximately -90%, while TG levels were reduced up to -59%. Thus, plozasiran and alternative RNA-based therapeutics directed against APOC3 represent transformational therapies for patients with FCS and related phenotypes characterized by severe recalcitrant hypertriglyceridemia.