Plozasiran: First Approval.

Plozasiran (Redemplo®) is a first-in-class GalNAc-conjugated small interfering RNA (siRNA) designed to reduce hepatic apolipoprotein C-III (ApoC3) production. It is being developed by Arrowhead Pharmaceuticals for the treatment of familial chylomicronemia syndrome (FCS), severe hypertriglyceridaemia and mixed hyperlipidaemia. Plozasiran degrades ApoC3 mRNA via RNA interference, reducing hepatic and serum ApoC3 levels and thereby enhancing catabolism and clearance of serum triglycerides. It received its first approval in the USA on 18 November 2025 as an adjunct to diet to reduce triglycerides in adults with FCS. This article summarizes the key milestones in the clinical development of plozasiran leading to its first approval for FCS.