New frontiers in the treatment of hypercholesterolaemia: oral inhibition of PCSK9

PCSK9 inhibitors represent a cornerstone of lipid-lowering therapy; however, the need for cost containment and simplified routes of administration has stimulated the development of oral small molecules and peptidomimetics capable of modulating or blocking the PCSK9–LDL receptor (LDL-R) interaction, inhibiting PCSK9 mRNA transcription, or preventing lysosomal degradation of the LDL-R. Agents in advanced development include enlicitide (MK-0616) and laroprovstat (AZD0780), while DC371739, NNC0385-0434 (development currently suspended), and CVI-LM001 should also be considered. Enlicitide decanoate, owing to improved intestinal permeability, significantly reduces free PCSK9 (>90%) and LDL-cholesterol (C) (≈60%) in Phase I–II studies, with excellent tolerability. Phase III trials (CORALreef–Lipids and CORALreef–HeFH) have confirmed LDL-C reductions of 55–60%, along with favourable effects on non-HDL-C, apolipoprotein B (apoB), and Lipoprotein(a) Lp(a), comparable to those achieved with monoclonal antibodies. AZD0780 demonstrates dose-dependent reductions in LDL-C (up to 50%) and potential synergism with rosuvastatin, whereas NNC0385-0434—despite documenting significant decreases in LDL-C and Lp(a)—has been discontinued. DC371739 (a dual PCSK9/ANGPTL3 inhibitor) and CVI-LM001 (a transcriptional modulator) may represent additional therapeutic perspectives. Overall, oral PCSK9 inhibitors show consistent efficacy and favourable safety profiles, positioning them as next-generation lipid-lowering therapies, pending cardiovascular outcome data from ongoing studies.