Oral PCSK9 inhibitors: closing the gap between potency and practicality

Oral proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors represent a new generation of lipid-lowering therapies that combine the potency of injectable PCSK9 inhibitors with the convenience of oral administration. This review examines the mechanisms, trial evidence, and implementation considerations for oral PCSK9 inhibitors that have reached phase 2 or later clinical development.

Two oral PCSK9 inhibitors, enlicitide and laroprovstat, have demonstrated that oral PCSK9 inhibition is pharmacologically viable through distinct mechanisms of action. Enlicitide, a macrocyclic peptide that competitively blocks the PCSK9-LDL receptor interaction, achieved placebo-corrected LDL-C reductions of ~60% across three phase 3 trials, with high adherence and a favorable safety profile over 52weeks. Laroprovstat, a small molecule that inhibits PCSK9-mediated lysosomal trafficking of the LDL receptor, produced dose-dependent LDL-C reductions of up to 51% in a phase 2 trial and is advancing through phase 3 evaluation. Large cardiovascular outcomes trials remain underway for both agents.

Oral PCSK9 inhibitors have the potential to improve the convenience and acceptability of PCSK9-targeted therapy. Whether these advantages translate into greater real-world uptake will depend on affordability, payer coverage, clinician adoption, and long-term adherence.