Third generation PCSK9-inhibitors

Graphical AbstractOpen in new tabDownload slideStrategies to inhibit the proprotein convertase subtilisin/kexin type 9 (PCSK9). Long-term LDL-C reductions have been observed in primates following one single genome editing treatment using the CRISPR-Cas system. The small interfering double-stranded modified RNA inclisiran neutralizes the mRNA of PCSK9 and thereby inhibits PCSK9 protein synthesis intracellularly. Inclisiran is subcutaneously injected every 6 months. A second strategy to inhibit intracellular PCSK9 RNA using antisense oligonucleotides is in early clinical development, both for subcutaneous and for oral application. The fully human monoclonal antibodies evolocumab and alirocumab are administered subcutaneously every 2–4 weeks and lower LDL-cholesterol by around 60%. Both antibodies successfully reduced cardiovascular endpoints and demonstrated safety in large outcome trials. Third generation PCSK9 inhibitors in phase 2 and 3 of their clinical development programmes are lerodalcibep, a fusion protein that consists of a synthetic anti-PCSK9-binding domain (adnectin) bound to human serum albumin and MK-0616, a macrocyclic peptide that binds to PCSK9 and is orally bioavailable.