Bempedoic acid within the phase ternary diagram governing biliary cholesterol solubilization and gallstone risk

Bempedoic acid has a powerful hypocholesterolemic activity and decreases the risk of major adverse cardiovascular events. However, results from the CLEAR Outcomes trial documented an increased incidence of gallstone disease, with mechanisms still unexplained. This evidence generates critical concerns in a worldwide scenario characterized by an increasing incidence of cholelithiasis and by an increasing prescribing trend of bempedoic acid. Therapy with bempedoic acid affects key pathways involved in cholesterol/bile acids secretion and in bile acid homeostasis, possibly leading to cholesterol gallstone formation. Bempedoic acid can increase the expression of ABCG5 and ABCG8 genes leading to increased cholesterol efflux, can inhibit the expression of the Cyp7a1 gene, leading to decreased bile acid synthesis (secondary to decreased Cyp7a1 mRNA and protein), and can inhibit OATP1B1 and OATP1B3 transporters, leading to reduced uptake of bile acids from the entero-hepatic circulation. Bempedoic acid can also inhibit liver MRP1 transporter and glutathione efflux into blood, can increase nuclear FXR transcriptional activity and can suppress PXR activation, with multi-level effects on bile acid/lipid homeostasis and bile lithogenicity, as anticipated by the analysis of the ternary cholesterol-phospholipid-bile salt phase diagram. The risk of cholesterol crystallization and lithogenesis increases on the background of well-known predisposing conditions such as advanced age, female gender, obesity, associated diseases or pharmacological treatments. Future lines of research need to better dissect the interplay between bempedoic acid and the pathogenesis of cholesterol gallstones, particularly in individuals at increased risk for gallstones.