PCSK9 and familial hypercholesterolemia: Furthermore, in an open-label, single-arm clinical trial involving patients with familial hypercholesterolemia but without clinical ASCVD, 78 weeks of PCSK9 monoclonal antibody alirocumab treatment led to a decrease in the coronary plaque burden from 34.6% to 30.4% (Pérez de Isla et al., 2023).