Immunomodulatory Effects of PCSK9 Inhibition

Cardiovascular disease (CVD) represents the leading cause of death worldwide. While medications, such as statins, significantly reduce atherosclerotic CVD (ASCVD) risk by lowering low density lipoprotein levels, they may also have pleiotropic effects on inflammation. The immunomodulatory effects of these medications are relevant to ASCVD risk reduction given that inflammation plays a central role in atherosclerotic plaque formation (atherogenesis) and influences the development of vulnerable plaque morphology. Patients on statins, however, may have residual inflammation contributing to incident ASCVD despite the potent LDL-lowering effects of statins. While new therapies, such as proprotein convertase subtilisin/kexin type 9 (PSCK9) inhibitors, further reduce incident ASCVD and drastically reduce LDL-C below that achieved by statin therapy alone, PCSK9 inhibitors may also have pleiotropic effects on inflammation. Thus, PCSK9 inhibitors may help reduce arterial inflammation to a level closer to that of patients without ASCVD. This study will apply a novel targeted molecular imaging approach, technetium 99m (99mTc)-tilmanocept SPECT/CT, to determine if residual macrophage-specific arterial inflammation is present with statin therapy and the immunomodulatory effects of PSCK9 inhibition. Given the continued high mortality and morbidity attributable to ASCVD, strong imperatives exist to better understand the immunomodulatory effects of lipid lowering therapies and residual inflammatory risk. This understanding, in turn, will inform the development of new ASCVD preventative and treatment strategies as well as elucidate other indications for established therapies.