PCSK9 Inhibitors in Cancer Patients Treated with Immune-Checkpoint Inhibitors to Reduce Cardiovascular Events: New Frontiers in Cardioncology

SIMPLE SUMMARY: Atherosclerosis is a critical cardiovascular disease associated with the use of immune checkpoint inhibitors (ICIs). Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key orchestrator of atherosclerotic process and it is also involved in cancer progression and immune-resistance. In this context, data from recent meta-analysis and cardiovascular outcome trials associate PCSK9 levels to reduced ICIs-related cancer responsiveness and to high risk of atherosclerotic cardiovascular diseases. This review summarizes the pleiotropic effects of PCSK9 in heart failure, atherosclerosis, and cancer immune recognition, and outlines its ability to represent a new pharmacological target in patients who develop ICIs-related atherosclerosis to reduce cardiovascular mortality and to improve overall survival. ABSTRACT: Cancer patients treated with immune checkpoint inhibitors (ICIs) are exposed to a high risk of atherosclerosis and cardiometabolic diseases due to systemic inflammatory conditions and immune-related atheroma destabilization. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein involved in metabolism of low-density lipoprotein (LDL) cholesterol. PCSK9 blocking agents are clinically available and involve monoclonal antibodies, and SiRNA reduces LDL levels in high-risk patients and atherosclerotic cardiovascular disease events in multiple patient cohorts. Moreover, PCSK9 induces peripheral immune tolerance (inhibition of cancer cell- immune recognition), reduces cardiac mitochondrial metabolism, and enhances cancer cell survival. The present review summarizes the potential benefits of PCSK9 inhibition through selective blocking antibodies and siRNA in patients with cancer, especially in those treated with ICIs therapies, in order to reduce atherosclerotic cardiovascular events and potentially improve ICIs-related anticancer functions.