How does Repatha (evolocumab) work in the body?
Repatha (evolocumab) is a monoclonal antibody that lowers LDL cholesterol by targeting PCSK9 (proprotein convertase subtilisin/kexin type 9). It binds to PCSK9 and prevents PCSK9 from interacting with LDL receptors on liver cells. With PCSK9 blocked, more LDL receptors remain available on the cell surface to pull LDL (“bad cholesterol”) out of the bloodstream, which reduces circulating LDL levels.
What happens to LDL receptors when PCSK9 is blocked?
Normally, PCSK9 helps remove LDL receptors from liver cells, which limits how much LDL can be cleared from blood. By neutralizing PCSK9, Repatha helps preserve LDL receptors and increases LDL clearance.
What does this mean for cholesterol lowering?
Because Repatha increases LDL receptor–mediated clearance of LDL cholesterol, it can produce significant reductions in LDL-C in patients with conditions such as hypercholesterolemia and/or atherosclerotic cardiovascular disease, often as an add-on to other lipid-lowering therapies (such as statins).
How is Repatha different from statins or ezetimibe?
Statins primarily reduce cholesterol synthesis in the liver and indirectly increase LDL receptor activity. Ezetimibe reduces cholesterol absorption in the intestine. Repatha acts differently: it directly targets PCSK9 to increase LDL receptor availability on liver cells, leading to enhanced LDL clearance.
What patient questions come up about the mechanism?
Patients often ask whether Repatha works “even if they already take a statin.” Mechanistically, yes: since it works through the PCSK9/LDL receptor pathway rather than cholesterol synthesis or absorption, it can further lower LDL-C on top of other therapies.