Repatha (evolocumab) is a monoclonal antibody that inhibits PCSK9 (proprotein convertase subtilisin kexin type 9). PCSK9 is a protein found in the liver that plays a key role in plasma cholesterol metabolism.
Once administered it binds to PCSK9 and prevents the circulating PCSK9 from binding to LDL receptors. This increases the amount of LDL receptors available to clear the ‘bad’ LDL cholesterol from the blood.