New class of drugs, fully humanized monoclonal antibodies, evolocumab and alirocumab, work as PCSK9 inhibitors. Evolocumab and alirocumab bind free plasma PCSK9 and lead to its degradation, as a result, less free PCSK9 is available in the plasma to bind to LDL-R which help the liver to remove more LDL-C from the circulation, which lower LDL-C plasma levels.