<prompt> Alirocumab and Evolocumab are:NPGL1 inhibitorsMicrosomal transport protein inhibitorsPCSK - 9 inhibitorsLipoprotein lipase inhibitors  <response>: PCSK - 9 expressed over many tissues which inhibits metabolism of LDL - receptors. Drugs like Alirocumab Evolocumab inhibit PCSK - 9 and increased LDL - receptor turnover. Thus they decrease the levels of LDL. 