PCSK9 inhibitors (inhibitors of proprotein convertase subtilisin/kexin type 9) offer a promising treatment strategy decreasing the concentrations of both atherogenic low density lipoprotein (LDL) and cholesterol contained within LDL. Alirocumab is one of two PCSK9 inhibitors that entered clinical practice so far.
Alirocumab is a specific antibody against PCSK9, manufactured using recombinant technique. When the antibody binds to the PCSK9 isoenzyme, no complex encompassing PCSK9 and LDL receptor can be formed, thus enabling further recirculation of the LDL receptor.
Increasing the amount of LDL receptors available on the cell membranes leads to higher internalization of LDL within cells and to lowering of LDL cholesterol concentration. It has been shown that alirocumab exerts favorable effect on atherogenic lipoproteins (i.e. decrease of concentrations of LDL cholesterol by more than 50%) both in monotherapy and in combination with statins or other hypolipidemics.
Analysis of data obtained in a smaller trial indicates that the hypolipidemic effect is also associated with a decrease of vascular risk, especially with a drop in coronary ischemic events rate. Large prognostic trials are under way, their results being awaited within the years to come.
Alirocumab should be mainly prescribed to patients with familiar hypercholesterolemia or to other patients with a very high risk score.