Anti-Complement C5 Antibody (Eculizumab)

Eculizumab is a humanized anti-complement C5 antibody. It inhibits the cleavage of C5 into C5a and C5b. Complement C5 is part of the complement system, a crucial system in inflammation and cell killing. Complement C5 is composed of alpha e beta polypeptide chains. Cleavage of the alpha peptide by C5 convertase generates C5a, which is an anaphylatoxin. C5b initiates the membrane attack complex (MAC), which forms a pore in the cell and leading to cell lysis. Deficiencies have been linked to liver fibrosis and RA (rheumatoid arthritis). Eculizumab, sold under the name Soliris, is an humanized monoclonal antibody that inhibits the cleavage of complement C5 by C5 convertase to C5a. It was approved by the FDA in 2007 for paroxysmal nocturnal hemoglobinuria, and later for atypical hemolytic uremic syndrome.