Definition

A recombinant small peptide inhibitor of the terminal complement pathway protein C5 originally derived from a protein in the saliva of the Ornithodoros moubata tick, with potential anti-inflammatory and cytoprotective activities. Upon administration, nomacopan targets and binds to a unique site on the terminal complement protein C5, which blocks C5 cleavage into the pro-inflammatory components C5a and C5b, and prevents the C5b-dependent assembly of the membrane-attack complex (MAC; C5b-9). This prevents MAC-mediated lysis and destruction of red blood cells (RBCs) in paroxysmal nocturnal hemoglobinuria (PNH) and prevents tissue destruction in various other complement-mediated inflammatory and autoimmune diseases. In addition, this C5 inhibitor targets, binds to and inhibits the activity of leukotriene B4 (LTB4), thereby further preventing inflammatory-mediated cell destruction.