Used in the treatment of paroxysmal nocturnal hemoglobinuria (PNH), this antibody inhibits the complement protein C5, preventing its cleavage into C5a and C5b. By blocking this step, it stops the formation of the membrane attack complex (MAC), which reduces intravascular hemolysis. It is also investigated for use in other complement-mediated disorders such as atypical hemolytic uremic syndrome (aHUS) and neuromyelitis optica spectrum disorder (NMOSD). The antibody helps control disease progression by modulating the immune system’s complement activity, reducing the need for blood transfusions and improving patient quality of life.