Ravulizumab (subcutaneous formulation) for treating paroxysmal nocturnal haemoglobinuria and atypical haemolytic uraemic syndrome

The subcutaneous formulation of ravulizumab (ravulizumab SC) is in clinical development for the treatment of paroxysmal nocturnal haemoglobinuria (PNH) and atypical haemolytic uraemic syndrome (aHUS). In PNH and aHUS, proteins known as the 'complement system', which is part of the immune system, become overactive and start to attack the body’s own cells. This occurs due to a genetic fault in the complement system in aHUS, and an acquired mutation in a class of blood cell protective proteins in PNH. This results in the destruction of red blood cells in PNH, and the formation of blood clots in small blood vessels (thrombotic microangiopathy) in aHUS. PNH results in anaemia, thrombosis (blood clots in the blood vessels), pancytopenia (low blood cell counts) and dark urine. aHUS results in anaemia, thrombocytopenia (a decrease in the number of platelets, components that help the blood to clot) and kidney failure.