Eculizumab in paroxysmal nocturnal haemoglobinuria.

Eculizumab is a monoclonal antibody that binds with high affinity to the complement protein C5, preventing terminal complement-mediated intravascular haemolysis in patients with paroxysmal nocturnal haemoglobinuria (PNH). In three well designed clinical trials in patients with PNH, eculizumab blocked serum haemolytic activity and decreased transfusion rates. Pooled data from the three clinical trials demonstrated that eculizumab treatment decreased the overall thromboembolism rate in patients with PNH. Eculizumab carries a black box warning for the potential increased risk of meningococcal infections and requires patients to receive the meningococcal vaccine at least 2 weeks before starting treatment. Eculizumab is the first drug to be approved by the US FDA for the treatment of PNH and is a novel treatment that offers a new option for patients with PNH.