Long term treatment with eculizumab in paroxysmal nocturnal hemoglobinuria: sustained efficacy and improved survival

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic disorder with increased mortality and morbidity resulting from intravascular hemolysis. Eculizumab, a monoclonal antibody against the complement protein 5, stops the intravascular hemolysis in PNH. We evaluated 79 consecutive patients treated with eculizumab in Leeds between May 2002 and July 2010. The survival of patients treated with eculizumab was not different from age- and sex-matched normal controls ( P = .46) but was significantly better than 30 similar patients managed before eculizumab ( P = .030). Three patients on eculizumab, all over 50 years old, died of causes unrelated to PNH. Twenty-one patients (27%) had a thrombosis before starting eculizumab (5.6 events per 100 patient-years) compared with 2 thromboses on eculizumab (0.8 events per 100 patient-years; P P