Long‐term outcomes of patients with paroxysmal nocturnal hemoglobinuria treated with eculizumab in a real‐world setting

Describe the real-world clinical profile of eculizumab-treated patients by characterizing their short- and long-term clinical and laboratory outcomes.This retrospective study used preexisting medical records of eculizumab-treated patients with paroxysmal nocturnal hemoglobinuria (PNH) at the University Hospital Essen. Hematologic response, breakthrough hemolysis, transfusion dependence, and other outcomes were assessed.Of 85 patients with PNH, 76 received eculizumab for ≥24 weeks (mean follow-up: 5.59 years; total: 425 person-years). At 24 weeks (n = 57 patients with data), 7% and 9% had complete and major hematologic response, respectively. Breakthrough hemolysis occurred in 8%, and 38% required a blood transfusion. Over long-term follow-up (25-264 weeks), 70%-82% of patients did not achieve complete or major hematologic response in any 24-week period. Breakthrough symptoms, breakthrough hemolysis, and transfusion dependence occurred in 63%, 43%, and 63% of patients, respectively, at any point during follow-up. The majority (79%-89%) of patients did not achieve normalized hemoglobin, with 76%-93% having elevated bilirubin or absolute reticulocyte count in any 24-week window. Mean percentage reduction in lactate dehydrogenase (baseline to end of follow-up) was 80.3% (95% CI, 64.0-96.6).A considerable proportion of patients with PNH receiving eculizumab did not achieve optimal clinical outcomes and had an ongoing disease burden.