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

OBJECTIVE: Describe the real-world clinical profile of eculizumab-treated patients by characterizing their short- and long-term clinical and laboratory outcomes. METHODS: 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. RESULTS: 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). CONCLUSIONS: A considerable proportion of patients with PNH receiving eculizumab did not achieve optimal clinical outcomes and had an ongoing disease burden.