Impact of eculizumab treatment on paroxysmal nocturnal hemoglobinuria: a treatment versus no-treatment study.

Intravascular hemolysisin Paroxysmal nocturnal hemoglobinuria(PNH) can effectively be controlled with eculizumab, a humanized monoclonal antibody that binds complement protein C5. We report here a retrospective comparison study between 123 patients treated with eculizumabin the recent period (>2005) and 191 historical controls (from the French registry). Overall survival (OS) at 6 years was 92% (95%CI, 87 to 98) in the eculizumabcohort versus 80% (95%CI 70 to 91) in historical controls diagnosed after 1985 (HR 0.38 [0.15 to 0.94], P = 0.037). There were significantly fewer thrombotic events (TEs) in the group of patients treated with eculizumab(4% [1–10]) as compared to the historical cohort (27% [20–34]). However, we found that TEs may still occur after the initiation of eculizumabtreatment and that previous TEs still have a negative impact on survival. Evolutions to myelodysplastic syndromeor acute leukemia were similar in both cohorts. There was less evolution to aplastic anemiain the treatment group. In multivariate analysis, absence of a previous TE and treatment with eculizumabwere associated with a better OS. Treatment with eculizumabimproves overall survival in classic PNH patients without increasing the risk of clonal evolution. Am. J. Hematol. 91:366–370, 2016. © 2016 Wiley Periodicals, Inc.