Post-Allogeneic Hematopoietic Stem Cell Transplantation Eculizumab as Prophylaxis Against Hemolysis and Thrombosis for Patients with Hematologic Disorders Associated with Paroxysmal Nocturnal Hemoglobinuria Clones.

Paroxysmal nocturnal hemoglobinuria (PNH) is frequently seen in the context of other aplastic anemia and myelodysplastic syndromes and is associated with hemolysis and increased thromboembolic events. Allogeneic hematopoietic stem cell transplantation (alloHCT) is the sole curative treatment but is associated with significant morbidity. The terminal complement inhibitor eculizumab reduces hemolysis and thromboembolic events and is the sole Food and Drug Administration-approved therapy for PNH. Prophylactic administration of this agent in the early post-transplantation setting to prevent hemolysis and thrombosis has not been described in the literature. We describe our institutional experience of 8 patients with PNH who underwent alloHCT and who received at least 1 dose of eculizumab within 30 days of alloHCT for prevention of thrombosis and hemolysis. One patient with underlying aplastic anemia who received bone marrow stem cells failed to engraft. Another patient experienced steroid-refractory grade IV acute graft-versus-host disease and died of a fungal infection. The other patients engrafted well; no hemolysis, thrombotic events, or infections associated with encapsulated bacteria occurred in any of the 8 patients.