Defibrotide for Treatment of Severe Veno-Occlusive Disease in Pediatrics and Adults: An Exploratory Analysis Using Data from the Center for International Blood and Marrow Transplant Research.

Veno-occlusive disease (VOD) is an early and serious complication of hematopoietic cell transplantation (HCT) that is associated with inferior survival, particularly when it is complicated by multiorgan failure (severe VOD). We evaluated the efficacy of defibrotide in the treatment of severe VOD using observational data from the Center for International Blood and Marrow Transplant Research (CIBMTR). Eight thousand three hundred forty-one patients treated by HCT between 2008 and 2011 were identified from the CIBMTR clinical database; 3.2% met criteria for VOD and 1.2% met criteria for severe VOD. Patients with a diagnosis of VOD as reported to the CIBMTR by their transplanting centers, who had no prior history of cirrhosis, and who had a maximum total bilirubin level > 2.0 mg/dL by day +100 post-HCT were selected for study. Severe VOD was defined as VOD occurring in the setting of renal impairment requiring dialysis or any noninfectious pulmonary abnormality. Patients with severe VOD were divided into 2 groups for analysis: those treated with defibrotide (n = 41) and those not treated with defibrotide (n = 55). Patients in the nondefibrotide group were older, were more likely to be male, were more likely to have a history of previous fungal infection, and had a higher proportion of clinically significant pre-existing disease or organ impairment. Survival rate at day +100 was 39% (95% CI, 24.8% to 54.3%) in patients receiving defibrotide and 30.9% (95% CI, 19.5% to 43.6%) in those not receiving defibrotide. Resolution rate of VOD at day +100 was 51% in the defibrotide group and 29% in the nondefibrotide group (difference, 22.1%; 95% CI, 2.6% to 42%). The results of our study are consistent with previously reported experiences with defibrotide, confirm the poor outcome of this syndrome, and suggest defibrotide is effective in the treatment of severe VOD.