Treatment of severe veno-occlusive disease with defibrotide : Compassionate use results in response without significant toxicity in a high-risk population

Hepatic veno-occlusive disease (VOD) is the most common of the regimen-related toxicities accompanying stem cell transplantation (SCT). Despite aggressive therapies, including the combination of tissue plasminogen activator (t-PA) and heparin, severe VOD is almost uniformly fatal. Defibrotide (DF) is a polydeoxyribonucleotide with activity in several vascular disorders and, unlike t-PA and heparin, produces no systemic anticoagulant effects. Nineteen patients who developed severe VOD after SCT were treated with DF on a compassionate-use basis. Patients had clinically established VOD and met risk criteria predicting progression and fatality. At the initiation of DF, all 19 patients had evidence of multiorgan dysfunction; median bilirubin was 22.3 mg/dL, 12 patients had renal insufficiency (5 dialysis dependent), 14 required oxygen supplementation, and encephalopathy was present in 8 patients. Beginning a median of 6 days after diagnosis of VOD, DF was administered intravenously in doses ranging from 5 to 60 mg/kg/d for a planned minimum course of 14 days. In no case was DF discontinued for attributable toxicity. No severe hemorrhage related to DF administration was observed. Resolution of VOD (bilirubin