Defibrotide for the treatment of hepatic veno-occlusive disease: results of the European compassionate-use study

Severe hepatic veno-occlusive disease (VOD) is a recognized complication of autologous and allogeneic stem cell transplantation (SCT) that is often fatal, Defibrotide (DF) is a polydeoxyribonucleotide that has been found to have anti-thrombotic, anti-ischaemic and thrombolytic properties without causing significant anticoagulation. Preliminary studies have demonstrated activity for DF in the treatment of VOD, with minimal associated toxicity. In the present study, 40 patients who fulfilled established criteria for VOD were treated with DF on compassionate grounds in 19 European centres: 28 patients met risk criteria predicting progression of VOD and fatality or had evidence of multiorgan failure (MOF), and were defined as 'poor-risk', DF was commenced intravenously at a median of 14 d (range, -2 d to 53 d) post SCT at doses ranging from 10 to 40 mg/kg, The median duration of therapy was 18 d (range, 2-71 d), Twenty-two patients showed a complete response (CR) (bilirubin < 34.2 <mu>mol/l and resolution of signs/symptoms of VOD and end-organ dysfunction) [CR = 55%, confidence interval (CI) 40-70%] and 17 patients (43%) are alive beyond d +100. Tell poor-risk patients showed a complete response (CR = 36%. CI 21-51%). These results demonstrate that DF is an active treatment for VOD following SCT and a randomized trial is now underway in order to further evaluate its role.