Defibrotide in the prevention and treatment of veno‐occlusive disease in autologous and allogeneic stem cell transplantation in children

Abstract

Hepatic veno-occlusive disease (VOD) is a common (10-50%) and serious complication of haematological stem cell transplantation (HSCT), with up to 90% mortality rates. We carried out a study to assess whether the use of prophylactic defibrotide in paediatric patients undergoing HSCT results in a lower frequency or severity of hepatic VOD. Forty-seven successive patients who underwent transplantation between April 2004 and December 2005 were given defibrotide prophylaxis and were compared with 56 historical controls transplanted between November 2001 and April 2004. No serious side effects were reported. High risk patients in the control group received ursodeoxycholic acid and tinzaparin as VOD prophylaxis. The groups were matched for sex, age, type of transplant and risk. In the defibrotide group, four patients developed clinical VOD (Seattle criteria) although two had liver biopsies which showed graft versus host disease (GvHD). Defibrotide dose was increased and symptoms resolved within 14 days. Of the control group four patients had VOD. Two of these patients had reversed hepatic vein flow and died 30 days post-transplant, partly due to VOD. VOD was associated with busulfan conditioning (P = 0.001) and not with age, sex, type of transplant, GvHD, abnormal liver function prior to transplant or type of antifungal prophylaxis. VOD incidence and severity was reduced in the defibrotide group which suggests that defibrotide might be effective in preventing and treating VOD. Sufficiently powered randomised trials are now required to definitively test the role of defibrotide in this setting.