Defibrotide combined with triple therapy including posttransplant cyclophosphamide, low dose rabbit anti-t-lymphocyte globulin and cyclosporine is effective in prevention of graft versus host disease after allogeneic peripheral blood stem cell transplantation for hematologic malignancies.

Endothelial dysfunction and damage play important roles in the pathophysiology of graft versus host disease (GvHD) and hepatic venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS). Preliminary evidence suggests that defibrotide (DF) may decrease the risk of GvHD. We speculated that DF prophylaxis may have a synergistic effect with other immunosupressive agents by decreasing the incidence of GvHD and retrospectively evaluated the impact of a DF prophylaxis on the development of GvHD. Thirty-eight adult patients with various hematological neoplasms who underwent peripheral blood allogeneic hematopoietic stem cell transplantation from all donor types were included. All patients received DF for prevention of VOD/SOS. GvHD prophylaxis included rabbit anti-T lymphocyte globulin (rATLG), posttransplant cyclophosphamide (PTCy) and cyclosporine (CsA). The median follow-up of the surviving patients was 484 (365-814) days. The cumulative incidence of grade III-IV acute GvHD and moderate/severe chronic GvHD requiring systemic immunosupression at 1 year were 20.6 % and 5.3 %, respectively. Non-relapse mortality, GvHD-relapse-free survival, and overall survival of the study cohort at 1-year were 21.1 %, 44.7 % and 57.9 %, respectively. Our preliminary results suggest that DF may act as a global endothelial protectant and decrease the risk of GvHD in combination with rATLG, PTCy and CsA.