Objectives Determine the effectiveness and cost of defibrotide in patients with severe hepatic sinusoidal obstruction syndrome following haematopoietic stem cell transplantation in a tertiary hospital.

Methods A retrospective observational study. Adults or children treated with defibrotide at a mean dose of 6.8 mg/kg every 6 hours, until the total bilirubin levels are normalised, were included. Main endpoint was complete response, defined as normalised total serum bilirubin levels and resolution of multiple organ failure. Secondary endpoints were survival by 100 days post-transplant, influence of risks factors in effectiveness and cost of treatment.

Results 51 patients (36 adults and 15 children) received defibrotide; median dose of defibrotide administered was 25.19 mg/kg/day (10.0–100.3). Complete response was achieved in 19 (37.3%) patients. By 100 days post-transplant complete response was achieved in 18 (35.3%) patients and the survival rate was 29 (56.9%) patients. There were no significant differences in effectiveness between adults versus paediatrics and between patients who presented risk factors. The mean cost of treatment per patient was €32 916, mean costs in adults was €104 292 and €17 394 in children.

Conclusion Regarding the results of our study, it is convenient to identify the patients who will be able to benefit from this treatment according to clinical conditions, medical history and prognosis. Given the great economic impact of defibrotide, we consider that more cost-effectiveness studies are required.

Trial registration number EPA-OD, number LBM-DEF-2016-01