Safety and tolerability of deferasirox in pediatric hematopoietic stem cell transplant recipients: one facility's five years’ experience of chelation treatment

42 pediatric patients with iron overload, who underwent liver biopsy and DFX treatment after hematopoietic stem cell transplantation were included in the study group. The patients were divided into two groups diversified according to deferasirox trough plasma concentrations (DFX C(trough)) with cut-off equal to10 mcg/mL. The average dose of DFX was 25.9 mg/kg in the DFX C(trough) < 10 mcg/mL group versus 19.2 mg/kg in the DFX C(trough) > 10 mcg/mL group (p=0,0003). The mean duration of DFX treatment was 135.7 days in the DFX C(trough) < 10 mcg/mL group versus 41.8 days in the DFX C(trough) > 10 mcg/mL group (p<0.0001). The mean tissue iron concentration in the DFX C(trough) < 10 mcg/mL group was 261.9 μmol/g versus 133.4 μmol/g in the DFX C(trough) > 10 mcg/mL group (p < 0.0001). 21 patients (100%) in the DFX C(trough) > 10 mcg/mL group had ductopenia which was complete in 47.6% of them and severe in 52.4%. All patients with particularly high C(trough) (> 25 mcg/mL) were found to have total ductopenia. 90.5% of all deferasirox-related adverse events and 100% of major adverse events occurred in the DFX C(trough) > 10 mcg/mL group. In the DFX C(trough) < 10 mcg/mL group only one patient interrupted chelation therapy versus 16 (84.2%) patients in the DFX C(trough) > 10 mcg/mL group. We would recommend a close monitoring in pediatric hematopoietic transplant recipients subjected to deferasirox-based therapy because we have observed a high incidence of adverse events and discontinuation of chelation treatment.