Management of Oral Iron Chelator Deferasirox for Transfusion-Dependent Patients with Hematological Disorders: 2-year Experience at a Single Institution in Japan

Introduction: Deferasirox is an oral iron chelator, approved worldwide for the treatment of chronic iron overload due to transfusion. Deferasirox was permitted two years ago in Japan, but there is little known regarding its efficacy and tolerability in clinical practice. Methods: We conducted a retrospective study of 18 patients with transfusion-dependent anemias treated by deferasirox at our institution. The starting dose was individualized and ranged from 6.4 to 26.3 mg/kg/day. Routine clinical laboratory data were followed, and serum ferritin was assessed every 4 weeks. Results: The mean serum ferritin level of 18 patients at the time of deferasirox induction was 3162 ng/ml. 10 of 18 patients could sustain deferasirox treatment for at least 6 months, at an average maintenance dose of 10.8 mg/kg/day. Serum ferritin reduction was observed in 4 patients, at doses less than 20 mg/kg/day. Eighty-nine percent of the patients had adverse events and 13 of them in all ultimately discontinued. Myelodysplastic syndrome (MDS) patients showed poor tolerability. Severe infections of grade 3 or more were documented in 6 patients, and 2 of them were fatal. Conclusions: The potential for beneficial iron chelation of deferasirox at less than the recommended 20-mg/kg dose was demonstrated. On the contrary, poor tolerability was documented, with adverse events such as severe infections, especially in MDS patients. Although it was not clearly demonstrated that deferasirox was responsible for impaired immunity, careful watching is required to administrate deferasirox.