Safety and Efficacy of Alternate Desferrioxamine and Deferiprone Compared to Desferrioxamine Alone in the Treatment of Iron Overload in Transfusion-Dependent Thalassemia Patients.

The safety and efficacy of alternating desferrioxamine and deferiprone for the treatment of iron overload in patients with transfusion-dependent anemias was studied in 60 thalassemia patients regularly treated with desferrioxamine. Patients were randomized to continue desferrioxamine alone (20–60 mg/kg/day, 5–7 days/week) or to alternate desferrioxamine (20–60 mg/kg/day, 2 days/week) with oral deferiprone (25 mg/kg tid, 5 days/week). Both treatment groups were similar for age (19.8 ± 6.1 years for desferrioxamine alone and 18.7 ± 4.8 years for alternate therapy) as was gender distribution and mean standard dose of desferrioxamine at the time of study initiation. Over the following 12 months, all patients were monitored weekly for adverse events and for their white blood cell count. Efficacy of the chelation was evaluated by measurement of the serum ferritin, liver iron concentration (magnetic susceptometry by SQUID), and by Non-Transferrin Bound Iron (NTBI). Compliance was comparable for both arms (96.1 ± 5.0% for alternate therapy vs 95.7 ± 5.7 % for desferrioxamine alone; p=0.7883). There was no significant difference in the proportion of patients with adverse events in the two therapy groups but the chelation regimens were associated with distinct adverse events. The alternate therapy was associated with transient gastrointestinal symptoms, such as vomiting in 5 patients (17%), abdominal pain in 3 patients (10%), or diarrhea in one patient (3%), or transient increase of serum ALT levels in one patient (3%), occurring mainly in the first weeks of therapy and were mild/moderate in severity. Daily infusions of desferrioxamine were associated with abscess at the site of infusion in one patient (3%), and allergic reactions in another patient (3%). Mean serum ALT levels were not significantly different between the two therapies. There were no episodes of agranulocytosis and only one patient, treated with desferrioxamine alone, experienced milder neutropenia.

Both therapies resulted in similar decreases of serum ferritin (−349 ± 573 mg/L for the desferrioxamine arm; −248 ± 791 for the alternate arm; p=0.5802), and of liver iron concentrations (−239 ± 474 μg/g wet weight for the desferrioxamine arm; −65 ± 615 μg/g wet weight for the alternate therapy arm; p=0.2263) by the end of the treatment period. No significant changes in NTBI were observed between the two treatment arms (1.10 ± 7.19 μmol/L for the desferrioxamine arm; −0.03 ± 8.13 μmol/L for the alternate arm; p=0.5775). In conclusion, this 12 month study in transfusion-dependent thalassemia demonstrated that the alternating therapy with deferiprone and desferrioxamine is not associated with a significant increase in the incidence of adverse events and that it has comparable efficacy to desferrioxamine alone in controlling iron overload.