Deferasirox for the treatment of chronic iron overload in transfusional hemosiderosis

This report describes the Food and Drug Administration's review of data and analyses leading to the approval of the oral iron chelator, deferasirox for the treatment of chronic iron overload due to transfusional hemosiderosis.

The FDA reviewed findings of a controlled, open-label, randomized multicenter phase III study of deferasirox vs. deferoxamine in 586 patients with beta-thalessemia and transfusional hemosiderosis. The study results as well as the results of the FDA review of chemistry, preclinical pharmacology, and supportive studies are described.

Following 48 weeks of treatment in the phase III study, patients' liver iron concentrations (a key endpoint variable) had decreased an average of 2.4 mg of iron (Fe)/g dry weight (dw) and 2.9 mg Fe/g dw in the deferasirox and deferoxamine groups, respectively, despite continued blood transfusions in both cohorts. Deferasirox was associated with serum creatinine increases in approximately a third of patients. Common adverse events included gastrointestinal symptoms and skin rash. Other data provided supportive evidence of deferasirox safety and efficacy.

The FDA granted deferasirox accelerated approval on November 2, 2005, for use in treating chronic iron overload due to transfusional hemosiderosis in patients > or =2 years of age. The sponsor must obtain clinical data demonstrating the drug's long-term safety and effectiveness.