Optimizing iron chelation strategies in β-thalassaemia major

Abstract

β-thalassaemia has served as a paradigm for chelation management for over three decades, both in terms of defining the complications of transfusional iron overload, and demonstrating the benefits of chelation therapy. Iron chelation therapy can be used to reduce unacceptably high tissue iron levels, or to maintain current levels if these are deemed safe, by matching the rate of transfused iron. Chelation therapy should be tailored to the individual patient, based on the transfusional iron loading rate and the current level of iron load both intra- and extra-hepatically, for example in the myocardium. In general, it is preferable to prevent extra-hepatic complications by controlling the body iron load rather than attempting to rescue patients once extra-hepatic complications have developed. Deferoxamine, which has been available since the late 1970s and is given parenterally, has been shown to prolong life and decrease morbidity from iron overload in patients who comply with therapy. Deferiprone may control body iron as oral monotherapy in a variable proportion of patients but is now more frequently used in combinations with deferoxamine, either to control total levels of body iron or to reduce increased levels of myocardial iron. In this article, recent advances in the use of deferasirox, a once-daily oral iron chelator, are reviewed. Large-scale prospective trials show efficacy with an acceptable safety profile in adults and children with up to 5 years follow-up. Recent evidence suggests that deferasirox up to 30 mg/kg/day can be safely administered to patients with serum ferritin levels between 500 and 1000 mg/L, while doses above 30 mg/kg/day can be given to patients with substantial iron overload or with high transfusion rates. Further, prospective data show that myocardial iron can be effectively decreased with this chelation treatment.