Deferasirox--current knowledge and future challenges.

Since the last Cooley's symposium in 2005, our knowledge and clinical experience with deferasirox had advanced considerably. This has been based on prospective multicenter clinical trials, on a scale hitherto unprecedented for chelation therapy, now totalling over 7,400 patients. Here, current knowledge about the clinical effects of deferasirox is described in key areas, namely, the pharmacokinetics and its relevance to mechanisms of action; effects on iron balance; effects on serum ferritin; long-term tolerability; and effects on cardiac iron removal. Challenges for future research include a better understanding of the relationship of serum ferritin to iron balance; the optimal target level and rate of decrease in serum ferritin to achieve a "soft landing," as ferritin values fall below 500-1,000 microg/L; the use of surrogate markers, such as mT2*, to infer the likely effects on long-term survival; and the safety and efficacy of deferasirox when combined with other chelators.