Future chelation monotherapy and combination therapy strategies in thalassemia and other conditions. comparison of defemprone, deferoxampne, ICL670, GT56-252, L1NAII and starch deferoxamine polymers

Deferiprone (L1), and appropriate combinations with deferoxamine (DFO), can be used effectively for the treatment of thalassemia, and other transfusional iron loading conditions. A number of experimental iron chelators such as deferasirox or ICL670 or Exjade (4-(3,5-bis (2-hydroxphenyl)-1,2,4-triazol-1-yl)-benzoic acid), deferitrin (4,5-dihydro-2-(Z4-dihydroxyphenyl)-4-methylthiazole-4 (S)-carboxylic acid) or G756-252, 1-allyl-2-methyl-3-hydroxypyrid-4-one or L1NAll and starch DFO polymers, are under clinical evaluation. ICL670 is the most advanced in development and appears to be effective in reducing liver iron in some patients but is overall ineffective in causing negative iron balance. It is also suspected that it is not effective in cardiac iron removal. Combination therapies using L1, DTO and new iron chelating drugs may cause higher efficacy and lower toxicity by comparison to monotherapies. However, several limitations including the high cost of the new chelating drugs may not facilitate the availability of these new treatments to the vast majority of thalassemia patients, most of whom live in developing countries.