RESUMO
Chronic myeloid leukaemia is triphasic, clonal malignancy, arising from the haemopoeitic stem cell. It is characterized by the presence of philadelphia chromosome, which result from reciprocal translocation between chromosome 9 and 22. The resulting oncogen- brc-abl has proliferative activity and survival advantage against normal cell and this account for the clinical and laboratory manifestation of this myeloproliferative disorder. Imatinib, a tyrosine kinase inhibitor (TKIs) is currently the first line of treatment, however, one third of patient develope resistance to it, thus necessitating alternative TKIs. Many factors are associated with the development of resistance to imatinib, such as mutation in the brc-abl gene, increase production of the mutant protein and activation of alternatve pathways amongst other causes. The aim of this reveiw is to explore these factors, and also to avaluate current TKIs that are use as alternative in Imatinib resistant cases