Emerging therapies in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) therapy has dramatically changed in the last decade due to the introduction of tyrosine kinase inhibitors (TKIs) - imatinib, nilotinib and dasatinib. Despite the significant prolongation of overall survival of CML patients there is still room for improvement. Approximately 20-25% of patients initially treated with imatinib will need alternative therapy, due to drug resistance which is often caused by the appearance of clones expressing mutant forms of BCR-ABL. Second generation TKIs dasatinib and nilotinib have shown promising results in imatinibresistant or intolerant CML patients, but are not active against CML clones with highly resistant T315I mutation. In recent years special attention is placed on small pool of leukemic stem cells which may contribute to the persistence of the leukemia. This article provides a review of preclinical and clinical data concerning the most promising new directions in CML treatment, with special emphasis on new drugs active in T315I mutation and compounds affecting leukemic stem cells.