Current therapy of chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disorder molecularly defined by the BCR-ABL gene and its products. The protein encoded by this chimeric gene is a constitutively activated tyrosine kinase that alters multiple signal transduction pathways inducing malignant transformation. Until recently, treatment options for patients with CML consisted of hydroxyurea, interferon-based therapies or allogeneic stem cell transplantation (alloSCT). Treatment decisions were generally based on the age of the patient and the phase of the disease. Recently, several new therapies have been developed that may change the natural history of CML and patient prognosis. In particular imatinib mesylate (STI571, Gleevec) an oral Bcr-Abl kinase inhibitor, has demonstrated activity in all phases of CML, and may replace interferon and alloSCT as the initial therapy for this disease. Other agents and therapies with potential value, either alone or in combination, include polyethyleneglycol (PEG) interferon, homoharringtonine, decitabine, oral cytarabine, and growth factor modulation. In this article, we discuss the biological and clinical characteristics of CML, as well as the different therapeutic alternatives for patients with this disorder.