Tyrosine kinase inhibitors: a cure for chronic myeloid leukemia?

Chronic myeloid leukemia (CML), a malignant transformation of hematopoietic cells, accounts for one-fifth of all leukemias and will be diagnosed in 4,400 individuals in the United States this year. CML has three phases: chronic, accelerated, and blastic. Interferon, hydroxyurea, busulfan, and bone marrow and stem cell transplantation are used to treat CML, but individuals who are in the accelerated phases or blast crisis usually respond poorly to treatment. A new tyrosine kinase inhibitor, STI 571, is being evaluated in clinical trials. STI 571 is highly bioavailable in oral form and produced minimal toxicities in phase I studies. Further research is needed to determine the rate of response and survival data, but STI 571 holds great promise in the treatment of CML.