Dasatinib and chronic myeloid leukemia: two-year follow-up in eight clinical trials.

Imatinib is currently regarded as the best initial treatment for patients with chronic myeloid leukemia (CML). However, a significant proportion of patients who relapse, fail to respond, or develop intolerance might benefit from the use of second-generation tyrosine kinase inhibitors. In this review, we report the 2-year results in 8 clinical trials involving more than 2000 patients treated with dasatinib (phases I-III). Patients with CML who had failed to respond or were intolerant to imatinib were enrolled in a phase I trial. The positive results emanating from this study led to a series of 5 phase II trials known as START (SRC/ABL tyrosine kinase inhibition activity: research trials of dasatinib). In addition, 2 phase III dose-optimization trials have now been completed. These trials demonstrate that dasatinib offers clinical benefit to patients resistant or intolerant to imatinib, with a well-described and manageable adverse event profile.