Treatment-free Remission Accomplished With Dasatinib in Patients With CML

The purpose of this study is to find out how to increase the potential for achieving an "operational cure" from chronic myeloid leukemia. An "operational cure" is a state in which a person does not require further treatment, although there may be some remaining cancer cells. Patients would normally remain on a TK inhibitor indefinitely within a standard of care setting for chronic myeloid leukemia. Within this clinical trial, patients will discontinue their TK inhibitor prematurely. If any signs of progression are identified, dasatinib will be introduced. This research is being done because dasatinib has been shown to achieve a greater response in a much higher proportion of patients as compared to imatinib. Dasatinib is approximately 300 times more potent than imatinib, and it is possible that a greater response can be achieved by dasatinib than by imatinib.