Dasatinib is an orally bioavailable potent inhibitor of multiple tyrosine kinases, including ABL and SRC. Preclinical studies have shown dasatinib to be a much more potent inhibitor of BCR-ABL than imatinib is, and to harbor efficacy against nearly all imatinib-resistant BCR-ABL mutants. Phase I clinical studies have been conducted in imatinib-resistant and -intolerant chronic myeloid leukemia and Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia. No dose-limiting toxicity was observed at doses that harbored substantial clinical efficacy. Multinational phase II studies have confirmed the phase I experience and have led to accelerated approval by the U.S. Food and Drug Administration for the treatment of imatinib-resistant and -intolerant chronic myeloid leukemia as well as its full approval for the treatment of therapy-resistant Ph+ acute lymphoblastic leukemia.