BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Furthermore, in a randomized clinical trial, dasatinib demonstrated superior efficacy compared to high-dose (HD) imatinib in patients with imatinib-resistant CP CML, and major cytogenetic responses (CyRs) were achieved in 55% (28/51) of patients without a BCR-ABL mutation at baseline compared with 34% (12/35) observed with HD imatinib [79].