Due to its relatively clear etiology, Chronic myelogenous leukemia (CML) represents an ideal disease target for a therapy using a selective inhibitor of the Bcr-Abl tyrosine protein kinase Extensive optimization of the class of phenylamino-pyrimidines yielded highly potent and selective Bcr-Abl kinase inhibitors. Compound 1 shows high potency (IC50 = 38 nM) and selectivity for the Abl tyrosine protein kinase at the in vitro level.