Imatinib Mesylate (Gleevec) is an orally designed BCR/ABL protein tyrosine kinase inhibitor against BCR/ABL, platelet-derived growth factor receptor (PDGF-R), and c-kit.[10] This oral therapy is the first choice of treatment for almost 80% to 90% of CML patients of all phases.[11] Imatinib Mesylate orally at 400 mg/daily dos indeciduate complete hematologic response in 95% of CML patients and complete cytogenetic responses in 61% to 90.[12] After 18 months of follow-up, about 90% of CML patients are unable to transform to the accelerated or blastic phases. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.