Once-Daily Dasatinib for Treatment of Patients with Chronic Myeloid Leukemia

Abstract

To discuss the new dasatinib dosing regimen for the treatment of chronic phase chronic myelogenous leukemia (CP CML) in patients who failed or were intolerant to imatinib therapy. Literature published between July 2008 and December 2008 was accessed via MEDLINE, the Proceedings of the American Society of Hematology, and the Proceedings of the American Society of Clinical Oncology using the key words chronic myelogenous leukemia, chronic myeloid leukemia, dasatinib, imatinib, nilotinib, pharmacokinetics, and regimen. Meeting abstracts and reports of major Phase 1-3 studies published in English are included. Imatinib is the standard first-line therapy for CML; however, some patients develop resistance or are intolerant to the drug. Dasatinib was approved for the treatment of imatinib-resistant/intolerant patients with CML or Philadelphia chromosome-positive acute lymphoblastic leukemia at the dosage of 70 mg twice daily. A Phase 3 dose-optimization study was performed to compare this regimen with others, including dasatinib 100 mg once daily, in patients with CP CML. Results of this study showed that there was no significant difference in efficacy between these 2 regimens. The safety profile was improved in the 100-mg once-daily dasatinib arm with significantly reduced frequencies of grade 3-4 thrombocytopenia and all-grade pleural effusions. The number of patients who had to discontinue, reduce, or interrupt their dosage was also less among patients taking dasatinib 100 mg once daily. Dasatinib 100 mg once daily has a more favorable risk to benefit assessment compared with the previous 70 mg twice-daily regimen and is now the recommended schedule for patients with CP CML.