Medline ® Abstract for Reference 6
of 'Treatment of chronic myeloid leukemia in chronic phase after failure of initial therapy'
Dose escalation of imatinib mesylate can overcome resistance to standard-dose therapy in patients with chronic myelogenous leukemia.
Kantarjian HM, Talpaz M, O'Brien S, Giles F, Garcia-Manero G, Faderl S, Thomas D, Shan J, Rios MB, Cortes J
Blood. 2003;101(2):473. Epub 2002 Sep 12.
We investigated whether increasing the dose of imatinib mesylate might overcome drug resistance in patients with Philadelphia chromosome-positive (Ph(+)) chronic myelogenous leukemia (CML) whose disease manifests relapse or refractoriness to therapy. Fifty-four patients with Ph(+) CML in chronic phase and with hematologic or cytogenetic resistance or relapse on imatinib mesylate therapy at 400 mg orally daily were treated with a higher dose of 400 mg orally twice daily (800 mg daily, 47 patients; or 600 mg daily increased from 300 mg daily, 7 patients). Among 20 patients treated for hematologic resistance or relapse, 13 (65%) achieved a complete (n = 9) or partial (n = 4) hematologic response, but only 1 had a cytogenetic partial response (Ph reduction from 100% to 10%) and 1 had a minor response (Ph reduction from 100% to 50%). Among 34 patients treated for cytogenetic resistance or relapse, 19 (56%) achieved a complete (n = 6) or partial (n = 7) cytogenetic response. We conclude that higher doses of imatinib mesylate may overcome disease-poor response to conventional doses and that this approach deserves further evaluation as frontline therapy for newly diagnosed CML.
Department of Leukemia, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.