Dose escalation of imatinib mesylate can overcome resistance to standard-dose therapy in patients with chronic myelogenous leukemia.
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.
Kantarjian
Hagop M
HM
Department of Leukemia, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Talpaz
Moshe
M
O'Brien
Susan
S
Giles
Francis
F
Garcia-Manero
Guillermo
G
Faderl
Stefan
S
Thomas
Deborah
D
Shan
Jianqin
J
Rios
Mary Beth
MB
Cortes
Jorge
J
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001549:Benzamides; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000008:administration & dosage*; D011743:Pyrimidines / Q000008:administration & dosage*; D012074:Remission Induction / Q000379:methods; D016879:Salvage Therapy; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate