[Efficacy of imatinib mesylate, a specific inhibitor of BCR/ABL tyrosine kinase, on chronic myeloid leukemia in blast phase].
OBJECTIVE
Chronic myeloid leukemia (CML) in blast phase is refractory with a poor prognosis. This study was to evaluate efficacy of imatinib mesylate, a specific inhibitor of BCR/ABL tyrosine kinase, on CML in blast phase.


METHODS
Nineteen patients with CML in blast phase (imatinib treatment group) received induction of cytarabine-based standard chemotherapy for 2 cycles, and 400 mg/d of imatinib mesylate for 4 weeks. Patients with no remission received 600 mg/d of imatinib mesylate for another 8 weeks. Treatment of 600 mg/d of imatinib mesylate was maintained if it showed effects after 8 weeks, otherwise it would be stopped. Twenty-two patients with CML in blast phase (historical control group) received inducement of cytarabine-based chemotherapy for 2 cycles, and other regimens of consolidation or continuous induction.


RESULTS
Sixteen patients of imatinib treatment group achieved no hematologic remission after induction. After treated with imatinib mesylate, 6 of 16 (38%) achieved hematologic complete remission (CHR), and major cytogenetic response; 2 of 16(13%) achieved hematologic partial remission (PHR); 1 of 16 (6%) returned to chronic phase with minor cytogenetic response. Total hematologic response rate of imatinib treatment group was 57%; 1-year survival rate was 38% (6/16). Eighteen patients of historical control group achieved no hematologic remission after inducement. After treated with other regimens, 2 (11%) achieved CHR, and 1 (6%) achieved PHR. Total hematologic response rate of historical control group was 17%; 1-year survival rate was 6%(1/18), significantly lower than that of imatinib treatment group (P< 0.05).


CONCLUSIONS
Imatinib mesylate may have anti-leukemic activity, and prolong survival time of patients with CML in blast phase. But problems of tumor relapse, and drug resistance are still present.
Zhang
Guo-Cai
GC
Department of Hematology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China. zhangguocai1946@21cn.com
Zheng
Dong
D
Li
Qun-Hua
QH
Li
Xiao-Hu
XH
Cai
Cheng-Cai
CC
Luo
Shao-Kai
SK
Li
Juan
J
Peng
Ai-Hua
AH
Tong
Xiu-Zhen
XZ
Tan
En-Xun
EX
Hong
Wen-De
WD
D000293:Adolescent; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001549:Benzamides; D001752:Blast Crisis / Q000188:drug therapy*; D019008:Drug Resistance, Neoplasm; D005260:Female; D016044:Fusion Proteins, bcr-abl; D006801:Humans; D000068877:Imatinib Mesylate; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000494:pharmacology / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D011743:Pyrimidines / Q000494:pharmacology / Q000627:therapeutic use*; D012008:Recurrence; D012074:Remission Induction; D015996:Survival Rate
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D016044:Fusion Proteins, bcr-abl