Imatinib induces hematologic and cytogenetic responses in patients with chronic myelogenous leukemia in myeloid blast crisis: results of a phase II study.
Blast crisis is the most advanced stage of chronic myelogenous leukemia (CML) and is highly refractory to therapy. CML is caused by expression of the chimeric BCR-ABL tyrosine kinase oncogene, the product of the t(9;22) Philadelphia translocation. Imatinib (Glivec, formerly STI571) is a rationally developed, orally administered inhibitor of the Bcr-Abl tyrosine kinase. A total of 260 patients with CML were enrolled in a phase II trial, of whom 229 had a confirmed diagnosis of CML in blast crisis. Patients were treated with imatinib in daily oral doses of 400 mg or 600 mg. Imatinib induced hematologic responses in 52% of patients and sustained hematologic responses lasting at least 4 weeks in 31% of patients, including complete hematologic responses in 8%. For patients with a sustained response, the estimated median response duration was 10 months. Imatinib induced major cytogenetic responses in 16% of patients, with 7% of the responses being complete. Median survival time was 6.9 months. Nonhematologic adverse reactions were frequent but generally mild or moderate. Episodes of severe cytopenia were also frequent and were attributable to the underlying condition and treatment with imatinib. Drug-related adverse events led to discontinuation of therapy in 5% of patients, most often because of cytopenia, skin disorders, or gastrointestinal reactions. These results demonstrate that imatinib has substantial activity and a favorable safety profile when used as a single agent in patients with CML in blast crisis. Additional clinical studies are warranted to explore the efficacy and feasibility of imatinib used in combination with other antileukemic drugs.
Sawyers
Charles L
CL
Department of Medicine and Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA. csawyers@mednet.ucla.edu
Hochhaus
Andreas
A
Feldman
Eric
E
Goldman
John M
JM
Miller
Carole B
CB
Ottmann
Oliver G
OG
Schiffer
Charles A
CA
Talpaz
Moshe
M
Guilhot
Francois
F
Deininger
Michael W N
MW
Fischer
Thomas
T
O'Brien
Steve G
SG
Stone
Richard M
RM
Gambacorti-Passerini
Carlo B
CB
Russell
Nigel H
NH
Reiffers
Jose J
JJ
Shea
Thomas C
TC
Chapuis
Bernard
B
Coutre
Steven
S
Tura
Sante
S
Morra
Enrica
E
Larson
Richard A
RA
Saven
Alan
A
Peschel
Christian
C
Gratwohl
Alois
A
Mandelli
Franco
F
Ben-Am
Monique
M
Gathmann
Insa
I
Capdeville
Renaud
R
Paquette
Ronald L
RL
Druker
Brian J
BJ
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001549:Benzamides; D001752:Blast Crisis / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D001772:Blood Cell Count; D020732:Cytogenetic Analysis; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors*; D006801:Humans; D000068877:Imatinib Mesylate; D007700:Kinetics; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011379:Prognosis; D011743:Pyrimidines / Q000009:adverse effects / Q000627:therapeutic use*; D015996:Survival Rate; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D004791:Enzyme Inhibitors; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl