In:
Blood, American Society of Hematology, Vol. 101, No. 1 ( 2003-01-01), p. 85-90
Abstract:
The Abl kinase inhibitor imatinib mesylate (STI571) has significant and rapid antileukemic activity in Philadelphia chromosome/Bcr-Abl–positive acute lymphoblastic leukemia (Ph+ ALL) but such activity is usually of short duration except for a small proportion of patients. To determine the prognostic significance of early Bcr-Abl levels and changes in peripheral blood (PB) and bone marrow (BM), serial samples of 56 patients with relapsed or refractory Ph+ ALL treated in phase 2 trials of imatinib were analyzed by quantitative polymerase chain reaction (PCR). Imatinib induced a complete hematologic response (CHR) or complete marrow response (marrow-CR) in 40 patients (good responders) and a partial (n = 2) or no (n = 14) remission in the remaining patients (poor responders). Compared with baseline, the median Bcr-Abl/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) ratios decreased significantly in PB by 2.65, 2.64, and 3.11 log steps after 2 weeks, 4 weeks, and at the time of best response, respectively. In BM, the decline of median Bcr-Abl/GAPDH was 0.75, 1.37, and 2.78 logs, respectively. Thus, Bcr-Abl levels decreased more rapidly in PB than in BM (median time to best level 31 vs 39 days). Low Bcr-Abl/GAPDH ratios below 10−4 in PB and below 10−2 in BM after 2 weeks were significantly associated with good responses after 4 weeks. Moreover, Bcr-Abl levels ( & lt; 10−2) in BM of good responders after 4 weeks discriminated between 2 groups of patients with significantly different median time to progression (139 vs 22 days). The data show that Bcr-Abl levels in PB and BM after 2 weeks of imatinib treatment and in BM after 4 weeks have predictive relevance and may guide the application of additional therapies.
Type of Medium:
Online Resource
ISSN:
1528-0020
,
0006-4971
DOI:
10.1182/blood-2002-02-0360
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2003
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7