[Clinical study of imatinib for treatment of Philadelphia chromosome positive acute lymphoblastic leukemia.].

Objective: To explore the efficacy and therapeutic outcome of imatinib combined with chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT) for Philadelphia chromosome positive acute lymphoblastic leukemia (ALL).

Methods: Thirty patients from Jan 2006 to Mar 2009 were enrolled in this study. All patients received CDOLP induction chemotherapy regimen. Sixteen patients insensitive to chemotherapy were given imatinib simultaneously. Eleven of 30 patients underwent HSCT. The other 19 cases received consolidation therapy including HD-Ara-C, HD-MTX and HD-CTX. Maintenance therapy regimens were VP combined with imatinib.

Results: The white blood cell (WBC) count in 17 patients was higher than 30 x 10(9)/L. Of 30 patients, 29 were B cell phenotype and 1 T cell phenotype, 24 had additional chromosomal abnormalities. The overall complete remission (CR) rate was 96.7%. The median CR duration was 9 (2 - 20) months. The 1-year and 3-year overall survival (OS) rates were (64.7 +/- 9.8)% and (30.0 +/- 12.4)%, and the event free survival (EFS) rates were (28.8 +/- 9.5)% and (19.2 +/- 10.1)%, respectively. The bcr-abl transcripts in 13 of 30 patients were continuous negative. The OS rate in patients with negative bcr-abl transcripts was higher than that with positive bcr-abl (70.7% vs 61.3%) (P = 0.189). The EFS rate of patients with continuous negative bcr-abl transcripts was significantly higher than that of patients with continuous positive bcr-abl transcripts (P = 0.01). The median overall survival duration of higher WBC count group and normal WBC count group were 10 (4 - 18) and 29(5 - 36) months, respectively. The patients of higher WBC count had lower OS and EFS rates than that of normal WBC count (46.9% and 15.5% vs 83.5% and 50.8%, respectively) (P = 0.003 and 0.009, respectively).

Conclusion: Imatinib can significantly improve molecular CR rate and CR duration for Ph(+) ALL patients. Imatinib combined with allo-HSCT is expectable to improve the curative ratio of these patients.