[Application of imatinib in BCR- ABL positive acute lymphoblastic leukemia treatment in the real world]

Objective: To explore the efficacy and prognostic factors of imatinib(IM)combined with chemotherapy for BCR-ABL gene positive acute lymphoblastic leukemia(ALL). Methods: A total of 209 BCR-ABL⁺ALL patients treated with imatinib plus chemotherapy from April 2003 to August 2015 were enrolled in the study, and 106 patients underwent hematopoietic stem cell transplantation(HSCT). Results: The complete remission(CR)rate was 97.9% in newly diagnosed patients. WBC≥100×10⁹/L at diagnosis was a poor factor for overall survival(OS)(P=0.043). Without HSCT, not achieved CR within 4 weeks in the first cycle induction chemotherapy and complete molecular remission(CMR)not achieved during the treatment were adverse factors for OS(P<0.001, P=0.009, P<0.001, respectively), as well as for relapse free survival(RFS)(P<0.001, <0.001 and <0.001, respectively). Of the 106 patients who underwent allo-HSCT or auto-HSCT, there was no statistically significant difference on the OS and RFS. There was no significant difference on OS in patients treated with imatinib or not in the induction chemotherapy, but the former showed higher 5-year RFS rate(37.0% vs 24.0%, P=0.005). The survival of the patients who took tyrosine kinase inhibitors(TKIs)regularly and continuously was the best(40 patients changed to other TKI due to relapse/unsatisfactory decrease in transcription level/occurrence of mutation), followed by those who interrupted TKIs during the bone marrow suppression, those who took TKIs irregularly the worst. The 5- year OS rates among three groups were 46.0%, 28.0% and 17.0%, respectively(P=0.004). The 5- year EFS rates among three groups were 38.0%, 28.0% and 17.0%, respectively(P<0.001). Conclusion: TKIs plus chemotherapy followed by HSCT improved the prognosis of the patients with BCR-ABL⁺ALL patients. It is important to administer TKIs regularly and continuously to improve the outcome of BCR-ABL⁺ALL patients.