Analysis of Efficacy and Related Factors of Acquired Deep Molecular Response in Chronic Myeloid Leukemia Patients Treated with TKI

Abstract

To evaluate the efficacy and related factors of acquired deep molecular response(DMR) for treating patients with chronic myeloid leukemia(CML) by using TKI. The clinical data of 131 TKI-treated patients with CML were analyzed retrospectively. The therapeutic effects of each time-points were evaluated, and the related factors of MR4.5 were analyzed. The median follow up-time of 131 cases with CML was 24 months (6-120 months), among them the treatment of 30 patient was converted to nilotinib after a median of 12 months (1-69.6 months) with imatinib, and 13 patient was converted to dasatinib treatment after a median of 31.2 month (3.1-87.6 months) with imatinib. After treatment for 3, 6 and 12 month, the rate of major cytogenetic response (MCyR) was 78%, 79.4% and 95.9%, and the complete cytogenetic response (CCyR) rate was 48.8%, 66.7% and 73.5%, respectively. 60% patients obtained BCR-ABLIS<10% at 3 months, 56.3% patients obtained BCR-ABLIS<1% at 6 months, 55.2% patients obtained BCR-ABLIS<0.1% at 12 months. In continued imatinib therapy group, 53 patients (60.9%) obtained MR4.5, and 33 cases (37.9%) obtained stable MR4.5. Multivariate analysis showed that sex, WBC count at the time of diagnosis and BCR-ABLIS level at 3 months were independent factors for obtaining MR4.5. The 3-month BCR-ABLIS level was an independent factor to obtain stable MR4.5. 18 cases (40.9%) in the second-generation TKI group received MR4.5 and the 3-month BCR-ABLIS level was also an independent predictor for MR4.5. The excellent cytogenetic and molecular responses are observed in CML patients treated with cmatinib. Conversion to second-generation TKI therapy for patients with resistant or intolerant to imatinib also can achieve a satisfactory response and a higher rate of deeper molecular remission. The higher incidence of early molecular response predicting MR4.5 and stable MR4.5 is achieved.