Efficacy Evaluation Of Imatinib Mesvlate For Chronic Myeloid Leukemia Patients In Chronic Phase

Objective To evaluate the efficacy and safety of imatinib mesylate (imatinib) in patients with Philadelphia chromosome-positive(Ph-positive)chronic myeloid leukemia (CML) in chronic phase.Methods Seventy-three patients with Ph-positive CML in the first chronic phase (most patients were in early chronic phase after diagnosis) were treated with imatinib400mg once daily. During treatment, imatinib doses adjusted according to side effects and the treatment effects.Results With a median follow-up of26(range6-85) months, cumulative complete hematological response (CHR) rate was100%, major cytogenetic response (MCyR) rate91.8%and complete cytogenetic response (CCyR) rate83.6%. Among patients with CCyR, cumulative major molecular response (MMR) rate71.2%and complete molecular response (CMR) rate56.2%. During follow-up,10cases (13.7%)were treatment failure, all patients were alive. The estimated60month progression-free survival rate was92.0%, and failure-free survival was80.0%. Of the73patients in the study,1developed additional karyotypic abnormalities in Ph-positive and Ph-negative cells, respectively. After continuing imatinib treatment, the additional karyotypic abnormalities turned to normality. Early molecular response at3month (BCR-ABL<1%vs BCR-ABL1-10%vs BCR-ABL>10%) showed MMR achieved higher and faster on BCR-ABL<1%(P<0.05). Early cytogenetic response at3month (Ph+<35%vs Ph+>35%) showed CCyR achieved higher and faster on Ph+≤35%(P<0.05). Among patients who had achieved a CCyR, none of those who had achieved an MMR (54.8%) progressed to AP/BC at24months compared with14.3%for patients who had not achieved a similar3-log reduction in BCR-ABL transcript levels(P<0.05). Multivariate analysis for MCyR or CCyR showed that high thrombocyte before therapy (>450109/L vs≤450109/L, P=0.02) was risk factors for optimal responses grade3/4leukocytopenia occurred in16.4%of the patients. and grade3/4thrombocytopenia in28.0%during therapy. Nonhematological toxicities were common and tolerable.Conclusions Imatinib significantly improves cytogenetic and molecular response rates, and progression-free survival for patients with Ph-positive CML in chronic phase. Early molecular and cytogenetic response is predictive for the MMR and CCyR. Among patients who had achieved a CCyR, who had achieved an MMR maybe have better survival without progression to AP/BC. The side effects of imatinib mostly mild, have good tolerance.