Investigation of long-term follow-up results of 135 patients with chronic myeloid leukemia receiving imatinib

Abstract

Objective To evaluate the efficacy and safety of imatinib in chronic myeloid leukemia (CML) patients and analyse the factors affecting the survival. Methods 135 CML patients receiving imatinib were evaluated for hematologic, cytogenetic, and molecular responses and adverse events. Results The median follow-up was 20 (range 3-67) months. The rate of cumulative complete hematological response (CHR), major cytogenetic response (MCyR), complete cytogenetic response( CCyR ) and complete molecular response (CMoR) in chronic phase CML patients were 97.9 %, 78.3 %, 72.2 % and 35.1%, respectively.These rates were significantly higher in chronic phase than in accelerated phase and blastic phase (P ＜0.001).The rate of CCyR in low-risk patients was significantly higher than high-risk patients (P =0.048). The estimated overall survival (OS) rate at 1, 3 and 5 year for chronic phase patients were (97.8±1.5) %, (95.2±2.4) % and (91.9±3.2) %, respectively. The estimated progression-free (PFS) survival rate at 1, 3 and 5 year were (92.6±2.7) %, (85.5±3.7) % and (81.3±4.3) %, respectively. The OS rate for accelerated phase patients at 6, 12 and 24 month were (93.8±6.1) %, (72.5±11.8) % and (64.5±12.9) %, the PFS rate were (92.3±7.4) %,(64.5±14.7) %, (53.7±15.7) %, respectively. The OS rate for blastic phase patients at 6, 12 and 19 month were (86.4±7.3) %, (45.4±11.4) %, (19.4±9.8) %, the PFS rate were (70.1±12.6) %, (37.6±15.6) % and (18.8±15.4) %, respectively. The OS and PFS of patients in chronic phase who achieved CCyR or CMoR were better than patients only achieved CHR (P ≤0.001). Multivariate analysis for survival of chronic phase patients indicated that imatinib resistance was the unfavourable factor for PFS (P =0.000, RR =46.744) and OS(P =0.007, RR =20.270). The non-hematological toxicity of imatinib was slight and tolerable, severe hematological toxicity was the major reason for dose reduction or drug discontinuation. Conclusion The efficacy of imatinib in chronic phase CML patients is significantly superior to which in accelerated phase and blastic phase; Achieving CCyR even CMoR is the most important thing for longer survival, iinatinib resistance is the major problem in the treatment with imatinib. Key words: Leukemia, myeloid, chronic; Imatinib