[Treatment efficacy of imatinib mesylate versus allogeneic hematopoietic stem cell transplantation for patients with chronic myeloid leukemia in chronic phase].

OBJECTIVE: To compare the treatment efficacy of imatinib mesylate versus allogeneic hematopoietic stem cell transplantation (allo-HSCT) for patients with chronic myeloid leukemia in chronic phase.

METHODS: The efficacy, overall survival, progression-free survival and adverse events were evaluated in 198 patients on these two therapies from February 2002 to December 2012 at our hospital. One hundred and fifteen cases in imatinib group (n = 115) received imatinib at an initial daily dose of 400 mg and then dose was adjusted according to blood routine test and therapy response. All patients were evaluated for hematologic, cytogenetic and molecular responses every 1-3 months. The allo-HSCT group (n = 83) received myeloablative preconditioning regimen and methotrexate (MTX) and cyclosporine A (CsA) were used for graft-versus-host disease (GVHD) partially plus mycophenolate mofetil (MMF) and antihuman thymocyte globulin (ATG). The engraftment evidence and evolution of cytogenetic and molecular response was conventionally detected after allo-HSCT.

RESULTS: In imatinib group, 59 of 86 (68.6%) cases achieved complete cytogenetic response (CCyR) in the 12 months after therapy, while 67 of 70 (95.7%) cases achieved CCyR in allo-HSCT group. The relapse rates of two groups were 14.8% (17/115) , 12.3% (10/81) respectively. The adverse reaction of imatinib in imatinib group was obviously much more tolerable for patients compared with frequently occurred GVHD and infection in allo-HSCT group. The 10-year cumulative overall survival (OS) rate was 93.9% in imatinib group and 77.1% in allo-HSCT group (P = 0.015). And the 10-year cumulative progression-free survival (PFS) rate was 86.1% in imatinib group versus 88.0% in allo-HSCT group (P = 0.508) . For Sokal rating stratified analysis, the cumulative OS rates of two groups were 96.4% and 68.0% (P = 0.049) for intermediate-risk patients, 92.6% and 57.1% (P = 0.017) for high-risk patients while the cumulative PFS rates of two groups were 89.3% and 88.0% for intermediate-risk patients (P = 0.942), 70.4% and 85.7% for high-risk patients (P = 0.405). The rates of OS and PFS were not significantly different for low-risk patients. The cumulative OS rates of two groups were 94.7% and 73.5% (P = 0.009) for those ≥ 30 years old and the cumulative PFS rates of two groups 84.2% and 94.1% respectively (P = 0.147).

CONCLUSION: Imatinib mesylate is superior to allo-HSCT for patients with chronic myeloid leukemia in chronic phase.