Superiority of allogeneic hematopoietic stem cell transplantation to nilotinib and dasatinib for adult patients with chronic myelogenous leukemia in the accelerated phase

Abstract

In the tyrosine kinase inhibitor (TKI) era, imatinib is the first-line therapy for patients with chronic myeloid leukemia (CML) in chronic or accelerated phase. Although second-generation TKIs (TKI2), including dasatinib and nilotinib, are appropriate treatment regimens for patients with disease that progressed to accelerated phase following imatinib therapy, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy. This study retrospectively analyzed the efficacy of TKI2 and HSCT for treatment of CML in accelerated phase. Ninety-three patients with CML registered in the Chinese CML alliance database from February 2001 to February 2014 were enrolled and divided into the TKI2 (n = 33) and allo-HSCT (n = 60) groups. In the TKI2 group, 26 and 7 patients received nilotinib and dasatinib, respectively, as initial TKI2 and 11 patients transferred to the alternative TKI2 after failure to one TKI2. In the allo-HSCT group, 22 (36.7%), 35 (58.3%), and 3 (10%) patients underwent allo-HSCT from an HLA-matched sibling donor, HLA mismatched/haploidentical donor, and unrelated donor, respectively. All patients in the HSCT group were engrafted. Overall, 69.7%, 48.5%, and 45.5% of patients presented hematological, cytogenetic, and major molecular responses, respectively, to at least one of TKI2. All 60 patients (100%) achieved CHR and cytogenetic response in the HSCT group. Patients in the TKI2 group exhibited lower 5-year overall survival rate (42.9% vs. 86.4%, P = 0.002), 5-year event-free survival rate (14.3% vs. 76.1%, P < 0.001), and 5-year progression-free survival (28.6% vs. 78.1%, P < 0.001) than those in the allo-HSCT group. Multivariate analysis showed that male sex and TKI2 therapy were predictors of poor overall survival, whereas hemoglobin < 100 g/L and TKI2 therapy were predictors of poor event-free survival and progression-free survival. These results indicated that allo-HSCT may be superior to nilotinib and dasatinib for adult patients with CML in accelerated phase.