Clinical Features and Treatment Outcomes of 51 Patients with Chronic Myeloid Leukemia Treated with a Tyrosine Kinase Inhibitor at a Single Institution from 2002 to 2014.

Although clinical trials of first- and second-generation tyrosine kinase inhibitors (TKIs) have been shown to improve the prognosis of chronic myeloid leukemia (CML), there is still uncertainty about the clinical features, treatment outcomes, adverse effects, and other possible problems of their use in the clinical setting. We retrospectively analyzed 51 CML patients treated with TKIs at a single institution between 2002 and 2014. The patients (median age: 53.8 years) were classified as having chronic (n = 48), accelerated (n = 2), or blastic phase (n = 1) CML. Our treatments included both 1st generation TKIs (60.8%) and 2nd generation TKIs (39.2%). We found that the overall response rates of complete cytogenetic response (CCyR), major molecular response (MMR), and MR4 (molecular response 4) were 90.2%, 78.4%, and 64.7%, respectively. Second line 2nd generation TKIs had response rates equivalent to those of 1st line 1st generation TKIs. Moreover, 1st line 2nd generation TKIs tended to achieve an early response rate. Overall survival (OS) at 5 years was 93.2%. Sudden blastic crisis (BC) occurred in 2 CML patients receiving TKI with CCyR status. Hematopoietic stem cell transplantation was performed for BC (n = 1) and sudden BC (n = 2). Side effects of all grades (1-3) and grade 3 alone were 64.7% and 11.8%, respectively. Dose reduction, replacement with another TKI, or low dose TKI treatment may be useful methods to control side effects. Further reasons of TKI discontinuation were economic problems (n = 3) and pregnancy (n = 1). Consequently, our treatment strategy for CML demonstrated good response rate and OS. Currently, treatment discontinuation due to intolerance, resistance, economic problems, pregnancy, and sudden BC remains a concern in clinical practice.