Abstract
This study was conducted to determine the percentage and predictive factors of patients achieving a sustained molecular response (MR)4.0 over 24 months. We included 93 patients diagnosed with chronic myeloid leukemia (CML) in chronic phase, continuously treated with imatinib and achieving negative nested reverse transcriptase-polymerase chain reaction or at least MR3.0 by real-time quantitative - polymerase chain reaction for at least 3 months. Patients with at least MR4.0 achievement were serially tested by droplet digital polymerase chain reaction every 6 to 8 months for 24 months. Median age of patients at diagnosis was 42 years. The 2 most common clinical features, anemia and splenomegaly, were detected in 88.6% and 70.1% of patients, respectively. The percentage of high Sokal risk (72.3%) was predominant. Variant Philadelphia was reported in 10.8% of patients. Percentage of female in achieving MR4.0 was higher than in not achieving group. Median time of imatinib therapy in patients who achieved MR4.0 was significantly longer than that of patients who did not reach MR4.0. After a median imatinib duration of 71 months, 60.2% of chronic phase CML patients met the National Comprehensive Cancer Network 2019 tyrosine kinase inhibitor discontinuation criteria. Predictive factors of achieved stable MR4.0 were female and duration of imatinib treatment. This study indicated promising results in terms of imatinib discontinuation in CML patients in developing countries such as Vietnam.