Long-Term Outcomes with Sequential Tyrosine Kinase Inhibitors Treatment in Chronic Myeloid Leukemia Patients

Abstract

Objective: Tyrosine kinase inhibitor (TKI) is the standard treatment for chronic myeloid leukemia (CML).In the national list of essential medicines in Thailand, the first, second, and third-line treatments are imatinib, nilotinib, and dasatinib, sequentially, different from the European Leukemia Net guidelines. This study aimed to evaluate the outcomes of CML patients who received sequential treatment with TKI. Methods: This study enrolled CML patients diagnosed between 2008 and 2020 at Chiang Mai University Hospital who received TKI. Medical records were reviewed for demographic data, risk score, treatment response, event-free survival (EFS), and overall survival (OS). Result: One hundred and fifty patients were included in the study, 68 patients (45.3%) were female. The mean age is 45.9 ± 15.8 years. Most patients (88.6%) had good ECOG status (0-1). The CML diagnosis was in the chronic phase in 136 patients (90.6%). The EUTOS long-term survival (ELTS) score revealed a high of 36.7%. At the median follow-up of 8.3 years, 88.6% of patients were in complete cytogenetic response (CCyR), whereas 58.0% were in major molecular response (MMR). The 10-year OS and EFS were 81.33% and 79.33%, respectively. The factors associated with poor OS were high ELTS score (P = 0.01), poor ECOG performance status (P < 0.001), not achieved MMR within 15 months (P = 0.014), and not achieved CCyR within 12 months (P < 0.001). Conclusion: The sequential treatment for CML patients had a good response. Factors predicting survival were ELTS score, ECOG performance status, and early achieving MMR and CCyR.