Long-term Results of Imatinib Discontinuation in Patients with Chronic Phase Chronic Myeloid Leukemia: National Multicenter Prospective Study.

The discovery of imatinib is a milestone for chronic myeloid leukemia (CML) (1). As life expectancy in CML patients has approached that of the general population (2), research has shifted towards improving quality of life and economic considerations. After 2010, it has been shown that some patients could maintain molecular response even after discontinuing imatinib (3). This national multicenter prospective cohort study aimed to observe the long-term consequences of discontinuing imatinib therapy in adult chronic phase CML patients. A total of 41 patients were included. The median follow-up time after imatinib discontinuation was 48 months (minimum-maximum 6-81 months). The rate of molecular relapse-free survival (MRFS) at 48 months was 33,2% (CI:48.2-18.2). Twenty-seven of 41 patients lost their major molecular response MMR, treatment was started again, and the molecular response was re-achieved with imatinib in all patients. There was no significant relationship between molecular relapse and clinical factors like duration of treatment or molecular response status. Discontinuing imatinib resulted in approximately 4,392,000 Turkish Liras (TRY) or 245,150 US dollars (USD) in savings. In conclusion, imatinib discontinuation with close molecular monitoring is a safe option and provides important national economic benefits and enhanced quality of life. This approach should be considered for all eligible patients. This is the first tyrosine kinase inhibitor discontinuation study from Turkey.