Abstract
PURPOSE: Tyrosine kinase inhibitors (TKIs) have improved the prognosis of chronic myeloid leukaemia (CML), allowing patients with favourable disease profiles and molecular responses to attempt treatment-free remission (TFR). We aim to establish the relapse-free survival (RFS) outcomes and identify prognostic factors for successful remission maintenance among those who attempt TFR. METHODS: Adult CML patients who had undergone TFR from January 1, 2016, to June 30, 2024, were included. Upon TKI discontinuation, real-time quantitative polymerase chain reaction (RQ-PCR) was monitored monthly for the first 12 months, then every 3 months, with TKI reinitiated upon a transcript level above 0.1% (IS). Data analysis was performed using SPSS version 29.0 (SPSS Inc., Chicago, IL, USA). RESULTS: Fifty-seven patients (27 males and 30 females) with a median age of 46 years (range 16 - 70) were analysed. The majority had a low EUTOS long-term survival (ELTS) score (61.4%, n = 35) and received imatinib (87.7%, n = 50). The median treatment duration was 8.8 years (range 4.2 - 18.8), and the median duration for sustained deep molecular remission (DMR) was 4.6 years (range 2.1 - 11.1). RFS was 70.2% at 6 months, 62.5% at 12 months and 56.8% at 2 years after a median follow-up of 34 months (range 9 - 101). The MR5 level was identified as an independent factor associated with sustained remission. All relapsed patients achieved DMR upon treatment reinitiation. CONCLUSION: Treatment discontinuation can be safely performed, with many achieving long-term treatment-free remission. A deeper molecular response (MR5) is associated with an improved likelihood of remission maintenance.