[Analysis the influence factors of treatment free remission outcome with chronic myeloid leukemia patients who discontinued tyrosine kinase inhibitors].

Objective: To explore the related factors affecting the outcome of treatment free remission (TFR) in patients with chronic myeloid leukemia (CML). Methods: Clinical data of CML patients with automatic discontinuation of tyrosine kinase inhibitor (TKI) from the CML cooperative organization of Henan province between June 2, 2013 to March 27, 2021 and the follow-up time was ≥ 6 months were retrospectively analyzed. Log-rank test was used for univariate analysis and Cox proportional risk regression model was used for multivariate analysis. Results: A total of 135 patients were enrolled, and 69 patients (51.1%) were femal and 66 patients (48.9%)were male. Median age was[M(Q1,Q3)] 49 years (38, 58)at discontinuation.Before discontinuation, 72 patients (53.3%) were on treatment with second-generation TKI, 63 patients (46.7%) were on treatment with IM, 17patients (12.6%) had a history of TKI reduction/withdrawal;median duration of treatment was months 84 (68, 108) for all patients;median time of TKI treatment to DMR was months 12(8, 26);median duration of DMR was months 65 (54, 84), and 9 patients (6.7%) had unsustained DMR.The median follow-up time was months 16(6-96), 35 patients (25.9%) lost MMR at a median months 3(1-22), overall estimated TFR was 74.1%.The univariate analysis results showed that:second-generation TKI was used, the time of TKI treatment to DMR was ≤12 months, DMR duration time ≥48 months, had sustained DMR, without TKI reduction/withdrawal history were favorable factors affecting of TFR in patients with TKI discontinuation (all P<0.05).The TFR rate of the second-generation TKI therapy group was significantly higher than the IM therapy group (81.9% vs 65.1%, P=0.019).The multivariate analysis results showed that second-generation TKI treatment[RR=0.451, 95%CI (0.227-0.896), P=0.023] and had sustained DMR [RR=0.120, 95%CI (0.053-0.271), P<0.001] were the protective factors of TFR in patients with TKI discontinuation. Conclusions: Treated with second-generation TKI and had sustained DMR are the protective factors of TFR in patients with TKI discontinuation.The CML patients who had sustained DMR more≥48 months before TKI discontinuation showed a better TFR.