The initial molecular response predicts the deep molecular response but not treatment-free remission maintenance in a real-world chronic myeloid leukemia cohort

Haematologica. 2024 Sep 1;109(9):2893-2907. doi: 10.3324/haematol.2023.284860.

Abstract

In chronic myeloid leukemia, the identification of early molecular predictors of stable treatment-free remission (TFR) after tyrosine kinase inhibitor (TKI) discontinuation is challenging. The predictive values of residual disease (BCR::ABL1 quantification) at month 3 and 6 and more recently, BCR::ABL1 transcript halving time (HT) have been described, but no study compared the predictive value of different early parameters. Using a real-world cohort of 408 patients, we compared the performance of the EUTOS long-term survival (ELTS) score, BCR::ABL1 HT, and residual disease at month 3 and 6 to predict the molecular response, achievement of the TKI discontinuation criteria, and TFR maintenance. The performances of BCR::ABL1 HT and residual disease at month 3 were similar. Residual disease at month 6 displayed the best performance for predicting the optimal response (area under the ROC curve between 0.81 and 0.92; cut-off values: 0.11% for MR4 at month 24 and 0.12% for MR4.5 at month 48). Conversely, no early parameter predicted reaching the TKI discontinuation criteria and TFR maintenance. We obtained similar results when patients were divided in subgroups by first-line treatment (imatinib vs. second-generation TKI [2G-TKI]). We identified a relationship between ELTS score, earlier milestones and TFR maintenance only in the 2G-TKI group. In conclusion, this first comparative study of early therapeutic response parameters showed that they are excellent indicators of TKI efficacy (BCR::ABL1 transcript reduction) and best responders. Conversely, they did not predict the achievement of the TKI discontinuation criteria and TFR maintenance, suggesting that other parameters are involved in TFR maintenance.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Female
  • Fusion Proteins, bcr-abl / antagonists & inhibitors
  • Fusion Proteins, bcr-abl / genetics
  • Humans
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / diagnosis
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / drug therapy
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / genetics
  • Leukemia, Myelogenous, Chronic, BCR-ABL Positive* / mortality
  • Male
  • Middle Aged
  • Neoplasm, Residual* / diagnosis
  • Prognosis
  • Protein Kinase Inhibitors* / therapeutic use
  • Remission Induction*
  • Treatment Outcome
  • Young Adult

Substances

  • Protein Kinase Inhibitors
  • Fusion Proteins, bcr-abl