Optimal duration of imatinib treatment/deep molecular response for treatment‐free remission after imatinib discontinuation from a Canadian tyrosine kinase inhibitor discontinuation trial Academic Article uri icon

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  • Although total duration of tyrosine kinase inhibitor (TKI) therapy and of molecular response at 4 log reduction or deeper (MR4) correlates with treatment-free remission (TFR) success after TKI discontinuation, the optimal cut-off values of the duration remain unresolved. Thus, 131 patients were enrolled into the Canadian TKI discontinuation study. The molecular relapse-free survival (mRFS) was defined from imatinib discontinuation till molecular recurrence, that is, major molecular response (MMR) loss and/or MR4 loss. We evaluated mRFS at 12 months after imatinib discontinuation, analyzed it according to the imatinib treatment duration and MR4 duration, and calculated P value, positive (PPV) and negative predictive value (NPV) in the yearly cut-off period of time. The shortest cut-off was sought that met the joint criteria of a P value ≤ 0·05, PPV ≥ 60% and NPV ≥ 60%. We propose six years as the shortest imatinib duration cut-off with a P value 0·01, PPV 68% and NPV 62%: The patients treated with imatinib duration ≥ 6 years showed a superior mRFS rate (61·8%) compared to those with less treatment (36·0%). Also, 4·5 years MR4 duration as the shortest cut-off with a P value 0·003, PPV 63% and NPV 61%: those with MR4 duration ≥ 4·5 years showed a higher mRFS rate (64·2%) than those with a shorter MR4 duration (41·9%).


  • Kim, Dennis DH
  • Novitzky‐Basso, Igor
  • Kim, Taehyung S
  • Atenafu, Eshetu G
  • Forrest, Donna
  • Savoie, Lynn
  • Bence‐Bruckler, Isabelle
  • Keating, Mary‐Margaret
  • Busque, Lambert
  • Delage, Robert
  • Xenocostas, Anargyros
  • Liew, Elena
  • Paulson, Kristjan
  • Stockley, Tracy
  • Laneuville, Pierre
  • Lipton, Jeffrey H
  • Kamel‐Reid, Suzanne
  • Leber, Brian

publication date

  • May 2021