Some patients who achieve deep molecular remission (DMR) can successfully discontinue tyrosine kinase inhibitors (TKI). TKI discontinuation in chronic phase CML is being implemented in the clinical routine.

To investigate the outcome of the patients with chronic myeloid leukemia (CML) discontinued tyrosine kinase inhibitors (TKI) therapy

TKI was prospectively discontinued in patients who were diagnosed with CML in the chronic phase treated with TKI for ≥5 years, and sustained molecular response 4.5 (MR4.5) for ≥2 years. Molecular relapse was defined as a single loss of major molecular response (MMR) (BCR-ABL1IS >0.1%).

Standard qRT-PCR techniques were performed to evaluate minimal residual disease (MRD)

Twenty-one patients with chronic-phase CML were enrolled. The median duration of TKI treatment before discontinuation was 117 months (49-177) months. The median follow-up time after TKI discontinuation was 20 months (range: 1-117 months). The estimated TFR rate was 62% and 47.6% at 12 and 24 months after discontinuation respectively. Five patients experienced loss of MMR within 7 months after TKI discontinuation. All relapsed patients promptly resumed TKI therapy and regained at least major molecular response.

Our data on the Tunisian population may provide a basis for the safety and feasibility of TKI discontinuation particularly in CML patients who are in sustained deep molecular response with longer TKI treatment duration.