In a nutshell
This study aimed to investigate treatment-free remission in patients with chronic myeloid leukemia. This study concluded that some patients can experience late relapses and that long term follow-up is mandatory for these patients.
Some background
Treatment-free remission (TFR) can be used in patients with chronic myeloid leukemia (CML). TFR is achieved when a patient who has stopped tyrosine kinase inhibitor (TKI) treatment maintains a major molecular response (MMR) and does not need to restart therapy. TKIs such as imatinib (Gleevec) are targeted therapies used in CML. MMR is when the level of the BCR-ABL gene is very low. This gene is found in cancerous cells.
It was unknown if TFR was safe and effective in patients with CML.
Methods & findings
This study involved 128 patients with CML who stopped imatinib treatment. Molecular recurrence (MRec) of CML was measured. MRec was defined by the loss of MMR. At first TFR attempt, patients had been treated with TKI for an average of 7.1 years and had molecular response 4 (MR4) for an average of 4 years. MR4 is a level of BCR-ABL1 of 0.01% or less. Patients were followed up after an average of 6.5 years.
After 7 years, the TFR rate was estimated at 45.6%. 14% of patients experienced MRec and recurrence occurred after 2 years in TFR.
The probability of remaining in TFR was 65.4% for patients who experienced fluctuations of minimal residual disease (MRD) compared to 100% for patients with stable MRD. MRD is a small number of cancer cells remaining after treatment.
65 patients restarted TKI treatment. Of these, 49.2% tried another TFR. 46.8% of patients were still in the second TFR after 1 year, 35.8% after 3 years, and 31.3% after 5 years.
The bottom line
This study concluded that a long term molecular follow-up remains mandatory for CML patients in TFR.
The fine print
This study took place in one hospital only. Also, it did not evaluate whether the type of TKI influenced TFR. Further studies are needed.
Published By :
Blood advances
Date :
Jul 14, 2020
