In a nutshell
This study aimed to investigate the ending of imatinib treatment in patients with chronic-phase chronic myeloid leukemia who had at least 2 years of deep molecular response from imatinib first line treatment.
This study concluded that the duration of treatment and residual leukemic cell load were predictive factors for ending of imatinib treatment in these patients.
Imatinib (Gleevec) is a tyrosine kinase inhibitor (TKI). It is a targeted therapy for cancer. It works by blocking cancer cell growth. For patients with chronic myeloid leukemia (CML) ending TKI treatment is a goal. Some studies have shown that imatinib treatment can be safely ended. A deep molecular response (DMR) is needed before a patient can attempt to end TKI treatment. DMR is when the level of the cancer gene (BCR-ABL) in the blood is very low.
The predictive factors for selecting the best patients for successful TKI cessation were unknown.
Methods & findings
This study involved 218 patients who had chronic-phase CML (CP-CML). Patients were followed for an average of 23.5 months after imatinib treatment ended.
2 patients died from unrelated causes and 107 patients experienced an increase in BCR-ABL levels (molecular recurrence). The molecular recurrence-free survival rate was 52% at 6 months and 50% at 24 months.
Droplet digital PCR (ddPCR) was used to accurately evaluate the low level of BCR-ABL in 80% of patients at imatinib cessation. ddPCR is a way to measure BCR-ABL levels. The duration of TKI treatment (shorter than 74.8 months) and ddPCR were found to be the two predictive factors of molecular recurrence.
The bottom line
This study concluded that the duration of TKI treatment and residual leukemic cell load as determined by ddPCR are key factors for predicting successful cessation of treatment for patients with CP-CML.
The fine print
This was a small study. Larger studies are needed for stronger evidence.
Published By :
Clinical Cancer Research
Jul 10, 2019