Monitoring BCR-ABL1 levels in chronic myeloid leukemia patients

This study aimed to investigate the benefits of monitoring early molecular response markers for chronic myeloid leukemia. This study concluded that monitoring BCR-ABL1 values at an early stage could help with assessing response and making decisions regarding timing of treatments.

Measuring molecular response markers can be used to monitor response to treatment. The BCR-ABL1 gene is one such marker. It is present in chronic myeloid leukemia (CML) patients. Molecular response is measured by the amount of BCR-ABL1 gene that is present during and following treatment.

It was not known if there were benefits to monitoring early molecular response markers for chronic myeloid leukemia.

This study involved 476 Chinese patients with CML who were treated with imatinib (Gleevec). Imatinib is a tyrosine kinase inhibitor used to treat CML.  Three early molecular response markers were studied. These were BCR-ABL1 values at 3 months, log reduction (a log is equal to a 90% reduction) and halving time between diagnosis and 3 months.

All outcomes for patients with 3-month BCR-ABL1 levels of less than or equal to 10% and BCR-ABL1 greater than 0.61 log reduction were superior. Patients with the most favorable outcome had BCR-ABL1 halving time of less than or equal to 22 days. Patients with a halving time of more than 44 days and BCR-ABL1 more than 10% at 3 months had the poorest prognosis. A BCR-ABL1 log reduction at 3 months of 0.61 was the only variable that significantly predicted for overall survival.

It was found that a rapid initial decline of BCR-ABL1 was an indicator of a satisfactory outcome.

This study concluded that monitoring BCR-ABL1 values at an early stage could help with assessing response and making decisions regarding the timing of treatments.

This study needs to be carried out in a more diverse population.

Consult your physician about monitoring of BCR-ABL1 levels.