Can chronic myeloid leukemia patients discontinue dasatinib after a year of deep molecular response?

This study aimed to investigate if dasatinib could be successfully discontinued in chronic myeloid leukemia patients who were receiving it as a second line treatment after a year of deep molecular response. This study concluded that it was possible to discontinue dasatinib use in this group of patients.

Imatinib (Gleevec) is a targeted therapy used for first line treatment for chronic myeloid leukemia (CML). Dasatinib (Sprycel) is a chemotherapy that is used as second line treatment for CML patients. A deep molecular response (DMR) can indicate that a treatment has been successful. To achieve DMR there must be no cancerous DNA found when molecular tests are done. 

Studies have shown that it is possible for patients who achieve a DMR to stop imatinib treatment. It was not known if dasatinib treatment could be discontinued once DMR for more than one year was achieved.

This study involved 63 CML patients who achieved DMR for more than one year when treated with dasatinib as a second line treatment. Patients were followed for an average of 44 months. The predicative factors of treatment-free remission (TFR, time without disease while not treated) were analyzed.

The estimated overall TFR rate at 36 months was 44.4%. Two patients developed a molecular relapse after the one year cut off point.

Patients who had imatinib resistance were at risk of a molecular relapse. High natural killer (NK) cell counts before discontinuation indicated successful therapy discontinuation, as did low levels of certain types of T-cells (immune cells).

This study concluded that discontinuation of second line dasatinib after DMR of greater than one year is possible for CML patients who are not imatinib resistant. It was also concluded that the NK cell count was associated with TFR.

Studies of longer duration need to be carried out.

Consult your physician about the possibility of dasatinib discontinuation.