Lower doses of dasatinib for chronic myeloid leukemia patients

This study aimed to investigate the effectiveness and safety of a lower dose of dasatinib in chronic phase chronic myeloid leukemia patients. This study concluded that the lower dose of dasatinib was as effective and safer than the standard dose in these patients.

Dasatinib (Sprycel) is a tyrosine kinase inhibitor (TKI). TKIs are therapies that block proteins involved in cancer cell growth.  Dasatinib is currently used to treat chronic phase chronic myeloid leukemia (CP-CML) at a dose of 100 mg a day. This dosage can cause myelosuppression (fewer blood cells produced) and pleural effusions (build-up of fluid around the lungs which interferes with breathing). Previous research has suggested that lower doses could be as effective and less toxic.

It was unknown if a 50 mg daily dose would be as effective and less toxic than the 100 mg dose.

This study involved 75 patients with newly diagnosed CP-CML. All patients received 50 mg of dasatinib daily. Patients were followed for an average of 9 months.

At 3 months, 93% of patients achieved BCR-ABL1 transcript levels (levels of cells with a genetic abnormality that leads to CML) of less than or equal to 10%. 72% of patients achieved 1% or less. 

The rate of complete cytogenetic response (no cancer cells found) was 86% at 6 months and at 88% at 12 months. The rate of major molecular response (most of cancer cells gone) was 79% at 12 months.

9 patients had treatment interruption for 14 days or less. One patient developed pleural effusion which required dose reduction.

After 3 months, all patients were still alive. No patients experienced accelerated or blast phase CML (transformation to a more serious form of CML).

This study concluded that 50 mg daily of dasatinib is effective and safe in patients with newly diagnosed CML-CP. It was also concluded that it should be explored further.