According to a story from The ASCO Post, the drug dasatinib (marketed as Sprycel), was officially approved as a treatment for chronic myeloid leukemia by the US Food and Drug Administration (FDA) on November 9th, 2017. The treatment was specifically approved for pediatric patients whose disease is Philadelphia chromosome positive. In this story, we will provide an overview of the use of dasatinib as a treatment for this form of leukemia.
About Chronic Myeloid Leukemia (CML)
Chronic myeloid leukemia, which is sometimes also referred to as chronic myelogenous leukemia, is a form of blood cancer that affects a class of white blood cells called granulocytes. It is distinguished from other similar cancers by a distinctive chromosomal translocation, dubbed the “Philadelphia chromsome.” In the vast majority of cases, no precise cause of chronic myeloid leukemia can be identified. Risk factors for the disease include being male, exposure to ionizing radiation, and old age. The disease has three distinct phases: the chronic phase, the accelerated phase, and the “blast crisis.” The chronic phase often presents with no symptoms, but when they are present, they include loss of weight and appetite, enlarged spleen and liver, night sweats, and fever. Ecchymosis, petechiae, infections, bleeding, bone pain, and bone marrow fibrosis occur in more advanced phases. Common treatment include bone marrow transplant and tyrosine kinase inhibitors; five year survival rate is favorable at 89 percent. To learn more about chronic myeloid leukemia, click here.
The appearance of this disease in children is uncommon, but not unheard of. Dasatinib is an inhibitor of the SRC, BCR-ABL family of kinases. The drug is effective as a treatment for disease that has developed resistance to other commonly used drugs, such as imatinib. The approval of the drug was based on results of trials that included 97 pediatric chronic myeloid leukemia patients. 46 patients had developed either resistance or intolerance to imatinib. Dasatinib produced a 96.1 percent complete response rate at 24 months for newly diagnosed patients and 82.6 percent in previously treated patients.
Dosing of dasatinib is typically based on the weight of the patient and is typically reassessed every three months. Treatment is continued until intolerability or disease progression; use of the drug should be avoided with CYP3A4 inhibitors (which includes a number of drugs and grapefruit juice). Adverse effects of treatment include headache, skin rash, nausea, diarrhea, abdominal pain, and pain in the extremities.