[Effect of low-dose dasatinib in an elderly patient with chronic myelogenous leukemia (CML)].

We experienced a case of chronic myelogenous leukemia (CML) treated successfully with low-dose dasatinib (20 mg/day). An 87-year-old man was diagnosed with CML in January 2003 and was given imatinib (200 mg/day). Although complete hematologic responses (CHR) were achieved, we replaced imatinib with hydroxycarbamide (HU) because of the renal dysfunction possibly due to imatinib. However, since the blood count was poorly controlled with HU, treatment with dasatinib, one of the second-generation tyrosine kinase inhibitors, was started at the accelerated phase (AP) in June 2009. Dasatinib was given in a daily dose of 20 mg, intending dose escalation after confirmation of its safety. White blood cells and platelets decreased rapidly, and after 18 days, CHR was achieved. Thereafter, daily dasatinib was reduced twice per week because of the cytopenia. However, the patient has continued CHR without developing AP for more than six months. Low-dose dasatinib might be a useful treatment in the control of selected patients with CML.