Activity of decitabine, a hypomethylating agent, in chronic myelomonocytic leukemia

BACKGROUND. Hypomethylating agents have activity in myelodysplastic syndrome (MDS) and have received approval for the treatment of both MDS and chronic myelomonocytic leukemia (CMML). The specific efficacy in CMML has not been detailed in a large number of patients. The aim of the study was to evaluate the activity and safety of decitabine in CMML. METHODS. Nineteen adults with a diagnosis of CMML treated on decitabine studies were analyzed. Decitabine was given at 100 mg/m(2) per course every 4 weeks. The median number of courses given was 9 (range, 1-18). RESULTS. Overall, 11 patients (58%) achieved complete response (CR) and 2 (11%) had hematologic improvement (HI), for an overall response rate of 69% according to the modified International Working Group (IWG) criteria. Median survival was 19 months. Severe (grade 3-4) extramedullary side effects were rare. CONCLUSIONS. Decitabine is active in CMML. Studies of combinations of decitabine with topoisomerase I inhibitors or other active anti-CMML agents are indicated.