Prolonged azacitidine treatment in the management of elderly patients with high risk myelodysplastic syndromes, chronic myelomonocytic leukemia and acute myeloid leukemia not eligible for standard intensive therapy

Clinical trials with Azacitidine (AZA), a cytosine analogue with hypomethylating activity, have documented an overall survival benefit and an improvement in quality of life for patients with high risk myelodysplastic syndromes (MDS). From October 2010 to April 2013, 37 consecutive elderly patients (17 males and 20 females, median age 76 years), with high risk MDS (RAEB-2, refractory anemia with excess of blasts type 2, n=20), chronic myelomonocytic leukemia (CMML, n=4) and acute myeloid leukemia (AML, n=13) not eligible for standard intensive chemotherapy were treated with AZA (75 mg/mq/day for 7 days every 28 days). All patients received at least 2 cycles of AZA, with a median of 6 cycles (range 2–19). Sixteen patients (13 MDS, 2 AML, 1 CMML) receiving at least 6 cycles of AZA were evaluable for response, according to International Working Group 2006 criteria. In this cohort of patients, 3 of them achieved complete remission (CR; 2 RAEB-2 and 1 CMML), 2 marrow CR (mCR), 2 partial response (PR), 4 patients showed stable disease (SD) and 3 progressive disease (PD), while two patients with AML showed PD after 6 cycles. However, 2 patients with RAEB-2 with mCR at the 6 months progressed in AML after 13 and 10 cycles, respectively. Hematological improvement was documented in the whole cohort of patients, with increase in platelet and neutrophil counts, as well as in hemoglobin after 7, 8, and 9 cycles of treatment, respectively. Hematologic toxicity (grade 3/4 neutropenia and thrombocytopenia) required growth factor administration and platelet transfusions in 35% and 15% of patients, respectively. No patient discontinued treatment due to toxicity and all responders after 6 cycles continued treatment until progression. Seventeen patients died: 7 with AML after a median of 3 months, 8 with RAEB-2 after a median of 8 months (7 due to AML transformation, 1 to infection), 2 with CMML after a median of 8 months (due to PD). With a median follow-up of 30 months, median overall survival for all patients treated with AZA was 13.1 months (14.1 months in MDS, 10.7 in CMML and 7.2 in AML; p<0.05). Our preliminary data further provide evidence that prolonged AZA treatment is effective and well tolerated in elderly patients with high risk MDS, CMML and AML not eligible for standard intensive treatment