Predictive factors of response and survival among chronic myelomonocytic leukemia patients treated with azacitidine

Treatment of CMML remains a clinical challenge, with no drug demonstrating clear clinical benefit. Even if azacitidine is approved in the treatment of CMML, its role remains disputed. We report a cohort of 76 CMML patients (according to WHO classification) treated with azacitidine in 3 programs (French AZA compassionate program, Cleveland Clinic Foundation and H. Lee Moffitt Cancer Center). 45% had CMML2, and 55% had splenomegaly and/or WBC counts >13 G/L, which are known to be poor prognostic factors in CMML. All patients received AZA for at least one cycle, and the median number of cycles administered was 6. Thirty-three patients (43%) achieved a response according to IWG 2006 criteria, including 13 complete remissions (17%). Median survival was 29 months. Increased bone marrow blast percentage and proliferative features of the disease, including splenomegaly and high WBC counts, were significantly associated with shorter survival. By multivariate analysis, only marrow blasts >10% and palpable splenomegaly had prognostic impact on survival. Although promising, the efficacy of azacitidine in advanced CMML needs to be confirmed in a randomized prospective study.