Successful long-term treatment with azacitidine in patient with chronic myelomonocytic leukemia

Abstract

CMML is clinically diverse malignant clonal hematopoietic stem cell disorder characterized by persistent peripheral monocytosis, bone marrow dysplasia and with features of both myelodysplastic  and myeloproliferative neoplasms (1). Generally, long term prognosis is poor with a median overall survival of 30 months and a relatively high risk of leukemic transformation,  up to 30 % (2). Hypomethylating agents belong to a class of drugs which inhibit DNA methyltransferase and consequently reduce DNA methylation. Utilization of HMA in CMML has been reported with seemingly unsatisfying results with overall response rates between 30 and 60% and median overall survival between 12 and 37 months (3,4). Previously only a few predictive factors (increased bone marrow blast count and proliferative features) were found to be associated with shorter survival (5). Surprisingly only age, but none of the other disease characteristics, was a prediction for a response(6).  In this case report, we describe an effective long term use of azacitidine in a patient with CMML and tried to find factors, which may contribute to long term azacitidine efficacy.