Azacitidine frontline therapy for unfit acute myeloid leukemia patients: clinical use and outcome prediction.

Hypomethylating agents are able to prolong the overall survival of some patients diagnosed with acute myeloid leukemia. The aim of this study was to evaluate the clinical use of azacitidine as front-line therapy in unfit acute myeloid leukemia (AML) patients and to develop a clinical prediction model to identify which patients may benefit more from the drug. One hundred and ten untreated unfit AML patients received front-line azacitidine therapy in Spain, and response and survival were evaluated in them following European LeukemiaNet (ELN) guidelines. A clinical prediction rule was obtained from this population that was validated and refined in 261 patients treated in France, Austria and Italy. ELN response was achieved in 21.0% of the 371 patients (CI95% 17.0-25.5) and did not depend on bone marrow blast cell percentage. Median overall survival was 9.6 months (CI95% 8.5-10.8) and 40.6% of the patients were alive at 1 year (CI95% 35.5-45.7). European ALMA score (E-ALMA), based on performance status, white blood cell counts at azacitidine onset and cytogenetics, discriminated three risk groups with different survival and response rates. Azacitidine seems a reasonable therapeutic option for most unfit AML patients, i.e. those displaying a favorable or intermediate E-ALMA score.