Azacitidine for the treatment of relapsed and refractory AML in older patients.

The prognosis of patients older than 50 with relapsed or refractory AML is dismal. Azacitidine has been investigated in older AML patients. Here we report the outcome of 130 patients older than 50 years included in a multicenter patient named program of azacitidine after relapse (n=67) or induction failure (n=63) of intensive chemotherapy. Median age was 67 years, cytogenetic risk was high in 28% and performance status ≥2 in 15% of cases. Most (72%) patients received azacitidine at the standard schedule (75mg/m(2)/d, 7 days/month) for a median of 4 courses. The overall response rate was 17% (CR: 10%, CRi: 7%). Median overall survival was 8.4 months. Achievement of CR/CRi was associated with prolonged survival (P=0.0001), whereas hematological improvement according to MDS criteria, achieved in 36% of patients with resistant disease, did not improve survival. In multivariate analysis, high risk cytogenetics (P=0.022) and peripheral blasts >10% (P<0.0001) at onset of azacitidine were independently predictive of poor prognosis. Combining these two factors, we identified a subgroup of 48% of patients with intermediate risk cytogenetics and peripheral blasts ≤10% and a median OS of 11.3 months. These results warrant further investigation of azacitidine-based regimens in this subgroup of patients.