Improved Outcome by Addition of Lomustine (CCNU) to Idarubicin and Cytarabine in Elderly Patients with De Novo Acute Myeloid Leukemia. A Report from the GOELAMS Group

In elderly patients with acute myeloid leukemia (AML) treated intensively, no improvement has been shown in the last 20 years. We performed a retrospective study in 847 patients over 60 years old, prospectively enrolled in 3 trials conducted in France between 1995 and 2005, with the aim to investigate prognostic factors for complete remission (CR) achievement and survival. Induction therapy consisted in the association of Idarubicin 8mg/m² d1-5 and Cytarabine 100mg/m² d1-7 (Group I, 339 patients) or the same drugs with the addition of lomustine (10mg\m² orally at day 1)(Group II, 508 patients). Consolidation therapy consisted of anthracycline and cytarabine courses at lower doses, preceded or not by a first course with intermediate dose cytarabine. The patients’ characteristics were similar between the two groups concerning sex, WBC count, ECOG, and cytogenetics, yet patients were older in Group II versus Group I (55% versus 45% over 69 years of age, p<0.0001).The CR rate was significantly higher for patients in Group II compared to Group I (67 % vs 57%, p= 0.002). The toxic death rate was not different between groups. In multivariate analysis, three good prognostic factors emerged for achieving complete remission: good or intermediate cytogenetics (p<0.0001), ECOG < 2 (p<0.0001), and adjunction of lomustine to induction chemotherapy (p=0.002). The median overall-survival was significantly improved for patients treated with lomustine (12.7± 2.2 months vs 8.7± 2.7 months, p=0.004). In multivariate analysis, five prognostic factors affected positively overall survival: adjunction of lomustine to induction chemotherapy (p < 0.0001), age < 69 years (p =0.001), ECOG < 2 (p =0.001), FAB other than AML0,6 or 7 (p = 0.004) and good or intermediate cytogenetics(p = 0.007). The median event-freesurvival was also improved for patients treated with lomustine (10.7± 2.2 months vs 7± 2.7 months, p=0.002). Event-free-survival was affected by the same prognostic factors as overall survival. We conclude that lomustine might be added in standard induction therapy as it allowed to obtain both better CR rate and survival in this retrospective study.