Two cycles of risk-adapted consolidation therapy in patients with acute promyelocytic leukemia. Results from the SAL-AIDA2000 trial.

The combination of all-trans retinoic acid (ATRA) and idarubicin (AIDA) for induction therapy followed by three cycles of risk-adapted consolidation cycles is considered standard of care for patients with acute promyelocytic leukemia (APL). We report the outcome of 141 patients (median age 51 years; range, 19-82, 31 % ≥60 years) enrolled into the prospective Study Alliance Leukemia (SAL)-AIDA2000 trial, which comprised AIDA-based induction followed by only two courses of risk-adapted consolidation (daunorubicin or mitoxantrone ± cytarabine) followed by 2-year maintenance treatment. The early death rate was 7 % (median age 66 years), and additional 9 % stopped further treatment after induction. The estimated 6-year disease-free survival (DFS) was 80 % in all patients, 84 % in patients ≤60 and 72 % in patients >60 years (p = 0.140). No significant survival differences were observed between the high-risk and the non-high-risk patients (6-year OS 78 vs. 81 %, p = 0.625). Our results confirm the efficacy of a risk-adapted approach in APL patients. Furthermore, long-term outcomes are comparable to the results obtained with three cycles of consolidation. A modification of the number and intensity of conventional consolidation treatment may be a less toxic but equally effective approach and should be considered for further evaluation in randomized clinical trials in APL.