Multinational phase 3 trial of arsenic trioxide and all-trans retionic acid combination therapy for high-risk acute promyelocytic leukemia

The multinational phase 3 APOLLO trial compared all-trans retinoic acid combined with arsenic trioxide (ATRA-ATO) plus low-dose idarubicin versus standard ATRA plus anthracycline-based chemotherapy (ATRA-CHT) for newly diagnosed high-risk acute promyelocytic leukemia (APL). After a median follow-up of 37 months (range 1.7-88.6) the 2-year event-free survival rate was 88% in the ATRA-ATO group and 71% in the ATRA-CHT group (HR 0.4; p=0.02). Serious treatment-emergent adverse events were reported for 32% of patients in the ATRA-ATO group and 68% in the ATRA-CHT group. The authors conclude that these results support the use of ATRA-ATO for newly diagnosed APL.