An Effective and Chemotherapy-free Strategy of All-trans Retinoic Acid and Arsenic Trioxide for Acute Promyelocytic Leukemia in All Risk Groups

Abstract The combination of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has been demonstrated to be at least equally effective to ATRA and chemotherapy (CHT) in non-high-risk acute promyelocytic leukemia (APL). However, the efficacy of ATRA-ATO compared to ATRA-ATO plus CHT in high-risk APL remains unknown. Here we performed a multi-center non-inferiority phase III study to compare the efficacy of ATRA-ATO and ATRA-ATO plus CHT in newly diagnosed all-risk APL to address this question. Patients were assigned to receive ATRA-ATO for induction, consolidation and maintenance or ATRA-ATO plus CHT for induction followed by three cycles of consolidation therapy, and maintenance therapy with ATRA-ATO. In the non-CHT group, hydroxyurea was used to control leukocytosis. A total of 128 patients were treated. The complete remission rate was 97% in both groups. The 2-year disease-free, event-free survival rates were 98% v 97% and 95% v 92% in the non-CHT group and CHT group in all-risk patients (P=0.62 and P=0.39, respectively). And they were 94% v 87% and 85% v 78% in the high-risk patients (P=0.52 and P=0.44, respectively). This study demonstrated that ATRA-ATO had the same efficacy as the ATRA-ATO plus CHT in the treatment of patients with all-risk APL.