Long-Term Efficacy of Low-Dose All-Trans Retinoic Acid Plus Individually Adapted Chemotherapy Induction Followed by Arsenic Trioxide Based Post-Remission Therapy in Adults with Newly Diagnosed Acute Promyelocytic Leukemia

Abstract Abstract 1480 Acute promyelocytic leukemia (APL) is a distinct subtype of acute myelogenous leukemia (AML), which usually presents with pancytopenia, coagulopathies and bleeding. Molecular studies have revealed that it was caused by leukemogenic PML-RARA fusion gene resulting from a specific chromosomal translocation t(15;17). The administration of target agent all-trans-retinoic acid (ATRA) combined with anthracycline-based chemotherapy for induction and consolidation followed by ATRA plus low-dose chemotherapy maintenance is the standard strategies for patients with newly diagnosed APL. However, despite the high cure rate, early death and leukemia relapse are the two main important obstacles. We evaluated the efficacy of low-dose All-trans-retinoic acid (ATRA) plus individually adapted chemotherapy for induction followed by arsenic trioxide (ATO) based post-remission therapy in newly diagnosed acute promyelocytic leukemia (APL). From January 2004 to September 2011, 109 patients with APL were enrolled the study. The complete remission (CR) rate was 96.3%. The early death rate was 0.9%. Two arms were assigned according to post-remission protocols: ATO group cases were treated with standard chemotherapy, ATO, and ATRA. Without ATO group cases were subsequently treated with chemotherapy and ATRA only. Patients were monitored by reverse transcriptase-polymerase chain reaction (RT-PCR) during and after treatment. The six-year relapse-free survival (RFS) was significantly better for patients in ATO group than in without ATO group, 94.4% versus 50.6% (P < 0.0001) and the six-year overall survival (OS) rate was 95.7% versus 64.1%, in two groups (P = 0.003). This study shows that low-dose ATRA plus tailored chemotherapy is effective in induction therapy, and the addition of ATO to post-remission therapy significantly improves the long-term outcome. Disclosures: No relevant conflicts of interest to declare.