New Cases of Acute Promyelocytic Leukemia Treatment by Arsenic Trioxide Alone and Their Long Term Follow up

Abstract Abstract 506 Long term follow-up of APL patients treated by ATRA and chemotherapy is available and shows promising results of DFS and OS. Although several studies show acceptable efficacy of Arsenic Trioxide in new cases of APL, its long term result needs better clarification. Materials and methods: one hundred ninety seven, new cases of APL treated by Arsenic trioxide (0.15 mg/kg daily i.v infusion till complete remission). After achieving to CR patients received 4 more courses of Arsenic trioxide as consolidation. Then patients followed by CBC and RT-PCR on peripheral blood for detection of MRD every three months or till relapse or death. Results: Morphologic complete remission rate was 85.8% and most common cause of remission failure was early death due to hemorrhage of APL differentiation syndrome.(14.7%) Most important prognostic factor for early mortality is high WBC count at presentation. Disease free survival was 90%+/−2%, 72.7%+/−3% and 66.7%+/−4% for 2, 3 and 5 years respectively. Relapse for patients who remained in CR after 5 years was very uncommon. Overall survival for patients after diagnosis by intention to treat analysis was 80.2%+/−3%, 75.9%+/−3% and 64.4%+/− 4% for 2, 3 and 5 years. Also OS and DFS were the same between patients with high and low WBC count. Conclusion: Long term follow up of newly diagnosed cases of APL, treated with single agent Arsenic Trioxide shows promising result. Arsenic trioxide potentially eliminates the adverse effect of prognostic factors of APL treatment such as high WBC count. We suggest that it is time to integrate Arsenic trioxide in treatment of new cases of APL. Disclosures: No relevant conflicts of interest to declare.