Frontline Oral Arsenic Trioxide for APL

The investigators have formulated an oral preparation of arsenic trioxide (oral-ATO), and shown that it is efficacious for APL in R1, inducing CR2 in more than 90% of patients \[8,9\]. Furthermore, in an effort to prevent relapse, the investigators have moved oral-ATO forward to the maintenance of CR1. This strategy results in favorable overall-survival (OS) and leukemia-free-survival (LFS) \[10\], implying that prolonged treatment with oral-ATO may prevent relapses. Current protocols have incorporated i.v.-ATO in the treatment of newly-diagnosed APL \[11-15\]. For regimens comprising oral-ATO, ATRA and chemotherapy, 5-year OS in excess of 90% is achieved \[11-15\]. The investigators have also published long-term data showing the use of oral-ATO is highly effective and safe in the relapsed and frontline settings \[16,17\]. In this study, the investigators evaluate the use of oral-ATO and ATRA based induction regimens in newly diagnosed patients with APL with no of minimal chemotherapy in a prospective multicentre phase 2 study.