Safety and efficacy of arsenic trioxide and all-trans retinoic acid therapy in acute promyelocytic leukemia patients with a high risk for early death

In this study, we investigated the safety and efficacy of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) in patients with acute promyelocytic leukemia (APL). The patients had been classified as unfit to receive anthracycline-based chemotherapy due to high-risk factors for early death. Twenty-five patients with APL receiving ATO/ATRA between 2007 and 2018 were divided into 3 groups as follows: elderly patients (age ≥ 70 years) with poor performance status (32%); patients with severe active infections at diagnosis (56%); and patients with multiple significant comorbidities (24%) who were unfit for conventional chemotherapy, regardless of age. Induction therapy comprised 0.15 mg/kg/day ATO combined with 45 mg/m²/day ATRA until patients attained complete remission (CR). Notably, only one patient (4.0%) died of septic shock 2 days after the ATO treatment had been initiated. The remaining 24 patients attained CR despite their serious and desperate conditions at diagnosis. In total, 44%, 28%, and 32% of the patients experienced neutropenia (grade 3 or 4), thrombocytopenia, and hepatopathy, respectively. Twenty-three of the 24 patients in CR proceeded to consolidation therapy and attained complete molecular remission with favorable overall survival (90.7%). This study demonstrates the safety and efficacy profile of ATO/ATRA first-line therapy for patients with APL and high-risk features for early death.