Efficacy and safety of early switching to an outpatient therapy model using oral arsenic plus retinoic acid based-regimen in newly diagnosed acute promyelocytic leukemia.

Realgar-Indigo naturalis formula(RIF)is an oral form of arsenic developed for treatment of acute promyelocytic leukemia (APL). We retrospectively evaluated the efficacy and safety of a novel RIF combined with all-trans retinoic acid (ATRA) based chemotherapy-free approach in newly diagnosed APL patients. Patients received oral ATRA (25 mg/m/day in 2 divided doses) plus intravenous arsenic trioxide (0.15 mg/kg/day) or oral RIF (60 mg/kg/day in 3 divided doses) as induction chemotherapy, followed by 2 consolidations with ATRA plus RIF and maintenance therapy with intermittent ATRA and RIF. From January 2015 to December 2017, 40 subjects were enrolled. Eighteen subjects were male. Median age was 42 years (range, 14-77 years) and 10 subjects were ≥ 60 years. All subjects achieved a complete morphologic remission after initial induction. Molecular complete remission achieved 100% after second RIF plus ATRA consolidation. Median follow-up of survivors was 27 months (range, 7-43 months). The 2-year event-free survival (EFS) and overall survival (OS) were both 100%. Adverse events were modest and all patients needed only outpatient care during postremission therapy. Compared to our historical RIF plus ATRA with chemotherapy regimen (the Chinese APL07 trial), the inpatient treatment duration was greatly reduced by the RIF plus ATRA regimen. Our data indicates that early switching to RIF plus ATRA based chemotherapy-free approach has yielded encouraging outcomes and might be considered a practicable option to treat patients with newly diagnosed APL.