Treatment of non-high-risk acute promyelocytic leukemia with realgar-indigo naturalis formula (RIF) and all-trans retinoid acid (ATRA): study protocol for a randomized controlled trial

Acute promyelocytic leukemia (APL) is a highly curable disease when treated with all-trans retinoid acid (ATRA) and arsenic trioxide (ATO). The combination of ATO and ATRA has become the standard therapeutic protocol for induction therapy in non-high-risk APL. An oral arsenic realgar-indigo naturalis formula (RIF) has also showed high efficacy and it has a more convenient route of administration than the standard intravenous regimen. Unlike in previous trials, the arsenical agent was used simultaneously with ATRA during post-remission therapy in this trial. This study was designed as a multicenter, randomized controlled trial. The trial has a non-inferiority design with superiority being explored if non-inferiority is identified. All patients receive ATRA-ATO during the induction therapy. After achieving hematologic complete remission (HCR), patients were randomly assigned (1:1) to receive treatment with ATRA-RIF (experimental group) or ATRA-ATO (control group) as the consolidation therapy. During the consolidation therapy, the two groups receive ATRA plus RIF or intravenous ATO 2 weeks on and 2 to ~ 4 weeks off until molecular complete remission (MCR), then ATRA and oral RIF 2 weeks on and 2 to ~ 4 weeks off giving a total of six courses. This trial aims to compare the efficacy of ATRA-ATO versus ATRA-RIF in non-high-risk patients with APL, to demonstrate that oral RIF application reduces the total hospitalization days and medical costs. The simple schedule was studied in this trial. ClinicalTrials.gov, NCT02899169. Registered on 14 September 2016.