Arsenic trioxide and all- trans retinoic acid treatment for acute promyelocytic leukaemia in all risk groups (AML17): results of a randomised, controlled, phase 3 trial

Summary Background Acute promyelocytic leukaemia is a chemotherapy-sensitive subgroup of acute myeloid leukaemia characterised by the presence of the PML–RARA fusion transcript. The present standard of care, chemotherapy and all- trans retinoic acid (ATRA), results in a high proportion of patients being cured. In this study, we compare a chemotherapy-free ATRA and arsenic trioxide treatment regimen with the standard chemotherapy-based regimen (ATRA and idarubicin) in both high-risk and low-risk patients with acute promyelocytic leukaemia. Methods In the randomised, controlled, multicentre, AML17 trial, eligible patients (aged ≥16 years) with acute promyelocytic leukaemia, confirmed by the presence of the PML–RARA transcript and without significant cardiac or pulmonary comorbidities or active malignancy, and who were not pregnant or breastfeeding, were enrolled from 81 UK hospitals and randomised 1:1 to receive treatment with ATRA and arsenic trioxide or ATRA and idarubicin. ATRA was given to participants in both groups in a daily divided oral dose of 45 mg/m2 until remission, or until day 60, and then in a 2 weeks on–2 weeks off schedule. In the ATRA and idarubicin group, idarubicin was given intravenously at 12 mg/m2 on days 2, 4, 6, and 8 of course 1, and then at 5 mg/m2 on days 1–4 of course 2; mitoxantrone at 10 mg/m2 on days 1–4 of course 3, and idarubicin at 12 mg/m2 on day 1 of the final (fourth) course. In the ATRA and arsenic trioxide group, arsenic trioxide was given intravenously at 0·3 mg/kg on days 1–5 of each course, and at 0·25 mg/kg twice weekly in weeks 2–8 of course 1 and weeks 2–4 of courses 2–5. High-risk patients (those presenting with a white blood cell count >10 × 109 cells per L) could receive an initial dose of the immunoconjugate gemtuzumab ozogamicin (6 mg/m2 intravenously). Neither maintenance treatment nor CNS prophylaxis was given to patients in either group. All patients were monitored by real-time quantitative PCR. Allocation was by central computer minimisation, stratified by age, performance status, and de-novo versus secondary disease. The primary endpoint was quality of life on the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 global health status. All analyses are by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN55675535. Findings Between May 8, 2009, and Oct 3, 2013, 235 patients were enrolled and randomly assigned to ATRA and idarubicin (n=119) or ATRA