Ravandi F, Assi R, Daver N, et al. - In this single-arm, phase II part of the phase I–II study performed on patients with newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome, researchers evaluated the addition of nivolumab to frontline therapy with idarubicin and cytarabine. This inquiry was held at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Cytarabine 1·5 g/m² was administered via 24-h continuous infusion daily on days 1–4 (3 days in patients > 60 years) and idarubicin 12 mg/m² daily was given on days 1–3, for induction. On day 24 (range 22–26), treatment with nivolumab 3 mg/kg was initiated and continued every 2 weeks for up to a year in responders. Either up to 5 consolidation cycles of attenuated doses of idarubicin and cytarabine, or allogeneic stem cell transplantation if eligible, was received by the responders. Findings revealed the feasibility of nivolumab added to induction chemotherapy with idarubicin and cytarabine in patients with newly diagnosed acute myeloid leukaemia or high-risk myelodysplastic syndrome. Improvement could be seen in posttransplant severe graft-versus-host disease. In future investigations, it is justifiable to start checkpoint inhibitor therapy earlier.