IL2 and neoplasm: The trial showed complete peripheral PD-1 target engagement at doses of 1 mg/kg or higher–confirmed by an ex-vivo interleukin-2 (IL-2) stimulation test–and no differences in durable anti-tumour activity and dose-limiting toxicities were seen at doses from 1 to 10 mg/kg Q2W (Renner et al., 2019; Low et al., 2021; Hirsch et al., 2022).