Pegylated engineered IL2 plus anti–PD-1 monoclonal antibody: The nectar comes from the combination

In this issue of Cancer Discovery, Diab and colleagues demonstrate in a phase I trial enrolling 38 patients diagnosed with advanced solid tumors that combining the pegylated IL2 bempegaldesleukin with an anti–PD-1 mAb is safe, with an overall response rate of 59.5%. This compelling clinical activity is supported by the potent immune proliferation and activation of circulating T and natural killer cells with a >4-fold increase in the CD8/regulatory T-cell ratio in tumors, independent of baseline PD-L1 expression.