Back to the Future: Rethinking and Retooling IL2 in the Immune Checkpoint Inhibitor Era.

IL2 is a type I cytokine that is associated, when given at high doses intravenously, with durable regressionin a subset of patients with metastatic melanoma and renal cell carcinoma, yet high toxicity limits its use. NKTR-214 is a novel pegylated IL2 with minor clinical activity as a single agent, but a favorable toxicity profile and compelling pharmacodynamic effects that predict utility in combination with immune checkpoint inhibition.See related article by Bentebibel et al., p. 711.