John DiPersio, MD, PhD, Washington University School of Medicine, Saint Louis, MO, discusses the potential of duvelisib, a novel dual PI3K-δ and Pi3K-γ inhibitor, as treatment for CAR-T mediated cytokine release syndrome (CRS). In vitro studies have demonstrated that duvelisib can inhibit CAR-T induced IL-6 production from immature dendritic cells in a dose-dependent manner, whilst having no inhibitory effect on CAR-T function at clinically relevant doses. To investigate its efficacy in vivo, a CRS murine model was used and showed that duvelisib treatment reduced mean plasma IL-6 levels significantly, consistent with in vitro findings. In vivo studies are ongoing to further characterize PI3K inhibition in humanized mouse models. This interview took place during the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, 2020.