Abstract 1477: Targeting immunosuppressive myeloid cells in oral cavity cancer with the PI3K isoform inhibitor duvelisib

BACKGROUND: IPI-145 (duvelisib) is an oral inhibitor of the p110 isoforms of phosphinositide 3-kinase (PI3K) that are differentially expressed in leukocytes. IPI-145 is currently under study in phase IIIII trials for the treatment of hematologic malignancies, but has not previously been studied in solid tumors. In this study we sought to determine if p110 inhibition could suppress solid tumor growth through functional inhibition of myeloid derived suppressor cells (MDSCs) within the tumor microenvironment of syngeneic murine oral cavity (MOC) tumor models of head and neck cancer.