197 (PB077) - Small molecule PD-L1 inhibitor modulates expression of PD-L1 on the cell surface – a potential mechanism of blocking interaction with PD-1

Abstract

Background: Blocking the PD1-PD-L1 interaction has been shown to stimulate anti-tumour responses. Although antibody-based drugs targeting either PD-1 or PD-L1 are approved, small molecule inhibitors of PD-L1 are currently in development. A subset of these small molecule inhibitors induce the loss of cell surface PD-L1 in a time- and concentration-dependent manner. INCB090244 is a small molecule that has previously been shown to bind to PD-L1 and disrupt the PD-L1/PD-1 interaction.