983P Phase I dose escalation study in patients (pts) with advanced solid tumours receiving first-in-class BI 765063, a selective signal-regulatory protein α (SIRPα) inhibitor, in combination with ezabenlimab (BI 754091), a programmed cell death protein 1 (PD-1) inhibitor

Abstract

BI 765063 is a first-in-class, humanised IgG4 monoclonal antibody antagonist of SIRPα (expressed on myeloid cells) that blocks the “don't eat me” signal of the SIRPα/CD47 axis, a critical innate immune checkpoint, enhancing tumour cell phagocytosis and increasing antigen presentation to drive anti-tumour responses. This dose escalation/expansion study aimed to evaluate the safety and efficacy of BI 765063 as monotherapy, then with ezabenlimab (PD-1 inhibitor) in pts with advanced solid tumours. BI 765063 monotherapy was well tolerated and demonstrated activity, including a PR in a pt with hepatocellular carcinoma.