534MO First in human study of ONO-4578, a PGE2-receptor EP4 antagonist, in monotherapy and combination with PD-1 checkpoint inhibitor nivolumab in patients with advanced or metastatic solid tumours

Abstract

Prostaglandin E2 (PGE2) contributes to immunosuppression in the tumour microenvironment through PGE2 receptor 4 (EP4). ONO-4578 is a novel, potent, and highly selective small-molecule antagonist of EP4. Our preclinical data showed that ONO-4578 promoted anti-tumour immunity and a combination of ONO-4578 and anti-PD-1 antibody resulted in enhanced anti-tumour effects in syngeneic mouse models compared with anti-PD-1 monotherapy. ONO-4578 in combination with Nivolumab may be useful in the treatment of cancer patients (pts).