P-47 A phase I/II study of pembrolizumab in combination with ibrutinib for advanced, refractory microsatellite stable colorectal cancers

Abstract

Nearly 50% of patients with colorectal cancer (CRC), one of the most common cancers worldwide, develop metastatic disease. Pre-clinical data suggest that ibrutinib, a BTK inhibitor used in several hematologic malignancies, may counteract the immune tumor escape mechanism in solid tumors. Pembrolizumab, a PD-1 checkpoint inhibitor, is effective in advanced CRC with microsatellite instability, but not microsatellite stable (MSS) disease. Given ibrutinib’s immune-modulatory function, it may display synergy with checkpoint inhibitors.