AN OPEN-LABEL, SINGLE-ARM, PHASE IB/IIA TRIAL TO EVALUATE THE SAFETY AND EFFICACY OF THE EP4 RECEPTOR ANTAGONIST CR6086 IN COMBINATION WITH THE PD-1 INHIBITOR BALSTILIMAB (AGEN2034), IN PATIENTS WITH PRETREATED MISMATCH-REPAIR-PROFICIENT AND MICROSATELLITE STABLE METASTATIC COLORECTAL CANCER, AND OTHER METASTATIC GI CANCERS