The purpose of this study is studying MK-2870 in Esophageal Squamous Cell Carcinoma (ESCC). Each sub study in the larger clinical trial is different testing different trial drugs and/or drug combinations in people with advanced ESCC. • Sub study 06B is testing Chemotherapy and MK-2870. The chemotherapies that will be used in this sub study B are paclitaxel or irinotecan. • Sub study 06C will be testing Pembrolizumab plus chemo. The chemotherapies that will be used in substudy 06C are capecitabine, oxaliplatin, 5-fluorouracil (5- FU) plus leucovorin or levoleucovorin. The trial drugs...
