{"groups":[{"description":"Participants received pembrolizumab 200 mg intravenously (IV) every 3 weeks (Q3W) plus standard of care (SOC) chemotherapy with cisplatin 80 mg/m\\^2 IV Q3W and 5-fluorouracil (5-FU) 800 mg/m\\^2/day continuous IV infusion on Days 1 to 5 (120 hours) Q3W. All treatments were administered on an outpatient basis beginning on Day 1 of each 3-week dosing cycle.","id":"FG000","title":"Pembrolizumab + SOC"},{"description":"Participants received placebo to pembrolizumab (saline) IV Q3W plus SOC chemotherapy with cisplatin 80 mg/m\\^2 IV Q3W and 5-FU 800 mg/m\\^2/day continuous IV infusion on Days 1 to 5 (120 hours) Q3W. All treatments were administered on an outpatient basis beginning on Day 1 of each 3-week dosing cycle.","id":"FG001","title":"Placebo + SOC"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"325"},{"groupId":"FG001","numSubjects":"361"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"0"}],"type":"Physician Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"40"},{"groupId":"FG001","numSubjects":"12"}],"type":"Sponsor Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"7"},{"groupId":"FG001","numSubjects":"3"}],"type":"Withdrawal by Subject"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"373"},{"groupId":"FG001","numSubjects":"376"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"370"},{"groupId":"FG001","numSubjects":"370"}],"type":"Treated"},{"achievements":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"0"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"373"},{"groupId":"FG001","numSubjects":"376"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"749 participants were randomized 1:1 to receive either pembrolizumab plus standard of care (SOC) chemotherapy, or placebo plus SOC chemotherapy."}