{"groups":[{"description":"Participants received pembrolizumab 200 mg intravenous (IV) on Day 1 of each 3-week cycle. Eligible participants who stopped the initial course of pembrolizumab with Stable Disease (SD) or better but progressed after discontinuation may have been able to initiate a second course of pembrolizumab for up to 17 cycles (up to approximately 1 additional year) at the investigator's discretion.","id":"FG000","title":"Pembrolizumab"},{"description":"Participants received standard treatment of either methotrexate 40 mg/m\\^2 IV (could be escalated to 60 mg/m\\^2 maximum dose) on Days 1, 8, and 15 of each 3-week cycle; or docetaxel 75 mg/m\\^2 IV on Day 1 of each 3- week cycle; or cetuximab 400 mg/m\\^2 IV loading dose on Day 1 and 250 mg/m\\^2 IV on Days 8 and 15 of Cycle 1, followed by cetuximab 250 mg/m\\^2 on Days 1, 8, and 15 of each subsequent 3-week cycle.","id":"FG001","title":"Standard Treatment"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"9"},{"groupId":"FG001","numSubjects":"6"}],"type":"Adverse Event"},{"reasons":[{"groupId":"FG000","numSubjects":"209"},{"groupId":"FG001","numSubjects":"217"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"2"}],"type":"Physician Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"7"},{"groupId":"FG001","numSubjects":"1"}],"type":"Transferred to Extension Study"},{"reasons":[{"groupId":"FG000","numSubjects":"7"},{"groupId":"FG001","numSubjects":"2"}],"type":"Did Not Continue on Extension Study"},{"reasons":[{"groupId":"FG000","numSubjects":"15"},{"groupId":"FG001","numSubjects":"20"}],"type":"Withdrawal by Subject"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"247"},{"groupId":"FG001","numSubjects":"248"}],"type":"STARTED"},{"achievements":[{"comment":"1 participant was randomized but did not receive study treatment.","groupId":"FG000","numSubjects":"246"},{"comment":"14 participants were randomized but did not receive study treatment.","groupId":"FG001","numSubjects":"234"}],"type":"Received First Course of Pembrolizumab"},{"achievements":[{"groupId":"FG000","numSubjects":"2"},{"groupId":"FG001","numSubjects":"0"}],"type":"Received Second Course of Pembrolizumab"},{"achievements":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"0"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"247"},{"groupId":"FG001","numSubjects":"248"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"495 participants were randomized 1:1 to receive either pembrolizumab or standard treatment. Per protocol, response/progression or adverse events (AEs) that occurred during the second course of pembrolizumab were not counted towards efficacy outcome measures or safety outcome measures, respectively."}