{"groups":[{"description":"Participants received pembrolizumab, 200 mg intravenous (IV) infusion, every 3 weeks (Q3W), Day 1 of each 3-week cycle for up to 35 cycles PLUS Gemcitabine, 1000 mg/m\\^2, IV infusion Q3W, Day 1 and Day 8 of each 3-week cycle until progressive disease or unacceptable toxicity PLUS Cisplatin, 25 mg/m\\^2 IV infusion, Q3W, Day 1 and Day 8 of each 3-week cycle for up to 8 cycles. Eligible participants who stopped the initial course of pembrolizumab with Stable Disease (SD) or better but progressed after discontinuation initiated a second course of pembrolizumab 200mg IV Q3W, Day 1 of each 3-week cycle for up to 17 cycles. Treatment with Gemcitabine could have been stopped at any time in first or second course due to toxicity or disease progression.","id":"FG000","title":"Arm A: Pembrolizumab + Chemotherapy"},{"description":"Participants received Placebo to Pembrolizumab, 200 mg IV infusion, every 3 weeks (Q3W), Day 1 of each 3-week cycle for up to 35 cycles PLUS Gemcitabine, 1000 mg/m\\^2 IV infusion, Q3W, Day 1 and Day 8 of each 3-week cycle until progressive disease or unacceptable toxicity PLUS Cisplatin, 25 mg/m\\^2 IV infusion, Q3W, Day 1 and Day 8 of each 3-week cycle for up to 8 cycles.","id":"FG001","title":"Arm B: Placebo + Chemotherapy"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"482"},{"groupId":"FG001","numSubjects":"504"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"0"}],"type":"Lost to Follow-up"},{"reasons":[{"groupId":"FG000","numSubjects":"7"},{"groupId":"FG001","numSubjects":"4"}],"type":"Withdrawal by Subject"},{"reasons":[{"groupId":"FG000","numSubjects":"43"},{"groupId":"FG001","numSubjects":"28"}],"type":"Sponsor decision"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"533"},{"groupId":"FG001","numSubjects":"536"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"529"},{"groupId":"FG001","numSubjects":"534"}],"type":"Treated"},{"achievements":[{"groupId":"FG000","numSubjects":"10"},{"groupId":"FG001","numSubjects":"0"}],"type":"Received a Second Course of Pembrolizumab"},{"achievements":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"0"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"533"},{"groupId":"FG001","numSubjects":"536"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"Per protocol, response or progression during the second course treatment was not counted towards efficacy outcome measures, and adverse events during the second course treatment were not counted towards safety outcome measures."}