{"groups":[{"description":"Participants received pertuzumab (840 mg loading dose, then 420 mg) and trastuzumab (8 mg/kg loading dose, then 6 mg/kg) intravenously (IV) every 3 weeks (Q3W) for 1 year (maximum 18 cycles) in combination with 1 of the following IV chemotherapy regimen (anthracycline-based or nonanthracycline-based) per Investigator's choice: 1) 3-4 cycles (Q3W) of 5-fluorouracil 500-600 mg/m\\^2 + epirubicin 90-120 mg/m\\^2 or doxorubicin 50 mg/m\\^2 + cyclophosphamide 500-600 mg/m\\^2 followed by either 3-4 cycles of docetaxel Q3W (100 mg/m\\^2 for 3 cycles, 75 mg/m\\^2 in first cycle and 100 mg/m\\^2 in subsequent cycles, or 75 mg/m\\^2 for 4 cycles) or 12 cycles of paclitaxel 80 mg/m\\^2 once weekly (QW); 2) 4 cycles (Q3W) of doxorubicin 60 mg/m\\^2 or epirubicin 90-120 mg/m\\^2 + cyclophosphamide 500-600 mg/m\\^2 followed by either 3-4 cycles of docetaxel Q3W or 12 cycles of paclitaxel QW (as described in Option 1); 3) 6 cycles (Q3W) of docetaxel 75 mg/m\\^2 + carboplatin area under the curve (AUC) 6 (up to 900 mg).","id":"FG000","title":"Pertuzumab + Trastuzumab + Chemotherapy"},{"description":"Participants received placebo matched to pertuzumab IV Q3W and trastuzumab (8 milligrams per kilogram \\[mg/kg\\] loading dose, then 6 mg/kg) IV Q3W for 1 year (maximum 18 cycles) in combination with 1 of the following IV chemotherapy regimen (anthracycline-based or nonanthracycline-based) per Investigator's choice: 1) 3-4 cycles (Q3W) of 5-fluorouracil 500-600 milligrams per square meter (mg/m\\^2) + epirubicin 90-120 mg/m\\^2 or doxorubicin 50 mg/m\\^2 + cyclophosphamide 500-600 mg/m\\^2 followed by either 3-4 cycles of docetaxel Q3W (100 mg/m\\^2 for 3 cycles, 75 mg/m\\^2 in first cycle and 100 mg/m\\^2 in subsequent cycles, or 75 mg/m\\^2 for 4 cycles) or 12 cycles of paclitaxel 80 mg/m\\^2 QW; 2) 4 cycles (Q3W) of doxorubicin 60 mg/m\\^2 or epirubicin 90-120 mg/m\\^2 + cyclophosphamide 500-600 mg/m\\^2 followed by either 3-4 cycles of docetaxel Q3W or 12 cycles of paclitaxel QW (as described in Option 1); 3) 6 cycles (Q3W) of docetaxel 75 mg/m\\^2 + carboplatin AUC 6 (up to 900 milligrams \\[mg\\]).","id":"FG001","title":"Placebo + Trastuzumab + Chemotherapy"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"475"},{"groupId":"FG001","numSubjects":"466"}],"type":"Withdrawal by Subject"},{"reasons":[{"groupId":"FG000","numSubjects":"181"},{"groupId":"FG001","numSubjects":"269"}],"type":"Recurrence of disease"},{"reasons":[{"groupId":"FG000","numSubjects":"181"},{"groupId":"FG001","numSubjects":"176"}],"type":"Lost to Follow-up"},{"reasons":[{"groupId":"FG000","numSubjects":"41"},{"groupId":"FG001","numSubjects":"46"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"39"},{"groupId":"FG001","numSubjects":"42"}],"type":"Adverse Event"},{"reasons":[{"groupId":"FG000","numSubjects":"43"},{"groupId":"FG001","numSubjects":"32"}],"type":"Physician Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"42"},{"groupId":"FG001","numSubjects":"28"}],"type":"Contralateral breast cancer"},{"reasons":[{"groupId":"FG000","numSubjects":"37"},{"groupId":"FG001","numSubjects":"29"}],"type":"Reason not specified"}],"milestones":[{"achievements":[{"comment":"A total of 22 participants randomized to the pertuzumab arm did not receive any study treatment.","groupId":"FG000","numSubjects":"2400"},{"comment":"A total of 13 participants randomized to the placebo arm did not receive any study treatment.","groupId":"FG001","numSubjects":"2404"}],"comment":"Intent-to-Treat (ITT) Population","type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"2340"},{"comment":"24 participants randomized to the placebo arm received at least 1 dose of pertuzumab in error. They were included in the pertuzumab arm for safety analyses.","groupId":"FG001","numSubjects":"24"}],"comment":"Pertuzumab Safety Population","type":"Received at Least 1 Dose of Pertuzumab"},{"achievements":[{"comment":"38 participants randomized to the pertuzumab arm did not receive any pertuzumab. They were included in the placebo arm for safety analyses.","groupId":"FG000","numSubjects":"38"},{"groupId":"FG001","numSubjects":"2367"}],"comment":"Placebo Safety Population","type":"Received Any Study Treatment Except for Pertuzumab"},{"achievements":[{"groupId":"FG000","numSubjects":"2369"},{"groupId":"FG001","numSubjects":"2381"}],"type":"Entered Follow-Up"},{"achievements":[{"groupId":"FG000","numSubjects":"1361"},{"groupId":"FG001","numSubjects":"1316"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"1039"},{"groupId":"FG001","numSubjects":"1088"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"A total of 6263 patients were screened for the study. The most common cause of screen failure was lack of confirmation of HER2-positivity by the central laboratory which accounted for approximately half of the screen failures.","recruitmentDetails":"Overall, 4804 patients were randomized in the study, 2400 in the Pertuzumab arm and 2404 in the Placebo arm."}