{"groups":[{"description":"Luspatercept (ACE-536) was administered subcutaneously (SC) at a starting dose level of 1 mg/kg once every 21 days. Participants could be dose-titrated to 1.25 mg/kg, but the maximum total dose should not exceed 120 mg, total dose per administration during the Treatment Period, the Long-term Treatment Period, and Open-Label Treatment Period. BSC = Best Supportive Care","id":"FG000","title":"Luspatercept + BSC"},{"description":"Placebo (normal saline) was administered subcutaneously (SC) in volumes to match active treatment once every 21 days. BSC = Best Supportive Care","id":"FG001","title":"Placebo + BSC"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"37"},{"groupId":"FG001","numSubjects":"16"}],"type":"Withdrawal by Subject"},{"reasons":[{"groupId":"FG000","numSubjects":"4"},{"groupId":"FG001","numSubjects":"0"}],"type":"Adverse Event"},{"reasons":[{"groupId":"FG000","numSubjects":"3"},{"groupId":"FG001","numSubjects":"5"}],"type":"Other reasons"},{"reasons":[{"groupId":"FG000","numSubjects":"4"},{"groupId":"FG001","numSubjects":"1"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"169"},{"groupId":"FG001","numSubjects":"82"}],"type":"Transition to Rollover Protocol"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"1"}],"type":"Physician Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"1"}],"type":"Lack of Efficacy"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"224"},{"groupId":"FG001","numSubjects":"112"}],"comment":"Participants randomized","type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"223"},{"groupId":"FG001","numSubjects":"109"}],"comment":"All participants who received at least 1 dose of study drug","type":"Participants Treated"},{"achievements":[{"groupId":"FG000","numSubjects":"211"},{"groupId":"FG001","numSubjects":"102"}],"type":"Completed 24 Weeks of Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"202"},{"groupId":"FG001","numSubjects":"96"}],"type":"Completed 48 Weeks of Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"155"},{"groupId":"FG001","numSubjects":"3"}],"type":"Completed 96 Weeks of Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"125"},{"groupId":"FG001","numSubjects":"0"}],"type":"Completed 144 Weeks of Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"6"},{"groupId":"FG001","numSubjects":"0"}],"type":"Completed 192 Weeks of Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"6"},{"groupId":"FG001","numSubjects":"6"}],"comment":"Completed study per original protocol","type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"218"},{"groupId":"FG001","numSubjects":"106"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"336 participants were randomized, 332 participants were treated."}