{"groups":[{"description":"Participants received weekly subcutaneous placebo for 24 weeks.","id":"FG000","title":"Placebo"},{"description":"Participants received once weekly subcutaneous romiplostim for 24 weeks at a starting dose of 1 µg/kg; weekly dose increases continued in increments of 1 µg/kg/week to a maximum dose of 10 µg/kg in an attempt to reach a target platelet count of ≥ 50 x 10\\^9/L.","id":"FG001","title":"Romiplostim"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"1"}],"type":"Ineligibility Determined"},{"reasons":[{"groupId":"FG000","numSubjects":"2"},{"groupId":"FG001","numSubjects":"0"}],"type":"Withdrawal by Subject"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"20"},{"groupId":"FG001","numSubjects":"42"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"19"},{"groupId":"FG001","numSubjects":"42"}],"type":"Received Treatment"},{"achievements":[{"groupId":"FG000","numSubjects":"18"},{"groupId":"FG001","numSubjects":"41"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"2"},{"groupId":"FG001","numSubjects":"1"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"Participants who met eligibility criteria were enrolled and stratified by the following 3 age categories: ≥ 1 to \\< 6 years; 6 to \\< 12 years; and 12 to \\< 18 years.","recruitmentDetails":"This study was conducted at 27 centers in the United States, Canada, and Australia. Participants were enrolled from 24 January 2012 to 03 September 2014."}