{"groups":[{"description":"Intravenous (IV) infusions of natalizumab 300 mg once every 28 days for 6 months.","id":"FG000","title":"Natalizumab 300 mg"},{"description":"Intravenous (IV) infusions of natalizumab 450 mg once every 28 days for 6 months.","id":"FG001","title":"Natalizumab 450 mg"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"2"},{"groupId":"FG001","numSubjects":"2"}],"type":"Disease Progression"},{"reasons":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"1"}],"type":"No Disease Response After Cycle 6"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"0"}],"type":"Physician Decision"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"3"},{"groupId":"FG001","numSubjects":"3"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"0"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"3"},{"groupId":"FG001","numSubjects":"3"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"This record includes data up to and including the last data values collected during long-term follow-up (27 January 2010)."}