{"groups":[{"description":"T-DM1 resistant/refractory (R/R) participants randomized to receive DS-8201a low dose (5.4 mg/kg) in the pharmacokinetic (PK) and dose-finding phases.","id":"FG000","title":"Part 1: DS-8201a Low Dose"},{"description":"T-DM1 resistant/refractory (R/R) participants randomized to receive DS-8201a medium dose (6.4 mg/kg) in the pharmacokinetic (PK) and dose-finding phases.","id":"FG001","title":"Part 1: DS-8201a Medium Dose"},{"description":"T-DM1 resistant/refractory (R/R) participants randomized to receive DS-8201a high dose (7.4 mg/kg) in the pharmacokinetic (PK) and dose-finding phase.","id":"FG002","title":"Part 1: DS-8201a High Dose"},{"description":"All T-DM1 resistant/refractory (R/R) participants who were treated at the recommended (5.4 mg/kg) dose in Part 2a in the continuation phase.","id":"FG003","title":"Part 2a: DS-8201a Low Dose"},{"description":"All participants who were previously treated with T-DM1 and were randomized to receive DS8201a low dose (5.4 mg/kg) in Part 2b in the continuation phase.","id":"FG004","title":"Part 2b (Exploratory): DS-8201a Low Dose"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"24"},{"groupId":"FG001","numSubjects":"23"},{"groupId":"FG002","numSubjects":"11"},{"groupId":"FG003","numSubjects":"66"},{"groupId":"FG004","numSubjects":"1"}],"type":"Progressive Disease"},{"reasons":[{"groupId":"FG000","numSubjects":"14"},{"groupId":"FG001","numSubjects":"13"},{"groupId":"FG002","numSubjects":"9"},{"groupId":"FG003","numSubjects":"22"},{"groupId":"FG004","numSubjects":"2"}],"type":"Adverse Event"},{"reasons":[{"groupId":"FG000","numSubjects":"5"},{"groupId":"FG001","numSubjects":"4"},{"groupId":"FG002","numSubjects":"0"},{"groupId":"FG003","numSubjects":"8"},{"groupId":"FG004","numSubjects":"1"}],"type":"Withdrawal by Subject"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"1"},{"groupId":"FG002","numSubjects":"1"},{"groupId":"FG003","numSubjects":"7"},{"groupId":"FG004","numSubjects":"0"}],"type":"Physician Decision"},{"reasons":[{"groupId":"FG000","numSubjects":"1"},{"groupId":"FG001","numSubjects":"1"},{"groupId":"FG002","numSubjects":"0"},{"groupId":"FG003","numSubjects":"6"},{"groupId":"FG004","numSubjects":"0"}],"type":"Death"},{"reasons":[{"groupId":"FG000","numSubjects":"3"},{"groupId":"FG001","numSubjects":"1"},{"groupId":"FG002","numSubjects":"0"},{"groupId":"FG003","numSubjects":"7"},{"groupId":"FG004","numSubjects":"0"}],"type":"Study Terminated by Sponsor"},{"reasons":[{"groupId":"FG000","numSubjects":"2"},{"groupId":"FG001","numSubjects":"5"},{"groupId":"FG002","numSubjects":"0"},{"groupId":"FG003","numSubjects":"14"},{"groupId":"FG004","numSubjects":"0"}],"type":"Other"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"50"},{"groupId":"FG001","numSubjects":"48"},{"groupId":"FG002","numSubjects":"21"},{"groupId":"FG003","numSubjects":"130"},{"groupId":"FG004","numSubjects":"4"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"0"},{"groupId":"FG001","numSubjects":"0"},{"groupId":"FG002","numSubjects":"0"},{"groupId":"FG003","numSubjects":"0"},{"groupId":"FG004","numSubjects":"0"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"50"},{"groupId":"FG001","numSubjects":"48"},{"groupId":"FG002","numSubjects":"21"},{"groupId":"FG003","numSubjects":"130"},{"groupId":"FG004","numSubjects":"4"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}],"preAssignmentDetails":"In Part 1, participants were randomized 1:1:1 to either 5.4 mg/kg, 6.4 mg/kg, or 7.4 mg/kg dose of DS-8201a. Two doses randomized 1:1 (5.4 or 6.4 mg/kg) were further evaluated. In Part 2, all T-DM1 resistant refractory participants (cohort 2a) or T-DM1 intolerant (cohort 2b) received DS-8201a at the recommended dose.","recruitmentDetails":"Participants who met all of the inclusion and none of the exclusion criteria were enrolled and randomized to treatment (Part 1) or received DS-8201a at the recommended dose (Part 2)."}