{"groups":[{"description":"Participants received ibrutinib 420 milligrams (mg) orally once daily for 3 cycles (each cycle is of 28 days) followed by the combination of ibrutinib 420 mg and venetoclax 400 mg orally once daily for 12 cycles (including a 5-week venetoclax dose ramp up starting in cycle 4). Participants who subsequently developed independent review committee (IRC)-confirmed progressive disease (PD) and had active disease requiring treatment were eligible to participate in the Subsequent Therapy Phase and received single-agent ibrutinib until disease progression or unacceptable toxicity.","id":"FG000","title":"Treatment Arm A (Ibrutinib + Venetoclax)"},{"description":"Participants received chlorambucil 0.5 milligrams per kilogram (mg/kg) body weight orally once daily on Days 1 and 15 of Cycles 1 to 6 in combination with obinutuzumab 1000 mgs intravenously (IV) once daily on Days 1, 8, and 15 of Cycle 1 and Day 1 of Cycles 2 to 6 (each cycle is of 28 days). Participants who subsequently developed IRC-confirmed progressive disease (PD) and had active disease requiring treatment were eligible to participate in the Subsequent Therapy Phase and received single-agent ibrutinib until disease progression or unacceptable toxicity.","id":"FG001","title":"Treatment Arm B (Chlorambucil + Obinutuzumab)"}],"periods":[{"dropWithdraws":[{"reasons":[{"groupId":"FG000","numSubjects":"4"},{"groupId":"FG001","numSubjects":"3"}],"type":"Withdrawal by Subject"},{"reasons":[{"groupId":"FG000","numSubjects":"87"},{"groupId":"FG001","numSubjects":"72"}],"type":"Ongoing"}],"milestones":[{"achievements":[{"groupId":"FG000","numSubjects":"106"},{"groupId":"FG001","numSubjects":"105"}],"type":"STARTED"},{"achievements":[{"groupId":"FG000","numSubjects":"15"},{"groupId":"FG001","numSubjects":"30"}],"type":"COMPLETED"},{"achievements":[{"groupId":"FG000","numSubjects":"91"},{"groupId":"FG001","numSubjects":"75"}],"type":"NOT COMPLETED"}],"title":"Overall Study"}]}