Ibrutinib PK data ( 3,477 observations/245 patients ) were available from the following clinical studies : ( 1 ) A phase I dose-escalation study in recurrent B cell malignancies ( dose levels of 1.25-12 .5 mg/kg/day and fixed dose of 560 mg/day ) ; ( 2 ) a phase II study in MCL ( fixed dose level of 560 mg/day ) ; ( 3 ) a phase Ib/II dose-finding study in CLL ( fixed dose levels of 420 and 840 mg/day ) .