21. Vaccinated with live, attenuated vaccines within 4 weeks of randomization. 22. Uncontrolled systemic infection requiring intravenous (IV) antibiotics. 23. Any life-threatening illness, medical condition, or organ system dysfunction which, in the investigator's opinion, could compromise the subject's safety, interfere with the absorption or metabolism of ibrutinib capsules, or put the study outcomes at undue risk.