This is an open-label (identity of assigned study drug will be known) study designed to collect long-term safety and efficacy data and provide ibrutinib access to participants in completed ibrutinib studies. PCI-32765 (Ibrutinib) is a first-in-class, potent, orally-administered, covalently-binding small molecule inhibitor of bruton's tyrosine kinase. "PCI-32765" and "ibrutinib" refer to the same molecule; hereafter, "ibrutinib" will be used. Participants will continue with the current ibrutinib dosing regimen established in the parent ibrutinib study until the investigator determines that the participant is no longer benefitting from treatment (ie, disease progression or unacceptable toxicity has occurred), the participant withdraws consent, alternative access to ibrutinib is available and feasible (example, participant assistance program or commercial source of ibrutinib), or for other reasons as defined in the protocol, or until the end of the study, whichever occurs earlier. Safety will be monitored throughout the study and summarized. Efficacy may be analyzed in combination with the data collected in the parent protocol. There is no formal hypothesis testing planned for this long-term extension study. Participants for whom alternative access to ibrutinib is not available and feasible can receive treatment with single-agent ibrutinib until end of study, which is defined as the time when all participants still receiving study treatment have transitioned to commercial or alternative access to ibrutinib, have stopped receiving ibrutinib treatment, or upon a decision by the sponsor to terminate the study, whichever occurs earlier.