Mantle cell lymphoma (MCL) is an uncommon and incurable clinicopathologic subtype of B-cell non-Hodgkin Lymphoma (NHL). Ibrutinib is a first-in-class potent, orally administered, covalently-binding small molecule inhibitor of Bruton's tyrosine kinase (BTKi) for the treatment of B-cell malignancies and chronic graft-versus-host disease. The primary hypothesis of the study is to provide continued access to treatment for participants who continue to benefit from treatment. The study will include a screening phase (up to 30 days prior to randomization), a treatment phase (from randomization until study treatment discontinuation). safety assessments include adverse events (AEs), serious adverse events (SAEs), clinical laboratory tests, vital signs, electrocardiogram (ECG), physical examination. The Phase 2 exploratory objectives and endpoints of characterization of pharmacokinetic and pharmacodynamic of ibrutinib may continue to be evaluated using blood samples already collected. The total duration of the study will be up to 2 years 1 month.
