Bruton's Tyrosine Kinase (BTK) Inhibitor, Ibrutinib, in Patients With Newly Diagnosed or Refractory/Recurrent Primary Central Nervous System Lymphoma (PCNSL) and Refractory/Recurrent Secondary Central Nervous System Lymphoma (SCNSL)

The population consists of adult patients with newly diagnosed or relapsed or refractory primary central nervous system lymphoma (PCNSL) or relapsed or refractory secondary central nervous system lymphoma (SCNSL) Patients eligible for inclusion in this study have to meet all the following criteria: Inclusion Criteria: * Participants must be able to understand and be willing to sign a written informed consent document * Men and woman who are at least 18 years of age on the day of consenting to the study * Histologically or cystologically documented PCNSL or histologically documented systemic diffuse large B-cell lymphoma (DLBCL) * Patients must have relapsed/refractory PCNSL or relapsed/refractory SCNSL (Arm A, B, C) or newly diagnosed PCNSL (Arm D) * All patients need to have received at least one prior CNS directed therapy. There is no restriction on the number of recurrences (Arm A, B , C only) * Patients with parenchymal lesions must have unequivocal evidence of disease progression on imaging (MRI of the brain or head CT) 21 days prior to study registration. For patients with leptomeningeal disease only, CSF cytology must document lymphoma cells and/or imaging findings consistent with CSF disease 21 days prior to study registration (at the discretion of the investigator) (Arm A, B , C only). * Participants must have an ECOG performance status of 0, 1, or 2 * Within the past 21 days prior to study registration (for Arm D: prior to treatment initiation) participants must …