Copanlisib With Ibrutinib for Patients With Recurrent/ Refractory Primary Central Nervous System Lymphoma (PCNSL)

Inclusion Criteria: Patients eligible for inclusion in this study must meet ALL the following criteria: * Men and woman who are at least 18 years of age on the day of consenting to the study. * Histologically documented PCNSL * Relapsed/refractory PCNSL or newly diagnosed PCNSL patients who are deemed medically ineligible by the treating investigator (phase II only) to receive standard first-line chemotherapy. All recurrent/refractory patients need to have received at least one prior CNS directed therapy. There is no restriction on the number of recurrences. * For recurrent/refractory patients, parenchymal lesions must have unequivocal evidence of disease progression on imaging (MRI of the brain or head CT) 21 days of study registration. For patients with leptomeningeal disease only, CSF cytology must document lymphoma cells and/or imaging findings consistent with CSF disease 21 days of study registration (at the discretion of the investigator). * ECOG performance status ≤ 2. * Life expectancy of \> 3 months (in the opinion of the investigator). * Adequate bone marrow and organ function shown by: * Absolute neutrophil count (ANC) ≥ 1.5 x 10\^9/L * Platelets ≥ 75 x 10\^9/L and no platelet transfusion within the past 14 days prior to study registration * Hemoglobin (Hgb) ≥ 8 g/dL and no red blood cell (RBC) transfusion within the past 14 days prior to study registration * International Normalized Ratio (INR) ≤ 1.5 and PTT (aPTT) ≤ 1.5 times the upper limit of normal …