RICE-ibrutinib in Relapsed DLBCL

All patients will receive R-ICE therapy for 2 cycles followed by PET-CT assessment (PET-2). Ibrutinib 560 mg will be added to the RICE regimen based on results of PET-2 as follows: * Patients in CR will continue with 2 more cycles of R-ICE and proceed onto ASCT. These patients will not receive ibrutinib. * In patients with stable disease or achieving a response that is less than CR, ibrutinib 560 mg will be added. The combination of ibrutinib-RICE will be given for 2 cycles and will be followed by PET-CT assessment (PET-4). Patients who achieve ≥ PR at this point will proceed onto ASCT. * Patients who have disease progression will be removed from the trial. Hematopoietic stem cell harvesting can be performed following count recovery at any cycle of R-ICE, but preferably cycle 2. Transplant conditioning regimen will be with standard BEAM chemotherapy (carmustine, etoposide, cytarabine, melphalan). Following ASCT, ibrutinib will be given as maintenance therapy for patients who did not achieve a CR at the time of PET-2 assessment. This will be continued for up to 1 year after ASCT.