Transformed Non-Hodgkin Lymphoma

Patients will receive one of two conditioning regimens (BEAM or CBV) before receiving an autologous stem cell transplant (ASCT). If patients achieve either complete, partial, or stable response following ASCT, they will receive an IV dose of Polatuzumab Vedotin once every 21 days until they receive 8 doses. After Polatuzumab Vedotin therapy is completed, patients will be followed every 4 months for about 2 years.

The goal of this clinical trial is to learn if a new type of chimeric antigen receptor (CAR) T-cell therapy called WZTL-002 is effective and safe for the treatment large B-cell lymphomas (LBCL) that have not responded to or have come back after standard chemotherapy. The main questions this trial aims to answer are: * What is the likelihood of complete response of the lymphoma after WZTL-002 treatment? * What is the risk of altered brain function (neurotoxicity) after WZTL-002? All eligible participants will receive WZTL-002; the researchers will compare the complete response rate and neurotoxicity rate with historical groups of patients who were treated with similar therapies. Participants will: * Have a procedure to gather white blood cells * Receive chemotherapy to prepare for the CAR T-cells * Receive WZTL-002 CAR T-cells through a vein * Be monitored closely for the first 14 days for certain side effects * Have scans 28 days and 3, 6, 12 and 24 months after WZTL-002 CAR T-cells to check if the treatment has worked

This phase I trial studies the safety and side effects of cytomegalovirus (CMV) specific CD19-chimeric antigen receptor (CAR) T-cells along with the CMV-modified vaccinia Ankara (MVA) triplex vaccine following a stem cell transplant in treating patients with high grade B-cell non-Hodgkin lymphoma. CAR T-cells are a type of treatment in which a patient's T-cells (a type of immune system cell) are changed in the laboratory so they will attack cancer cells. T-cells are taken from a patient's blood. Then the gene for a special receptor that binds to a certain protein on the patient's cancer cells is added in the laboratory. The special receptor is called a chimeric antigen receptor (CAR). Large numbers of the CAR T-cells are grown in the laboratory and given to the patient by infusion. Vaccines such as CMV-MVA triplex are made from gene-modified viruses and may help the body build an effective immune response to kill cancer cells. Giving CMV-specific CD19-CAR T-cells plus the CMV-MVA triplex vaccine following a stem cell transplant may help prevent the cancer from coming back.

This phase 2 trial studies the side effects and best dose of tazemetostat and zanubrutinib in combination with tafasitamab and lenalidomide, and to see how well these combinations work in treating patients with large B-cell lymphoma that returned or did not respond to earlier treatment. Tazemetostat is in a class of medications called EZH2 inhibitors. It helps to stop the spread of cancer cells. Zanubrutinib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps stop the spread of cancer cells. tafasitamab is a monoclonal antibody that may interfere with the ability of cancer cells to grow and spread. Lenalidomide is in a class of medications called immunomodulatory agents. It works by helping the bone marrow to produce normal blood cells and by killing abnormal cells in the bone marrow. The addition of tazemetostat or zanubrutinib to tafasitamab and lenalidomide may be able to shrink the cancer or extend the time without cancer symptoms coming back.