Fludarabine and Cyclophosphamide With or Without Rituximab Before CD19 Chimeric Antigen Receptor T Cells for the Treatment of Relapsed or Refractory Diffuse Large B-Cell Lymphoma

This phase I trial evaluates the best dose, possible benefits and/or side effects of fludarabine and cyclophosphamide with or without rituximab before CD19 chimeric antigen receptor T cells in treating patients with diffuse large B-cell lymphoma that has come back (relapsed) or has not responded to previous treatment (refractory). T-cells are a normal part of the immune system. To make the T-cell medication, T-cells are taken from the blood and altered in a laboratory. They are then returned to the body. The altered T-cells will latch on to a specific part of the cancer cells and hopefully kill them. Once the T-cells have been altered in the laboratory, they are called "CAR T-cells." CAR is short for "chimeric antigen receptors." These are structures on the surface of cells that allow the altered T-Cells to find and destroy the cancer cells. Another part of the T-Cell medication is called "CD19." This part is called a "biomarker." Biomarkers help doctors determine whether a cancer is getting worse and whether medications are working to stop it. The chemotherapy drugs that are given before the T-Cell therapy are cyclophosphamide, fludarabine and rituximab. Rituximab is an immunotherapy drug. These chemotherapy drugs will reduce the number of normal (unaltered) T-Cells in the body to make room for the altered T-cells to kill the cancer cells. Giving fludarabine and cyclophosphamide with or without rituximab before CD19 CAR T cell therapy may help improve response to CD19 CAR T cell therapy in patients with diffuse large B-cell lymphoma.