Relapsed or refractory diffuse large B-cell lymphoma (RR DLBCL) is an aggressive type of non-Hodgkin lymphoma (NHL) that does not respond to initial therapy or returns after a period of time. RR DLBCL commonly affects lymph nodes, spleen, liver, bone marrow, and other organs. The disease is characterized by heterogeneous and rapidly dividing malignant B lymphocytes found in the lymph system....