RecruitingBiological interventionCAR-20/19-T Cells in Patients With Relapsed Refractory B Cell MalignanciesThis is a Phase I/II, interventional, single-arm, open-label, treatment study designed to evaluate the safety and efficacy of Interleukin-7 and Interleukin-15 (IL-7/IL-15) manufactured chimeric antigen receptor (CAR)-20/19-T cells as well as the feasibility of a flexible manufacturing schema in adult patients with B cell malignancies that have failed prior therapies.