Treatment of Relapsed and/or Chemotherapy Refractory B-cell Malignancy by Tandem CAR T Cells Targeting CD19 and CD20

PRIMARY OBJECTIVES: To assess the efficacy of TanCAR19/20 T cells in relapsed or refractory NHL, defined as overall response rate (ORR). SECONDARY OBJECTIVES: I. To evaluate the safety and tolerability of TanCAR19/20 T cells. II. To evaluate time to response (TTR), duration of overall response (DOR), progression free survival (PFS) and overall survival (OS). III. To determine in vivo expansion and persistence of TanCAR19/20 T cells. OUTLINE: Patients are assigned to 1 group according to order of enrollment. Patients receive anti-CD19/20-CAR (coupled with CD137 and CD3 zeta signalling domains)vector-transduced autologous T cells on day1 in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed intensively for 6 months, every 3 months for 2 years, and annually thereafter for 3 years.