Safety and Efficiency Study of CD19-PD1-CART Cell in Relapsed/Refractory B Cell Lymphoma

Lymphoma is a malignant tumor originating from lymph nodes or other lymphoid tissues. It can be divided into B cells, T cells, and NK cell lymphomas depending on the origin of different lymphocytes. Among them, B cell lymphoma accounts for about 90% of lymphoma. Chimeric antigen receptor T (CART) cells is a promising treatment for lymphoma. T lymphocytes from patients are separated and engineered with CD19-CAR, to specifically recognize and eliminate CD19-positive tumor cells. At present, many CD19CART cells therapy studies are in the stage of clinical research and have achieved significant clinical effects. Although there are some CD9CART cells clinical trials, the therapeutic effect on lymphoma is significantly lower than that of acute leukemia. One of the reasons is that lymphoma has the nature of solid tumors, whichi has a certain immunosuppressive microenvironment. The clinical trials of anti-PD-1 antibody drugs against lymphoma also show good therapeutic efficacy. Therefore, the combination of anti-PD-1 or PD-L1 antibody and CD19CART is one of the ways to improve the therapeutic effect of CART cells. The investigators screened PD-1 mutants that have high bind with the PD-L1 ligand, and prepared CD19CART which secretes the mutant PD-1Fc fusion protein. Preclinical studies have shown that CD19CART cells secreting mutant PD-1Fc fusion protein have a superior killing effect to CD19CART cells which does not express PD-1 fusion protein. The trial was conducted to explore the safety and efficacy of CD19-PD1-CART cells in Relapsed/Refractory B Cell Lymphoma.