Safety and Efficacy Study of Anti-PD1 Armored CD19 CAR-T Cells in Adult Subjects With Relapsed or Refractory Diffuse Large B-cell Lymphoma

This is a prospective, open-label, single-arm clinical study to evaluate the safety, tolerability of anti-PD1 armored CD19 CAR-T Cells in adult subjects with relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL).The study plans to explore across three dose levels (1.00 × 10\^6, 3.00 × 10\^6, 9.00 × 10\^6 CAR+ T cells/kg), and 6.00×10\^8 CAR+T cells as maximum dose, aiming to evaluate the safety, tolerability of anti-PD1 armored CD19 CAR-T Cells in r/r DLBCL, explore Maximum Tolerated Dose (MTD) and determine the recommended dose for Phase II. Besides, efficacy, pharmacokinetics and persistence profile of CAR-T cells are also study objectives.