Exploratory Study of Anti-BCMA-CD19 CAR-T Cell Therapy in Relapsed or Refractory IgG4-Related Disease

Anti-BCMA-CD19 CAR-T cell injection is an autologous, dual-target chimeric antigen receptor T-cell therapy designed to target CD19 and BCMA antigens. Peripheral blood mononuclear cells (PBMCs) are collected from each participant and modified ex vivo using lentiviral transduction to express the CAR construct. Lymphodepletion with cyclophosphamide (250 mg/m\^2/day, IV) and fludarabine (30 mg/m\^2/day, IV) is administered for 3 days (Day -5 to Day -3). The doses of fludarabine and cyclophosphamide may be adjusted based on the patient's clinical condition. CAR-T cells are infused intravenously on Day 0 at one of three dose levels (1x10\^6, 2x10\^6, or 3x10\^6 CAR+ T cells/kg, ±20%). This product is being investigated in patients with relapsed or refractory IgG4-related disease (IgG4-RD) to assess safety and preliminary efficacy.