An Exploratory Study of CD19/CD22/BCMA CAR-T Cells (BZE2204) in Subjects With Relapsed or Refractory Autoimmune Diseases

This is a single-arm, open-label, early-phase dose-escalation and expansion study of autologous CD19/CD22/BCMA trispecific CAR T cells (BZE2204) in patients with relapsed or refractory autoimmune diseases. The primary objectives are to evaluate safety and tolerability and determine the maximum tolerated dose or recommended dose for further clinical development. Secondary objectives include pharmacokinetic and pharmacodynamic assessments, disease-specific clinical responses, time to treatment discontinuation of corticosteroids or immunosuppressants, and changes in serological biomarkers. BZE2204 is administered as a single intravenous infusion on Day 0 without prior lymphodepleting chemotherapy. The product is manufactured using a rapid, approximately 6-hour process without ex vivo cell expansion. Exploratory assessments include longitudinal single-cell transcriptomic profiling, B-cell and T-cell receptor repertoire analysis, and paired single-cell DNA methylation and transcriptomic profiling to characterize immune reconstitution. Optional lymph node biopsies may be performed in consenting participants to explore changes in tissue B-cell distribution and follicular organization. These biopsies are not required for enrollment or treatment. The main study assessment period extends through Month 6 after infusion. Participants subsequently enter an extended follow-up phase to evaluate longer-term safety and durability of clinical responses. Extended follow-up assessments are s