Anti-CD19 CAR T cell therapy for refractory SLE-ITP

Background Patients with systemic lupus erythematosus (SLE) complicated by immune thrombocytopenia (SLE-ITP) exhibit an increased incidence of bleeding events and significantly reduced long-term survival, with poor responses to conventional therapies as well as biologic agents. Methods In an investigator-initiated, single-arm, dose-escalation trial, six patients with refractory SLE-ITP received anti-CD19 chimeric antigen receptor (CAR) T cells after lymphodepleting chemotherapy. The primary outcome was safety. Secondary outcomes included overall response rate at time points (complete remission [CR]: platelet count ≥ 100 × 10 9 /L; partial remission [PR]: ≥30 × 10 9 /L with 2-fold baseline increase). Findings All patients achieved clinical response (CR or PR)—with three attaining CR—and discontinued immunosuppressants, with a median follow-up of 12 months. Treatment-related adverse events were limited to grade 1 cytokine release syndrome in two patients, and no immune effector cell-associated neurotoxicity syndrome (ICANS) occurred. Continuously accumulating bone marrow plasma cells, overactivated bone marrow B cell signaling pathways, and weakened activity of the megakaryocyte maturation pathway, along with dysregulated transcription factors, were observed in three PR patients by exploratory single-cell multi-omics. Conclusion These results preliminarily support CD19 CAR T cell therapy as a promising and safe treatment for refractory SLE-ITP. Large-scale trials are needed to verify these conclusions (ClinicalTrials.gov: NCT05930314). Funding This study was supported by the Chinese National Key Technology R&D Program, Ministry of Science and Technology (2021YFC2501300); the CAMS Innovation Fund for Medical Sciences (CIFMS) (2021-I2M-1-005); and National High Level Hospital Clinical Research Funding (2025-PUMCH-D-001, 2022-PUMCH-B-013, D-009). This study was also funded and supported by Juventas Cell Therapy Ltd.