This is a single-arm, open-label, phase I clinical study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of RD06-05, a universal CD19/BCMA dual-targeting chimeric antigen receptor T-cell (CAR-T), in pediatric and adolescent patients with refractory autoimmune diseases, including systemic lupus erythematosus/lupus nephritis (SLE/LN), systemic sclerosis (SSc), idiopathic inflammatory myopathy (IIM), multidrug-resistant nephrotic syndrome (MDR-NS), and refractory IgA nephropathy (IgAN).
Approximately 30 eligible patients will be enrolled and receive a single intravenous infusion of RD06-05 at an initial dose of 6×10⁶ CAR+ T cells/kg, with a potential dose escalation to 10×10⁶ CAR+ T cells/kg following review by a Safety Review Committee (SRC).
Voluntary participation with signed informed consent from patient or legal guardian.
Age >=5 to <20 years, male or female.
Important organ function meeting the following requirements (excluding abnormalities related to autoimmune disease activity): a) Bone marrow: ANC >=1.0x10^9/L, hemoglobin >=60 g/L, platelets >=30x10^9/L; b) Liver: ALT <=3xULN (except IIM-related elevation), AST <=3xULN, total bilirubin <=2xULN (<=3xULN for Gilbert syndrome); c) Kidney: eGFR >=30 mL/min/1.73m² (lower eGFR or on renal replacement may be allowed if benefit > risk by investigator judgment); d) Cardiac: LVEF >=55% by echocardiogram; e) Pulmonary: No severe lung disease, SpO2 >=92%.
Negative serum or urine pregnancy test for females of childbearing potential at screening.
Co-existing autoimmune disease that may interfere with disease activity attribution or add safety risk (unless stable >=3 months and approved).
Prior B-cell/ASC depletion therapy: a) Anti-CD20 or T-cell engager within 3 months (allowed if >3-6 months and CD19+ B-cells > LLN); b) Prior CD19 and BCMA dual-targeted therapy, or CD19 or BCMA targeted therapy within 6 months (allowed if >6 months and B-cells > LLN); c) Other B-cell/ASC targeted therapies require approval.
Rapidly progressive glomerulonephritis (RPGN): >=50% crescents on biopsy, or doubling of serum creatinine within 2 months, or investigator judgment.
Cardiac disease: NYHA class III/IV heart failure, MI, angioplasty/stent, unstable angina, or other severe cardiac disease within 12 months.