This is a open-label, exploratory trial to evaluate the safety, feasibility, and preliminary efficacy of RN1201, an Allogeneic CAR-T cell therapy, in patients with autoimmune diseases refractory to standard treatment. Eligible patients with moderate to severe activity of diseases will receive a single infusion of RN1201 following lymphodepletion. Primary endpoints include dose-limiting toxicity and treatment-emergent adverse events. Secondary and exploratory endpoints assess clinical response and cell pharmacokinetics.

Inclusion Criteria

1. Voluntary signed informed consent demonstrating understanding of the study and willingness/ability to comply with all trial procedures.
2. Age ≥18 years; both sexes eligible.
3. Documented diagnosis of an autoimmune disease for ≥6 months at screening, including but not limited to immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), systemic lupus erythematosus (SLE), immune-mediated necrotizing myopathy (IMNM), neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), myasthenia gravis (MG), etc.
4. Standard-of-care therapy for ≥8 weeks before screening without achieving complete remission or adequate disease control, with stable dose for >2 weeks.
5. Subjects on corticosteroid monotherapy at screening must be receiving ≥7.5 mg/day prednisone (or equivalent).
6. Disease activity score meeting criteria for moderate-to-severe active disease.
7. Adequate bone-marrow reserve, coagulation, cardiopulmonary, hepatic, and renal function.
8. Agreement to use effective contraception for 24 months after study enrollment.

Exclusion Criteria

Subjects meeting any of the following cannot be enrolled:

1. Known hypersensitivity, allergy, intolerance, or contraindication to RN1201 or any study drug component (fludarabine, cyclophosphamide, tocilizumab) or history of severe allergic reactions.
2. Severe cardiovascular disease or organ failure.
3. Active or uncontrolled infection requiring IV antibiotics or evidence of severe active infection.
4. Significant bleeding tendency (e.g., Gastrointestinal bleeding, coagulopathy, hypersplenism).
5. Hepatitis C virus, HIV, or syphilis infection.
6. History of epilepsy or severe neurological disorders/pathology not attributable to autoimmune disease.
7. Malignancy within 2 years before screening, except adequately treated carcinoma in situ of skin, cervix, or lung or other non-active tumors.
8. Prior CAR-T therapy or other genetically modified T-cell therapy.
9. Prednisone (or equivalent) ≥100 mg/day for ≥14 days within 4 weeks before screening.
10. Pregnancy, lactation, or planned pregnancy within 2 years.
11. Any condition that, in the investigator's judgment, may increase subject risk or interfere with study results.