CAR-T cell therapy for treating severe autoimmune diseases

Inclusion Criteria:

1. Age ≥ 18 years old, not exceeding 70 years old (including 70 years old);
2. If the kidneys are involved, estimate the glomerular filtration rate (eGFR) to be ≥ 15 mL/minute/1.73 m2;
3. The following test values within 3 days before the collection of mononuclear cells meet the following standards:

   1. Absolute lymphocyte count: ≥ 0.5 × 10 \^ 9/L \[The use of granulocyte colony-stimulating factor (G CSF) is allowed, but subjects are not allowed to receive this supportive treatment within 7 days before the screening period laboratory examination\];
   2. Absolute neutrophil count: ≥ 1.0 × 10 \^ 9/L \[The use of granulocyte colony-stimulating factor (G-CSF) is allowed, but subjects are not allowed to receive this supportive treatment within 7 days before the screening period laboratory examination\];
   3. Platelets: Subject platelet count ≥ 50 × 10 \^ 9/L (subjects are not allowed to receive blood transfusion support within 7 days before the screening period laboratory examination);
   4. Hemoglobin: ≥ 8.0 g/dL (allowing the use of recombinant human erythropoietin) \[subjects have not received red blood cell (RBC) infusion within 7 days prior to the screening period laboratory examination\];
   5. Creatinine clearance rate: (CrCl) or glomerular filtration rate (GFR) (Cockcroft Gault formula) ≥ 30 mL/min;
   6. Total bilirubin (serum): Total bilirubin (serum) ≤ 1.5 × ULN; Blood bilirubin\>1.5 × Gilbert subjects from ULN can be enrolled with the consent of the sponsor
   7. AST and ALT: ≤ 3.0 × ULN;
   8. Plasma prothrombin time (PT), international standardized ratio (INR), partial prothrombin time (APTT): PT ≤ 1.5 × ULN, APTT ≤ 1.5 × ULN, INR ≤ 1.5 × ULN
4. Willing to sign an informed consent form.
5. \- for refractory ANCA-associated vasculitis

   ①According to the 2022ACR/EULAR criteria, diagnosed with AAV (GPA or MPA subtype), who has not achieved remission (BVAS score of 0) for ≥ 3 months after receiving standardized treatment. Severe patients who have previously undergone standardized treatment to induce remission and are now relapsing after maintenance therapy; ②The patient is currently or has a positive ANCA during the course of the disease; ③Severe illness (severe organ involvement or life-threatening) requiring treatment (BVAS score ≥ 3.0); The definition of severe illness is vasculitis with life-threatening or organ manifestations.
6. \- for refractory LN

   * According to the 2019 American Society of Rheumatology (ACR) criteria, diagnosed with systemic lupus erythematosus, within 6 months prior to infusion, confirmed by renal tissue biopsy according to the 2003 International Society of Nephrology (ISN)/Society of Nephropathology (RPS) criteria as active, proliferative lupus nephritis (LN), type III or IV \[excluding III (C), IV S (C), and IV G (C)\], or type III/IV combined with type V, And have received standard treatment that is ineffective or relapses after disease remission. ②Positive anti-nuclear antibodies (ANA) and/or anti-dsDNA antibodies during the screening period. ③The SLE Disease Activity Index (SLEDAI-2000) score during the screening period is ≥ 8. SLEDAI-2000 clinical score ≥ 6 points, but low complement and/or anti ds-DNA positivity can be selected. ④The estimated survival period is at least 3 months.

Exclusion Criteria:

-Subjects who meet any of the following criteria should be excluded from this study:

1. Pregnant or lactating women;
2. If combined with alveolar hemorrhage, invasive pulmonary ventilation is required;
3. Refractory GPA and MPA: Combined with other autoimmune diseases involving multiple organ systems, such as EGPA, SLE, IgA vasculitis (Henoch Schönlein), rheumatoid arthritis, inflammatory myositis, anti-glomerular basement membrane disease, or cryoglobulinemia vasculitis;
4. Difficult to treat LN: severe extrarenal clinical manifestations such as lupus encephalopathy, pulmonary hemorrhage, lupus myocarditis, lupus enteritis, and lupus crisis; Other autoimmune diseases other than combined SLE, including dermatomyositis/polymyositis, mixed connective tissue disease, systemic sclerosis, rheumatoid arthritis, etc;
5. Individuals who are known to have allergic reactions, hypersensitivity reactions, intolerance, or contraindications to any component of PRG-1801 or drugs that may be used in the study (including fludarabine, cyclophosphamide, tocilizumab, albumin), or have experienced severe allergic reactions in the past;
6. A history of malignant tumors within 5 years (① subjects with cervical carcinoma in situ who have been completely removed and have not experienced recurrence or metastasis for at least 3 years may participate in this study. ② subjects with basal cell or squamous cell carcinoma who have been completely removed and have not experienced recurrence for at least 3 years may participate in this study);
7. Obvious evidence of cardiovascular disease as follows: a N-terminal B-type natriuretic peptide (NT proBNP)\>8500ng/L; b. The New York Heart Association (NYHA) classifies heart failure as Grade IV; c. Patients who received hospitalization for unstable angina or myocardial infarction within 6 months prior to the first administration, or patients who received percutaneous cardiac intervention and received the most recent stent placement within 6 months or coronary artery bypass grafting within 6 months;
8. Received the following medication treatment within the prescribed time before single collection: ① Received B cell depletion therapy such as rituximab within 24 weeks; ② Received biological agents (such as TNF) within 4 weeks or 2 half-lives - Treatment with inhibitors, interleukin receptor inhibitors, belizumab, and tamoxifen; ③ Received treatment such as immunosuppressants within 2 weeks or 5 half-lives ; ④ If systemic glucocorticoids need to be used for a long time from 2 weeks before single collection to the study period, the dose of the hormone should not exceed 10mg/day; ⑤ Received plasma exchange or immunosorbent therapy within 24 weeks, and received intravenous immunoglobulin (IVIG) therapy within 4 weeks.
9. Vaccinate with live/attenuated vaccines within 4 weeks prior to single collection or during the study period;
10. Chronic and active hepatitis B ( the HBV DNA test is higher than 500IU/ml), hepatitis C (HCV), human immunodeficiency virus (HIV) infection, or syphilis infection;
11. There is an active infection that requires intravenous injection of antibiotics or hospitalization treatment;
12. Major surgery or surgical treatment caused by any reason within 4 weeks prior to enrollment;
13. Any serious and/or uncontrollable comorbidities that the researcher believes may interfere with the evaluation during the research process;
14. Participated in other intervention clinical trials within 3 months prior to enrollment or within 5 drug half-lives (whichever is longer);
15. Other conditions determined by the researcher as unsuitable for lymphocyte clearance or cell infusion, or other unsuitable patients for study.