An Exploratory Clinical Study of Anti-CD19 CAR NK Cells in the Treatment of Systemic Lupus Erythematosus

Inclusion Criteria:

1. Age: ≥ 18 years old and ≤ 65 years old, male or female, subjects voluntarilyparticipate in this clinical study and sign the Informed Consent Form (ICF)

2. Previous diagnosis of systemic lupus erythematosus (SLE) (according to the 1997American Rheumatology Association criteria)

3. Females of childbearing potential must use effective contraception during studytreatment and for 90 days after the last dose of study treatment. In addition,subjects must not donate eggs during the study and for at least 90 days after thelast dose of study treatment

4. Subjects with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K) score ≥ 8 points prior to screening

5. Subject has ≥ 1 organ system with BILAG-2004 Class A mobility score or ≥ 2 organsystems with BILAG-2004 Class B mobility score prior to screening

6. Subjects meets one of the following:

7. Antinuclear antibody (ANA) ≥ 1:80, determined by immunofluorescence method;

8. Anti-dsDNA antibodies are higher than normal level;

9. Anti-Smith antibodies are higher than normal level

10. Absolute number of neutrophils ≥ 1.0×10^9/L, hemoglobin ≥ 60g/L

11. Left ventricular ejection fraction (LVEF) ≥ 50%

12. Subjects have been treated with oral corticosteroids (OCS) in combination with animmunosuppressive or biologic agent for at least 6 months prior to enrollment

Exclusion Criteria:

1. Subjects with known severe allergic reactions, hypersensitivity, contraindication toany medications during the trial (cyclophosphamide, fludarabine, obinutuzumab), orsubjects with a history of severe allergic reactions

2. Subjects with active infection receiving intravenous (IV) antibiotic treatment, orreceived intravenous (IV) antibiotic treatment within one week prior to anti-CD19CAR NK Cells infusion

3. Subjects with acquired and congenital immunodeficiency diseases

4. Subjects with grade III or IV heart failure (NYHA classification)

5. History of epilepsy or other central nervous system (CNS) diseases

6. History of severe herpetic infection, such as herpetic encephalitis, ocular herpes,or diffuse herpes

7. History of other primary malignant tumors except:

8. Cured non-melanoma skin cancer by surgical excision, for example basal cellcarcinoma (BCC) ;

9. Cured primary malignant tumors, such as cervical cancer, superficial bladdercancer, breast cancer

10. Signs of herpes or varicella-zoster virus infection (especially chickenpox,shingles) within 12 weeks prior to screening; History of any cardiac, endocrine,hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic,dermatologic, psychiatric, and renal disease or other major medical condition thatwould prevent the administration of anti-CD19 CAR NK Cells (KN5501), except forlupus (determined by the investigator)

11. Females who are pregnant, lactating, or planning a pregnancy within six months

12. Any active skin disease that may interfere with the study assessment of SLE,including but not limited to psoriasis, dermatomyositis, systemic sclerosis, non-LEcutaneous lupus manifestations (eg, cutaneous vascular disease, periungualtelangiectasia, fingertip sclerosis, rheumatoid nodules, erythema multiforme, legulcers) or drug-induced lupus

13. Subjects who have received other clinical trial treatment within 3 months

14. Subjects who have received B cell-targeted drug therapy within 1 month beforeenrollment

15. Any abnormal laboratory test results judged by the investigator to be clinicallysignificant and prevent the subject from participating in the study. Laboratory testvalues that are out of range and not of clinical significance will not be consideredas exclusion criteria

16. Any situation judged by the investigators that may increase the risk of the subjectsor interfere with the clinical trial outcome