Fourth-gen CAR T Cells Targeting BCMA/CD19 for Refractory Systemic Lupus Erythematosus (SLE)

Inclusion Criteria: * 18-90 years old; * Total score ≥ 10 on the EULAR/ACR 2019 SLE classification criteria. * SELENA-SLEDAI≥8. * Patients with CD19+ B-cell. * Hemoglobin≥85 g/L. * WBC≥2.5×10\^9/L. * NEUT≥1×10\^9/L. * BPC≥50×10\^9/L. * AST/ALT below 2 times the upper limit of normal; Creatinine clearance ≥30 mL/min; blood bilirubin ≤2.0 mg/dl; echocardiography indicates that the ejection fraction is ≥50%. * Adequate venous access for apheresis, and no other contraindications for leukapheresis. * Women of childbearing age should have a negative serum or urine pregnancy test at screening and baseline. * Subjects agree to take effective contraceptive measures during the trial until at least 1 year after CAR-T cells infusion. * Agree to attend follow-up visits as required. * Voluntary participation and informed consent signed by the patient or his/her legal/authorized representative. Exclusion Criteria: * Renal disease: severe lupus nephritis (serum creatinine \> 2.5 mg/dL or 221 μmol/L) within 8 weeks --Prior to leukapheresis, or subjects who need hemodialysis. * CNS disease: including epilepsy, psychosis, organic encephalopathy syndrome, cerebrovascular accident \[CVA\], encephalitis or CNS vasculitis, psychiatric patients with depression or suicidal thoughts. * Patients with serious lesions and a history of present illness of vital organs such as the heart, liver,kidney blood and endocrine system. * Patients with immunodeficiency, uncontrolled active infections and active or recurrent peptic ulcers; * Received immunosuppressive therapy within 1 week prior to leukapheresis. * Patients with HIV infection; Active infection of hepatitis B virus or hepatitis C virus. * Patients with syphilis infection. * The presence or suspicion of an active fungal, bacterial, viral or other infection that cannot be controlled during screening. * Received live vaccine treatment within 4 weeks prior to screening. * Severe allergies or hypersensitivity. * Contraindication to cyclophosphamide in combination with fludarabine. * Subjects who have undergone major surgery within 2 weeks prior to signing the informed consent form, or who are scheduled to have surgery (other than local anesthetic surgery) during the trial or within 2 weeks of the infusion. * Cannula or drainage tubes other than central venous catheters. * Pregnant or lactating women, or subjects who plan to have children within 1 year of treatment; * Subjects with prior CD19 or BCMA-targeted therapy. * Participated in any clinical study within 3 months prior to enrollment. * Subjects with malignant tumour, except for Non-melanoma Skin Cancer with PFS\>5yr; Cervical Cancer in situ; Bladder Cancer; Breast Cancer.