Anti CD19/BCMA CAR Gene Therapy for Relapsed/Refractory Immune Thrombocytopenia

Inclusion Criteria:

1. Age≥ 18 years old, regardless of gender. 2. Clinical diagnosis of primaryimmune thrombocytopenia for at least 6 months, platelet count < 30×10^9/Lwithin 48 hours before participating in the study.

2. Positive anti-platelet glycoprotein autoantibodies (such as GPIIb/IIIa). 4.Prior second-line ITP therapy (first-line treatment includes: corticosteroidsor immunoglobulins; Second-line therapies include thrombopoietin receptoragonists (eg, eltrombopag, romiplostim) and/or rituximab, but are ineffective (platelet count < 30×10^9/L after treatment, or platelet count does notincrease twice as much as baseline, or there is bleeding), or relapse aftereffective treatment (platelet count falls below 30×109/L after effectivetreatment, or falls below baseline, or bleeding symptoms) or is difficult tomaintain after discontinuation of TPO agonists.

3. Bone marrow examination shows megakaryocytosis or normal. 6. Basic normalfunctions of important organs:Echocardiography shows an ejection fraction of ≥50% and no significant abnormalities on ECG.Creatinine clearance (CrCl) (Cockcroft-Gault formula) ≥ 30 mL/min.Alanine aminotransferase (ALT) andaspartate aminotransferase (AST) ≤ 3.0 × upper limit of normal (ULN).Totalbilirubin (TBIL) and alkaline phosphatase (AKP or ALP) ≤ 2.0× ULN (Gilbert'ssyndrome ≤3.0×ULN).Absolute lymphocyte count (ALC) ≥ 0.5×10^9/L; Absoluteneutrophil count (ANC) ≥1×10^9/L; Hemoglobin (Hb) ≥ 60 g/L; Platelet count ≥ 10×10^9/L.Oxygen saturation > 92%.ECOG performance status ≤2 7. Males and womenof childbearing potential must agree to use effective contraception from thetime of signing the informed consent form until 1 year after the use of thestudy drug. Women of childbearing potential must have a negative bloodpregnancy test at screening and prior to drug infusion and must not bebreastfeeding.

Exclusion Criteria:

1. Thrombocytopenia caused by myelodysplastic syndrome, early aplastic anemia,atypical aplastic anemia, thrombotic thrombocytopenic purpura, etc.

2. During the screening period, bone marrow examination showed myelofibrosis MF≥2 (European consensus scoring standard Thieleja 2005) or bone marrow examinationshowed the presence of a primary disease other than ITP that can lead tothrombocytopenia.

3. History of hypersensitivity to any component of the therapeutic medication. 4.Major organs: NYHA class III to IV congestive heart failure. Myocardialinfarction or coronary artery bypass grafting (CABG) or coronary artery stentimplantation within 6 months. Ventricular arrhythmias, or history ofunexplained syncope (excluding vasovagal syncope or dehydration). History ofsevere non-ischemic cardiomyopathy.

4. Malignant disease within 3 years prior to screening, except for the following:malignant disease that has been curatively treated before enrollment and has noknown active disease for 3 years ≥; or well-treated non-melanoma skin cancerwith no evidence of disease.

5. Symptomatic deep vein thrombosis or pulmonary embolism within the past 6 monthsor currently requiring anticoagulation.

6. Participated in other interventional clinical studies within 1 month prior toscreening.

7. Vaccination of live attenuated vaccine within 4 weeks prior to screening. 9.Stroke or seizure within 6 months prior to signing the ICF (excluding oldlacunar cerebral infarction).

8. Positive for hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) and peripheral blood hepatitis B virus (HBV) DNA titer test exceeds thenormal range; Hepatitis C virus (HCV) antibody is positive and the hepatitis Cvirus (HCV) RNA titer in peripheral blood exceeds the normal range; positivefor human immunodeficiency virus (HIV) antibodies; Positive syphilis test.

9. Known history of bone marrow stem cell disease 12. Other conditions that theinvestigators consider unsuitable to participate in the study.