Exploratory Clinical Study on the Safety of STR-P004

Inclusion Criteria:

1. Fully understand the purpose, nature, method of the trial and possible adversereactions, voluntarily participate as a subject, and sign the informed consent form.

2. Aged ≥18 years (including the boundary value, based on the time of signing theinformed consent form), male or female;

3. Applicable to Systemic Lupus Erythematosus (SLE):

4. Diagnosed with Systemic Lupus Erythematosus (SLE) according to the 2019European League Against Rheumatism (EULAR)/1997 American College ofRheumatology (ACR) classification criteria for diagnosis.

5. SLE-ITP: platelet count < 50×10^9/L in at least 2 consecutive blood routinetests; no obvious abnormalities in blood cell morphology by peripheral bloodsmear microscopy; bone marrow cell morphology consistent with immunethrombocytopenia; excluding thrombocytopenia caused by other non-SLE reasons,such as infection, bone marrow suppression, splenomegaly, hypersplenism, etc.;failed to achieve at least partial response after receiving at least 1 courseof MP pulse therapy (1g×3 days) or high-dose hormone (1mg/kg/d equivalentglucocorticoid) combined with 1 or more immunosuppressants. Note: CompleteResponse (CR): platelet count ≥100×10^9/L; Partial Response (PR): plateletcount 30-100×10^9/L, at least twice the pre-treatment level, and no bleeding.

6. Other SLE: despite standard treatment, SLEDAI-2000 score ≥8 points and at least oneBILAG Grade A or two BILAG Grade B; meeting one of the following conditions:positive antinuclear antibody (ANA) confirmed during screening, or anti-dsDNAantibody higher than normal level at screening, or anti-Sm antibody higher thannormal level at screening; before the first administration of the trial drug, thesubject has received at least one of the following standard treatments for 12 weeks,and the dose must be stable (dose reduction is allowed, dose increase is notallowed) for at least 30 days. Standard treatment regimens refer to stable use ofany of the following: a. Antimalarial drugs combined with oral glucocorticoids (OCS,such as prednisone or equivalent dose of other hormones) and/or immunosuppressants (including mycophenolate mofetil, cyclophosphamide, leflunomide, methotrexate,tacrolimus, cyclosporine, azathioprine, tripterygium wilfordii); b. OCS and/orimmunosuppressant combination therapy. If the subject is receiving OCS (such asprednisone or equivalent dose of other hormones), the following conditions must bemet: the maximum dose of OCS at screening and during screening is 30 mg/dayprednisone (or equivalent dose of other hormones); other drugs and traditionalChinese medicines that affect immunity can be continued at the discretion of theinvestigator; Applicable to Idiopathic Inflammatory Myopathies (IIM):

7. Diagnosed with possible or definite Idiopathic Inflammatory Myopathies (IIM)according to the 2017 European League Against Rheumatism (EULAR)/AmericanCollege of Rheumatology (ACR) classification criteria for diagnosis -- possibleIIM: score of 5.5 points without biopsy; definite IIM: score of 6.7 points withbiopsy; meeting the definition of refractory or relapsed IIM;

8. Definition of refractory IIM: receiving at least one immunosuppressant (such asazathioprine, methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus,cyclophosphamide, leflunomide, etc.) at a stable dose for more than 2 months,and when glucocorticoids are reduced to 10mg prednisone per day or equivalentdose or higher, at least one of the following deteriorations occurs: (i)progression of ILD, worsening of exertional dyspnea, or increase in ILD scoreon lung HRCT, or decrease in FVC% predicted value of pulmonary function by morethan 5%, or decrease in DLco% by >10%; (ii) worsening of myositis, decrease inMMT-8 by >5 points/150 points, or increase in creatine kinase by >100U/Lcompared with previous levels;

9. Definition of relapsed IIM: recurrence of active IIM causing new organinvolvement or aggravation of originally involved organs after 6 months ofcontinuous remission, or requiring an increase in glucocorticoids andimmunosuppressants.

Exclusion Criteria:

1. Severe lupus nephritis within 8 weeks before screening (defined as urinary protein >6 g/24 hours or serum creatinine >2.5 mg/dL or 221 μmol/L), or need to useprotocol-prohibited drugs to treat active nephritis, or need hemodialysis or receiveprednisone ≥100 mg/d or equivalent glucocorticoid treatment for ≥14 days;

2. Central nervous system diseases caused by SLE or non-SLE within 8 weeks beforescreening (including but not limited to epilepsy, psychosis, interstitialencephalopathy syndrome, cerebrovascular accident, encephalitis, central nervoussystem vasculitis, etc.);

3. Other types of idiopathic inflammatory myopathies: inclusion body myositis, atrophicdiabetes, juvenile myositis; patients with severe muscle damage or myositis withpermanent weakness or cardiac involvement caused by non-IIM reasons (such asstroke);

4. SSc-related pulmonary hypertension requiring treatment; or rapidly progressiveSSc-related lower gastrointestinal tract (small and large intestine) involvement (requiring parenteral nutrition), active gastric antral vascular ectasia; previousrenal crisis caused by SSc;

5. History of important organ transplantation (such as heart, lung, kidney, liver) orhematopoietic stem cell/bone marrow transplantation;

6. Concurrent with two or more immune diseases requiring systemic treatment, which theinvestigator deems unsuitable for enrollment;

7. Suffering from IgA deficiency (serum IgA level <10 mg/dL);

8. Participation in any other clinical trial within 4 weeks before screening or within 5 half-lives of the trial drug (whichever is longer);

9. Previous receipt of CAR-T therapy or other cell or gene therapy;

10. Receipt of belimumab within 2 weeks before screening; receipt of B cell-depletingdrugs such as rituximab or equivalent therapy (targeting CD19, CD20, BAFF, etc.)within 1 month before screening, unless it can be proven that B cells have recoveredto pre-treatment levels or within the normal range;

11. Receipt of anti-SLE treatment other than standard treatment (such as Saphnelo)within 3 months before screening or within 5 half-lives of the drug (whichever islonger);

12. Receipt of live/attenuated vaccine within 4 weeks before screening or planned toreceive live/attenuated vaccine during the trial;

13. Uncontrolled active infection;

14. Admission or evidence of use of illicit drugs, drug abuse, or alcoholism;

15. Receipt of major surgery within 4 weeks before screening or minor surgery within 2weeks before screening; wounds must be completely healed (surgical procedures suchas catheter placement are not exclusion criteria);

16. History of any of the following cardiovascular diseases within 6 months beforescreening: New York Heart Association (NYHA) class III or IV heart failure,myocardial infarction, unstable angina pectoris, uncontrolled or symptomatic atrialarrhythmia, any ventricular arrhythmia, or other heart diseases with significantclinical significance;

17. Any other severe underlying diseases (such as active gastric ulcer, uncontrolledepileptic seizures, cerebrovascular events, gastrointestinal bleeding, severe signsand symptoms of coagulation and coagulation dysfunction, heart disease), mentaldiseases, psychological, familial, or regional diseases that the investigatordetermines may interfere with planned staging, treatment, and follow-up, affectpatient compliance, or put the patient at high risk of complications;

18. Evidence of concurrent malignant tumors within <5 years before screening, except forfully treated cervical carcinoma in situ, localized cutaneous squamous cellcarcinoma, basal cell carcinoma, localized prostate cancer, breast ductal carcinomain situ, or ≤T1 urothelial carcinoma. Patients with prostate cancer under activesurveillance are eligible to participate in this study;

19. Pregnant or lactating women;

20. Viral serological test during screening: positive for human immunodeficiency virusantibody (HIV-Ab); positive for hepatitis B surface antigen (HBsAg) and/or hepatitisB core antibody (HBc-Ab), and HBV-DNA copy number greater than the measurable lowerlimit; positive for hepatitis C antibody (HCV-Ab) and HCV-RNA copy number greaterthan the measurable lower limit; or subjects with positive treponema pallidumantibody (TP-Ab);

21. Subjects with active or latent tuberculosis (positive T-SPOT) detected duringscreening;

22. Receipt of splenectomy for treatment within 6 months before screening;

23. Other subjects deemed unsuitable for participation in this trial by theinvestigator.