Clinical Study of AFN50 Injection in the Autoimmune Diseases

Inclusion Criteria:

1. Be able to understand and voluntarily sign the written informed consent form;

2. Patients aged between 18 and 69 (inclusive), of any gender, diagnosed with SLEaccording to the 2019 EULAR/ACR SLE diagnostic criteria;

3. A history of SLE for at least 6 months, having used a stable standard treatmentregimen for at least 8 weeks, with the dosage stable for 2 weeks, yet the diseaseremains active or has relapsed; Standard treatment refers to the stable use of thefollowing drugs alone or in combination: non-steroidal anti-inflammatory drugs (NSAIDs), antimalarials, corticosteroids; immunosuppressants (including but notlimited to cyclophosphamide, methotrexate, azathioprine, mycophenolate mofetil,leflunomide, tacrolimus, cyclosporine); targeted drugs (including but not limited tobelimumab, telitacicept, eculizumab, rituximab);

4. Oral corticosteroids are prednisone (or equivalent drug) ≥7.5mg/day and ≤30mg/day.If used in combination with immunosuppressants, there is no minimum daily doserequirement;

5. Standardized treatment failure with hydroxychloroquine or at least twoimmunosuppressants;

6. Screening period tests meet: positive blood antinuclear antibody (ANA), and/orpositive anti-double-stranded DNA (anti-dsDNA) antibodies, and/or hypocomplementemia (low C3 and/or C4);

7. Screening period SLEDAI-2K score ≥6 points. If scoring includes low complementand/or anti-ds-DNA antibodies, the score for SLEDAI-2K clinical symptoms (excludinglow complement and/or anti-ds-DNA antibodies) should be ≥4 points;

8. Appropriate bone marrow, coagulation, cardiopulmonary, liver, and kidney functions. Bone marrow function: Absolute Neutrophil Count (ANC) ≥1.5×10⁹/L (no granulocytecolony-stimulating factor (G-CSF) administered within 7 days prior to screening; a 14-day interval required for long-acting G-CSF); Hemoglobin (Hb) ≥80 g/L (no redblood cell transfusion within 14 days prior to screening; recombinant humanerythropoietin is permitted. For patients meeting the Hb ≥80 g/L inclusioncriterion, red blood cell transfusion is allowed during treatment to maintainhemoglobin level at ≥80 g/L); Platelet Count (PLT) ≥50×10⁹/L, Absolute LymphocyteCount (ALC) ≥0.8×10⁹/L. Coagulation function: International Normalized Ratio (INR) or Activated PartialThromboplastin Time (APTT) ≤1.5 times the upper limit of normal (ULN). Cardiac function: Left Ventricular Ejection Fraction (LVEF) ≥40% as measured byechocardiography (ECHO). Pulmonary function: Dyspnea of ≤CTCAE Grade 1; pulse oxygen saturation (SpO2) >92%under room air. Hepatic function: Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) ≤2.5×ULN; total bilirubin ≤1.5×ULN. Renal function: Creatinine clearance rate (calculated by the Cockcroft-Gaultformula) ≥50 mL/min, without the need for fluid support;

9. Baseline oxygen saturation >92% without oxygen supplementation;

10. Non-pregnant/non-lactating participants. Women of childbearing potential must have anegative serum or urine pregnancy test result (women who have undergone surgicalsterilization or postmenopausal women for at least 2 years are not considered womenof childbearing potential) and be willing to adopt contraceptive measures within 12months after drug infusion.

Exclusion Criteria:

1. Individuals with positive Hepatitis B surface antigen (HBsAg) and/or Hepatitis Bcore antibody (HBcAb), and Hepatitis B virus (HBV) DNA positivity or titers abovethe detection threshold; those with positive Hepatitis C virus (HCV) antibodies andHCV RNA positivity or titers above the detection threshold; individuals with HumanImmunodeficiency Virus (HIV) antibodies positivity, CMV DNA positivity or above thedetection limit; those with positive syphilis antigen or antibodies;

2. Presence of other uncontrolled active infections;

3. History of major organ transplantation (such as heart, lung, liver, kidney) or bonemarrow/hematopoietic stem cell transplantation;

4. Receiving any mRNA-LNP product or other LNP medications within the past two years,and with a history of allergy to LNP and its components;

5. History of live vaccine administration within the last 30 days;

6. History of any of the following cardiovascular diseases within the last 6 monthsbefore screening: Class III or IV heart failure defined by the New York HeartAssociation (NYHA), myocardial infarction, unstable angina, uncontrolled orsymptomatic atrial arrhythmias, any ventricular arrhythmias, or other clinicallysignificant cardiac diseases;

7. Pregnant or breastfeeding women;

8. Individuals with asthma, severe allergies;

9. In the investigator's judgment, the participate is unlikely to complete allprotocol-required study visits or procedures, including follow-up visits oradherence to the study participation requirements.

10. Other conditions deemed inappropriate for participation in this clinical study bythe investigator.