A Phase Ib Study of QLS4131 in Subjects With Systemic Lupus Erythematosus

Inclusion Criteria: * Aged 18 to 70 (inclusive); * Diagnosis of SLE according to the 2019 European League Against Rheumatism/American College of Rheumatology (ACR) Classification Criteria at least 12 weeks or more prior to screening; * Participants with positive antinuclear antibody (ANA) (≥ 1:80), or positive anti-dsDNA antibody and/or positive anti-Sm antibody at screening; * Active SLE disease at screening, as demonstrated by a SLEDAI-2K \>= 8 at screening, or SLEDAI-2K \>= 6 at the presence of low complement and/or positive anti-dsDNA antibodies; * Current receipt of one or more of the following classes of standard therapies for the treatment of SLE at stable doses: oral corticosteroids, antimalarial agents, and conventional immunosuppressants: 1. For participants receiving an oral corticosteroid, treatment with ≤40 mg/day prednisone or equivalent, at a dose that has been stable for at least 4 weeks prior to first dose; 2. For participants receiving an antimalarial, the medication(s) must have been at a stable dose ≥ 4 weeks prior to the first dose; 3. For participants receiving immunosuppressants, treatment with a single immunosuppressant at a stable dose for ≥ 4 weeks prior to the first dose: conventional immunosuppressants include azathioprine, mycophenolate mofetil, mycophenolic acid, and methotrexate (oral, subcutaneous or intravenous routes). * Participants who understand and abide by the study procedures, voluntarily participate in this study, and sign the Informed Consent Form in person. Exclusion Criteria: * Participants with known intolerance or allergy to the investigational product or drugs that may be used in the study (e.g., Tocilizumab) and any components; * Participants with active severe active or unstable lupus-associated neuropsychiatric disease; * Participants with other autoimmune diseases that may affect the efficacy evaluation; * Participants with poorly controlled hypertension and diabetes; * Participants with severe lupus nephritis; * Participants with a history of malignancy within 5 years prior to screening; * Participants with a previous history of vital organ transplantation; * Participants who have had opportunistic infections within 12 weeks prior to the first dose; * Receipt of any CAR-T, CAR-NK or other gene therapy; * Pregnant or lactating women.