Clinical Research Directory

Inclusion Criteria: 1. Male or female participants aged 18 to 70 years (inclusive) at the time of ICF signing. 2. Able to understand and voluntarily sign the written informed consent form (ICF). 3. For SLE: Diagnosed with SLE per 2019 EULAR/ACR classification criteria; disease duration ≥ 24 weeks; SLEDAI-2K ≥ 4; inadequate response or intolerance to glucocorticoids combined with at least one immunosuppressant or biologic agent. 4. For RA: Diagnosed with RA per 2010 ACR/EULAR classification criteria; disease duration ≥ 12 weeks; DAS28-CRP ≥ 3.2; TJC28 ≥ 4 and SJC28 ≥ 4; inadequate response to at least one csDMARD combined with at least one bDMARD/tsDMARD. 5. For pSS: Diagnosed with pSS per 2016 ACR/EULAR classification criteria; disease duration ≥ 12 weeks and ≤ 10 years; clinESSDAI ≥ 5; positive ANA, anti-SSA/Ro, anti-SSB/La, or RF. 6. For SSc: Diagnosed with diffuse cutaneous SSc per 2013 ACR/EULAR classification criteria; disease duration ≤ 7 years; mRSS \> 10; PhGA ≥ 3.0. 7. Women of childbearing potential must agree to use highly effective contraception throughout the study period and for 3 months after the last dose. Exclusion Criteria: 1. History of catastrophic antiphospholipid syndrome or saddle pulmonary embolism; new thromboembolic events within 1 year prior to screening; currently on anticoagulation therapy. 2. Clinically significant cardiovascular or cerebrovascular disease, including decompensated heart failure (NYHA III/IV), uncontrolled severe hypertension, or severe arrhythmia. 3. Severe respiratory disease, including severe pulmonary arterial hypertension, FVC% \< 60%, or DLCOc% \< 40%. 4. History of malignancy within 5 years prior to screening (except adequately treated basal cell carcinoma, squamous cell carcinoma of skin, cervical carcinoma in situ, or papillary thyroid carcinoma). 5. Active or chronic infections, including HIV infection, chronic HBV/HCV infection, latent or active tuberculosis (as applicable to study part). 6. Known hypersensitivity to QLS2416 or any of its excipients; history of severe atopic disease or anaphylaxis. 7. Prior bone marrow transplantation; prior CAR-T, CAR-NK, or T-cell engager therapy. 8. Laboratory abnormalities: hemoglobin \< 80 g/L, WBC \< 2.5×10\^9/L, ANC \< 1.0×10\^9/L, platelets \< 50×10\^9/L, ALT/AST \> 2×ULN, eGFR \< 45 mL/min/1.73m², or IgG \< 6 g/L. 9. Pregnant or breastfeeding women. 10. Major surgery within 2 months prior to screening; live vaccine within 4 weeks prior to screening.