∙ Part A (healthy volunteers)

• Male healthy adults aged 18-50 years (inclusive);

• Male participants weighed 50-100 kg (inclusive) with the body mass index of 19.0-27.0 kg/m2 (inclusive);

• Participants whose partners are of childbearing potential must agree to use effective contraceptive methods throughout the study period and for 6 months following the last dose.

∙ Part B (SLE participants)

• Males or females aged 18-65 years (inclusive);

• BMI 18.5-30.0 kg/m2 (inclusive);

• Have diagnosed as SLE based on the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) SLE classification criteria, with inadequate response or intolerance to or having relapsed despite the standard treatment;

• SELENA-SLEDAI score \>4 and ≤12;

• Serologically ANA and/or anti-ds-DNA antibody tested positive;

• Having received a standard treatment for at least 12 weeks prior to the first dose that has remained at a stable dose for at least 4 weeks prior to the first dose;

• Laboratory values at screening meets the following criteria:

‣ Liver function: aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2ULN, total bilirubin \<1.5×ULN;

⁃ Renal function: creatinine (Cr) and urea ≤1.5×ULN; eGFR \>60 ml/min (calculated by the MDRD formula); urine total protein-creatinine ratio ≤3.0 g/g or 24h urine protein ≤3.5 g;

⁃ Bone marrow function: Hb≥100g/L, WBC≥3.0×109/L, PLT≥75×109/L;

⁃ Participants who are of childbearing potential or whose partners are of childbearing potential must agree to use effective contraceptive methods throughout the study period and for 6 months following the last dose.