Recombinant human anti-CD38 momoclonal antibody(Hangzhou Sumgen)

Primary objective: To evaluate the safety and tolerability of SG301 SC injection after single administration in healthy subjects and multiple administration in subjects with systemic lupus erythematosus (SLE). Secondary objectives: (Part A - healthy subjects) Evaluate the single-dose PK characteristics and immunogenicity characteristics of SG301 SC injection in healthy subjects; Secondary objectives (Part B - SLE subjects) Determine the RP2D of SG301 SC injection in SLE subjects; Evaluate the PK characteristics of single/multiple administrations, immunogenicity of multiple administrations, and CD38 receptor occupancy of multiple administrations of SG301 SC injection in SLE subjects; Preliminary evaluation of changes in biomarkers and changes in disease activity of multiple administrations of SG301 SC injection in SLE subjects; Exploratory objectives (Part B - SLE subjects) Explore the changes in immune cell subsets, immunoglobulins, BILAG-2004 and PGA of SG301 SC injection in SLE subjects.