Tocilizumab biosimilar (Taizhou Mabtech)

1. Compare the similarity of the efficacy of CMAB806 and Acteluo® in combination with methotrexate in the treatment of moderately and severely active rheumatoid arthritis in adults; 2. Compare the safety of CMAB806 and Acteluo® in combination with methotrexate in the treatment of moderately and severely active rheumatoid arthritis in adults; 3. Compare the immunogenicity of CMAB806 and Acteluo® in adults with moderately and severely active rheumatoid arthritis;