This is a study to compare the efficacy, safety and immunogenicity of AVT05 versus EU-Simponi® in combination with methotrexate (MTX) in subjects with moderate to severe rheumatoid arthritis (RA).

The study will consist of up to 4-week Screening Period, a 48-week Treatment Period, and a 4-week Safety Follow-up Period.

Inclusion Criteria:

• Subjects diagnosed with active RA according to ACR/EULAR 2010 classification criteria
• Subjects diagnosed with moderately to severe active RA as defined by ≥ 6 swollen (out of 66) and ≥6 tender (out of 68) joint counts, CRP >1mg/l and with at least one of positive rheumatoid factor, positive anti-citrullinated peptide antibodies and/or evidence of 1 joint erosion of hands, wrist of dominant hand or feet at screening
• Subjects must have taken methotrexate for ≥12 weeks

Exclusion Criteria:

• Prior treatment with biologics or Janus kinase inhibitors that may be used as disease-modifying anti-rheumatic drugs
• Any past or concurrent medical conditions that could potentially increase the subject's risks or that would interfere with the study evaluation, procedures or study completion
• Major chronic inflammatory disease or connective tissue disease other than RA or any active autoimmune disease
• Presence of chronic obstructive pulmonary disease
• Presence of chronic heart failure NYHA class III or IV