BCD-055-3 is international multi-center comparative double-blind randomized clinical trial of efficacy and safety of BCD-055 (JSC "BIOCAD", Russia) and Remicade® in combination with methotrexate in patients with active rheumatoid arthritis.

Inclusion Criteria:

• Signed informed consent
• Active rheumatoid arthritis according to criteria of American College of Rheumatologists (2010), that was diagnosed at least 6 months prior to screening.
• Active rheumatoid arthritis at screening despite of therapy with methotrexate for 3 last months.
• Use of methotrexate in stable dose for at least 4 weeks before screening (10-25 mg per week).
• History of ineffective treatment with basic antiinflammatory drugs (including methotrexate).

Exclusion Criteria:

• Previous therapy of rheumatoid arthritis with monoclonal antibodies (including anti-tumor necrosis factor drugs)
• Felty's syndrome
• Functional status - class IV according to ACR classification (1991)
• Low activity of rheumatoid arthritis (DAS28-CRP(4) index less than 3.2)
• Patient needs corticosteroids in a dose more than 10 mg (recalculated to prednisolone) before signing informed consent.
• Patients needs equal of less than 10 mg prednisolone but the dose was not stable for last 4 weeks prior to infliximab treatment
• Prior use of disease-modifying antirheumatic drugs including methotrexate, sulfasalazin, chloroquine or hydroxychloroquine for up to 4 weeks before randomization.
• Prior use of alkylating agents for up to 12 months prior to signing informed consent.
• Intraarticular use of corticosteroids for up to 4 weeks before randomization.
• Prior use of live or attenuated vaccines for up to 8 weeks before signing informed consent.
• Diagnosis of tuberculosis.
• Body mass more than 130 kg.