An Efficacy and Safety Study of Infliximab in Participants With Rheumatoid Arthritis

The purpose of this study is to compare the effectiveness of iInfliximab plus methotrexate (MTX) in treatment of Rheumatoid rheumatoid Arthritis arthritis (RA) (it is an autoimmune disease that causes pain, swelling, stiffness and loss of function in joints) in participants with moderate disease versus participants with severe disease and to compare the efficacy and safety of the MTX subgroups.

This is an open-label (all people know the identity of the intervention), multi-center (study conducted in more than 1 center), prospective (study following participants forward in time) study comparing the American College of Rheumatology (ACR) scores of participants with moderate RA (defined as having a score greater than 3.2, but less than 5.1 on the Disease Activity Score 28 \[DAS 28\]) to those participants with severe RA (defined as having a score greater than 5.1 on the DAS 28 score) disease while being treated with infliximab and MTX. DAS evaluates RA activity by several parameters including the number of swollen and tender joints and the participant's own assessment of their pain. Participants will receive infliximab 3 milligram (mg) per kilogram (kg) intravenous infusion (drug given into a vein) (over no less than 2 hours) at Weeks 0, 2, 6, 14 and 22 along oral MTX in a stable dose of 7.5 to 20 mg per week (equal to the dose used before participation in the study) for 22 Weeks. Participants will have a follow-up visit on Week 26. Efficacy will primarily be assessed by the percentage of participants obtaining ACR20, ACR50 and ACR70 response at Week 26. Participants' safety will be assessed throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants who have a definitive diagnosis of rheumatoid arthritis (RA) based on the American College of Rheumatology Criteria 1987
* Participants must have been on Methotrexate (MTX) for 12 weeks at the stable dose for at least 4 weeks
* Participants using oral corticosteroids, must have been on a stable dose of prednisone less than 10 milligram per day (mg/day) or its equivalent for at least 4 weeks before screening or if currently not using corticosteroids, the participant must not have received corticosteroids for at least 4 weeks before screening
* Participants with moderate to severe RA (Disease Activity Score \[DAS28\] greater than 3.2)
* Male participants shall adopt contraceptive measures during the trial and within 6 months after the completion of trial (such as spermicidal barrier), or their female sexual partners shall agree to adopt effective contraceptive measures during the trial or within 6 months after the completion of trial (such as oral contraceptives, contraceptives for injection, intrauterine device \[IUD\], or sterilization by surgery); female participants of childbearing potential with negative urine pregnancy test upon enrollment in addition to adopting the said contraceptive measures

Exclusion Criteria:

* Participant who has a known allergy to human immunoglobulin proteins or other components of infliximab
* Participant who has a history of receiving infliximab or any other biological preparations
* Participant who is in stage IV RA evaluated by X-ray
* Participants suffering from tuberculosis
* Female participant or male participant's wife who plans to become pregnant during this study and within 6 months after completion of this study