• Improvement from baseline in clinical signs and symptoms, prevention of structural damage, and prevention of physical disability evaluated at week 54.
  

• Safety assessments throughout the study.
  

This is a randomized, multicenter, double-blind, active-treatment-controlled, three-arm, parallel study of chronic treatment with infliximab. This study will determine whether infliximab, at two different doses (3 mg/kg or 6 mg/kg) in combination with methotrexate (MTX), reduces the signs and symptoms (such as joint pain, swelling and stiffness) of rheumatoid arthritis. The study will also compare their effect on slowing down the joint damage associated with rheumatoid arthritis. Additional information on the safety of infliximab treatment will be obtained. The study will last for about 1 year. Patients will receive methotrexate and total of eight intravenous infusions of the study medication (Infliximab or placebo) spaced out over the first year. After the final infusion of study medication, several follow-up visits are to be made.

Patients will receive methotrexate (start at 7.5mg/wk, increased to 20mg/wk by week8) and intravenous infusions of the study medication (Infliximab 3 or 6mg/kg, or placebo) at week 0, 2, and 6, and every 8 weeks thereafter through week 46.