• The proportion of patients with improvements in the Juvenile Rheumatoid Arthritis core set criteria at Week 14 in the placebo group with that in the 3 mg/kg infliximab plus concomitant methotrexate therapy group.
  

• To evaluate pharmacokinetics (rate of movement in the body and then the clearance)of infliximab over a maximum time period of 52 wks; to evaluate the safety profile of infliximab in patients with JRA
  

The purpose of this study is to determine if infliximab in combination with methotrexate is safe and effective in the treatment of patients with juvenile rheumatoid arthritis. The second purpose of this study is to see how children's bodies react to the combination of study drug and methotrexate. Patients will receive either infliximab at 3 mg/kg for 44 weeks or, placebo for 14 weeks followed by infliximab at 6 mg/kg for 30 weeks. Patients who complete the original study are eligible for additional treatment with 3 to 6 mg/kg of infliximab every 8 weeks for up to three years. Safety evaluations will be performed at specified intervals throughout the study and will consist of laboratory tests, vital signs (such as blood pressure), physical examinations and the occurrence and severity of adverse events as well as other study specific procedures.

Patients will receive either infliximab at 3 mg/kg for 44 weeks or, placebo for 14 weeks followed by infliximab at 6 mg/kg for 30 weeks. Patients who complete the original study are eligible for additional treatment with 3 to 6 mg/kg of infliximab every 8 weeks for up to three years