Safety and Efficacy of Etanercept (Recombinant Human Tumor Necrosis Factor Receptor Fusion Protein [TNFR:Fc]) in Children with Juvenile Rheumatoid Arthritis (JRA)

- Diagnosis of JRA by the American College of Rheumatology (ACR) criteria. - Disease course must be polyarticular with disease duration long enough to have been given an adequate trial of non-steroidal anti-inflammatory drugs (NSAIDs) and low-dose methotrexate at a dose of at least 10 mg/m²/week - Continuing active disease, defined as ≥ 5 swollen joints and ≥ 3 joints with limitation of motion accompanied by pain, tenderness or warmth. - Disease refractory to methotrexate or intolerant of methotrexate. - Have not received disease-modifying anti-rheumatic drugs (DMARDs) within 28 days prior to enrollment. - Have not received methotrexate within 14 days prior to dosing of study drug.

- Pregnant or nursing female - Functional class IV by ACR criteria - Unable to meet concomitant medication restrictions - Intraarticular corticosteroid injection within 4 weeks prior to enrollment - Clinically significant deviations from normal, defined as: -- thrombocytopenia; platelet count < 100,000/cmm -- leukopenia; total white cell count < 4000 cells/cmm -- neutropenia; neutrophils < 1000 cells/cmm -- hepatic transaminase levels > two times the upper limit of normal (ULN) -- serum bilirubin > 2 times ULN -- creatinine clearance < 90 mL/min/1.73 m² body surface area (BSA) and/or a glomerular filtration rate (GFR) < 90 mL/min/1.73 m² BSA. -- known human immunodeficiency virus (HIV), hepatitis B surface antigen positivity, or hepatitis C positivity. -- anti-double-stranded deoxyribonucleic acid (dsDNA) antibodies or anti-cardiolipin antibodies present. - Previously received antibody to TNF, antibody to cluster of differentiation (CD)4, or diphtheria interleukin (IL)-2-fusion protein (DAB-IL-2) - Participated in a study of an investigational drug or biologic requiring informed consent within 3 months prior to study entry. - Any concurrent medical condition which would, in the investigator's opinion, compromise the patient's ability to tolerate the study drug or make the patient unable to cooperate with the protocol. - History of or current psychiatric illness that would interfere with ability to comply with protocol requirements or informed consent. - History or drug or alcohol abuse that would interfere with ability to comply with protocol requirements