To determine whether aggressive treatment initiated early in the course of rheumatoid factor (RF)-positive or RF-negative polyarticular juvenile idiopathic arthritis (JIA) can induce clinical inactive disease within 6 months.
Between May 2007 and October 2010, a multicenter, prospective, randomized, double-blind, placebo-controlled trial of 2 aggressive treatments was conducted in 85 children ages 2-16 years with polyarticular JIA of <12 months' duration. Patients received either methotrexate (MTX) 0.5 mg/kg/week (maximum 40 mg) subcutaneously, etanercept 0.8 mg/kg/week (maximum 50 mg), and prednisolone 0.5 mg/kg/day (maximum 60 mg) tapered to 0 by 17 weeks (arm 1), or MTX (same dosage as arm 1), etanercept placebo, and prednisolone placebo (arm 2). The primary outcome measure was clinical inactive disease at 6 months. An exploratory phase determined the rate of clinical remission on medication (6 months of continuous clinical inactive disease) at 12 months.
By 6 months, clinical inactive disease had been achieved in 17 (40%) of 42 patients in arm 1 and 10 (23%) of 43 patients in arm 2 (χ(2)  = 2.91, P = 0.088). After 12 months, clinical remission on medication was achieved in 9 patients in arm 1 and 3 patients in arm 2 (P = 0.053). There were no significant interarm differences in adverse events.
Although this study did not meet its primary end point, early aggressive therapy in this cohort of children with recent-onset polyarticular JIA resulted in clinical inactive disease by 6 months and clinical remission on medication within 12 months of treatment in substantial proportions of patients in both arms.