Clinically inactive disease in a cohort of children with new-onset polyarticular juvenile idiopathic arthritis treated with early aggressive therapy: time to achievement, total duration, and predictors.

Objective: To determine the elapsed time while receiving aggressive therapy to the first observation of clinically inactive disease (CID), total duration of CID and potential predictors of this response in a cohort of children with recent onset of polyarticular juvenile idiopathic arthritis (poly-JIA).

Methods: Eighty-five children were randomized blindly to methotrexate (MTX), etanercept, and rapidly tapered prednisolone (MEP) or MTX monotherapy and assessed for CID over 1 year of treatment. Patients who failed to achieve intermediary endpoints were switched to open-label MEP treatment.

Results: Fifty-eight (68.2%) of the 85 patients achieved CID at 1 or more visits including 18 who received blinded MEP, 11 while receiving MTX monotherapy, and 29 while receiving open-label MEP. Patients starting on MEP achieved CID earlier and had more study days in CID compared to those starting MTX, but the differences were not significantly different. Patients given MEP (more aggressive therapy) earlier in the disease course were statistically more likely to have a higher proportion of followup visits in CID than those with longer disease course at baseline. Those who achieved American College of Rheumatology Pediatric 70 response at 4 months had a significantly greater proportion of followup visits in CID, compared to those who failed to achieve this improvement (p < 0.0001). Of the 32 patients who met criteria for CID and then lost CID status, only 3 fulfilled the definition of disease flare.

Conclusion: Shorter disease duration prior to treatment, a robust response at 4 months, and more aggressive therapy result in a higher likelihood and longer duration of CID in patients with poly-JIA. The original trial from which data for this analysis were obtained is registered on www.clinicaltrials.gov NCT 00443430.