Effectiveness and Safety of High-Dose Biologics in Juvenile Idiopathic Arthritis in the Childhood Arthritis and Rheumatology Research Alliance.

OBJECTIVE To describe high-dose biologic use when treating juvenile idiopathic arthritis (JIA). METHODS Patients with JIA enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry and treated with a biologic after enrollment were eligible. We described frequency of high-dose biologic use and characteristics of patients on high-dose biologics. We utilized regression modeling to compare 6-month outcomes (using disease activity measures) between those who increased their biologic from standard to high dose (high dose) to those who initiated and remained on standard dosing (no change), and to those who switched biologic agents (biologic switch). We also compared serious adverse events (SAEs) between groups. RESULTS 5,352 patients with JIA were treated with biologics following enrollment; 1,080 (20%) had ever received a high-dose biologic. There were no significant differences in outcomes between the high dose group and the biologic switch group; both improved disease activity measures including clinical juvenile arthritis disease activity score-10 (-3.53 and -3.95, respectively; p=0.68). Although the SAE rates in the high-dose group and the biologic switch group were numerically higher than the no change group, the event rates were similar and neither rate was significantly higher than the no change group (unadjusted incident rate ratio 2.5 [0.7-8.5] and 1.8 [0.7-4.6], respectively). CONCLUSION Dosing escalation appears to be a reasonable choice to improve disease control, however, large, prospective, randomized studies evaluating specific biologic agents are needed.