Objective: To evaluate the efficacy and safety of adalimumab in patients with juvenile idiopathic arthritis (JIA).

Methods: Baseline demographic and clinical characteristics and disease activity parameters were prospectively documented in the German Biologics JIA Registry. Efficacy was determined using the American College of Rheumatology (ACR) Pediatric (Pedi) response criteria and the Juvenile Arthritis Disease Activity Score based on a 10-joint count (JADAS-10). Safety assessments were based on adverse event reports from the responsible physician.

Results: Two hundred eighty-nine patients with a total of 1,046 visits were identified (435.7 patient-years). A high proportion of patients demonstrated a significant response to treatment, with a marked decrease in the JADAS-10 score in both the biologics-naive group (which consisted of patients who had not received therapy with a biologic agent prior to initiation of adalimumab) and the biologic-switcher group (which consisted of patients who had been treated with a different biologic agent prior to initiation of adalimumab). The median JADAS-10 score at treatment start was significantly higher in the biologics-naive group than in the biologic-switcher group (12.9 versus 8.5; P = 0.00044), although the score in the biologics-naive group was lower over the course of adalimumab treatment. ACR Pedi 30, 50, 70, and 90 scores were achieved in 63.4%, 61.0%, 48.8%, and 34.2% of biologics-naive patients, respectively, at 6 months of treatment, while ACR Pedi 30, 50, 70, and 90 scores were achieved in 47.6%, 38.1%, 21.9%, and 15.2% of biologic-switcher patients, respectively. Forty-eight patients experienced 222 adverse events (50.9 per 100 patient-years). Eleven were reported as serious (2.5 per 100 patient-years). No malignancies were observed during adalimumab exposure. There were 16 uveitis flares in 11 patients. Treatment was discontinued in 58 patients for the following reasons: inefficacy 11.1%, adverse events 5.2%, remission 4.5%, patient request 11.8%, and other reasons 7.9%.

Conclusion: Adalimumab appears to be highly effective in children and adolescents with JIA who have been previously treated with biologic agents and in children and adolescents who switched biologic agents. The treatment is safe and its efficacy is similar to that of other biologic agents used to treat JIA. Few patients discontinued therapy due to intolerance or inefficacy.