Background: Treatment of systemic onset juvenile idiopathic arthritis JIA (sJIA), although dramatically improved, remains a challenge. Experience from clinical practice will be presented using data from the German Biologics register (BiKeR) for evaluation of efficacy and safety of treatment with etanercept (ETA), tocilizumab (TOC) and the interleukin-1 inhibitors anakinra and canakinumab (IL-1i) in sJIA.
Methods: Patients with sJIA documented in the BIKeR register, who were exposed to ETA, TOC or IL-1i were identified. Baseline demographics, clinical characteristics and disease activity parameters have been documented. Efficacy was determined using the JIA-American College of Rheumatology (ACR) response criteria and the Juvenile Disease Activity Score 10 (JADAS10). An intention-to-treat analysis was performed and patients who discontinued due to inefficacy or intolerance were analysed as non-responders. Safety assessments were based on adverse events (AEs) reports.
Results: Since 2000, 245 sJIA patients (50.3% male) exposed to biologic agents have been identified: 143 patients treated with ETA, 71 with TOC and 60 with IL-1i (anakinra 38, canakinumab 22). All patients received systemic steroids for pre-treatment but less frequently with TOC and IL-1i than with ETA for concomitant treatment. At baseline, the ETA cohort had fewer systemic disease manifestations but more active joints. The JIA-ACR 30/50/70/90 response over a period of 24 months was reached more often in the IL-1i and TOC cohort than with ETA. ETA/TOC/IL1i JADAS-remission (JADAS ≤1) was reached in 20%/37%/52%, minimal disease activity (JADAS ≤3.8 in 35%/61%/68% and ACR inactive disease in 24%/33%/56%). As compared to ETA, rates of AEs were significantly higher in the TOC cohort (risk ratio (RR) 5.3/patient-year; p < 0.0001) and serious AE were observed more frequently with TOC (RR 2.5; p < 0.5) and IL1i (2.9; p < 0.01).
Conclusions: A large proportion of patients gained significant response to treatment especially with TOC or IL-1is. After 6 months on treatment, JADAS remission was reached by up to half of patients while up to two thirds reached JADAS minimal disease activity. ETA has been used in the past but it is clearly less effective and its use in systemic JIA has markedly decreased in Germany.
Keywords: Anakinra; Canakinumab; Etanercept; Still’s disease; Systemic onset juvenile idiopathic arthritis; Tocilizumab.