To examine whether treatment with interleukin (IL)-1-, IL-6-, tumour necrosis factor α (TNFα)-inhibitors or Abatacept is associated with an increased risk of common infections, infections requiring hospitalization (SAE) or opportunistic infections among real-world juvenile idiopathic arthritis (JIA) patients. Furthermore, the influence of other patient-related covariates on the occurrence of infections was investigated. Patients diagnosed with JIA and treated with biologics were selected from the German BIKER registry. Incidence rates (IR) of infections per 100 person years were calculated and compared between the different cohorts. Using multivariate logistic regression, odds ratios with 95% confidence intervals (CI) were determined for the influence of patient-related covariates (age, diagnosis, laboratory data, concomitant medication, JIA activity, comorbidities, and premedication) on the occurrence of infections. 3258 patients entered the analysis. A total of 3654 treatment episodes were distributed among TNFα- (Etanercept, Adalimumab, Golimumab, Infliximab, n = 3044), IL-1- (Anakinra, Canakinumab, n = 105), IL-6- (Tocilizumab, n = 400) and T-cell activation inhibitors (Abatacept, n = 105). 813 (22.2%) patients had at least one infection, 103 (2.8%) patients suffered from an SAE infection. Both common and SAE infections were significantly more frequent in IL-1 (IR 17.3, 95% CI 12.5/24 and IR 4.3, 95% CI 2.3/8.3) and IL-6 cohort (IR 16.7, 95% CI 13.9/20 and IR 2.8, 95% CI 1.8/4.4) compared to TNFα-inhibitor cohort (IR 8.7, 95% CI 8.1/9.4 and IR 1, 95% CI 0.8/1.3). When comparing the influencing factors for various infectious diseases, the use of corticosteroids, younger age, cardiac comorbidities and higher JIA-activity are the most striking risk factors. Relative to TNFα inhibitors and Abatacept, IL-1 and IL-6 inhibitors were associated with an increased risk of common and SAE infections. The influencing covariates identified may be helpful for the choice of a suitable biologic to treat JIA.

Objective. Analysis of etanercept biosimilars in pediatric patients with juvenile idiopathic arthritis (JIA) in comparison with the etanercept originator in terms of efficacy and safety.Methods. Patients diagnosed with JIA who started treatment with either the etanercept originator or a biosimilar after January 1, 2017, were selected from the German BIKER registry (Biologics in Paediatric Rheumatology Registry). Furthermore, patients who started therapy with the originator and switched to a biosimilar during the course of therapy were identified. For both patient groups, disease activity and safety were examined and compared separately.Results. After January 1, 2017, 348 patients started treatment with the etanercept originator (n = 293) or a biosimilar (n = 55). Another 57 patients switched to a biosimilar during the course of therapy. A significant decrease or a stable remission of disease activity was observed in both patient groups. The safety profiles were comparable, and frequencies and types of adverse events (AEs) and serious AEs were similar in patients starting therapy with the originator or a biosimilar. Only injection site reactions occurred slightly more frequently under biosimilar therapy, without having an impact on therapy adherence. In patients who switched therapy, the AE rate per 100 patient-years was comparable before (26.4) and after (32.1) the switch.Conclusion. In patients with JIA who require treatment with etanercept, the originator is still used much more frequently. However, our study highlights the equivalence of etanercept biosimilars for therapy for JIA. Increased use of these biosimilars in pediatric patients can therefore be recommended without hesitation.

Objective To investigate the impact of additionally given methotrexate (MTX) on biologic treatment of polyarticular juvenile idiopathic arthritis (JIA) in terms of effectiveness, safety and drug survival. Methods Patients suffering from polyarticular JIA and treated with either monotherapy with a first biologic or a combination of a biologic and MTX were selected from the BIKER registry. The tumour necrosis factor α-inhibitors (TNFi) adalimumab, etanercept and golimumab and the interleukin-6 inhibitor tocilizumab were considered. Upon a non-randomised study design, we adjusted the different cohorts using propensity score matching to improve comparability. Results A total of 2148 patients entered the analysis, who were either treated by combination (n = 1464) or monotherapy (n = 684). Disease activity declined significantly greater in patients upon combination therapy than upon biologic monotherapy. Comparison of adjusted cohorts revealed that patients who received TNFi gained more benefit from additionally given MTX than patients treated with tocilizumab. Median survival time of therapy with biologics was significantly longer upon combination (3.1 years) than with monotherapy (2.7 years), as demonstrated by a Kaplan-Meier analysis (log rank test: p= 0.002). The safety profile was moderately affected by additional MTX due to increased incidence of gastrointestinal and hepatic adverse events. Serious adverse events occurred at an equal rate of 3.6 events per 100 patient-years in both cohorts. Conclusion Additionally given MTX improves the effectiveness of biologic treatment in polyarticular JIA without seriously compromising treatment safety. Especially TNFi benefit from combination, while no improvement in outcome has been observed by combining tocilizumab with MTX.