Efficacy and safety of tocilizumab in a real-life observational cohort of patients with polyarticular juvenile idiopathic arthritis.

Objectives: To evaluate the patterns of usage, efficacy and safety of tocilizumab in polyarticular JIA.

Methods: An observational study of 56 consecutive polyarticular JIA patients was conducted using patient charts and electronic JIA databases. Efficacy was assessed by tocilizumab survival, rates of low disease activity (LDA) and of inactive disease by 10-joint Juvenile Arthritis Disease Activity Score (JADAS-10), and of clinically inactive disease according to Wallace's preliminary criteria. Efficacy and rate of adverse events (AEs) were evaluated during a 24-month period after tocilizumab commencement.

Results: Tocilizumab was started on average as third-line biological agent (median, range first- to fourth-line) at a median disease duration of 5.2 years (interquartile range 3.0-7.7). Survival rates were 82% at 12 months and 64% at 24 months. The reasons for discontinuation were inadequate treatment effect in 50%, AE plus inadequate treatment effect in 37.5% and AE alone in 12.5%. LDA (JADAS-10 ⩽3.9) was reached in 58% at 12 months and in 84% at 24 months, inactive disease (JADAS-10 ⩽0.7) in 19% and 44%, and clinically inactive disease in 28% and 46%, respectively. The rate of AEs was 200.9/100 patient years and of serious AEs 12.9/100 patient years.

Conclusion: Survival of tocilizumab was high and a large proportion of the treatment-resistant patients reached LDA at 12 months of treatment. The LDA rate continued to increase throughout 24 months. The rates of AEs and serious AEs were higher than in register studies but lower than in the originator study of tocilizumab.