OBSIDIAN - real-world evidence of originator to biosimilar drug switch in juvenile idiopathic arthritis.

Objectives: Limited data about use of biosimilars (BIOs) are available in children with JIA. This study therefore aimed to evaluate long-term efficacy and safety of switching from etanercept (ETA) and adalimumab (ADA) originators to their biosimilars (BIOs), in children with JIA, in a real-world setting.

Methods: This is a retro-prospective non-interventional multicentre Italian comparative cohort study. Medical charts of JIA children treated with biosimilars of ETA or ADA were included. Efficacy and safety of TNF-inhibitors therapy was evaluated at last follow-up during originator and at 3, 6 and 12 months following the switch to biosimilar.

Results: A total of 59 children (42 female, median age at onset 88 months) were treated with biosimilar of ETA (21) and ADA (38). Forty-five switched from the originator to the BIO (17 ETA, 28 ADA). At time of switch, 12/17 patients on ETA and 18/28 on ADA were in remission. No significant difference has been found at 3, 6 and 12 months after the switch. Ten patients discontinued biosimilars due to disease remission (4 ETA, 3 ADA), family willing (1 ETA), occurrence of burning at injection site (1 ETA) and persistent activity (1 ADA). No statistically significant difference was observed between originator and BIOs, nor between originator and BIOs, and between ADA and ETA in time to disease remission achievement, time to relapse and number of patients who experienced adverse event (AE).

Conclusion: Our real-life results seem to confirm the efficacy and safety profile of switching from originator of ADA and ETA to their respective BIOs, also in paediatric patients with JIA.