FRI0357 Certolizumab pegol is effective in children with JIA not responsive to other TNF alpha antagonists

Background Patients with polyarticular juvenile idiopathic arthritis (JIA) may not respond sufficiently to methotrexate (MTX) combined with TNF Alpha antagonists (TNFA). In this cases switching to another TNFA might be beneficial. In case of non-response to the second TNFA it is recommended to change the treatment principle to another biologic. Certolizumab pegol (CZP) consists in a Fab fragment of a pegolated monoclonal TNF Alpha antibody. CZP is the only pegolated (conjugated with polyethylenglycol) TNFA so far. Pegolation is meant to be one of the reasons for improved pharmacokinetic properties leading to site dedicated suppression of the inflammation. Objectives The aim of the retrospective study was to evaluate the efficacy and safety of CZP in children with polyarticular course JIA not responsive to other TNFA. Methods Based on a search of the hospital database patients with polyarticular course JIA treated with CZP and at least one other TNFA (prior to CZP) were identified. The active joint count was documented at week 0, week 6-12 and week 24-36. Efficacy was evaluated by the decrease of the number of active joints over time. For the safety analysis adverse events (AE) were documented. Results 22 patients (4 boys) were identified. The age range at initiation of CZP treatment was 9-17 years. 18 children were treated with 2 TNFA before CZP was introduced. 18 patients received concomitantly subcutaneous MTX. At week 0 all patients had active joints (median 14, min. 3, max. 36). At week 6-12 one patient did not respond. Out of the remaining 21 patients 0 active joints were found in 11; the active joint count has decreased in the remaining 9 (median 2, min. 0, max. 4). At week 24-36 the number of patients with active joints has further decreased to 6 (15 patients had 0 active joints). The remaining 6 patients had a median active joint count of 2 (min. 1, max. 4). In this cohort only one AE occurred – skin reaction to CZP, which disappeared spontaneously. Conclusions Despite the recommendation of switching the treatment principle after non-response to two TNFA in children with JIA, the results of this study point to the capacity of CZP to gain control over the disease in this short-term analysis and therefore CZP might become a treatment option in those cases (the drug is still off-label use). CZP treatment was overall well tolerated. Disclosure of Interest None Declared