Background/Purpose: The management of juvenile idiopathic arthritis (JIA) has been revolutionised by the introduction of biologic therapy, although the majority remain unlicensed for children. Until recently, etanercept (ETN) was the only choice of licensed therapy in the UK, with recent additions of adalimumab (age ≥ 4 years), abatacept (age ≥ 6 years) and tocilizumab (systemic arthritis). It is not yet known how and when non-ETN biologics are being prescribed in JIA. The purpose of this analysis was to describe the pattern of use of non-ETN biologics in children with JIA.

Methods: Since 2010, the Biologics for Children with Rheumatic Diseases (BCRD) study, an ongoing prospective observational cohort study, has been collecting detailed information on children <18 years newly starting a non-ETN biologic therapy for JIA. There are no other exclusion criteria.  At baseline, detailed demographic and disease information, including details of past biologic therapies, are collected. The use of non-ETN therapy as a first-line or subsequent biologic therapy was compared, including patterns of prescription, use under licensed indications, ILAR subtypes and disease activity/severity using non-parametric descriptive statistics.

Results: To 06/21/2012, 136 children across the UK had been recruited: median age 10 years, 65% female. The most common ILAR subtypes were systemic arthritis (26.5%) and rheumatoid factor (RF) negative polyarthritis (27.2%) (see Table). Sixty four patients (47.1%) were starting a non-ETN biologic as first-line biologic therapy, of which 33 (51.6%) were prescribed off-license. Off-license use was more common among first-line users (p=0.047), largely accounted for by infliximab and anakinra. All patients on anakinra had systemic arthritis, whereas only 67.7% of those were prescribed tocilizumab. Forty-eight percent of first line users versus 26% of subsequent users had a history of chronic anterior uveitis (p=0.028). Of those registered at the point of starting a subsequent biologic, 71% had received prior ETN. The majority had received only 1 prior biologic although 17 children had received 2 prior biologics, 3 children had received 3 and 1 child (RF negative) had received 5 previous biologics. Disease severity was moderate to high and largely comparable between first-line and subsequent biologic users, although subsequent biologic users had a higher limited joint count.

Conclusion: Many children are now receiving non-ETN biologics in the UK, although almost half of these are being prescribed off-license. Ongoing follow-up will help to address the question of best choice of biologic therapy for children with JIA, both as first-line and subsequent use, as well as determine the safety of these drugs in children, for which limited clinical experience exists.