THU0557 Therapeutic drug monitoring of biologicals in children with juvenile idiopathic arthritis(JIA): an overview of current practice in anti-tnf therapy. (12th June 2018)

• Record Type: Journal Article
• Authors: Nassar-Sheikh Rashid, A.; Schonenberg-Meinema, D.; de Vries, A.; Rispens, T.; Kuijpers, T.W.; Wolbink, G.; van den Berg, J.M.
• Is Part Of: Annals of the rheumatic diseases. Volume 77(2018)Supplement 2
• Page Start: 480
• Page End: 481
• Publication Date: 2018-06-12
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2018-eular.2944
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Juvenile idiopathic arthritis (JIA) is the most prevalent paediatric rheumatic disease. 1 Long term complications include physical disability and a decreased quality of life. 2, 3 Since the introduction of anti-TNF drugs for JIA, its prognosis has improved significantly. 1 Personalised medicine is the next step to improve treatment in JIA. Anti-TNF trough levels and demonstration of the presence of anti-drug antibodies (ADA) could help individualise treatment decisions in JIA patients, but evidence supporting this is missing. Objectives: To describe cross-sectional data of anti-TNF trough levels and ADA, combined with decision effects, in children with JIA. Methods: Patients' records in children with JIA using etanercept, adalimumab or infliximab were retrospectively checked for measurements of anti-TNF trough levels and ADA. Anti-TNF trough concentrations and ADA were measured using an enzyme-linked immunosorbent assay (ELISA) and antigen-binding test. Data on age, sex, JIA subtype, reason for testing and the decision effect of trough level or presence of ADA on the current therapy were collected. Results: Eighty-one anti-TNF trough levels were measured in 45 children with JIA. A wide variety of anti-TNF trough levels was found. Therapeutic drug concentrations, according to adult ranges in RA and IBD, 4, 5, 6 were found in 11 (58%) patients on etanercept (n=19), 2 (14%) on adalimumab (n=14) and 8 (17%) on infliximab (n=48). Four patients on adalimumab and one patient on infliximab showed ADA. All of these five patients had non-detectable drug trough levels. Reasons for testing trough level and/or presence of ADA were loss of response (20%), partial or no response (40%), measurement after dosage increase (2%), remission (17%), uveitis flare (9%) and allergic reaction (11%). Treatment decisions were influenced by trough levels in 70/81 (86.4%) of measurements and in 5/5 (100%) of patients with ADA. Conclusions: Measuring anti-TNF trough levels and ADA was a valuable tool in making personalised treatment decisions in JIA. Treatment changes included dose/frequency increase, or stopping and switching treatment in the presence of ADA combined with undetectable drug levels. More data are needed to access optimal therapeutic drug levels in anti-TNF treatment in JIA and to implement this strategy more widely. References: [1] Blazina S, et al. Paediatr Drugs2016;18(6):397–412. [2] Tambralli A, et al. J Rheumatol2013;40(10):1749–55. [3] Haverman L, et al. Rheumatology (Oxford)2012;51(2):368–74. [4] Kneepkens EL, et al. Ann Rheum Dis2015;74(10):1825–9. [5] Pouw MF, et al. Ann Rheum Dis2015;74(3):513–8. [6] Singh N, Dubinsky DC. Gastroenterol Hepatol (NY)2015;11(1): 48–55. Disclosure of Interest: None declared