P797 The inexorable increase of biological exposure in paediatric inflammatory bowel disease: a Scottish population-based, longitudinal study 2015–2019

Abstract

Abstract Background The use of biologics in paediatric inflammatory bowel disease (PIBD) is rapidly changing with the introduction of new mode of action medications, cheaper biosimilar alternatives, improved convenience with home care options and an increasing focus on early intensified management. No nationwide paediatric data is available to objectively capture this shifting landscape and its effect on healthcare resources. We aimed to identify the incidence and prevalence of biologic use within Scottish PIBD services. Methods In Scotland, specialist paediatric gastroenterology, hepatology and nutrition (PGHAN) services are coordinated through three tertiary academic centres (Glasgow, Edinburgh and Aberdeen) which act as regional referral hubs covering all district general hospitals. A nationwide cohort of prospectively identified PIBD cases less than 18 years of age with paediatric-onset IBD (A1 phenotype; diagnosed <17 years of age) were captured within paediatric services over a 4.5-year period (01.01.2015–30.06.2019). All patients who received infliximab (IFX), adalimumab (ADA), vedolizumab (VDZ) or ustekinumab (UST) during the study period (prevalent cases) or received their first dose of these biologics (incident cases not including biosimilar switches) were retrospectively audited. Point prevalence was calculated on 30 June each year and period prevalence as 6 month epochs. Results In total 495 incident new start biological therapies were commenced on 403 PIBD patients over the study period; 295 IFX (60%), 161 ADA (32%), 24 VDZ (5%), 15 UST (3%). The proportion of new start biologics changed over time with IFX initiation rates decreasing (87–54%) while ADA (13–31%), VDZ (0–10%) and UST (0–6%) all increased. Biosimilar penetration of new start anti-tumour necrosis factor (anti-TNF) biologics increased from 3% to 91% by 30.06.2019. The overall number of prevalent PIBD patients increased from 554 to 644 over the study period. Point prevalent rates of current biologic therapy usage increased from 20.2% on 30.06.15 to 43.5% on 30.06.19; an average annual percentage increase of 29%. Conclusion Complete accrual of Scottish nationwide biologic usage within paediatric services demonstrates a rapidly changing PIBD treatment landscape with a significant increase in biologic therapy (from 20% to 43% in just 4 years), a near-complete shift to biosimilar anti-TNF and use of biologics with new modes of action which are as yet unlicensed for PIBD.