Abstract
BACKGROUND: The availability of subcutaneous (SC) administration devices of biologics in addition to intravenous (IV) administration has influenced patients’ and clinicians’ preferences towards initiating or transitioning to SC administration particularly during the COVID-19 pandemic. Whilst SC administration improves patient convenience and reduces demands on infusion centres we hypothesised that the reduction in healthcare contact associated with SC therapies may reduce the opportunities available for objective disease assessment. We aimed to compare the uptake of objective assessment of disease activity between patients receiving IV and SC biologic therapy. METHODS: Patients on maintenance infusion-based or subcutaneous biologic therapy for IBD between 09/2020 and 02/2021 were identified from a prospectively maintained database at an Australian tertiary IBD centre. Patients scheduled for review in IBD clinic for a prescription of maintenance biologic therapy during the follow-up period were included. Clinic records were reviewed to determine whether patients had undergone objective disease assessment including: biochemical investigation (C-Reactive protein) and Faecal Calprotectin (FCP) within the preceding 8 weeks and/or endoscopic/imaging assessment within the preceding 6 months of clinic review. Frequency of objective disease assessment was compared between patients who received IV versus SC maintenance biologic therapy. RESULTS: A total of 307 patients were included: IV maintenance n=195 (Infliximab n=135; Vedolizumab n= 60) and SC maintenance n=112 (Adalimumab n=54; Ustekinumab n=54; Golimumab n=4). Patients who received IV biologics were more likely than the SC cohort to have had biochemical assessment in the form of CRP (90% vs 72%, p<0.001) and FCP (54% vs 46%, p=0.16). Patients in the SC biologic cohort were more likely not to have had investigations completed prior to their clinical review (20% versus 4%, p<0.001). There was no difference in the overall rates of complete objective disease assessment (CRP/FCP and endoscopy/imaging) between the IV and SC cohort (28% vs 30% (p=0.74). CONCLUSION: Patients on subcutaneous biologic therapies in our cohort were less likely to have had objective disease monitoring than those receiving intravenous biologics prior to scheduled IBD clinic review. Route of of biologic administration may influence rates of uptake of objective disease activity assessment. Tools that safeguard against the disparity of monitoring uptake, including messaging prompts and patient-centric mobile applications may help standardise the approach to objective disease assessment independent of the route of biologic administration.