P704 Association between trough levels of vedolizumab and therapy outcome in a cohort of patients with inflammatory bowel disease
J. O'Connell1, P. McDonagh1, K. Hazel2, J. Fiona3, C. Dunne1,4, R. Farrell2, G. Harewood3, K. Hartery1,4, O. Kelly2, F. MacCarthy4,5, S. McKiernan1,4, F. Murray3, C. O'Morain6, O. Aoibhlinn3, D. Kevans1,4
1St James's Hospital, Department of Gastroenterology, Dublin, Ireland, 2Connolly Hospital Blanchardstown, Gastroenterology, Dublin, Ireland, 3Beaumont Hospital, Gastroenterology, Dublin, Ireland, 4INITIative, Investigator Network Inflammatory bowel disease Therapy in Ireland, Dublin, Ireland, 5St James's Hospital, Gastroenterology, Dublin, Ireland, 6Beacon Hospital, Gastroenterology, Dublin, Ireland
Vedolizumab(VDZ) is an α4β7 integrin antagonist for the treatment of IBD. The role of VDZ therapeutic drug monitoring has not been clearly defined. We aimed to investigate the association between VDZ trough levels and therapy outcome in a cohort of patients with inflammatory bowel disease (IBD) and the association between VDZ trough levels and clinical and biochemical variables.
IBD patients receiving VDZ were identified in a cross-sectional study where serum samples were not collected at a pre-specified time point. Ulcerative colitis(UC) and Crohn’s disease(CD) clinical activity was quantified using Mayo clinical subscore (MCS, remission MCS ≤ 1) and Harvey–Bradshaw Index (HBI, remission HBI < 5). VDZ and antibody-to-vedolizumab (AVA) concentrations determined by Prometheus® Anser® laboratories using non-radio-labelled liquid-phase mobility shift assays. p-values < 0.05 were considered significant.
In a real-world study of IBD patients receiving VDZ no clear association between VDZ trough levels and therapy outcome was observed. Significant immunogenicity was not observed supporting the use of VDZ monotherapy in uncomplicated patients. Further study is required to determine the utility of therapeutic drug monitoring in VDZ-treated patients.