OP40 Transcriptomic signature of response to vedolizumab in patients with moderate-to-severe ulcerative colitis: Results from an international, multicentre, retrospective cohort study

Abstract

Abstract Background Transcriptomic analysis has the potential to facilitate drug development and clinical decision making in inflammatory bowel disease. Current understanding of pharmacodynamic response to vedolizumab is limited by a lack of publicly available mucosal biopsy RNA samples/sequencing data and corresponding clinical information. We aimed to identify gene signatures associated with response to vedolizumab in ulcerative colitis (UC) patients by pooling data from 3 international sites. Methods Patients receiving vedolizumab for the treatment of moderate-to-severe UC at Hospital Clínic de Barcelona (IDIBAPS), Mount Sinai Hospital (MSH), and University of California, San Diego (UCSD) with baseline and post-treatment (week 14 [± 4 weeks]) mucosal biopsy RNA-sequencing data and Mayo Clinic endoscopic subscores (MCES) were eligible for inclusion. Endoscopic response was defined as an MCES <1. Demographic and clinical data were collected. Differential expressed genes (DEGs) between baseline and week 14 were identified using linear mixed models with a >1.5 or <-1.5-fold change (adjusted P-value <.05). Enrichment was performed using Reactome pathway analysis and a previously published UC gene signature (adjusted P-value <.05).1 Analyses were performed using R version 4.3.0. Results Twenty-three patients were included (IDIBAPS: n=12; MSH: n=8; UCSD: n=3). Site-specific differences in sex, surgical history, and corticosteroid use were observed (Table). Analysing data by site yielded a relatively small number of DEGs between baseline and week 14 (IDIBAPS=57 [27 up-regulated, 30 down-regulated]; MSH=0; UCSD=0) among endoscopic responders (IDIBAPS: n=5; MSH: n=7; UCSD: n=2). Combining data from the 3 sites increased the number of DEGs among endoscopic responders at week 14 (n=14) to 1162 (662 up-regulated and 500 down-regulated). The down-regulated DEGs were enriched for genes involved in 37 of 103 up-regulated Reactome pathways in UC, including neutrophil degranulation, interleukin-4 and interleukin-13 signalling, interleukin-10 signalling, and integrin cell surface interactions. The up-regulated DEGs were enriched for genes involved in 1 of 39 down-regulated Reactome pathways in UC (Drug ADME). Conclusion We defined a pharmacodynamic signature using mucosal biopsies from UC patients who had endoscopic response to vedolizumab at week 14. The signature was enriched for several, but not all, pathways involved in UC. In addition to providing insight into vedolizumab’s mechanism of action, we underscored the utility of multi-site collaboration to access data, increase statistical power, and enhance the generalizability of research findings. Reference: 1. Linggi et al. Sci Rep 2021;11:18243.