Ex Vivo Comparison Of Combination Versus Single Therapeutic Pathway Inhibition In Human Intestinal Mucosa From Patients With Inflammatory Bowel Disease

The study is built on the hypothesis that the simultaneous blockade of TL1A, IL-23, and α4β7 pathways will exert a synergistic anti-inflammatory effect on the intestinal mucosa of IBD patients compared to single-agent inhibition, thereby potentially overcoming resistance to standard biological therapies. To test this, a monocentric, national, interventional ex vivo clinical study will be conducted at the IRCCS Ospedale San Raffaele using organotypic tissue cultures. The parallel-group design is based on three distinct clinical cohorts consisting of participants with Ulcerative Colitis, participants with Crohn's Disease, and non-IBD control subjects. To minimize bias and ensure scientific integrity, laboratory operators performing the molecular and transcriptomic analyses will be blinded to the clinical and response data of the source tissue until final statistical analysis. Participants will undergo a clinically indicated, routinely scheduled standard-of-care colonoscopy. During the procedure, 8 additional mucosal biopsies will be collected for research purposes according to a standardized sampling protocol, together with an additional 2 mL blood sample collected during routine phlebotomy. No investigational product or treatment will be administered directly to study participants. Instead, the active experimental phase will be conducted entirely ex vivo in the laboratory, where the collected intestinal tissue samples will be exposed to ATTO-1091, individual pathway inhibitors, or control conditions for a standardized culture period of 16 hours. Participant involvement will be completed within a single day and fully integrated into routinely scheduled clinical care, with no additional study-specific clinical examinations or post-treatment follow-up visits required. There are no sub-studies included in this protocol. Biological data will be generated via high-throughput laboratory assays, specifically organotypic tissue cultures, enzyme-linked immunosorbent assays (ELISA) for cytokine evaluation, and RNA sequencing (RNA-seq) to map gene expression. These molecular methods are selected because they provide comprehensive measurements of cellular inflammation and pathway inhibition and allow comparison of the biological effects of combined pathway inhibition with single-pathway inhibition and control conditions. Finally, any new future research or secondary use of the collected data and biological samples not explicitly described in this protocol will be submitted to the Ethics Committee for formal approval before initiation.