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

Overview

The purpose of this study is to evaluate whether simultaneously targeting three inflammatory pathways (TL1A, IL-23, and α4β7) produces a stronger anti-inflammatory effect in intestinal tissue from patients with Inflammatory Bowel Disease (IBD) compared with targeting individual pathways. The study aims to investigate whether this combined approach may help overcome limitations associated with single-pathway inhibition. This is a single-center, interventional ex vivo study conducted at IRCCS Ospedale San Raffaele. The study includes 30 participants divided into three cohorts: 10 patients with Ulcerative Colitis, 10 patients with Crohn's Disease, and 10 non-IBD control participants. Participant involvement is limited to a single day and is integrated into a clinically indicated, routinely scheduled colonoscopy and routine phlebotomy. During the scheduled colonoscopy, 8 additional mucosal biopsies are collected for research purposes, together with an additional 2 mL blood sample. No additional endoscopic procedure or separate study visit is required. No investigational drug or treatment is administered directly to participants. The collected intestinal biopsies are instead treated ex vivo in the laboratory with ATTO-1091, individual pathway inhibitors, or control conditions for 16 hours. Biological and molecular responses are evaluated using laboratory techniques including ELISA and RNA sequencing to assess inflammatory markers and gene expression. Laboratory personnel performing molecular and transcriptomic analyses are blinded to participants' clinical profiles until final data analysis.

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.