An observational study in Ulcerative Colitis, sponsored by University Hospitals Coventry and Warwickshire NHS Trust. Not yet recruiting at 1 site in United Kingdom. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by University Hospitals Coventry and Warwickshire NHS Trust · Observational
Ulcerative colitis (UC) is a long-term inflammatory bowel condition. Many patients are treated with intravenous biologic drugs such as infliximab or vedolizumab. Measuring the level of these drugs in the blood helps doctors adjust treatment, but results can take one to two weeks to come back.
Volatile organic compounds (VOCs) are gases released from stool and urine that reflect activity in the gut, including gut bacteria and inflammation. They can be measured quickly and without needles.
This study will find out whether VOCs in stool and urine can tell apart patients with adequate drug levels from those with low drug levels. It will also look at whether VOCs can identify patients whose UC is in remission versus those whose disease is flaring, and how VOCs relate to blood inflammation markers, gut bacteria and DNA methylation (chemical tags on genes).
Adults with UC already receiving maintenance intravenous infliximab or vedolizumab at University Hospitals Coventry and Warwickshire will be invited to take part. Participants will provide stool, urine and blood samples at four of their routine infusion appointments. No extra visits are needed and treatment is not changed by the study.
Design: Single-centre, prospective, longitudinal observational cohort study at University Hospitals Coventry and Warwickshire NHS Trust (UHCW), UK. No intervention is assigned; participants continue standard-care maintenance intravenous biologic therapy.
Population: Adults (≥18 years) with ulcerative colitis (UC), confirmed by clinical, endoscopic and histological criteria per ECCO guidelines, established on maintenance intravenous infliximab or vedolizumab and attending the UHCW medical day unit. Patients in the induction phase are not eligible. Target enrolment is 99 participants.
Procedures: Participants are assessed at four consecutive routine infusion visits (every 4, 6 or 8 weeks; follow-up 12-24 weeks). At each visit, pre-infusion blood is taken for biologic trough concentration, anti-drug antibodies, C-reactive protein (CRP), full blood count, cytokines (IL-6, IL-10, IL-23) and DNA methylation. Stool and urine are collected at home before the visit. Stool is used for faecal calprotectin (FCP), VOC analysis and whole-genome shotgun metagenomic sequencing; urine is used for VOC analysis. Research samples are stored at -80 °C at the Arden Tissue Bank, UHCW, and VOC analysis is performed at the University of Warwick.
Classification: Trough concentrations are classified as sub-therapeutic at ≤1 µg/mL for infliximab and \<12.7 µg/mL for vedolizumab, according to the reporting laboratories' thresholds, fixed before any VOC analysis. Remission is defined as FCP \<250 µg/g and CRP ≤10 mg/L; relapse as FCP ≥250 µg/g and/or CRP >10 mg/L, or corticosteroid rescue, biologic dose escalation, or hospitalisation for UC flare (STRIDE-II).
Analysis: The primary analysis uses one baseline sample per participant. A pre-specified set of supervised machine-learning classifiers will be evaluated using nested cross-validation stratified by trough status and biologic agent, with feature selection and tuning confined to training folds. The primary outcome is cross-validated AUROC (95% CI); the hypothesis is supported if the lower 95% CI bound exceeds 0.5, with AUROC ≥0.70 considered acceptable. The urinary VOC analysis is tested in fixed sequence after the primary analysis. False discovery rate correction is applied to multi-VOC association analyses. Repeated-visit analyses use participant-grouped cross-validation.
Sample size: 77 participants (23 sub-therapeutic, 54 therapeutic) provide 80% power at two-sided α=0.05 to detect AUROC 0.70 versus 0.50 (Hanley-McNeil), assuming 30% sub-therapeutic. Allowing 20% attrition, 99 participants will be recruited.
1,853 studies on the registry are indexed under Colitis, Ulcerative; 472 are open to participants now.
This study's planned enrollment of 99 is below the median of 198 across 551 observational studies indexed under Colitis, Ulcerative.
Browse Colitis, Ulcerative studies →University Hospitals Coventry and Warwickshire NHS Trust is the lead sponsor of 57 studies on the registry; 8 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adults (aged 18 years or older) with ulcerative colitis, confirmed by clinical, endoscopic and histological criteria, who are established on maintenance intravenous biologic therapy (infliximab or vedolizumab) and attend the medical day unit at University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK, for routine infusions. Eligible patients are identified by weekly screening of day unit infusion lists.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults with UC on maintenance IV infliximab. Standard-care maintenance intravenous therapy; not assigned or altered by the study.
Adults with UC on maintenance IV vedolizumab. Standard-care maintenance intravenous therapy; not assigned or altered by the study.
Faecal VOC discrimination of therapeutic versus sub-therapeutic biologic trough concentration
Cross-validated AUROC (95% CI) of the pre-specified machine-learning framework. Sensitivity, specificity, PPV and NPV also reported.
Time frame: From enrollment to the end of treatment at 8 weeks
Urinary VOC discrimination of therapeutic versus sub-therapeutic trough concentration (cross-validated AUROC, 95% CI)
Time frame: From enrollment to the end of treatment at 8 weeks
Change in cross-validated AUROC when VOC features are added to models containing FCP, CRP and cytokines
Time frame: From enrollment to the end of treatment at 8 weeks
Association between faecal VOC features and microbiota composition and diversity (FDR-adjusted)
Time frame: From enrollment to the end of treatment at 8 weeks
Association between faecal VOC features and blood DNA methylation, including interaction with remission/relapse status (FDR-adjusted
Time frame: From enrollment to the end of treatment at 8 weeks
Faecal VOC discrimination of remission versus relapse (cross-validated AUROC, 95% CI)
Time frame: From enrollment to the end of treatment at 8 weeks
Difference in cross-validated AUROC between faecal and urinary VOC models (paired DeLong test)
Time frame: From enrollment to the end of treatment at 8 weeks
Plan to share: No — Individual participant data will not be shared. Data are owned by the study sponsor (University Hospitals Coventry and Warwickshire NHS Trust) and participant consent does not cover sharing of individual-level data. Summary results will be posted on ClinicalTrials.gov and published in peer-reviewed journals.
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Sep 2027, 9 months later.
Of 188 non-industry observational studies under Colitis, Ulcerative, half reached primary completion within 51 months of starting (the median), counting those still running; a quarter within 30 and three quarters within 119. This study's planned 9 months is below that.
Counting every sponsor, half of 271 studies reached it within 47 months; a quarter within 29 and three quarters within 90.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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University Hospitals Coventry and Warwickshire NHS Trust