P518 Vedolizumab trough concentrations are associated with endoscopic response in patients with inflammatory bowel disease
Bibliographic record
Abstract
Vedolizumab (VDZ) is an effective therapy for Crohn’s disease (CD) and ulcerative colitis (UC). Therapeutic drug monitoring may guide the use of VDZ to improve outcomes. We aim to investigate the association between VDZ trough level (TL) and clinical, biochemical and endoscopic outcomes. We recruited patients on VDZ for treatment for CD or UC from February 2016 to June 2017; including a prospective cohort which was assessed at Weeks 6, 10, 14, 30, and 54 and a cross-sectional cohort that was assessed at one or more of these time points. Clinical (defined as clinical remission with Harvey Bradshaw Index [HBI] score <5/Partial Mayo score [PMS] < 2), biochemical (C-reactive protein [CRP] normalisation with serum CRP <5mg/l and faecal calprotectin [FCP] normalisation with level <250 µg/g) and endoscopic (endoscopic remission with Simple Endoscopic score for CD [SESCD] score of <2/Mayo endoscopy score [MES] of <2; endoscopic response with 50% reduction of SESCD/≥1 MES reduction) endpoints were correlated with VDZ TL and antibody levels (A-VDL). VDZ TL and A-VDL testing were performed with an ELISA based assay (LISA TRACKER®, Theradiag France). Combined assessment for 40 patients (median age 49, 57.5% male, 55% CD, 22.5% on immunomodulator and 15% biologic naive) with outcome data at Week 30 or beyond showed 62.5% clinical remission rate, 48.7% CRP normalisation, 48.5% FCP normalisation, 46.9% (N = 15 of 32) endoscopic response and 21.9% endoscopic remission. Endoscopic response rates were numerically higher in UC than in CD patients (62.5% vs. 31.3%, p = 0.156) and 31.3% of the endoscopic cohort patients were on every four-week dosing. In the combined CD and UC cohort, VDZ TL ≥15 µg/ml showed a trend toward association with endoscopic response (59.1% vs. 20%, p = 0.079). Significant association was found in the CD subset (N = 16) where TL ≥22 µg/ml was associated with endoscopic response (62.5% vs. 0%, p = 0.026). Mean TL was significantly higher in CD patients with endoscopic response than in UC (mean 38.8 ± 11.1 vs. 20.8 ± 10.4, p = 0.014). Week 14 (N = 11, CD and UC) TL of >12.1 µg/ml also showed association with endoscopic response (100% vs. 16.7%, p = 0.015) at Week 30 or beyond. No definitive relationship between VDZ TL and clinical or biochemical outcomes were demonstrated. No anti-VDZ antibodies were identified. Endoscopic response rate at Week 30 of 54. Vedolizumab serum trough level is associated with endoscopic response, particularly in Crohn’s disease where higher concentrations may be required to achieve endoscopic improvement than in ulcerative colitis.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".