Reverse metabolomics for the discovery of chemical structures from humans.

Determining the structure and phenotypic context of molecules detected in untargeted metabolomics experiments remains challenging. Here we present reverse metabolomics as a discovery strategy, whereby tandem mass spectrometry spectra acquired from newly synthesized compounds are searched for in public metabolomics datasets to uncover phenotypic associations. To demonstrate the concept, we broadly synthesized and explored multiple classes of metabolites in humans, including N-acyl amides, fatty acid esters of hydroxy fatty acids, bile acid esters and conjugated bile acids. Using repository-scale analysis1,2, we discovered that some conjugated bile acids are associated with inflammatory bowel disease (IBD). Validation using four distinct human IBD cohorts showed that cholic acids conjugated to Glu, Ile/Leu, Phe, Thr, Trp or Tyr are increased in Crohn's disease. Several of these compounds and related structures affected pathways associated with IBD, such as interferon-γ production in CD4+ T cells3 and agonism of the pregnane X receptor4. Culture of bacteria belonging to the Bifidobacterium, Clostridium and Enterococcus genera produced these bile amidates. Because searching repositories with tandem mass spectrometry spectra has only recently become possible, this reverse metabolomics approach can now be used as a general strategy to discover other molecules from human and animal ecosystems.

Reliability and Responsiveness of Histologic Indices for the Assessment of Crohn's Disease Activity.

BACKGROUND & AIMS: The operating properties of histologic indices for evaluating Crohn's disease (CD) activity are poorly characterized. We assessed the reliability and responsiveness of existing histologic indices/items used in CD and ulcerative colitis (UC), in addition to 3 novel items, and developed exploratory ileal, colonic, and colonic-ileal CD instruments. METHODS: Blinded central readers independently reviewed paired baseline and week 12 image sets from the EXTEND trial. Disease activity was scored using 4 indices (the Global Histologic Activity Score, Geboes Score, Nancy Histological Index, and Robarts Histopathology Index) and 3 items identified by an expert panel (mucin depletion, basal plasmacytosis, and ileal pyloric gland metaplasia). Reliability and responsiveness were quantified using the intraclass correlation coefficient (ICC) and area under the receiver operating curve (AUC), respectively. Exploratory indices were developed using backward stepwise linear regression analysis. Candidate independent variables were items with an inter-rater ICC ≥0.40 and AUC ≥0.56. The dependent variable was histologic disease activity measured by a 100-mm visual analogue scale. RESULTS: Paired image sets were available from 55 patients. Substantial to almost perfect inter-rater reliability (ICC, 0.63-0.87) and some responsiveness (AUC, 0.57-0.94) were observed for all existing indices regardless of whether individual colonic and ileal segments, combined colonic segments, or combined colonic and ileal segments were assessed and the calculation method used. Five items were tested as candidate items, and exploratory colonic, ileal, and colonic-ileal indices were developed. CONCLUSIONS: CD and UC indices were similarly reliable and responsive in measuring histologic CD activity. Exploratory index development did not offer benefit over current histologic instruments.

CORE-IBD: A Multidisciplinary International Consensus Initiative to Develop a Core Outcome Set for Randomized Controlled Trials in Inflammatory Bowel Disease.

BACKGROUND & AIMS: End points to determine the efficacy and safety of medical therapies for Crohn's disease (CD) and ulcerative colitis (UC) are evolving. Given the heterogeneity in current outcome measures, harmonizing end points in a core outcome set for randomized controlled trials is a priority for drug development in inflammatory bowel disease. METHODS: Candidate outcome domains and outcome measures were generated from systematic literature reviews and patient engagement surveys and interviews. An iterative Delphi process was conducted to establish consensus: panelists anonymously voted on items using a 9-point Likert scale, and feedback was incorporated between rounds to refine statements. Consensus meetings were held to ratify the outcome domains and core outcome measures. Stakeholders were recruited internationally, and included gastroenterologists, colorectal surgeons, methodologists, and clinical trialists. RESULTS: A total of 235 patients and 53 experts participated. Patient-reported outcomes, quality of life, endoscopy, biomarkers, and safety were considered core domains; histopathology was an additional domain for UC. In CD, there was consensus to use the 2-item patient-reported outcome (ie, abdominal pain and stool frequency), Crohn's Disease Activity Index, Simple Endoscopic Score for Crohn's Disease, C-reactive protein, fecal calprotectin, and co-primary end points of symptomatic remission and endoscopic response. In UC, there was consensus to use the 9-point Mayo Clinic Score, fecal urgency, Robarts Histopathology Index or Geboes Score, fecal calprotectin, and a composite primary end point including both symptomatic and endoscopic remission. Safety outcomes should be reported using the Medical Dictionary for Regulatory Activities. CONCLUSIONS: This multidisciplinary collaboration involving patients and clinical experts has produced the first core outcome set that can be applied to randomized controlled trials of CD and UC.

Higher Postinduction Infliximab Concentrations Are Associated With Favorable Clinical Outcomes in Pediatric Crohn's Disease: A Post Hoc Analysis of the REACH Trial.

INTRODUCTION: Exposure-outcome relationship data show that higher infliximab concentrations are associated with better outcomes in patients with Crohn's disease (CD). However, most of these data were derived from adult patients on maintenance therapy. We aimed to investigate the association of infliximab concentrations during and early after induction therapy of infliximab with short-term and long-term clinical outcomes in a pediatric CD population. METHODS: We conducted a post hoc analysis of the REACH trial which included pediatric patients with moderate-to-severe CD treated with infliximab (n = 103). The investigated outcomes were early clinical remission (CR) defined as a pediatric CD activity index score of ≤ 10, assessed at week 10, and long-term clinical response (LTCR) defined as a decrease from baseline in the pediatric CD activity index score of at least 15 points, with a total score of ≤ 30 and no need for drug discontinuation, assessed at weeks 30 and 54. RESULTS: Based on multivariable logistic regression analysis, higher week 10 infliximab concentrations were independently associated with CR at week 10 (odds ratio: 1.54; 95% confidence interval: 1.06-2.22; P = 0.022) and LTCR at week 30 (odds ratio: 1.62; 95% confidence interval: 1.12-2.36; P = 0.010). Receiver operating characteristic analysis identified week 10 infliximab concentration thresholds of ≥7.1 µg/mL and ≥6.5 µg/mL to be associated with CR at week 10 and LTCR at week 30, respectively. DISCUSSION: Higher postinduction infliximab concentrations are associated with both short-term and long-term favorable clinical outcomes in pediatric patients with CD. Tailoring dosing during induction to achieve higher infliximab exposure may lead to better outcomes in pediatric patients with CD.

Measuring Serum Vedolizumab and Vedolizumab Antibodies: Comparison of Commercial Assays with the Vedolizumab Clinical Development Assay.

BACKGROUND: Vedolizumab (VDZ) is an anti-α 4 ß 7 integrin monoclonal antibody approved for inflammatory bowel disease treatment. VDZ serum and antidrug antibody (ADA) concentrations may be used for treatment optimization. In this article, the results of 5 commercial assays (Grifols, Immundiagnostik, Progenika, Sanquin, and Theradiag) measuring VDZ concentration and ADA were compared with those of the reference assays used in VDZ clinical studies. Our findings will assist clinicians in interpreting commercial assay results in the context of VDZ clinical trial data. METHODS: VDZ-treated patient samples were used to evaluate the agreement between commercial assays and the reference VDZ serum concentration assay, based on linear regression, Bland-Altman, and qualitative agreement analyses. VDZ ADAs were detected using qualitative assays. Specificity, selectivity, accuracy, and precision were assessed using serum samples from healthy donors or patients with IBD (VDZ serum concentration <0.5 mcg/mL) spiked with VDZ, with/without other biologics (identical sample sets per assay). RESULTS: All assays were specific and selective for VDZ. Overall, the commercial assay results for VDZ-spiked samples correlated well with those of the reference serum concentration assay (R 2 ≥ 0.98). Compared with the Immundiagnostik and Theradiag assays, the Grifols, Sanquin, and Progenika assays had the best reference assay agreement (based on regression analysis, Bland-Altman plots, and qualitative agreement [Cohen's kappa ≥0.92]). All immunogenicity assays detected VDZ ADAs; only the reference assay detected VDZ ADAs in the presence of 15 mcg/mL VDZ, advising caution with commercial ADA assays if VDZ is present. CONCLUSIONS: All 5 commercial assays are suitable for VDZ therapeutic monitoring and ADA testing. However, the absolute values from the reference assays and the different commercial assays were not comparable, indicating that the same assay must be used for repeated monitoring of VDZ serum concentrations.

Endoscopic Assessment of Inflammatory Bowel Disease Activity in Clinical Trials.

In patients with Crohn's disease and ulcerative colitis, poor correlation between symptoms and active luminal inflammation has been well established. As a result, the field has moved towards the use of endoscopic assessment to evaluate inflammatory activity. Numerous endoscopic indices have been used for this purpose although none are completely validated. The Simple Endoscopic Score for Crohn's Disease and the Crohn's Disease Endoscopic Index of Severity have been used most frequently; however in addition to incomplete validation, they have important limitations for clinical use, including complexity of scoring and poor reliability of items such as stenosis. The Rutgeerts' score for postoperative Crohn's disease was developed primarily as a prognostic rather than evaluative tool and also requires additional validation. In ulcerative colitis, the Mayo endoscopic subscore has been used as the regulatory standard, although the Ulcerative Colitis Endoscopic Index of Severity may provide a more granular assessment of individual components of disease activity. The use of combined outcomes with patient reported outcomes (PROs) and endoscopic indices has received favor by regulatory bodies but require further validation. This review describes the indications for endoscopic assessment in trials, the indices most frequently utilized for these purposes, and potential future approaches to assessment of disease activity.

Patients With Low Drug Levels or Antibodies to a Prior Anti-Tumor Necrosis Factor Are More Likely to Develop Antibodies to a Subsequent Anti-Tumor Necrosis Factor.

Therapeutic drug monitoring (TDM) with measurement of serum drug and antidrug antibodies (ADAb) is used widely to confirm therapeutic exposure, rule out immunogenicity, and optimize treatment of biologics in patients with inflammatory bowel diseases.1 A recent genome-wide association study found the variant HLA-DQA1∗05 to increase the risk of development of antibodies against infliximab (IFX) and adalimumab (ADM) 2-fold, regardless of concomitant immunomodulator use.2,3 However, there is currently limited evidence showing whether patients who develop antibodies to 1 anti-tumor necrosis factor (TNF) are prone to develop antibodies to the subsequent anti-TNF. Our aim was to investigate the risk of subsequent antibody development in cases (with ADAb to prior anti-TNF) versus control subjects (without ADAb to prior anti-TNF) using a large cohort of patients with inflammatory bowel diseases who underwent TDM with a drug-tolerant assay.

An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials.

BACKGROUND & AIMS: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment. METHODS: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting. RESULTS: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations. CONCLUSIONS: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.

Pharmacological Interventions for the Prevention and Treatment of Immune Checkpoint Inhibitor-Associated Enterocolitis: A Systematic Review.

BACKGROUND: Patients treated with immune checkpoint inhibitors (ICIs) may develop ICI-associated enterocolitis, for which there is no approved treatment. AIMS: We aimed to systematically review the efficacy and safety of medical interventions for the prevention and treatment of ICI-associated enterocolitis. METHODS: MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomized controlled trials (RCTs), cohort and case-control studies, and case series/reports, evaluating interventions (including corticosteroids, biologics, aminosalicylates, immunosuppressants, and fecal transplantation) for ICI-associated enterocolitis. Clinical, endoscopic, and histologic efficacy endpoints were evaluated. The Grading of Recommendations, Assessment, Development, and Evaluation criteria were used to assess overall quality of evidence. RESULTS: A total of 160 studies (n = 1514) were included (one RCT, 3 retrospective cohort studies, 156 case reports/case series). Very low quality evidence from one RCT suggests budesonide is not effective for prevention of ICI-associated enterocolitis in ipilimumab-treated patients (relative risk 0.93 [95% confidence interval 0.56, 1.56]). Very low quality evidence suggests that corticosteroids, infliximab, and vedolizumab may be effective for treatment of ICI-associated enterocolitis by inducing clinical response and remission. No validated indices for measuring disease activity were used. Biologic treatment was used in 42% (641/1528) of patients, as reported in 97 studies. ICIs were discontinued in 65% (457/702) of patients, as reported in 63 studies. CONCLUSIONS: Current treatment recommendations for ICI-associated enterocolitis are based on very low quality evidence, primarily from case reports and case series. Large-scale prospective cohort studies and RCTs are needed to develop prophylactic and therapeutic treatments to minimize interruption or discontinuation of oncological therapies.

Development and Validation of a Clinical Decision Support Tool That Incorporates Pharmacokinetic Data to Predict Endoscopic Healing in Patients Treated With Infliximab.

BACKGROUND & AIMS: Infliximab is an effective treatment for moderate to severe ulcerative colitis (UC). Little is known about patient-related factors that might be used to predict endoscopic healing with infliximab therapy. METHODS: We analyzed data from 484 patients included in the randomized trials of the effects of infliximab therapy for patients with UC (Active Ulcerative Colitis Trials [ACT]-1 and ACT-2). We used a 2-compartment population pharmacokinetic model to calculate baseline infliximab clearance. Two multivariable regression models were derived and validated for their ability to identify patients with endoscopic healing (Mayo endoscopic score, ≤1) at weeks 8 and 30, using only baseline variables. We developed a clinical decision support tool (CDST) and calculator to determine the probability of endoscopic healing in patients starting infliximab. RESULTS: Higher baseline infliximab clearance, stool frequency, and rectal bleeding scores were associated negatively with endoscopic healing at week 8. In the validation set, a CDST score of 9 points or fewer identified patients without endoscopic healing at week 8 with 82% sensitivity (95% CI, 76%-88%), whereas a CDST score of 16 points or more identified patients with endoscopic healing at week 8 with 87% specificity (95% CI, 81%-94%). Higher baseline infliximab clearance, stool frequency score, white blood cell count, and lower body weight were associated negatively with endoscopic healing at week 30. In the validation set, CDST scores of 17 points or fewer identified patients without endoscopic healing at week 30 with 90% sensitivity (95% CI, 85%-95%), whereas scores greater than 22 points identified patients with endoscopic healing at week 30 with 80% specificity (95% CI, 73%-87%). External validation models had a modest predictive value, with an area under of the curve of 0.67 (95% CI, 0.61-0.74). Patient-level probabilities of endoscopic healing at weeks 8 or 30 can be calculated online (www.premedibd.com). CONCLUSIONS: Using data from 2 clinical trials of patients receiving infliximab therapy for UC, we developed and validated the CDST, which uses data on infliximab clearance and baseline patient and disease measures to identify patients most likely to have endoscopic healing. This tool will facilitate therapy decision making and precision medicine.

Baseline Clearance of Infliximab Is Associated With Requirement for Colectomy in Patients With Acute Severe Ulcerative Colitis.

BACKGROUND & AIMS: Hospitalized patients with acute severe ulcerative colitis (ASUC) often require surgery. Although the tumor necrosis factor antagonist infliximab is an effective salvage therapy to prevent colectomy in patients with ASUC, optimal dosing is unclear. Calculated infliximab clearance has been associated with important outcomes in patients with ulcerative colitis, but its utility in patients with ASUC has not been established. We assessed the relationship between calculated the baseline infliximab clearance before infliximab salvage therapy and the requirement for colectomy in patients hospitalized for ASUC. METHODS: We obtained data from hospitalized patients with ASUC who initiated infliximab therapy. We then calculated the baseline infliximab drug clearance in these patients based on an existing formula. The primary aim was to compare clearance between patients who required colectomy 6 months later and patients who did not require colectomy. Receiver operating characteristic curve analyses evaluated clearance thresholds for colectomy. Multivariable logistic regression analysis evaluated factors associated with colectomy. RESULTS: In 39 patients with ASUC, the median baseline calculated clearance was higher in patients requiring colectomy at 6 months than in patients without colectomy (0.733 vs 0.569 L/d; P = .005). An infliximab clearance threshold of 0.627 L/d identified patients who required colectomy with 80.0% sensitivity and 82.8% specificity (area under the curve, 0.80). A higher proportion of patients with infliximab clearance of 0.627 L/d or more underwent colectomy within 6 months (61.5%) than patients with lower infliximab clearance values (7.7%) (P = .001). Multivariable analysis identified baseline infliximab clearance as the only factor associated with colectomy. The infliximab dose in the hospital was higher in patients who required colectomy. Results were similar at 30 days and 1 year. CONCLUSIONS: In patients hospitalized with ASUC, higher values of calculated infliximab clearance before infliximab administration is associated with higher rates of colectomy. Although patients who required colectomies received higher doses, data on infliximab concentrations are lacking. Infliximab pharmacokinetic models are needed for patients with ASUC to allow comparative trials on clearance-based vs standard dosing.

Comparison of Assays for Therapeutic Monitoring of Infliximab and Adalimumab in Patients With Inflammatory Bowel Diseases.

Comparison data regarding anti-tumor necrosis factor drug concentrations in inflammatory bowel disease (IBD) between the enzyme-linked immunosorbent assay (ELISA) and the homogenous mobility shift assay (HMSA) are scarce.1-3 As decisions in clinical practice depend on the thresholds that define a therapeutic drug concentration, it is important to determine if this varies based on the type of assay used for therapeutic drug monitoring.4 We recently showed a discrepancy between a commercially available ELISA and the HMSA for both infliximab and adalimumab concentrations in patients with IBD.5 Based on the results of the study, Prometheus Laboratories (San Diego, CA) initiated a comprehensive review of their HMSA assays and found that there was an upward drift for both infliximab (from December 2017 to May 2019) and adalimumab (from August 2017 to May 2019), including when our study was performed. Prometheus Laboratories corrected the errant values and reported the revised drug concentrations to physicians (Supplementary Methods). We aimed to compare the corrected infliximab and adalimumab concentrations with the original ELISA values.

Higher Postinduction Infliximab Concentrations Are Associated With Improved Clinical Outcomes in Fistulizing Crohn's Disease: An ACCENT-II Post Hoc Analysis.

INTRODUCTION: There are only limited data regarding the role of therapeutic drug monitoring in fistulizing Crohn's disease (CD). We investigated the association between both induction and maintenance serum infliximab concentrations and favorable therapeutic outcomes in patients with fistulizing CD. METHODS: This was a post hoc analysis of the ACCENT-II trial evaluating patients with fistulizing CD receiving induction (n = 282) and maintenance infliximab therapy (n = 139). Investigated therapeutic outcomes at both week 14 and week 54 included fistula response, complete fistula response, C-reactive protein (CRP) normalization (≤5 mg/L) in patients with an elevated baseline CRP, and a more stringent outcome of composite remission, defined as combined complete fistula response and CRP normalization. Associations between serum infliximab concentrations and outcomes were assessed by multivariable logistic regression models. RESULTS: Higher week 14 infliximab concentrations were independently associated with week 14 fistula response (odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.02-1.32; P = 0.019), and composite remission (OR: 2.32; 95% CI: 1.55-3.49; P < 0.001). Higher week 14 infliximab concentrations were also independently associated with week 54 composite remission (OR: 2.05; 95% CI: 1.10-3.82; P = 0.023). Based on receiver operating characteristic curve analysis, week 14 infliximab concentrations thresholds with combined maximal sensitivity and specificity of ≥20.2 µg/mL at week 2, ≥15 µg/mL at week 6, and ≥7.2 µg/mL at week 14 were associated with week 14 composite remission. DISCUSSION: Higher post-induction infliximab concentrations are associated with early and long-term favorable therapeutic outcomes in patients with fistulizing CD.

Similar pharmacokinetics of three dosing regimens comprising two oral delayed-release mesalamine formulations in healthy adult volunteers: Randomised, open-label, parallel-group study.

AIMS: Mesalamine is the first-line therapy for treating mild-to-moderate ulcerative colitis. Multiple mesalamine formulations are available, with similar safety and efficacy profiles. Mesalamine is commonly administered as divided dosing, although once-daily dosing may provide benefits for patients. We evaluated the pharmacokinetics of three dosing regimens of two oral delayed-release mesalamine formulations in healthy adult volunteers. METHODS: A randomised, open-label, parallel-group study of mesalamine pharmacokinetics following Lialda 2 × 1.2 g once daily (QD) (dose A), Asacol 6 × 400 mg QD (dose B), or Asacol 2 × 400 mg three times daily (TID) (dose C) over 7 days. Assessments included 5-aminosalicylic acid (5-ASA) and N-acetyl 5-aminosalicylic acid (N-Ac-5-ASA, primary metabolite) pharmacokinetics (Ae (%), AUC0-24 and Cmax ), safety and tolerability. RESULTS: All enrolled volunteers (n = 37) completed the study. Steady state was achieved for all treatments by day 4. Ratios (95% CI) of means for steady-state AUC0-24 (dose A vs B 90.3% [39.8, 204.8], dose A vs C 123.5% [55.3, 275.7], dose B vs C 136.8% [61.3, 305.5]) and Cmax (dose A vs B 106.0% [46.4, 242.2], dose A vs C 133.0% [59.1, 299.0], dose B vs C 125.5% [55.8, 282.1]) were similar for all 5-ASA treatments. Mean urinary excretion of 5-ASA plus N-Ac-5-ASA was comparable between treatments (dose A 21.3%, dose B 20.2%, dose C 17.9%). All treatment regimens were well tolerated; no safety issues were observed. CONCLUSIONS: Plasma and urine pharmacokinetics for Asacol TID, Asacol QD, and Lialda QD are similar, suggesting similar daily systemic exposures can be obtained with either TID or QD dosing. NCT00751699.

Association Between Vedolizumab Levels, Anti-vedolizumab Antibodies, and Endoscopic Healing Index in a Large Population of Patients with Inflammatory Bowel Diseases.

BACKGROUND: The aim of this study was to assess the relationship between serum vedolizumab (VDZ) concentrations and antibodies to VDZ (ATV) in a large cohort of patients with inflammatory bowel diseases. Furthermore, we evaluated the association between serum VDZ concentrations and a novel serum-based biomarker panel designated as the endoscopic healing index (EHI), developed and validated for identifying mucosal inflammation in patients with Crohn's disease (CD). METHODS: Retrospective study where results from patient samples submitted to a commercial clinical laboratory were included. Serum VDZ and ATV levels were analyzed using a drug-tolerant assay. In CD patients for whom both VDZ and EHI were available, VDZ concentrations were correlated with EHI. serum VDZ threshold analysis was performed using ROC curves, and the serum VDZ concentrations that best differentiated EHI < 20 (previously associated with endoscopic remission) were chosen. RESULTS: A total of 9356 patients were included in the VDZ/ATV analysis. Detectable ATV was observed in 2.9% patients with significantly lower serum VDZ concentrations when compared to those with undetectable ATV [3.9 µg/mL (0-9.0) vs. 11.3 µg/mL (5.9-20.6), p < 0.0001]. Of the patients with serum VDZ result, 287 patients had a concomitant EHI test. An inverse correlation was observed between VDZ concentration and EHI (rho = - 0.20, p < 0.001). A serum VDZ concentration ≥ 15.7 µg/ml was best correlated wi th an EHI < 20 [AUROC: 0.67 (95% CI 0.57-0.77)]. CONCLUSIONS: Incidence of ATVs was low, but significantly associated with lower VDZ levels. A serum VDZ concentration threshold of ≥ 15.7 µg/ml was associated with endoscopic remission as defined by an EHI < 20.

Development and Validation of Clinical Scoring Tool to Predict Outcomes of Treatment With Vedolizumab in Patients With Ulcerative Colitis.

BACKGROUND & AIMS: We created and validated a clinical decision support tool (CDST) to predict outcomes of vedolizumab therapy for ulcerative colitis (UC). METHODS: We performed logistic regression analyses of data from the GEMINI 1 trial, from 620 patients with UC who received vedolizumab induction and maintenance therapy (derivation cohort), to identify factors associated with corticosteroid-free remission (full Mayo score of 2 or less, no subscore above 1). We used these factors to develop a model to predict outcomes of treatment, which we called the vedolizumab CDST. We evaluated the correlation between exposure and efficacy. We validated the CDST in using data from 199 patients treated with vedolizumab in routine practice in the United States from May 2014 through December 2017. RESULTS: Absence of exposure to a tumor necrosis factor (TNF) antagonist (+3 points), disease duration of 2 y or more (+3 points), baseline endoscopic activity (moderate vs severe) (+2 points), and baseline albumin concentration (+0.65 points per 1 g/L) were independently associated with corticosteroid-free remission during vedolizumab therapy. Patients in the derivation and validation cohorts were assigned to groups of low (CDST score, 26 points or less), intermediate (CDST score, 27-32 points), or high (CDST score, 33 points or more) probability of vedolizumab response. We observed a statistically significant linear relationship between probability group and efficacy (area under the receiver operating characteristic curve, 0.65), as well as drug exposure (P < .001) in the derivation cohort. In the validation cohort, a cutoff value of 26 points identified patients who did not respond to vedolizumab with high sensitivity (93%); only the low and intermediate probability groups benefited from reducing intervals of vedolizumab administration due to lack of response (P = .02). The vedolizumab CDST did not identify patients with corticosteroid-free remission during TNF antagonist therapy. CONCLUSIONS: We used data from a trial of patients with UC to develop a scoring system, called the CDST, which identified patients most likely to enter corticosteroid-free remission during vedolizumab therapy, but not anti-TNF therapy. We validated the vedolizumab CDST in a separate cohort of patients in clinical practice. The CDST identified patients most likely to benefited from reducing intervals of vedolizumab administration due to lack of initial response. ClinicalTrials.gov no: NCT00783718.

Incorporating Fecal Calprotectin Into Clinical Practice for Patients With Moderate-to-Severely Active Ulcerative Colitis Treated With Biologics or Small-Molecule Inhibitors.

INTRODUCTION: We applied the Grading of Recommendations, Assessment, Development, and Evaluation framework to evaluate the performance of fecal calprotectin (FC) as an alternative to endoscopy in patients with moderate-to-severe ulcerative colitis (UC) treated with a biologic agent or tofacitinib. METHODS: Individual participant data from the trials of infliximab, golimumab, vedolizumab, and tofacitinib for UC were pooled to generate prevalence of endoscopic activity (Mayo endoscopy score) across different combinations of the rectal bleeding score (RBS) and stool frequency score (SFS). These estimates were then combined with the data from an updated systematic review of the operating properties of FC to generate clinical scenario-specific assessments of the performance of FC as a predictor of endoscopic disease activity. A prespecified threshold of acceptability for false-negative (FN) and false-positive (FP) test results was set at 5%. RESULTS: For patients with UC achieving RBS 0 + SFS 0/1, FC ≤ 50 µg/g may avoid endoscopy in 50% patients with a FN rate <5%. Similarly, for patients with RBS 2/3 + SFS 2/3, FC ≥ 250 µg/g potentially avoids endoscopy in approximately 50% patients with an FP rate <5%. The greatest uncertainty in the diagnostic performance for FC was observed in patients with UC achieving RBS 0 but having SFS 2/3, where FN and FP rates were consistently >10%, and endoscopic evaluation may be warranted. DISCUSSION: Two clinical scenarios were identified where FC can be used with confidence for monitoring treatment response to biologics or tofacitinib in patients with UC without the requirement for endoscopy.

Responsiveness of histological disease activity indices in ulcerative colitis: a post hoc analysis using data from the TOUCHSTONE randomised controlled trial.

OBJECTIVE: We evaluated the reliability and responsiveness of available but incompletely validated UC histological disease activity indices using standardised rules for centralised assessment. DESIGN: Disease activity was assessed in biopsies collected in a phase II placebo-controlled ozanimod trial by four blinded pathologists using the Geboes (GS) and modified Riley (MRS) scores, the Robarts Histopathology (RHI) and Nancy Histological (NHI) indices and a Visual Analogue Scale. Reliability was assessed with intraclass correlation coefficients (ICCs). Index responsiveness was evaluated by assessing longitudinal validity (Pearson correlations of changes in index scores and other disease measures), and effect size estimates (standardised effect size (SES)) using two criteria for change (treatment assignment and >2 point decrease in total Mayo Clinic score). Area under the receiver operating characteristic (AUROC) curve estimates evaluated the probability of the indices to discriminate between treatment and placebo. RESULTS: Inter-rater reliability of the histological indices was substantial to almost perfect (ICC>0.61), and responsiveness was moderate to large (SES estimates>0.5); 0.81 (0.52, 1.10), 0.87 (0.58, 1.17), 0.57 (0.30, 0.84) and 0.81 (0.52, 1.09) when treatment assignment was the criterion for change and 1.05 (0.80, 1.31), 1.13 (0.87, 1.39), 0.88 (0.64, 1.12) and 1.06 (0.80, 1.31) for the change in Mayo score criterion for the GS, MRS, RHI and NHI, respectively. The indices had similar drisciminative ability based on AUROC estimates (range 0.608-0.649). CONCLUSION: All four existing histological indices were similarly reliable and responsive based on this dataset.

Infliximab Exposure-Response Relationship and Thresholds Associated With Endoscopic Healing in Patients With Ulcerative Colitis.

BACKGROUND & AIMS: Therapeutic drug monitoring might be used to personalize infliximab treatment of patients with ulcerative colitis (UC), although exposure thresholds associated with endoscopic healing are uncertain. We aimed to determine infliximab concentration thresholds associated with endoscopic outcomes during induction and maintenance therapy for patients with UC. METHODS: We analyzed data from 484 patients with active UC included in 2 randomized controlled trials of infliximab vs placebo. Mayo endoscopic scores (MES) were available from weeks 0, 8, and 30. A 2-compartment population pharmacokinetic model was used to calculate infliximab clearance at baseline. We tested the linear trend between baseline infliximab clearance and MES at week 8. Receiver operating curve analysis identified infliximab clearance and concentration thresholds with a maximum Youden index corresponding to a MES of 0 or ≤1. RESULTS: We found a linear relationship between baseline infliximab clearance and week 8 MES (P < .001); a threshold of <0.397 L/d was associated with week 8 MES ≤1. Infliximab concentrations ≥18.6 µg/mL at week 2, ≥10.6 µg/mL at week 6, and ≥34.9 µg/mL at week 8 were associated with a week 8 MES of ≤1. Infliximab concentrations ≥5.1 µg/mL at week 14 and ≥2.3 µg/mL at week 30 were associated with a week 30 MES of ≤1. Infliximab concentrations ≥6.7 µg/mL at week 14 and ≥3.8 µg/mL at week 30 were associated with a week 30 MES of 0. CONCLUSIONS: Baseline clearance of infliximab and drug concentrations during induction and maintenance infliximab therapy are associated with short- and long-term endoscopic healing. Interventional studies that incorporate individualized dosing based on these parameters are required to show improved patient outcomes.

Should We Divide Crohn's Disease Into Ileum-Dominant and Isolated Colonic Diseases?

Crohn's disease (CD) is an inflammatory bowel disease that can involve any region of the gastrointestinal tract. First described in 1932 as terminal ileitis or regional enteritis, it predominately involves the ileum with or without colonic involvement. Isolated colonic CD was first described in 1960 and since then the phenotypic classification of CD has evolved to stratify patients into isolated ileal, ileocolonic, or isolated colonic involvement. In the current review we evaluate the published literature regarding differences in epidemiology, natural history, pathogenesis, response to therapy, and disease monitoring, when stratified by disease location. Based on the available evidence consideration could be given to a new classification for CD, which splits it into ileum dominant (isolated ileal and ileocolonic) and isolated colonic disease. This may allow for a more optimized approach to clinical care and scientific research for CD.