A Prediction Model for Successful Increase of Adalimumab Dose Intervals in Patients with Crohn's Disease: Secondary Analysis of the Pragmatic Open-Label Randomised Controlled Non-inferiority LADI Trial.

BACKGROUND: In the pragmatic open-label randomised controlled non-inferiority LADI trial we showed that increasing adalimumab (ADA) dose intervals was non-inferior to conventional dosing for persistent flares in patients with Crohn's disease (CD) in clinical and biochemical remission. AIMS: To develop a prediction model to identify patients who can successfully increase their ADA dose interval based on secondary analysis of trial data. METHODS: Patients in the intervention group of the LADI trial increased ADA intervals to 3 and then to 4 weeks. The dose interval increase was defined as successful when patients had no persistent flare (> 8 weeks), no intervention-related severe adverse events, no rescue medication use during the study, and were on an increased dose interval while in clinical and biochemical remission at week 48. Prediction models were based on logistic regression with relaxed LASSO. Models were internally validated using bootstrap optimism correction. RESULTS: We included 109 patients, of which 60.6% successfully increased their dose interval. Patients that were active smokers (odds ratio [OR] 0.90), had previous CD-related intra-abdominal surgeries (OR 0.85), proximal small bowel disease (OR 0.92), an increased Harvey-Bradshaw Index (OR 0.99) or increased faecal calprotectin (OR 0.997) were less likely to successfully increase their dose interval. The model had fair discriminative ability (AUC = 0.63) and net benefit analysis showed that the model could be used to select patients who could increase their dose interval. CONCLUSION: The final prediction model seems promising to select patients who could successfully increase their ADA dose interval. The model should be validated externally before it may be applied in clinical practice. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, number NCT03172377.

Early fecal calprotectin levels at week 8 may guide therapeutic decisions on Ustekinumab therapy in patients with Crohn's disease.

BACKGROUND: Response evaluation after induction therapy with ustekinumab (UST) in Crohn's disease (CD) is important for decisions on maintenance therapy. We aimed to assess the potential of fecal calprotectin (FC) levels to predict endoscopic response at week 16. METHODS: CD patients with FC >100 µg/g and endoscopic active disease (SES-CD> 2, Rutgeerts' score ≥ i2) at initiation of UST therapy were enrolled. FC was determined at weeks 0, 2, 4, 8 and 16 and patients underwent a colonoscopy at week 16. The primary outcome was an endoscopic response at week 16 (SES-CD score ≥50% decrease or a decrease of ≥1 points in Rutgeerts' score). The optimal cut-off levels of FC and change in FC to predict endoscopic response were determined using ROC statistics. RESULTS: 59 CD patients were included. Endoscopic response was observed in 21/59 (36%) patients. The diagnostic accuracy for FC levels at week 8 to predict endoscopic response at week 16 showed a predictive value of 0.71. A decrease in FC levels ≥500 µg/g between baseline at week 8 indicates endoscopic response (PPV = 89%), whereas absence of any decrease indicates endoscopic non-response after induction (NPV = 81%). CONCLUSIONS: Continuation of UST therapy without endoscopic response evaluation may be considered in patients with a decrease in FC levels of ≥500 µg/g at week 8. The decision on continuation of UST therapy or therapy optimization needs reconsideration in patients without a decrease of FC level. In all other patients, endoscopic response evaluation of induction therapy remains essential for therapeutic decisions.

Prediction of Relapse After Anti-Tumor Necrosis Factor Cessation in Crohn's Disease: Individual Participant Data Meta-analysis of 1317 Patients From 14 Studies.

BACKGROUND & AIMS: Tools for stratification of relapse risk of Crohn's disease (CD) after anti-tumor necrosis factor (TNF) therapy cessation are needed. We aimed to validate a previously developed prediction model from the diSconTinuation in CrOhn's disease patients in stable Remission on combined therapy with Immunosuppressants (STORI) trial, and to develop an updated model. METHODS: Cohort studies were selected that reported on anti-TNF cessation in 30 or more CD patients in remission. Individual participant data were requested for luminal CD patients and anti-TNF treatment duration of 6 months or longer. The discriminative ability (concordance-statistic [C-statistic]) and calibration (agreement between observed and predicted risks) were explored for the STORI model. Next, an updated prognostic model was constructed, with performance assessment by cross-validation. RESULTS: This individual participant data meta-analysis included 1317 patients from 14 studies in 11 countries. Relapses after anti-TNF cessation occurred in 632 of 1317 patients after a median of 13 months. The pooled 1-year relapse rate was 38%. The STORI prediction model showed poor discriminative ability (C-statistic, 0.51). The updated model reached a moderate discriminative ability (C-statistic, 0.59), and included clinical symptoms at cessation (hazard ratio [HR], 2.2; 95% CI, 1.2-4), younger age at diagnosis (HR, 1.5 for A1 (age at diagnosis ≤16 years) vs A2 (age at diagnosis 17 - 40 years); 95% CI, 1.11-1.89), no concomitant immunosuppressants (HR, 1.4; 95% CI, 1.18-172), smoking (HR, 1.4; 95% CI, 1.15-1.67), second line anti-TNF (HR, 1.3; 95% CI, 1.01-1.69), upper gastrointestinal tract involvement (HR, 1.3 for L4 vs non-L4; 95% CI, 0.96-1.79), adalimumab (HR, 1.22 vs infliximab; 95% CI, 0.99-1.50), age at cessation (HR, 1.2 per 10 years younger; 95% CI, 1-1.33), C-reactive protein (HR, 1.04 per doubling; 95% CI, 1.00-1.08), and longer disease duration (HR, 1.07 per 5 years; 95% CI, 0.98-1.17). In subanalysis, the discriminative ability of the model improved by adding fecal calprotectin (C-statistic, 0.63). CONCLUSIONS: This updated prediction model showed a reasonable discriminative ability, exceeding the performance of a previously published model. It might be useful to guide clinical decisions on anti-TNF therapy cessation in CD patients after further validation.

Discontinuation of Anti-Tumour Necrosis Factor Therapy in Patients with Perianal Fistulizing Crohn's Disease: Individual Participant Data Meta-Analysis of 309 Patients from 12 Studies.

BACKGROUND: The risk of relapse after anti-tumour necrosis factor [TNF] therapy discontinuation in Crohn's disease patients with perianal fistulas [pCD] is unclear. We aimed to assess this risk. METHODS: A systematic literature search was conducted to identify cohort studies on the incidence of relapse following anti-TNF discontinuation in pCD patients. Individual participant data were requested from the original study cohorts. Inclusion criteria were age ≥16 years, pCD as a (co)indication for start of anti-TNF therapy, more than three doses, and remission of luminal and pCD at anti-TNF discontinuation. The primary outcome was the cumulative incidence of CD relapse using Kaplan-Meier estimates. Secondary outcomes included response to re-treatment and risk factors associated with relapse as assessed by Cox regression analysis. RESULTS: In total, 309 patients from 12 studies in ten countries were included. The median duration of anti-TNF treatment was 14 months [interquartile range 5.8-32.5]. Most patients were treated for pCD without active luminal disease [89%], received first-line anti-TNF therapy [87%], and continued immunomodulatory therapy following anti-TNF discontinuation [78%]. The overall cumulative incidence of relapse was 36% (95% confidence interval [CI] 25-48%) and 42% [95% CI 32-53%] at 1 and 2 years after anti-TNF discontinuation, respectively. Risk factors for relapse included smoking (hazard ratio [HR] 1.5 [1.0, 2.1]) and history of proctitis (HR 1.7 [1.1, 2.5]). The overall re-treatment response rate was 82%. CONCLUSIONS: This individual participant data meta-analysis, on predominantly patients with pCD without active luminal disease and first-line anti-TNF therapy, shows that over half of patients remain in remission 2 years after anti-TNF discontinuation. Therefore, anti-TNF discontinuation may be considered in this subgroup.

Modulation of Indoleamine 2,3-Dioxygenase 1 During Inflammatory Bowel Disease Activity in Humans and Mice.

Background and Aims: Indoleamine 2,3 dioxygenase-1 (IDO1), a key enzyme in tryptophan metabolism, is strongly up-regulated both in human inflammatory bowel disease (IBD) and animal models of colitis, however its role in the pathogenesis is still controversial. In this study, we investigated IDO1 expression and activity in a mouse model of DSS-induced chronic colitis as well as in colon biopsies and sera from IBD patients. Methods: Chronic colitis was induced in mice through the oral administration of dextran sodium sulfate (DSS), and IDO1 activity was induced by i.p. treatment with N-acetyl serotonin (NAS). IDO1 expression and catalytic activity (measured as Kyn/Trp ratio) was evaluated in sera and tissue samples collected from mice and 93 IBD patients under immunotherapy with Vedolizumab (VDZ) or Ustekinumab (UST). Results: Strong up-regulation of IDO1 was found in colons of mice with acute colitis, which follows disease activity. Enhanced IDO1 activity by NAS treatment protects the intestinal mucosa during the recovery phase of chronic colitis. In IBD patients, IDO1 expression and activity correlate with the severity of mucosal inflammation with inflamed regions showing higher IDO1 expression compared to non-inflamed regions within the same patient. Endoscopic response to VDZ/UST treatment is associated with decreased expression of IDO1. Conclusions: This is the first study demonstrating immunomodulatory activity of IDO1 in a chronic mouse model of DSS-induced colitis. As its expression and catalytic activity correlate with the grade of mucosal inflammation and treatment response, IDO1 could represent a promising biomarker for disease severity and treatment monitoring in IBD.

Ustekinumab Tissue and Serum Levels in Patients With Crohn's Disease Are Closely Correlated Though Not Consistently Associated With Objective Response After Induction.

BACKGROUND: Ustekinumab (UST), which targets p40/interleukin (IL)-23 and IL-12, is an effective treatment for Crohn's disease (CD). Therapeutic drug monitoring may optimize UST posology. The aim of this study was to investigate UST and IL-23 serum and tissue concentrations in relation to mucosal inflammation and treatment response at an early time point. METHODS: CD patients starting UST between December 2016 and November 2018 were prospectively enrolled. Endoscopies were performed at baseline and week 16. UST and IL-23 serum and tissue concentrations were measured at week 16. Clinical and biochemical response were defined as decline of ≥3 points in Harvey-Bradshaw Index and reduction of ≥50% in fecal calprotectin levels. Endoscopic response was defined as a ≥50% decline in Simple Endoscopic Score or a decline of ≥1 points in Rutgeerts score. Histological remission was defined as Global Histologic Disease Activity Score ≤4. RESULTS: Of 56 included patients, 17 (30%) of 56 showed clinical response, 16 (30%) of 53 showed biochemical response, and 20 (36%) of 56 showed endoscopic response. UST, but not IL-23, concentration in biopsies was correlated to levels in corresponding sera (P < .0001). No correlation was found between UST tissue levels and treatment response. Patients achieving biochemical response showed significantly higher UST serum levels (3.12 µg/mL vs 1.41 µg/mL; P = .01). Tissue IL-23-to-UST ratio correlated with mucosal inflammation (P = .01). CONCLUSIONS: This is the first study to demonstrate a correlation between serum and tissue UST levels. While tissue IL-23-to-UST ratio correlated with mucosal inflammation, UST serum levels were more indicative for biochemical response. The role of UST levels for therapeutic drug monitoring in inflammatory bowel disease needs further research.

Ustekinumab (UST) serum levels correlate with UST tissue levels in patients with Crohn's disease. Tissue interleukin-23-to-UST ratio correlates with histological inflammation (Global Histologic Disease Activity Score). Serum UST levels correlate with biochemical response (reduction of ≥50% in fecal calprotectin levels).

Increased versus conventional adalimumab dose interval for patients with Crohn's disease in stable remission (LADI): a pragmatic, open-label, non-inferiority, randomised controlled trial.

BACKGROUND: Despite its effectiveness in treating Crohn's disease, adalimumab is associated with an increased risk of infections and high health-care costs. We aimed to assess clinical outcomes of increased adalimumab dose intervals versus conventional dosing in patients with Crohn's disease in stable remission. METHODS: The LADI study was a pragmatic, open-label, multicentre, non-inferiority, parallel, randomised controlled trial, done in six academic hospitals and 14 general hospitals in the Netherlands. Adults (aged ≥18 years) diagnosed with luminal Crohn's disease (with or without concomitant perianal disease) were eligible when in steroid-free clinical and biochemical remission (defined as Harvey-Bradshaw Index [HBI] score <5, faecal calprotectin <150 µg/g, and C-reactive protein <10 mg/L) for at least 9 months on a stable dose of 40 mg subcutaneous adalimumab every 2 weeks. Patients were randomly assigned (2:1) to the intervention group or control group by the coordinating investigator using a secure web-based system with variable block randomisation (block sizes of 6, 9, and 12). Randomisation was stratified on concomitant use of thiopurines and methotrexate. Patients and health-care providers were not masked to group assignment. Patients allocated to the intervention group increased adalimumab dose intervals to 40 mg every 3 weeks at baseline and further to every 4 weeks if they remained in clinical and biochemical remission at week 24. Patients in the control group continued their 2-weekly dose interval. The primary outcome was the cumulative incidence of persistent flares at week 48 defined as the presence of at least two of the following criteria: HBI score of 5 or more, C-reactive protein 10 mg/L or more, and faecal calprotectin more than 250 µg/g for more than 8 weeks and a concurrent decrease in the adalimumab dose interval or start of escape medication. The non-inferiority margin was 15% on a risk difference scale. All analyses were done in the intention-to-treat and per-protocol populations. This trial was registered at ClinicalTrials.gov, NCT03172377, and is not recruiting. FINDINGS: Between May 3, 2017, and July 6, 2020, 174 patients were randomly assigned to the intervention group (n=113) or the control group (n=61). Four patients from the intervention group and one patient from the control group were excluded from the analysis for not meeting inclusion criteria. 85 (50%) of 169 participants were female and 84 (50%) were male. At week 48, the cumulative incidence of persistent flares in the intervention group (three [3%] of 109) was non-inferior compared with the control group (zero; pooled adjusted risk difference 1·86% [90% CI -0·35 to 4·07). Seven serious adverse events occurred, all in the intervention group, of which two (both patients with intestinal obstruction) were possibly related to the intervention. Per 100 person-years, 168·35 total adverse events, 59·99 infection-related adverse events, and 42·57 gastrointestinal adverse events occurred in the intervention group versus 134·67, 75·03, and 5·77 in the control group, respectively. INTERPRETATION: The individual benefit of increasing adalimumab dose intervals versus the risk of disease recurrence is a trade-off that should take patient preferences regarding medication and the risk of a flare into account. FUNDING: Netherlands Organisation for Health Research and Development.

Cost-Effectiveness Analysis of Increased Adalimumab Dose Intervals in Crohn's Disease Patients in Stable Remission: The Randomized Controlled LADI Trial.

BACKGROUND AND AIMS: We aimed to assess cost-effectiveness of increasing adalimumab dose intervals compared to the conventional dosing interval in patients with Crohn's disease [CD] in stable clinical and biochemical remission. DESIGN: We conducted a pragmatic, open-label, randomized controlled non-inferiority trial, comparing increased adalimumab intervals with the 2-weekly interval in adult CD patients in clinical remission. Quality of life was measured with the EQ-5D-5L. Costs were measured from a societal perspective. Results are shown as differences and incremental net monetary benefit [iNMB] at relevant willingness to accept [WTA] levels. RESULTS: We randomized 174 patients to the intervention [n = 113] and control [n = 61] groups. No difference was found in utility (difference: -0.017, 95% confidence interval [-0.044; 0.004]) and total costs (-€943, [-€2226; €1367]) over the 48-week study period between the two groups. Medication costs per patient were lower (-€2545, [-€2780; -€2192]) in the intervention group, but non-medication healthcare (+€474, [+€149; +€952]) and patient costs (+€365 [+€92; €1058]) were higher. Cost-utility analysis showed that the iNMB was €594 [-€2099; €2050], €69 [-€2908; €1965] and -€455 [-€4,096; €1984] at WTA levels of €20 000, €50 000 and €80 000, respectively. Increasing adalimumab dose intervals was more likely to be cost-effective at WTA levels below €53 960 per quality-adjusted life year. Above €53 960 continuing the conventional dose interval was more likely to be cost-effective. CONCLUSION: When the loss of a quality-adjusted life year is valued at less than €53 960, increasing the adalimumab dose interval is a cost-effective strategy in CD patients in stable clinical and biochemical remission. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, number NCT03172377.

Vedolizumab Tissue Concentration Correlates to Mucosal Inflammation and Objective Treatment Response in Inflammatory Bowel Disease.

BACKGROUND: The association between vedolizumab (VDZ) exposure and treatment response is unclear and seems insufficiently explained by serum levels. The aim of this study was to assess the correlation between VDZ concentrations in serum and intestinal tissue and their association with mucosal inflammation and response to VDZ. METHODS: This prospective study included 37 adult patients with inflammatory bowel disease with endoscopic inflammation at baseline who started VDZ. At week 16, serum and biopsies were collected for VDZ measurement by enzyme-linked immunosorbent assay. Nonlinear mixed-effects modeling was used to calculate serum trough concentrations and to assess intestinal tissue concentrations. Validated clinical and endoscopic scores were used to define clinical and endoscopic response and remission, and fecal calprotectin levels were used to assess biochemical response. Histologic remission was determined by the Nancy score. RESULTS: A positive correlation was observed between VDZ concentrations in serum and tissue (r2 = 0.83; P < 0.0001). High mucosal rather than serum VDZ levels correlated with a reduced endoscopic (P = 0.06) grade of mucosal inflammation. Furthermore, patients with a positive biochemical and endoscopic outcome had higher tissue levels of VDZ than patients without biochemical and endoscopic response (P < 0.01 and P = 0.04, respectively). CONCLUSIONS: Tissue levels of VDZ may provide a better marker than serum levels for mucosal inflammation and objective treatment outcome at week 16. The potential of VDZ tissue levels for therapeutic drug monitoring in inflammatory bowel disease warrants further exploration.

Fecal calprotectin is an early predictor of endoscopic response and histologic remission after the start of vedolizumab in inflammatory bowel disease.

BACKGROUND AND AIMS: Early prediction of the effect of vedolizumab (VDZ) in inflammatory bowel disease (IBD) is of paramount importance to guide clinical decisions. This study assessed whether early fecal calprotectin (FC) can predict endoscopic response and histologic remission after VDZ initiation. METHODS: This was a prospective study. Inclusion criteria were endoscopic inflammation and FC >100 µg/g. FC was determined at baseline and weeks 2, 4, 8 and 16. At week 16, endoscopies with ileal and colonic biopsies were performed. FC changes were assessed with Wilcoxon Rank Sum tests. ROC statistics were used to assess the diagnostic accuracy of FC. RESULTS: In total, 45 patients [27 Crohn's disease (CD), 16/2 ulcerative colitis (UC)/IBD-unclassified] [40% males, median age 39 (28-51) years] were included. Week 16 endoscopic response and histologic remission rates were 58% and 33%. A median 37% decline in FC at week 2 was observed only in endoscopic responders, p = 0.025. FC <250 µg/g at week 8 predicted endoscopic response in both UC and CD (positive predictive value 100%), whereas absence of FC decline at week 8 corresponded with absence of endoscopic response in CD [negative predictive value (NPV) 82%] and absence of histologic remission in both UC and CD (NPV 90%). CONCLUSION: The onset of a decline in FC as early as week 2 is associated with endoscopic response to VDZ induction. FC <250 µg/g at week 8 is associated with endoscopic response, whereas absence of FC decline at week 8 is associated with absence of both endoscopic response and histologic remission. FC levels 8 weeks after the start of VDZ could be used to guide clinical decisions and might substitute for endoscopic response evaluation.