Defining Endoscopic Remission in Ileocolonic Crohn's Disease: Let's Start from Scratch

Targeting mucosal healing in Crohn's disease: efficacy of novel pathways and therapeutic targets

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease affecting the entire gastrointestinal tract with a progressive and relapsing course. Achieving mucosal healing has emerged as a critical therapeutic goal, as it is associated with sustained clinical remission, reduced hospitalizations, and fewer surgery rates. Therefore, targeting mucosal healing is essential for long-term control in CD.

AREAS COVERED

This review evaluates the efficacy of novel biologic therapies and small molecules in inducing mucosal healing, specifically targeting pathways like IL-12/23, IL-23, α4β7 integrins, Janus kinase 1 (JAK1), and sphingosine-1-phosphate receptor (S1PR) in adults (≥18 years) with moderate-to-severe CD. The rationale for selecting these specific pathways is their central role in modulating key inflammatory processes implicated in CD pathogenesis. We compare these therapies with placebo for both induction and maintenance of remission, based on a PubMed literature review for published articles and ClinicalTrials.gov for ongoing trials.

EXPERT OPINION

Upadacitinib and anti-IL23p19 agents (risankizumab, guselkumab and mirikizumab) are promising advanced non-TNF-targeting therapies for inducing endoscopic remission and mucosal healing but further studies are needed to integrate mucosal healing into a broader definition of endoscopic response, with a unified and precise definition.

Magnetic resonance Index of Activity (MaRIA) is reliable in assessing response to treatment in patients with Crohn's disease (CD)

AIM

To assess the accuracy of Magnetic Resonance Index of Activity (MaRIA) in evaluating therapeutic efficacy in Crohn's disease (CD) patients with different activity levels using ileocolonoscopy as the reference standard.

MATERIALS AND METHODS

Forty-eight patients underwent magnetic resonance enterography (MRE) and ileocolonoscopy at baseline, week 26, and week 52, along with the Simple Endoscopic Score for Crohn's Disease (SES-CD) and MaRIA scores. According to the SES-CD score at baseline, all patients were subdivided into mild, moderate, and severe activity subgroups. The identification of endoscopic mucosal healing (MH) was explored primarily. Moreover, the Crohn's Disease Activity Index (CDAI), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), and interleukin-6 (IL-6) levels were collected and analysed.

RESULTS

MaRIA correlated significantly with SES-CD and CRP at baseline, week 26, and week 52. The discrepancies in MaRIA and SES-CD were statistically significant before and after treatment. MaRIA = 24.43 and ΔMaRIA = 12.77 as the cut-off points were found to have high diagnostic accuracy for predicting MH. MaRIA (p<0.001), SES-CD (p<0.001), CRP (p<0.05), ESR (p<0.05), and CDAI score (p<0.05) in patients with MH were considerably decreased compared to those in patients without MH.

CONCLUSIONS

MRE has good application value in evaluating the therapeutic response of CD patients treated with biological agents. MaRIA is a reliable indicator in the follow-up of CD patients, which is strongly correlated with SES-CD, and it has high accuracy in predicting endoscopic MH.

To STRIDE or not to STRIDE: a critique of "treat to target" in Crohn´s disease

INTRODUCTION

The STRIDE consensus suggested to focus on mucosal healing, based on biomarkers and endoscopy, in addition to clinical endpoints as treatment target. This narrative review provides a critique of this concept in Crohn´s disease.

AREAS COVERED

We analyze and discuss the limitations of endpoints as targets, their currently limited achievability, and the controversial evidence relating to 'treat to target.' The relevant publications in Pubmed were identified in a literature review with the key word 'Crohn´s disease.'

EXPERT OPINION

All targets and endpoints have their limitations, and, even if reached, not all have unequivocally been shown to improve prognosis. The major deficiency of STRIDE is not only the lack of validation and agreement upon endpoints but little evidence of their achievability in a sizable proportion of patients by dose or timing adjustments or switching the medication. Above all, the concept should be based on clear evidence that patients indeed benefit from appropriate escalation of treatment and relevant controlled studies in this regard have been controversial. Until the STRIDE approach is proven to be superior to standard treatment focusing on clinical well-being, the field should remain reluctant and expect more convincing evidence before new targets are approved.

Defining Biological Remission in Crohn's Disease: Interest, Challenges and Future Directions

In Crohn's disease, the treat-to-target strategy has been greatly encouraged and has become a standard of care. In this context, defining the target [remission] constitutes a major stake and is fuelling the literature. Currently, clinical remission [symptom control] is no longer the only objective of treatments since it does not allow to closely control inflammation-induced tissue damage. The introduction of endoscopic remission as a therapeutic target clearly represented progress but this examination remains invasive, costly, not well accepted by patients and does not allow tight control of disease activity. More fundamentally, morphological techniques [e.g. endoscopy, histology, ultrasonography] are limited since they do not evaluate the biological activity of the disease but only its consequences. Besides, emerging evidence suggests that biological signs of disease activity could better guide treatment decisions than clinical parameters. In this context, we stress the necessity to define a novel treatment target: biological remission. Based on our previous work, we propose a conceptual definition of biological remission which goes beyond the classical normalization of inflammatory markers [C-reactive protein and faecal calprotectin]: absence of biological signs associated with the risk of short-term relapse and mid-/long-term relapse. The risk of short-term relapse seems essentially to be characterized by a persistent inflammatory state while the risk of mid-/long-term relapse implies a more heterogeneous biology. We discuss the value of our proposal [guiding treatment maintenance, escalation or de-escalation] but also the fact that its clinical implementation would require overcoming major challenges. Finally, future directions are proposed to better define biological remission.

Transrectal Absorber Guide Raster-Scanning Optoacoustic Mesoscopy for Label-Free In Vivo Assessment of Colitis

Optoacoustic imaging (OAI) enables microscale imaging of endogenous chromophores such as hemoglobin at significantly higher penetration depths compared to other optical imaging technologies. Raster-scanning optoacoustic mesoscopy (RSOM) has recently been shown to identify superficial microvascular changes associated with human skin pathologies. In animal models, the imaging depth afforded by RSOM can enable entirely new capabilities for noninvasive imaging of vascular structures in the gastrointestinal tract, but exact localization of intra-abdominal organs is still elusive. Herein the development and application of a novel transrectal absorber guide for RSOM (TAG-RSOM) is presented to enable accurate transabdominal localization and assessment of colonic vascular networks in vivo. The potential of TAG-RSOM is demonstrated through application during mild and severe acute colitis in mice. TAG-RSOM enables visualization of transmural vascular networks, with changes in colon wall thickness, blood volume, and OAI signal intensities corresponding to colitis-associated inflammatory changes. These findings suggest TAG-RSOM can provide a novel monitoring tool in preclinical IBD models, refining animal procedures and underlines the capabilities of such technologies to address inflammatory bowel diseases in humans.

Effectiveness of swapping to ustekinumab after vedolizumab failure in patients with multi-refractory Crohn's disease

BACKGROUND

Ustekinumab (UST) and vedolizumab (VDZ) are biologic therapies for moderate-to-severe Crohn's disease (CD) in patients who failed or had contraindication to anti-TNF treatment.

AIMS

To evaluate ustekinumab efficacy as third-line treatment after swapping from VDZ for failure.

METHODS

We conducted a monocentric, retrospective, observational study where CD patients were followed for 12 months from the beginning of UST therapy. We assessed clinical activity (HBI) and laboratory markers (CRP) at the initiation of UST therapy (T0) and after 2(T2), 6(T6) and 12(T12) months. Endoscopic activity was recorded at T0 and T12. We registered data regarding their clinical history and previous biologic treatments. Steroid-free clinical remission was defined as HBI ≤ 4 without need for steroids. Clinical response was defined as HBI reduction of at least three points or the suspension of steroids.

RESULTS

27 CD patients treated with UST after VDZ failure had a minimum follow up of 12 months and were included. All patients had previously been treated with anti-TNF agents. After 12 months, steroid-free clinical remission was evident in 15 (55.5%) patients, 5 (18.5%) had clinical response, while 7 (26%) had suspended for failure or persisted on treatment after optimization.

CONCLUSIONS

Ustekinumab should be considered as third-line biologic treatment in multi-refractory CD patients.

Etrolizumab as induction and maintenance therapy in patients with moderately to severely active Crohn's disease (BERGAMOT): a randomised, placebo-controlled, double-blind, phase 3 trial

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 monoclonal antibody targeting α4β7 and αEβ7 integrins. We aimed to compare the safety and efficacy of two doses of etrolizumab with placebo in patients with Crohn's disease.

METHODS

BERGAMOT was a randomised, placebo-controlled, double-blind, phase 3 study done at 326 treatment centres worldwide. We included patients aged 18-80 years with moderately to severely active Crohn's disease (Crohn's Disease Activity Index [CDAI] score of 220-480, and a mean daily stool frequency score of ≥6 or a mean daily stool frequency score of >3, and a mean daily abdominal pain score of >1, as well as the presence of active inflammation on screening ileocolonoscopy) who had intolerance, inadequate response, or no response to one or more of corticosteroids, immunosuppressants, or anti-TNF therapy within the past 5 years. BERGAMOT consisted of three induction cohorts (a placebo-controlled, double-blind exploratory cohort [cohort 1]; an active treatment cohort not containing a placebo control [cohort 2]; and a placebo-controlled, double-blind pivotal cohort [cohort 3]) and one maintenance cohort. In induction cohort 3, during the 14-week induction, patients were randomly assigned (2:3:3) to receive matched placebo, 105 mg etrolizumab subcutaneously every 4 weeks (at weeks 0, 4, 8, and 12) or 210 mg etrolizumab subcutaneously (at weeks 0, 2, 4, 8, and 12), stratified by concomitant treatment with oral corticosteroids, concomitant treatment with immunosuppressants, baseline disease activity, and previous exposure to anti-TNF therapy. To preserve masking, all patients received two injections at weeks 0, 4, 8, and 12 and one injection at week 2. Week 14 etrolizumab responders from all cohorts were re-randomly assigned (1:1) to receive 105 mg etrolizumab (etrolizumab maintenance group) or placebo (placebo maintenance group) every 4 weeks for 52 weeks; patients in the induction placebo group underwent a sham re-randomisation to preserve masking. During maintenance, randomisation was stratified by CDAI remission status, concomitant treatment with oral corticosteroids, induction dose regimen, and previous exposure to anti-TNF therapy. All participants and study site personnel were masked to treatment assignment for both induction and maintenance. Co-primary induction endpoints at week 14 (placebo vs 210 mg etrolizumab) were clinical remission (mean stool frequency ≤3 and mean abdominal pain ≤1, with no worsening) and endoscopic improvement (≥50% reduction in Simple Endoscopic Score for Crohn's Disease [SES-CD]). Co-primary maintenance endpoints at week 66 (placebo vs etrolizumab) were clinical remission and endoscopic improvement. Efficacy was analysed using a modified intention-to-treat (mITT) population, defined as all randomised patients who received at least one dose of study drug (induction) and as all patients re-randomised into maintenance who received at least one dose of study drug in the maintenance phase (maintenance). Safety analyses included all patients who received at least one dose of study drug. Maintenance safety analyses include all adverse events occurring in both induction and maintenance. This trial is registered with ClinicalTrials.gov, NCT02394028, and is closed to recruitment.

FINDINGS

Between March 20, 2015, and Sept 7, 2021, 385 patients (209 [54%] male and 326 [85%] white) were randomly assigned in induction cohort 3 to receive placebo (n=97), 105 mg etrolizumab (n=143), or 210 mg etrolizumab (n=145). 487 patients had a CDAI-70 response in any of the induction cohorts and were enrolled into the maintenance cohort, of whom 434 had a response to etrolizumab and were randomly assigned to placebo (n=217) or 105 mg etrolizumab (n=217). At week 14, 48 (33%) of 145 patients in the 210 mg induction etrolizumab group versus 28 (29%) of 96 patients in the placebo induction group were in clinical remission (adjusted treatment difference 3·8% [95% CI -8·3 to 15·3]; p=0·52), and 40 (27%) versus 21 (22%) showed endoscopic improvement (5·8% [-5·4 to 17·1]; p=0·32). At week 66, a significantly higher proportion of patients receiving etrolizumab than those receiving placebo had clinical remission (76 [35%] of 217 vs 52 [24%] of 217; adjusted treatment difference 11·3% [95% CI 2·7-19·7]; p=0·0088) and endoscopic improvement (51 [24%] vs 26 [12%]; 11·5% [4·1-18·8]; p=0·0026). Similar proportions of patients reported one or more adverse events during induction (95 [66%] of 143 in the 105 mg etrolizumab group, 85 [59%] of 145 in the 210 mg etrolizumab group, and 51 [53%] of 96 in the placebo group) and maintenance (189 [87%] of 217 in the etrolizumab group and 190 [88%] of 217 in the placebo group). During induction, the most common treatment-related adverse events were injection site erythema (six [4%] of 143 in the 105 mg etrolizumab group, four [3%] of 145 in the 210 mg etrolizumab group, and none of 96 in the placebo group), and arthralgia (two [1%], one [1%], and four [4%]). In the maintenance cohort, the most common treatment-related adverse events were injection site erythema (six [3%] of 217 in the etrolizumab group vs 14 [6%] of 217 in the placebo: group), arthralgia (five [2%] vs eight [4%]), and headache (five [2%] vs seven [3%]). The most common serious adverse event was exacerbation of Crohn's disease (14 [6%] of 217 patients taking placebo and four [2%] of 217 patients taking 105 mg etrolizumab in the maintenance cohort).

INTERPRETATION

A significantly higher proportion of patients with moderately to severely active Crohn's disease achieved clinical remission and endoscopic improvement with etrolizumab than placebo during maintenance, but not during induction.

FUNDING

F Hoffmann-La Roche.

Predicting endoscopic remission in Crohn's disease by the modified multiplier SES-CD (MM-SES-CD)

BACKGROUND AND AIMS

The Simple Endoscopic Score for Crohn's disease (SES-CD) is the primary tool for measurement of mucosal inflammation in clinical trials but lacks prognostic potential. We set to develop and validate a modified multiplier of the SES-CD (MM-SES-CD), which takes into consideration each individual parameter's prognostic value for achieving endoscopic remission (ER) while on active therapy.

METHODS

In this posthoc analysis of three CD clinical trial programmes (n=350 patients, baseline SES-CD ≥ 3 with confirmed ulceration), data were pooled and randomly split into a 70% training and 30% testing cohort. The MM-SES-CD was designed using weights for individual parameters as determined by logistic regression modelling, with 1-year ER (SES-CD < 3) being the dependent variable. A cut point score for low and high probability of ER was determined by using the maximum Youden Index and validated in the testing cohort.

RESULTS

Baseline ulcer size, extent of ulceration and presence of non-passable strictures had the strongest association with 1-year ER as compared with affected surface area, with differential weighting of individual parameters across disease segments being observed during logistic regression. The MM-SES-CD was generated using this weighted regression model and demonstrated strong discrimination for ER in the training dataset (area under the receiver operator curve (AUC) 0.83, 95% CI 0.78 to 0.94) and in the testing dataset (AUC 0.82, 95% CI 0.77 to 0.92). In comparison to the MM-SES-CD scoring model, the original SES-CD score lacks accuracy (AUC 0.60, 95% CI 0.55 to 0.65) for predicting the achievement of ER.

CONCLUSIONS

We developed and internally validated the MM-SES-CD as an endoscopic severity assessment tool to predict one-year ER in patients with CD on active therapy.

Predictive value of blood concentration of biologics on endoscopic inactivity in inflammatory bowel disease: A systematic review

BACKGROUND

Although blood concentration of biologics is an important composition of disease management in inflammatory bowel disease (IBD) patients, complexity and uncertainty of biological management encourage many disputes in predicting the outcome of IBD patients through blood concentration of biologics.

AIM

To verify the predictive value of blood concentration of biologics on endoscopic inactivity in IBD patients under different situations.

METHODS

We searched PubMed/MEDLINE, Embase, and Web of Science up to May 2020 and identified IBD patients as the research cohort as well as the correlations between blood concentration of biologics and endoscopic inactivity in IBD patients as the research direction.

RESULTS

A total of 23 articles with 30 clinical studies and 1939 IBD patients were included. The predictive cut-off value of blood concentration of infliximab on mucosal healing should be 2.7-10.6 μg/mL in IBD. Blood concentration of infliximab reaching 5.0-12.7 μg/mL or more increased the probability of fistula healing/closure in perianal fistulizing Crohn's disease. Blood concentration of adalimumab reaching 7.2-16.2 μg/mL or more could predict mucosal healing in IBD. The predictive cut-off value of blood concentration of adalimumab on fistula healing/closure should be 5.9-9.8 μg/mL in perianal fistulizing Crohn's disease. Blood concentration of vedolizumab surpassing 25.0 μg/mL indicated mucosal healing in ulcerative colitis patients under maintenance therapy and the predictive cut-off value of blood concentration on mucosal healing or endoscopic remission under induction therapy in IBD could be 8.0-28.9 μg/mL.

CONCLUSION

Blood concentration of biologics should not be utilized to predict endoscopic inactivity of IBD independently due to discrepancies in clinical studies, whereas conducting therapeutic drug monitoring intensively contributes to precise therapy.

Location but Not Severity of Endoscopic Lesions Influences Endoscopic Remission Rates in Crohn's Disease: A Post Hoc Analysis of TAILORIX

INTRODUCTION

The impact of severity and location of Crohn's disease (CD) endoscopic ulcers on endoscopic remission in patients treated with antitumor necrosis factor is poorly known. We aimed to describe the endoscopic evolution of CD lesions in a prospective cohort of patients treated with infliximab (IFX) in combo therapy.

METHODS

We conducted a post hoc analysis of the TAILORIX randomized controlled trial, which studied biologic-naïve patients with active CD and endoscopic ulcers receiving IFX combo therapy. Ileocolonoscopies were performed at week 0, 12, and 54. Endoscopic healing was defined as the absence of ulcers and complete endoscopic remission as CD Endoscopic Index of Severity (CDEIS) <3. Ileocolonic segments were scored separately for remission by blinded readers.

RESULTS

A total of 122 (median disease duration: 7 months) patients were included, corresponding with 379 diseased segments. The median (IQR) CDEIS scores at week 0, 12, and 54 were 9.9 (6.1-14.4), 2.4 (0.2-4.6), and 0.2 (0.0-3.7), respectively. At weeks 12 and 54, the rates of endoscopic healing and complete endoscopic remission were 41% and 61% and 61% and 73%, respectively. Median CDEIS scores were similar among patients with deep ulcers at baseline and those with only superficial ulcers at week 12 and 54. Segmental remission rates were lower both at week 12 and 54 in the ileum compared with colonic segments (P < 0.01 all comparisons) and in the rectum (P = 0.02 and P = 0.03).

DISCUSSION

In biologic-naive patients with CD treated with IFX combo therapy, the severity of endoscopic lesions at the baseline did not influence healing rates. Endoscopic remission occurs less frequently in the ileum compared with the colon.

Association of Biomarker Cutoffs and Endoscopic Outcomes in Crohn's Disease: A Post Hoc Analysis From the CALM Study

BACKGROUND

CALM was a randomized phase 3 trial in patients with Crohn's disease (CD) that demonstrated improved endoscopic outcomes when treatment was escalated based on cutoffs for inflammatory biomarkers, fecal calprotectin (FC), C-reactive protein (CRP), and CD Activity Index (CDAI) remission vs CDAI response alone. The purpose of this post hoc analysis of CALM was to identify drivers of treatment escalation and evaluate the association between biomarker cutoff concentrations and endoscopic end points.

METHODS

The proportion of patients achieving CD Endoscopic Index of Severity (CDEIS) <4 and no deep ulcers 48 weeks after randomization was evaluated according to CRP <5 mg/L or ≥5 mg/L and FC <250 μg/g or ≥250 μg/g. Subgroup analyses were performed according to disease location, and sensitivity analyses were conducted in patients with elevated CRP and/or FC at baseline. The association between endoscopic end points and biomarker cutoffs was performed using χ 2 test.

RESULTS

The proportion of patients who achieved the primary end point CDEIS <4 and no deep ulcers was significantly greater for those with FC <250 µg/g (74%; P < 0.001), with an additive effect for CRP <5 mg/L. The association of FC <250 µg/g with improved endoscopic outcomes was independent of disease location, although the greatest association was observed for ileocolonic disease. Fecal calprotectin <250 µg/g, CRP <5 mg/L, and CDAI <150 gave a sensitivity/specificity of 72%/63% and positive/negative predictive values of 86%/42% for CDEIS <4 and no deep ulcers 48 weeks after randomization.

CONCLUSION

This post hoc analysis of CALM demonstrated that a cutoff of FC <250 µg/g is a useful surrogate marker for mucosal healing in CD.

Systematic Review and External Validation of Prediction Models Based on Symptoms and Biomarkers for Identifying Endoscopic Activity in Crohn's Disease

BACKGROUND & AIMS

Endoscopic healing, an important target of treatment for Crohn's disease (CD), requires ileocolonoscopy, which is costly and burdensome. We investigated whether published noninvasive models (based on symptoms and biomarkers) to evaluate CD activity have sufficient accuracy to replace ileocolonoscopy.

METHODS

We performed a systematic review of published noninvasive diagnostic models to evaluate CD activity that used endoscopic features of activity (endoscopic activity) or healing as the reference standard. We externally validated these models for the outcome endoscopic activity (CD endoscopic index of severity scores, ≥3) using data from the a randomized controlled trial investigating tailored treatment with infliximab for active luminal Crohn's disease (TAILORIX) study (346 ileocolonoscopies in 155 patients) and the Utrecht Activity Index (UAI) study (93 ileocolonoscopies in 82 patients). We calculated the area under the receiver operating characteristic curves (AUROCs) for the models using data from these studies, and compared the performance of these models against measurements of fecal calprotectin (FC) and C-reactive protein (CRP).

RESULTS

We screened 5303 articles and identified 27 models (from 21 studies) for our analysis. Seven models could be validated externally; in the TAILORIX data set, these models identified patients with endoscopic activity with AUROC values ranging from 0.61 (95% CI, 0.51-0.70) to 0.81 (95% CI, 0.76-0.86). In this data set, the AUROC value for FC concentration was 0.79 (95% CI, 0.74-0.85) and the AUROC value for CRP level was 0.72 (95% CI, 0.66-0.77). The AUROC values for the validation in the UAI data set were similar. In the TAILORIX and/or UAI data set, 4 of the 7 models, as well as the FC and CRP assays, were able to identify patients with endoscopic activity with positive predictive values of 90% or more. Two of the 7 models (but not the FC or CRP values) identified patients without endoscopic activity with a negative predictive value (NPV) of 90% or more, leading to correct prediction of endoscopic healing in 3.2% to 11.3% of all patients. For example, applying the Herranz-Bachiller model (1 of 7 models) at a NPV of 92.1% and a positive predictive value of 91.9% correctly identified 35.7% of all patients in whom ileocolonoscopy could be avoided for expected endoscopic activity or healing but incorrectly identified 3.2% of all patients. Most ileocolonoscopies (66.5% in TAILORIX and 72.6% in the UAI of all ileocolonoscopies) could be avoided correctly based on concentrations of FC of 100 μg/g or less and 250 μg/g or higher. However, using this range of FC concentrations to identify patients who do not require ileocolonoscopy caused 18.7% of all patients in the TAILORIX cohort and 19.8% of all patients in the UAI cohort to be predicted incorrectly to have endoscopic activity or healing.

CONCLUSIONS

In a systematic review and external validation of noninvasive models to identify patients with endoscopic activity of CD, we found only 2 of 7 models evaluated to have NPVs of 90% or more, however, leading to correctly predicted EH in only a small proportion of patients. Ileocolonoscopy therefore remains the mainstay to evaluate CD mucosal disease activity and healing.

Mucosal Healing Is Associated With the Reduced Disabling Disease in Crohn's Disease

Mucosal healing (MH) is the goal of the “treat to target” strategy in Crohn's disease (CD), which seeks to prevent disability. However, evidence is limited regarding whether achieving MH can reduce disability in CD. We aimed to estimate the probability of disabling disease and to investigate the association between MH and disabling disease in CD.

Mucosal healing in Crohn's disease: new insights

INTRODUCTION

Traditional management of patients with Crohn's disease includes symptoms and quality of life improvement. With the advent of biological agents, mucosal healing has become an achievable goal, documented through endoscopy. However, due to the transmural nature of inflammation, the prevention of bowel damage should be included in the aims of a targeted therapeutic strategy.

AREAS COVERED

Updated literature has been searched in PubMed from 2008 to 2020. This review focuses on the state of the art in the innovative therapeutic goals in Crohn's disease, also considering still controversial aspects and future research topics in the management of Crohn's disease.

EXPERT OPINION

Although a widely agreed view supports the notion that mucosal healing and bowel damage control may promote beneficial outcomes (i.e. reduction in hospitalization and surgical rates, avoidance of steroids), long-term robust data are still missing. On the other hand, the development of -omics techniques has expanded our knowledge of the pathogenetic mechanism underlying inflammatory bowel disease and opened up new horizons in precision or personalized medicine.

Influence of Drug Exposure on Vedolizumab-Induced Endoscopic Remission in Anti-Tumour Necrosis Factor [TNF] Naïve and Anti-TNF Exposed IBD Patients

BACKGROUND AND OBJECTIVES

Vedolizumab has demonstrated efficacy and safety in patients with Crohn's disease [CD] and ulcerative colitis [UC]. Endoscopic outcome data are limited, especially in anti-tumour necrosis factor [TNF] naïve patients. The present study compared endoscopic outcome in anti-TNF naïve and exposed patients, and explored if this was affected by drug exposure.

METHODS

We retrospectively analysed all patients initiating vedolizumab at our tertiary referral centre since 2015. For UC, endoscopic improvement was defined as a Mayo endoscopic subscore ≤1 at week 14. For CD, endoscopic remission was defined as absence of ulcerations at week 22. Vedolizumab trough concentrations were measured at week 6, week 14 and during maintenance.

RESULTS

A total of 336 patients were identified [53.3% CD], 20% of them being anti-TNF naïve. Endoscopic improvement was achieved by 56.1% of UC patients and endoscopic remission by 39.1% of CD patients. Endoscopic outcomes were significantly better in anti-TNF naïve vs exposed patients [all: 67.2% vs 42.0%, p = 0.0002; UC: 74.4% vs 50.0%, p = 0.02; CD: 57.1% vs 35.8%, p = 0.03]. Achievement of endoscopic end points significantly impacted long-term treatment continuation [p = 9.7 × 10-13]. A better endoscopic outcome was associated with significantly higher drug exposure in both CD and UC.

CONCLUSIONS

The results of this observational, single-centre real-life study suggest that vedolizumab may induce endoscopic remission in both CD and UC. Although anti-TNF naïve patients had a significantly better outcome, 42% of anti-TNF exposed patients still benefited endoscopically. A clear exposure-endoscopic response relationship exists, but not all patients will benefit from treatment intensification. Hence, predictive biomarkers remain necessary.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

Outcomes and Strategies to Support a Treat-to-target Approach in Inflammatory Bowel Disease: A Systematic Review

BACKGROUND AND AIMS

Management of Crohn's disease and ulcerative colitis has typically relied upon treatment intensification driven by symptoms alone. However, a 'treat-to-target' management approach may help to address underlying inflammation, minimise disease activity at early stages of inflammatory bowel disease, limit progression, and improve long-term outcomes.

METHODS

A systematic literature review was conducted to identify data relevant to a treat-to-target approach in inflammatory bowel disease, published between January 1, 2007 and May 15, 2017.

RESULTS

Consistent with recommendations of the Selecting Therapeutic Targets in Inflammatory Bowel Disease [STRIDE] working group, studies have investigated factors influencing the achievement of both endoscopic and histological mucosal healing and patient-level outcomes in inflammatory bowel disease [IBD]. Histological healing and biomarker levels have also been shown to be modifiable outcomes. Although there is a lack of prospectively derived evidence validating mucosal healing as a treatment target, data are emerging to suggest that targeting mucosal healing or inflammation rather than symptoms may be cost-effective in some settings. The review highlighted several strategies that may support the implementation of a treat-to-target approach in IBD. The prospective randomised CALM study demonstrated how tight control [whereby treatment decisions are based on close monitoring of inflammatory biomarkers] leads to improvements in endoscopic and clinical outcomes. The review also considered the influence of coordinated care from a multidisciplinary team and patient engagement with improved adherence, as well as the role of therapeutic drug monitoring in inflammatory bowel disease management.

CONCLUSIONS

A treat-to-target strategy may impact on disease progression and improve outcomes in inflammatory bowel disease. Prospective studies including long-term data are required to ensure that the most appropriate targets and strategies are identified.

Endoscopic, Radiologic, and Histologic Healing With Vedolizumab in Patients With Active Crohn's Disease

BACKGROUND & AIMS

Vedolizumab is a gut-selective monoclonal antibody for the treatment of moderately to severely active Crohn's disease (CD). We performed a prospective study of endoscopic, radiologic, and histologic healing in patients with CD who received vedolizumab therapy.

METHODS

We performed a phase 3b, open-label, single-group study of 101 patients with at least 3 months of active CD (a CD Activity Index [CDAI] score of 220-450, a simple endoscopic score for CD [SES-CD] of 7 or more, 1 or more mucosal ulcerations [identified by endoscopy], and failure of conventional therapy) from March 2015 through December 2017. Among the patients enrolled, 54.5% had previous failure of 1 or more tumor necrosis factor (TNF) antagonists and 44.6% had severe endoscopic disease activity (SES-CD scores above 15) at baseline. Participants received vedolizumab (300 mg intravenously) at weeks 0, 2, and 6, and then every 8 weeks thereafter, for 26 weeks (primary study) or 52 weeks (substudy, 56 patients). The primary endpoint at week 26 was endoscopic remission (SES-CD score of 4 or less); other endpoints included endoscopic response (50% reduction in SES-CD), radiologic remission (magnetic resonance index of activity score below 7), and histologic response (modified global histologic disease activity score of 4 or less).

RESULTS

At week 26, 11.9% of patients were in endoscopic remission (95% confidence interval [CI] 6.3-9.8); at week 52, 17.9% of the patients were in endoscopic remission (95% CI 8.9-30.4). Higher proportions of patients naïve to TNF antagonists achieved endoscopic remission than patients with TNF-antagonist-failure at weeks 26 and 52. Higher proportion of patients with moderate CD (SES-CD scores, 7-15) achieved endoscopic remission at weeks 26 and 52 than patients with severe CD (SES-CD scores above 15). The proportion of patients with complete mucosal healing increased over time, with greater rates of healing in the colon than in the ileum. Remission was detected by magnetic resonance enterography in 21.9% of patients at week 26 (95% CI 9.3-40.0) and in 38.1% at week 52 (95% CI 18.1-61.6). At week 26, 24.4% of patients had a histologic response in the colon (95% CI 15.3-35.4) and 28.3% of patients had a histologic response in the ileum (95% CI 17.5-41.4). At week 52, 20.5% of patients had a histologic response in the colon (95% CI 9.8-35.3) and 34.3% of patients had a histologic response in the ileum (95% CI 19.1-52.2). There were no notable safety issues, including worsening of extraintestinal manifestations.

CONCLUSIONS

In a phase 3b trial, we found that 26 and 52 weeks of treatment with vedolizumab (300 mg, at weeks 0, 2, and 6, and then every 8 weeks thereafter) induces endoscopic, radiologic, and histologic healing in patients with moderately to severely active CD. ClinicalTrials.gov no: NCT02425111.

Ustekinumab Exposure-outcome Analysis in Crohn's Disease Only in Part Explains Limited Endoscopic Remission Rates

BACKGROUND AND AIMS

Ustekinumab, an anti-IL12/23p40 monoclonal antibody, has been approved for Crohn's disease [CD]. Real-life data in CD patients receiving ustekinumab intravenously [IV] during induction, followed by subcutaneous [SC] maintenance, are lacking. We assessed efficacy of ustekinumab and studied exposure-response correlations.

METHODS

We performed a prospective study in 86 CD patients predominantly refractory or intolerant to anti-tumour necrosis factor agents and/or vedolizumab. All received ustekinumab 6 mg/kg IV induction, with 90 mg SC every 8 weeks thereafter. Endoscopic response (50% decrease in Simple Endoscopic Score for CD [SES-CD] at Week 24), endoscopic remission [SES-CD ≤2], and clinical remission [daily stool frequency ≤2.8 and abdominal pain score ≤1] were assessed at weeks 4,8,16, and 24. Further serial analyses included patient-reported outcomes [PRO2], faecal calprotectin [fCal], and ustekinumab serum levels.

RESULTS

SES-CD decreased from 11.5 [8.0-18.0] at baseline to 9.0 [6.0-16.0] at week [w]24 [p = 0.0009], but proportions of patients achieving endoscopic response [20.5%] or endoscopic remission [7.1%] were low. Clinical remission rates were 39.5% at w24. After IV induction, fCal dropped from baseline [1242.9 μg/g] to w4 [529.0 μg/g] and w8 [372.2 μg/g], but increased again by w16 [537.4 μg/g] and w24 [749.0 μg/g]. A clear exposure-response relationship was observed, both during induction and during maintenance therapy, with different thresholds depending on the targeted outcome.

CONCLUSIONS

In this cohort of refractory CD patients, ustekinumab showed good clinical remission rates but limited endoscopic remission after 24 weeks. Our data suggest that higher doses may be required to achieve better endoscopic outcomes.

Targeting mucosal healing in Crohn's disease: what the clinician needs to know

In recent years, mucosal healing has emerged as a key therapeutic goal in the clinical management of patients with Crohn's disease, as it has been associated with improved long-term clinical outcomes. With the vast improvements in endoscopic imaging techniques and the increase in available treatment options, which reportedly are able to induce mucosal healing, the practising physician is left to wonder: how is endoscopic mucosal healing exactly defined in Crohn's disease, and how can it effectively be achieved and monitored in daily clinical practice? Within this review, we will give an overview of the ongoing debate about the definition of mucosal healing and the modalities to monitor inflammation, and finally present available therapies with the capacity to induce mucosal healing.

Advanced endoscopic techniques in the assessment of inflammatory bowel disease: new technology, new era

Endoscopic assessment of inflammation and mucosal healing is crucial for appropriate management in IBD. Current definition of endoscopic mucosal healing has been derived using previous generation of standard white light endoscopes. New endoscopy technologies widely available provide much more detailed images of mucosal and vascular patterns. Novel endoscopic techniques with high definition image, optical and digital enhancement have enhanced the quality and fine details of vascular and mucosal pattern so that endoscopic images have started to reflect histological changes for lesions and inflammation/healing. These technologies can now define subtle inflammatory changes and increase detection and characterisation of colonic lesions in patients with IBD. The best endoscopic technique to detect dysplasia in IBD is still debated. Dye chromoendoscopy with targeted biopsies is considered by Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in inflammatory Bowel Disease Patients: International Consensus Recommendations (SCENIC consensus the standard of care and recommended for adoption by gastroenterologists in practice. In future, it is possible that well-trained colonoscopists using high definition equipment with image enhancements may be able to obtain equivalent yield without pan-colonic dye spraying and characterise lesions. Finally, SCENIC introduced endoscopic resectability of some dysplastic colonic lesions-new techniques may now better characterise endoscopic resectability and limit the number of colectomies. In this review, we will provide a state-of-the-art opinion on the direction of technological advances in the assessment of IBD and how new concepts will refine clinical practice.