Early clinical remission and normalisation of CRP are the strongest predictors of efficacy, mucosal healing and dose escalation during the first year of adalimumab therapy in Crohn's disease

Predictors and optimal management of tumor necrosis factor antagonist nonresponse in inflammatory bowel disease: A literature review

Tumor necrosis factor-α (TNF-α) antagonists, the first biologics approved for treating patients with inflammatory bowel disease (IBD), are effective for the induction and maintenance of remission and significantly improving prognosis. However, up to one-third of treated patients show primary nonresponse (PNR) to anti-TNF-α therapies, and 23%-50% of IBD patients experience loss of response (LOR) to these biologics during subsequent treatment. There is still no recognized predictor for evaluating the efficacy of anti-TNF drugs. This review summarizes the existing predictors of PNR and LOR to anti-TNF in IBD patients. Most predictors remain controversial, and only previous surgical history, disease manifestations, drug concentrations, antidrug antibodies, serum albumin, some biologic markers, and some genetic markers may be potentially predictive. In addition, we also discuss the next steps of treatment for patients with PNR or LOR to TNF antagonists. Therapeutic drug monitoring plays an important role in treatment selection. Dose escalation, combination therapy, switching to a different anti-TNF drug, or switching to a biologic with a different mechanism of action can be selected based on the concentration of the drug and/or antidrug antibodies.

Dose Escalation Patterns of Advanced Therapies in Crohn's Disease and Ulcerative Colitis: A Systematic Literature Review

INTRODUCTION

Dose escalation is one of the treatment approaches studied and suggested in advanced therapies for Crohn's disease (CD) and ulcerative colitis (UC). This study aimed to identify and characterize the dosing escalation patterns of advanced therapies in CD and UC.

METHODS

Two systematic literature reviews (SLRs) were conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE®, Embase®, and Cochrane Library were searched for articles published between January 2011 and October 2021 and limited to non-interventional studies in English language. Congress and bibliographic searches were also conducted. Articles were screened by two independent researchers. Dose escalation patterns were described and summarized considering the regional regulatory label recommendation (in North America [NA] or outside of North America [ONA]).

RESULTS

Among 3190 CD and 2116 UC articles identified in the Ovid searches, 100 CD and 54 UC studies were included in the SLR, with more studies conducted ONA. Most studies reported an initial maintenance dose pattern aligned with the lower starting dose per local regulatory label; however, several ONA studies (n = 13 out of 14) reported ustekinumab every 8 weeks as starting maintenance pattern in CD. In ONA studies, the median within-guideline escalation rates in CD and UC were 43% in ustekinumab (CD only), 33% and 32% for vedolizumab; 29% and 39% for adalimumab; and 14% and 10% for infliximab. Evidence regarding dose escalation patterns for tofacitinib, certolizumab pegol, and golimumab was limited. Some dose escalation patterns outside of label recommendations were observed including ustekinumab every 8 weeks to every 4 weeks and vedolizumab every 8 weeks to every 6 weeks.

CONCLUSION

Dose escalation strategies are widely documented in the literature. The reported dose escalation patterns and escalation rates vary by region and by CD and UC. Most escalation patterns reported were aligned with regulatory recommendations while some reported more diverse or aggressive dose escalation.

PROSPERO REGISTRATION

CRD42021289251.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.

Active smoking is associated with the development of adverse events of biological therapy in patients with inflammatory bowel disease

INTRODUCTION

Smoking has been associated with lower levels of anti-TNF agents, higher antibodies and a reduced response to anti-TNF in patients with inflammatory bowel disease (IBD). The aim of this study was to investigate the possible association between smoking and adverse events (AEs) of biologics in patients with IBD.

MATERIAL AND METHODS

Consecutive IBD patients under biologics from a prospective, longitudinal registry of a tertiary center were included. A specially designed questionnaire including a wide range of AEs associated with biologics was also used.

RESULTS

A total of 147 patients with IBD under biologics [median age (IQR) 46 (32.5-56) years, Crohn's disease (CD) 109 (74%), female 51 (35%), under combination with immunosuppressants 60 (41 %), under intensified biologic therapy 50 (34%), under anti-TNF 132 (89%), vedolizumab 11 (7.5%), ustekinumab 3 (2%)] who had completed the questionnaire forms for AEs were included. There were 52 (35%) active smokers and 33 (22.5%) ex-smokers. The prevalence of all AEs was 88% in smokers, 87% in ex-smokers and 79% in nonsmokers. Active smoking was significantly associated with the presence of arthralgias and skin rashes ( P = 0.01 and 0.002, respectively). These correlations were the same for the CD and ulcerative colitis (UC), except for arthralgias where there was a significant correlation only with CD ( P = 0.001). There were no significant associations between smoking and other AEs ( P > 0.05).

CONCLUSION

Active smoking is associated with the development of dermatological manifestations (both in UC and CD) and arthralgias (in CD) in IBD patients under biologics.

Does Disease Activity After Induction Treatment With Biologics Predict Short-Term Outcome in Crohn's Disease and Ulcerative Colitis?

BACKGROUND

Secondary loss of response to biological therapy is a challenge when treating Crohn's disease (CD) and ulcerative colitis (UC). Currently, no single marker has been found to be valid as a prognostic indicator of response to biologic therapy in patients with CD and UC. In this study, we aimed to assess whether disease activity after 14 weeks of biologic therapy has a prognostic impact on surgery and steroid-free remission during 6 months following completion of induction therapy.

METHODS

In an unselected cohort study based on data from 4 national Danish health registries, we identified 493 patients with UC and 620 patients with CD who completed induction therapy with biologics from 2016 to 2019. Following induction therapy with biologics, we defined disease activity based on C-reactive protein and clinical scores of disease activity. The composite endpoint, "not being well treated," included surgery or use of corticosteroid within 6 months following induction therapy.

RESULTS

In patients with UC with disease activity following induction therapy, the adjusted odds ratio for surgery or steroid treatment during 6 months of follow-up was 3.9 (95% CI, 1.6-9.3) compared with patients without disease activity, and in patients with CD, the adjusted odds ratio was 3.6 (95% CI, 1.7-7.6).

CONCLUSIONS

A positive treatment response to biologic treatment after induction therapy (measured by C-reactive protein and clinical scores) predicts a better short-term outcome in patients with CD and UC.

Alterations and Potential Applications of Gut Microbiota in Biological Therapy for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a chronic immune-mediated inflammatory disorder of the gastrointestinal tract that is closely associated with dysbiosis of the intestinal microbiota. Currently, biologic agents are the mainstream therapies for IBD. With the increasing incidence of IBD, limitations of biologic agents have gradually emerged during treatment. Recent studies have indicated that gut microbiota is highly correlated with the efficacy of biologic agents. This review focuses on alterations in both the components and metabolites of gut microbiota during biological therapy for IBD, systematically summarises the specific gut microbiota closely related to the clinical efficacy, and compares current predictive models for the efficacy of biologics, further highlighting the predictive value of intestinal microbiota. Based on the mechanistic analysis of faecal microbiota transplantation (FMT) and biologic agents, a new therapeutic strategy, comprising a combination of FMT and biologics, has been proposed as a promising treatment for IBD with improved efficacy.

Risk Factors of Clinical Relapses in Pediatric Luminal Crohn's Disease: A Retrospective Cohort Study

INTRODUCTION

There is currently little knowledge on factors associated with the relapse of Crohn's disease (CD) in children. The aims of this study were to describe the risk factors associated with relapse in pediatric CD and the changes in the relapse rate over the past decade.

METHODS

Patients younger than 18 years and diagnosed between 2009 and 2019 were included in this retrospective cohort study. Clinical, endoscopic, histological, and laboratory data, as well as induction and maintenance treatments, were collected from the medical records. Survival analyses and Cox regression models were used to assess the impact of these risk factors on relapse.

RESULTS

Six hundred thirty-nine patients were included. There was a decrease in the clinical relapse rate over the past decade: 70.9% of the patients diagnosed between 2009 and 2014 relapsed as compared with 49.1% of the patients diagnosed between 2015 and 2019 (P < 0.0001). The following variables were associated with clinical relapse: female sex (adjusted hazard ratio [aHR] = 1.52, P = 0.0007), exposure to oral 5-ASA (aHR = 1.44, P = 0.04), use of immunomodulatory agents compared with tumor necrosis factor-alpha inhibitors (methotrexate aHR = 1.73, P = 0.003; thiopurines aHR = 1.63, P = 0.002), presence of granulomas (aHR = 1.34, P = 0.02) and increased eosinophils on intestinal biopsies (aHR = 1.36, P = 0.02), high levels of C-reactive protein (aHR = 1.01, P < 0.0001) and fecal calprotectin (aHR = 1.08, P < 0.0001), and low serum infliximab levels (aHR = 2.32, P = 0.001).

DISCUSSION

Relapse of pediatric CD has decreased in the past decade. The risk of relapse is significantly associated with clinical, endoscopic, histological, and laboratory variables and treatment strategies.

Model-Based Meta-Analysis on the Efficacy of Biologics and Small Targeted Molecules for Crohn’s Disease

Information on comparative drug efficacy is of great importance for drug development as well as clinical practice. Up to now, the relative efficacy of biologics and small targeted molecules for Crohn’s disease (CD) remains unclear. The objective of this study was to quantify the relative efficacy of investigational and approved biological treatments for CD measured in Crohn’s Disease Activity Index (CDAI), Inflammatory Bowel Disease Questionnaire (IBDQ), and C-reactive protein (CRP). The analysis dataset was composed of summary-level data from 46 trials, containing 12,846 patients, with treatment of 24 drugs. Six mathematical models with non-parametric placebo estimations were developed to describe the time course and dose–response of six efficacy measures. The effects of covariate were further evaluated. Time–response relationships were found in outcomes measured in CDAI. The patients’ age, disease duration, baseline CDAI, and CRP showed an impact on the efficacy. Model simulations were performed to compare the efficacies across different drugs. The most achievement in clinical remission (defined as CDAI less than 150) and clinical response (defined as the reduction in CDAI for 100 or 70) was observed in the simulation for PF-04236921 and infliximab, respectively. The most improvement in IBDQ was shown in tofacitinib. In general, tumor necrosis factor (TNF)-α inhibitors were the most effective biologics, and the highest efficacy of small targeted molecules was observed in janus kinase (JAK) inhibitors. These findings have important implications for clinical practice in CD.

Poor Concordance Between Clinical Activity and Endoscopic Severity in Pediatric Crohn's Disease: Before and After Induction Therapy

OBJECTIVES AND STUDY

Endoscopic assessments of disease activity are important to diagnose and evaluate treatment responses in patients with Crohn's disease (CD). However, the invasiveness of endoscopy limits the application of this technique in routine examination. Thus, interest has been increasing in identifying noninvasive surrogate markers to predict endoscopic CD activity.

METHODS

We retrospectively analyzed pediatric patients with new-onset CD from January 2013 to December 2018 at Zhejiang University Affiliated Children's Hospital. The disease severity was scored according to the Crohn's Disease Endoscopic Index of Severity (CDEIS). Routine blood tests were determined individually. Clinical activity was assessed based on the Pediatric Crohn's Disease Activity Index (PCDAI).

RESULTS

A total of 91 patients with CD had undergone one or more ileocolonoscopies (n = 146), the mean CDEIS for all the pediatric patients with CD was 7.0 (95% CI 5.7-8.2), and the mean PCDAI was 20.9 (95% CI 18.3-23.5). Pearson's linear analysis of the CDEIS and PCDAI in pediatric patients with CD showed a moderate correlation (r = 0.508, P < 0.001). Weak correlations were found between the PCDAI and CDEIS at the first diagnosis (r = 0.408, P < 0.001) and after completing induction therapy (r = 0.286, P < 0.05). Routine blood tests also did not correlate well with the CDEIS.

CONCLUSIONS

This study identified weak correlations between the PCDAI and CDEIS in assessing pediatric patients with CD severity both at first diagnosis and after induction therapy. A comprehensive assessment of PCDAI, CDEIS and multiple laboratory factors should be performed at diagnosis and during the follow-up of patients with CD.

Mucosal Healing in Crohn's Disease: Bull's Eye or Bust? "The Pro Position"

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory disorder affecting the gastrointestinal tract with disease behaviour based on the depth and severity of mucosal injury. Cumulative injury can result in complications including stricture formation and penetrating complications which often require surgical resection of diseased segments of the intestine resulting in significant morbidity. Accurate assessment of disease activity and appropriate treatment is essential in preventing complications.

SUMMARY

Treatment targets in the management of CD have evolved with the advent of more potent immunosuppressive therapy. Targeting the resolution of sub-clinical inflammation and achieving mucosal healing is associated with the prevention of stricturing and penetrating complications. Identifying non-invasive modalities to assess mucosal healing remains a challenge.

KEY MESSAGES

Mucosal healing minimizes the risk of developing disease complications, prolongs steroid-free survival, and reduces hospitalization and the need for surgical intervention.

Optimizing biologic therapy in inflammatory bowel disease: a Delphi consensus in the United Arab Emirates

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic, relapsing-remitting inflammatory conditions with a substantial negative impact on health-related quality of life and work productivity. Treatment of IBD has been revolutionized by the advent of biologic therapies, initially with anti-TNF agents and more recently with multiple alternatives targets, and yet more under development.

OBJECTIVES

Approximatively one third of patients do not respond to biologic therapy and more importantly a significant proportion experiences partial response or loss of response during treatment. The latter are common clinical situations and paradoxically are not addressed in the commercial drug labels and available guidelines. There is therefore a clinical need for physicians to understand when and how eventually to optimize the biologic therapy.

DESIGN

This consensus using a Delphi methodology was promoted and supported by the Emirates Society of Gastroenterology and Hepatology to close this gap.

DATA SOURCES AND METHODS

Following an extensive systematic review of over 60,000 studies, 81 studies with dose escalation and five addressing drug monitoring were selected and in addition five systematic reviews and three guidelines.

RESULTS AND CONCLUSION

after three rounds of voting 18 statements were selected with agreement ranging from of 80% to 100.

Predictors of drug survival: A cohort study comparing anti-tumour necrosis factor agents using the Swedish inflammatory bowel disease quality register

BACKGROUND

Whether long-term effectiveness differs between anti-tumour necrosis factor (anti-TNF) agents is unknown.

AIMS

To examine drug survival of first-line anti-TNF agents and identify predictors of discontinuation. To reduce channelling bias, we also compared drug survival of the second anti-TNF.

METHODS

Biologic-naïve patients (N = 955) recorded in the Swedish IBD Quality Register (SWIBREG) were examined. We used propensity score matching, comparing drug survival over up to three years of follow-up. Cox regression estimated adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs).

RESULTS

In Crohn's disease, discontinuation because of lack/loss of response was 32% [95%CI = 26%-38%] for infliximab versus 16% [95%CI = 11%-21%] for adalimumab. Infliximab [vs adalimumab; aHR = 1.96; 95%CI = 1.20-3.21] and colonic disease (L2) [vs no L2; aHR = 2.17; 95% CI = 1.26-3.75] were associated with higher discontinuation rates, whereas normalised CRP at three months [aHR = 0.40; 95% CI = 0.19-0.81] with a lower rate. Consistently, patients who switched from adalimumab to infliximab (vs infliximab to adalimumab) had earlier discontinuation (P = 0.04). Concomitant use of immunomodulators was associated with a lower adverse drug reaction-mediated discontinuation rate [aHR = 0.46; 95% CI = 0.28-0.77], in part explained by fewer infusion reactions [aHR = 0.27; 95% CI = 0.08-0.89]. In ulcerative colitis, the probability of discontinuation because of lack/loss of response was 40% [95% CI = 33%-47%] for infliximab versus 37% [95% CI = 21%-53%] for adalimumab. Disease duration ≥10 years [aHR = 0.25; 95% CI = 0.10-0.58] and normalised CRP after three months [aHR = 0.39; 95% CI = 0.18-0.84] were associated with lower discontinuation rates.

CONCLUSIONS

Clinical characterisation of patients may aid decision-making on anti-TNF treatment. The consistently shorter drug survival for infliximab (vs adalimumab) in Crohn's disease, suggests a potential difference between the two drugs.

Frequency and Effectiveness of Empirical Anti-TNF Dose Intensification in Inflammatory Bowel Disease: Systematic Review with Meta-Analysis

Loss of response to antitumor necrosis factor (anti-TNF) therapies in inflammatory bowel disease occurs in a high proportion of patients. Our aim was to evaluate the loss of response to anti-TNF therapy, considered as the need for dose intensification (DI), DI effectiveness and the possible variables influencing its requirements. Bibliographical searches were performed.

SELECTION

prospective and retrospective studies assessing DI in Crohn's disease and ulcerative colitis patients treated for at least 12 weeks with an anti-TNF drug.

EXCLUSION CRITERIA

studies using anti-TNF as a prophylaxis for the postoperative recurrence in Crohn's disease or those where DI was based on therapeutic drug monitoring.

DATA SYNTHESIS

effectiveness by intention-to-treat (random effects model). Data were stratified by medical condition (ulcerative colitis vs. Crohn's disease), anti-TNF drug and follow-up.

RESULTS

One hundred and seventy-three studies (33,241 patients) were included. Overall rate of the DI requirement after 12 months was 28% (95% CI 24-32, I2 = 96%, 41 studies) in naïve patients and 39% (95% CI 31-47, I2 = 86%, 18 studies) in non-naïve patients. The DI requirement rate was higher both in those with prior anti-TNF exposure (p = 0.01) and with ulcerative colitis (p = 0.02). The DI requirement rate in naïve patients after 36 months was 35% (95% CI 28-43%; I2 = 98%; 18 studies). The overall short-term response and remission rates of empirical DI in naïve patients were 63% (95% CI 48-78%; I2 = 99%; 32 studies) and 48% (95% CI: 39-58%; I2 = 92%; 25 studies), respectively. The loss of response to anti-TNF agents-and, consequently, DI-occurred frequently in inflammatory bowel disease (approximately in one-fourth at one year and in one-third at 3 years). Empirical DI was a relatively effective therapeutic option.

Predictors and Early Markers of Response to Biological Therapies in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) are chronic conditions that primarily affect the gastrointestinal tract, with a complex pathogenesis; they are characterized by a significant heterogeneity of clinical presentations and of inflammatory pathways that sustain intestinal damage. After the introduction of the first biological therapies, the pipeline of therapies for IBD has been constantly expanding, and a significant number of new molecules is expected in the next few years. Evidence from clinical trials and real-life experiences has taught us that up to 40% of patients do not respond to a specific drug. Unfortunately, to date, clinicians lack a valid tool that can predict each patient’s response to therapies and that could help them in choosing what drug to administer. Several candidate biomarkers have been investigated so far, with conflicting results: clinical, genetic, immunological, pharmacokinetic and microbial markers have been tested, but no ideal marker has been identified so far. Based on recent evidence, multiparametric models seemingly hold the greatest potential for predicting response to therapy. In this narrative review, we aim to summarize the current knowledge on predictors and early markers of response to biological therapies in IBD.

Pre-treatment magnetic resonance enterography findings predict the response to TNF-alpha inhibitors in Crohn's disease

BACKGROUND

Identifying predictors of therapeutic response is the cornerstone of personalised medicine.

AIM

To identify predictors of long-term healing of severe inflammatory lesions based on magnetic resonance enterography (MRE) findings in patients with Crohn's disease (CD) treated with tumour necrosis factor alpha (TNF-α) inhibitors.

METHODS

This prospective longitudinal single-centre study included patients with clinically active CD requiring treatment with TNF-α inhibitors with at least one intestinal segment with a severe inflammatory lesion detected by MRE (segmental MaRIA ≥11). MRE data were obtained at baseline, and at weeks 14 and 46. The primary endpoint was healing of severe inflammatory lesions (MaRIA <11) in each segment. The secondary endpoint was healing of all severe inflammatory lesions on a per-patient analysis.

RESULTS

We included 58 patients with 86 intestinal segments with severe inflammatory lesions. At week 46, healing of severe lesions was found in 51/86 (59.3%) segments, and complete healing of inflammatory lesions in all segments was found in 28/58 (48.6%) patients. Multivariable analysis found baseline-negative predictors of long-term healing of severe inflammation were ileal (as opposed to colonic) location (OR 0.00, [0.00-0.56] P = 0.002) and presence of creeping fat on MRE (OR 0.00 [0.00-0.57]; P = 0.001). Persistence of segmental MaRIA score >10.6 at week 14 was a negative predictor of healing at week 46 (OR 0.3 [0.04--0.38]; P < 0.001).

CONCLUSION

In patients with CD, the absence of creeping fat detected at baseline MRE and location of severe inflammatory lesions are clinically relevant predictors of long-term healing of severe inflammation under treatment with TNF-α inhibitors.

Combination Therapy of Adalimumab With an Immunomodulator Is Not More Effective Than Adalimumab Monotherapy in Children With Crohn's Disease: A Post Hoc Analysis of the PAILOT Randomized Controlled Trial

BACKGROUND

The PAILOT trial was a randomized controlled trial aimed to evaluate proactive vs reactive therapeutic drug monitoring in children with Crohn's disease (CD) treated with adalimumab. Our aim in this post hoc analysis of the PAILOT trial was to assess the efficacy and safety of adalimumab combination treatment in comparison with monotherapy at week 72 after adalimumab induction.

METHODS

Participants were children 6-17 years old, biologic naïve, with moderate to severe CD, who responded to adalimumab induction at week 4. Patients receiving immunomodulators at baseline maintained a stable dose until week 24; patients could then discontinue immunomodulators. At each visit, patients were assessed for disease index, serum biomarkers, fecal calprotectin, adalimumab trough concentration, and anti-adalimumab antibodies.

RESULTS

Out of the 78 patients (29% female; mean age, 14.3 ± 2.6 years), 34 patients (44%) received combination therapy. During the study period, there was no significant difference in the rates of sustained corticosteroid-free clinical remission (25/34, 73%, vs 28/44, 63%; P = 0.35) or sustained composite outcome of clinical remission, C-reactive protein ≤0.5 mg/dL, and calprotectin ≤150 µg/g (10/34, 29%, vs 14/44, 32%; P = 0.77) between the combination group and the monotherapy group, respectively. Clinical and biological outcomes did not differ between the proactive and reactive subgroups within the combination and monotherapy groups. Adalimumab trough concentrations and immunogenicity were not significantly different between groups. The rate of serious adverse events was not significantly different between groups but was numerically higher in the monotherapy group.

CONCLUSIONS

Combination therapy of adalimumab and an immunomodulator was not more effective than adalimumab monotherapy in children with CD (ClinicalTrials.gov No. NCT02256462).

Recent Advances in Smart Biomaterials for the Detection and Treatment of Autoimmune Diseases

Autoimmune diseases are a group of debilitating illnesses that are often idiopathic in nature. The steady rise in the prevalence of these conditions warrants new approaches for diagnosis and treatment. Stimuli-responsive biomaterials also known as "smart", "intelligent" or "recognitive" biomaterials are widely studied for their applications in drug delivery, biosensing and tissue engineering due to their ability to produce thermal, optical, chemical, or structural changes upon interacting with the biological environment. This critical analysis highlights studies within the last decade that harness the recognitive capabilities of these biomaterials towards the development of novel detection and treatment options for autoimmune diseases.

The shining DIAMOND for evidence-based treatment strategies for Crohn's disease

Anti-tumor necrosis factor (TNF)-α antibodies are effective therapeutic agents to treat inflammatory bowel disease (IBD). In the biologic era, the development of immunogenicity has been a critical issue for secondary loss of response. The superiority of anti-TNF therapy in combination with immunomodulators (IMs) is well-established for infliximab (IFX) but less evident for adalimumab (ADA). To clarify the contribution of thiopurines to ADA-treated patients with Crohn's disease (CD), the deep remission of immunomodulator and adalimumab combination therapy for Crohn's disease (DIAMOND) studies provided the first randomized comparison of efficacy between ADA monotherapy and ADA with thiopurine. The results of the DIAMOND and DIAMOND2 studies revealed the appropriate ADA therapeutic strategy for immunosuppressant-naïve patients with active CD based on therapeutic drug monitoring, endoscopic findings and clinical issues regarding the use of thiopurines.

Predictors of Primary Response to Biologic Treatment [Anti-TNF, Vedolizumab, and Ustekinumab] in Patients With Inflammatory Bowel Disease: From Basic Science to Clinical Practice

BACKGROUND

Inflammatory bowel diseases [IBD]-ulcerative colitis and Crohn's disease-are commonly treated with biologic drugs. However, only approximately two-thirds of patients have an initial response to these therapies. Personalised medicine has the potential to optimise efficacy, decrease the risk of adverse drug events, and reduce costs by establishing the most suitable therapy for a selected patient.

AIM

The present study reviews the potential predictors of short-term primary response to biologic treatment, including not only anti-tumour necrosis factor [TNF] agents [such as infliximab, adalimumab, certolizumab, and golimumab] but also vedolizumab and ustekinumab.

METHODS

We performed a systematic bibliographical search to identify studies investigating predictive factors of response to biologic therapy.

RESULTS

For anti-TNF agents, most of the evaluated factors have not demonstrated usefulness, and many others are still controversial. Thus, only a few factors may have a potential role in the prediction of the response, including disease behaviour/phenotype, disease severity, C-reactive protein, albumin, cytokine expression in serum, previous anti-TNF therapy, some proteomic markers, and some colorectal mucosa markers. For vedolizumab, the availability of useful predictive markers seems to be even lower, with only some factors showing a limited value, such as the expression of α4β7 integrin in blood, the faecal microbiota, some proteomic markers, and some colorectal mucosa markers. Finally, in the case of ustekinumab, no predictive factor has been reported yet to be helpful in clinical practice.

CONCLUSION

In summary, currently no single marker fulfils all criteria for being an appropriate prognostic indicator of response to any biologic treatment in IBD.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

Precision multiparameter tracking of inflammation on timescales of hours to years using serial dried blood spots

Aim: High-frequency longitudinal tracking of inflammation using dried blood microsamples provides a new window for personalized monitoring of infections, chronic inflammatory disease and clinical trials of anti-inflammatory drugs. Results/methodology: Using 1662 dried blood spot samples collected by 16 subjects over periods of weeks to years, we studied the behavior of 12 acute phase response and related proteins in inflammation events correlated with infection, vaccination, surgery, intense exercise and Crohn's disease. Proteins were measured using SISCAPA mass spectrometry and normalized to constant plasma volume using low-variance proteins, generating high precision within-person biomarker trajectories with well-characterized personal baselines. Discussion/conclusion: The results shed new light on the dynamic regulation of APR responses, offering a new approach to visualization of multidimensional inflammation trajectories.

Evolving therapeutic goals in Crohn's disease management

The main objectives in Crohn's disease are to avoid disease complications and preserve the patient's quality of life. Early disease control and close monitoring with specific targets to reach might be the only way to change the disease course. In two decades, we have moved from clinical response to full remission (clinical and endoscopic remission) requiring a tight monitoring of both symptoms and objective signs of inflammation. This review summarizes the concepts of tight control and treat-to-target and their potential for disease modification.

Patient sex does not affect endoscopic outcomes of biologicals in inflammatory bowel disease but is associated with adverse events

PURPOSE

Biological therapies are currently the mainstay in the treatment of patients with inflammatory bowel diseases (IBD). Several factors are known to influence the efficacy and tolerability of biologicals, such as CRP levels or previous biological use. Whether patient sex affects the efficacy or tolerability is unclear but would help with better risk and benefit stratification. This systematic review assesses patient sex on the efficacy and tolerability of biological therapies in IBD patients.

METHODS

A systematic literature review was performed using Embase (including MEDLINE), MEDLINE OvidSP, Cochrane Central Register of Controlled Trials, Web of Science and PubMed. The primary outcome was the influence of patient sex on endoscopic outcomes in IBD patients treated with biologicals. The secondary outcome was the influence of patient sex on adverse events. Studies were included in the assessment regardless of study type or setting.

RESULTS

The search yielded 19,461 citations; after review, 55 studies were included in the study, involving 28,465 patients treated with adalimumab, certolizumab pegol, infliximab, or vedolizumab. There was no significant association between patient sex and endoscopic efficacy in 41 relevant studies. Increased adverse events were associated with female sex in 7 out of 14 relevant studies.

CONCLUSIONS

There is no evidence for a sex difference in endoscopically measured response to biological therapies in IBD patients. However, there is an influence of sex on the occurrence of adverse events.

Disease monitoring strategies in inflammatory bowel diseases: What do we mean by "tight control"?

In recent years, there has been a critical change in treatment paradigms in inflammatory bowel diseases (IBD) triggered by the arrival of new effective treatments aiming to prevent disease progression, bowel damage and disability. The insufficiency of symptomatic disease control and the well-known discordance between symptoms and objective measures of disease activity lead to the need of reviewing conventional treatment algorithms and developing new concepts of optimal therapeutic strategy. The treat-to-target strategies, defined by the selecting therapeutic targets in inflammatory bowel disease consensus recommendation, move away from only symptomatic disease control and support targeting composite therapeutic endpoints (clinical and endoscopical remission) and timely assessment. Emerging data suggest that early therapy using a treat-to-target approach and an algorithmic therapy escalation using regular disease monitoring by clinical and biochemical markers (fecal calprotectin and C-reactive protein) leads to improved outcomes. This review aims to present the emerging strategies and supporting evidence in the current therapeutic paradigm of IBD including the concepts of "early intervention", "treat-to-target" and "tight control" strategies. We also discuss the real-word experience and applicability of these new strategies and give an overview on the future perspectives and areas in need of further research and potential improvement regarding treatment targets and ("tight") disease monitoring strategies.

Association of Infliximab Levels With Mucosal Healing Is Time-Dependent in Crohn's Disease: Higher Drug Exposure Is Required Postinduction Than During Maintenance Treatment

BACKGROUND

Infliximab levels have been reported to be associated with mucosal healing (MH) in Crohn's disease (CD). However, whether the association differs between postinduction (week 14) and maintenance (week 30) has seldom been investigated. We aimed to analyze the association between serum infliximab trough levels and MH at the 2 different time points.

METHODS

A retrospective study of CD patients treated with infliximab in a tertiary referral center between January 2012 and May 2018 was conducted. MH was defined as absence of ulceration by endoscopy. Correlations between infliximab level and MH were investigated at 2 specific time points, weeks 14 and 30.

RESULTS

Median infliximab levels were higher in patients with MH than those without at weeks 14 (7.5 vs 1.5 μg/mL; P < 0.001) and 30 (5.9 vs 0.5 μg/mL; P < 0.001). The median levels in patients with MH at week 14 were higher than at week 30 (7.5 vs 5.9 μg/mL; P < 0.05). Multivariate analysis showed that infliximab level was independently associated with MH (both P < 0.001 at weeks 14 and 30). Infliximab level above 4.85 μg/mL and 2.85 μg/mL identified patients with MH at week 14 (area under the curve [AUC], 0.796; P < 0.001) and week 30 (AUC, 0.780; P < 0.001) with 80% specificity. The rates of MH reached a plateau (>85%) when infliximab levels were above 10 and 6 μg/mL at weeks 14 and 30, respectively.

CONCLUSIONS

Infliximab levels correlated with MH at weeks 14 and 30 in CD patients. Higher levels might be required to achieve MH at postinduction than during maintenance treatment.

Best practices on immunomodulators and biologic agents for ulcerative colitis and Crohn's disease in Asia

The Asia-Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, under the auspices of the Asia-Pacific Association of Gastroenterology with the goal of improving inflammatory bowel disease care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn's and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in conjunction with conventional treatments for ulcerative colitis and Crohn's disease in Asia. These statements also address how pharmacogenetics influences the treatments of ulcerative colitis and Crohn's disease and provides guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of inflammatory bowel disease workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing, and future revisions are likely as new data continue to emerge.

Predictors of Long-term Clinical and Endoscopic Remission in Children With Crohn Disease Treated With Infliximab

OBJECTIVES

We aimed to identify early noninvasive predictors of clinical and endoscopic remission in children with Crohn disease (CD) under infliximab (IFX).

METHODS

Prospective observational study conducted in children with moderate-to-severe CD starting IFX. All patients underwent weighted pediatric CD activity index (wPCDAI) assessment, C-reactive protein and fecal calprotectin (FC) at week 0, 14, and 48. Endoscopy was performed at 0 and 48 weeks. The primary outcome was to determine the ability of 14-week wPCDAI, C-reactive protein, and FC to predict 1-year steroid-free clinical remission and mucosal healing. As a secondary outcome we evaluated their concordance with Simple Endoscopic Score for CD (SES-CD) at week 48.

RESULTS

Forty-one children were enrolled. At 1 year, 21 (51%) and 16 (39%) were in clinical and endoscopic remission. Only combined postinduction FC and wPCDAI were able to predict 1-year clinical and endoscopic remission (hazard ratio 4.81 [95% confidence interval 1.76-20.45], P = 0.05 and hazard ratio 5.51 [95% confidence interval 1.83-26.9], P = 0.03). One-year SES-CD moderately correlated with FC (r = 0.52; P = 0.001). The FC cut-off value for mucosal healing was 120.5 μg/g (area under the curve 0.863, 83% sensitivity, 75.5% specificity; P = 0.005). The concordance between wPCDAI and SES-CD was excellent and good for severe disease and remission (k 0.87 and 0.76).

CONCLUSIONS

Post induction FC combined with wPCDAI can predict 1-year clinical and endoscopic response to IFX in pediatric CD. FC shows a moderate correlation with SES-CD, whereas wPCDAI has a good concordance with endoscopic remission or severe disease, but not with mild and moderate disease.

Prediction of treatment outcome and relapse in inflammatory bowel disease

Prediction of treatment outcome and clinical relapse in patients with inflammatory bowel disease (IBD), either ulcerative colitis (UC) or Crohn's disease (CD), is particularly important because therapeutics for IBD are not always effective and patients in remission could frequently relapse. Because undergoing endoscopy for the purpose is sometimes invasive and burdensome to patients, the performance of surrogate biomarkers has been investigated. Areas covered: We particularly featured the performance of patient symptoms, blood markers including C-reactive protein (CRP), fecal markers including fecal calprotectin (Fcal) and fecal immunochemical test (FIT) for prediction of endoscopic mucosal healing (MH) and prediction of relapse. Studies of other modalities and therapeutic drug monitoring (TDM) have also been explored. Expert opinion: Meticulous evaluation of patient symptoms could be predictive for MH in UC. CRP and Fcal may be accurate in prediction of MH of CD when MH is evaluated throughout the entire intestine including the small bowel. Repeated measurements of fecal markers including Fcal and FIT in patients with clinical remission would raise predictability of relapse. Prediction of treatment outcome by monitoring with blood markers including CRP, fecal markers including Fcal, and TDM has frequently been performed in recent clinical trials and shown to be effective.

Best practices on immunomodulators and biologic agents for ulcerative colitis and Crohn's disease in Asia

The Asia-Pacific Working Group on inflammatory bowel disease (IBD) was established in Cebu, Philippines, under the auspices of the Asian Pacific Association of Gastroenterology with the goal of improving IBD care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn’s and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in the conjunction with conventional treatments for ulcerative colitis (UC) and Crohn’s disease (CD) in Asia. These statements also address how pharmacogenetics influence the treatments of UC and CD and provide guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of IBD workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing and future revisions are likely as new data continue to emerge.

Combined evaluation of biomarkers as predictor of maintained remission in Crohn’s disease

BACKGROUND

The individual performances and the complementarity of Crohn’s disease (CD) activity index (CDAI), C-reactive protein (CRP) and faecal calprotectin (Fcal) to monitor patients with CD remain poorly investigated in the era of “tight control” and “treat to target” strategies.

AIM

To assess CDAI, CRP and Fcal variation, alone or combined, after 12 wk (W12) of anti-tumor necrosis factor (TNF) therapy to predict corticosteroids-free remission (CFREM = CDAI < 150, CRP < 2.9 mg/L and Fcal < 250 μg/g with no therapeutic intensification and no surgery) at W52.

METHODS

CD adult patients needing anti-TNF therapy with CDAI > 150 and either CRP > 2.9 mg/L or Fcal > 250 μg/g were prospectively enrolled.

RESULTS

Among the 40 included patients, 13 patients (32.5%) achieved CFREM at W52. In univariable analysis, CDAI < 150 at W12 (P = 0.012), CRP level < 2.9 mg/L at W12 (P = 0.001) and Fcal improvement at W12 (Fcal < 300 μg/g; or, for patients with initial Fcal < 300 μg/g, at least 50% decrease of Fcal or normalization of Fcal (< 100 μg/g) (P = 0.001) were predictive of CFREM at W52. Combined endpoint (CDAI < 150 and CRP ≤ 2.9 mg/L and FCal improvement) at W12 was the best predictor of CFREM at W52 with positive predictive value = 100.0% (100.0-100.0) and negative predictive value = 87.1% (75.3-98.9). In multivariable analysis, Fcal improvement at W12 [odd ratio (OR) = 45.1 (2.96-687.9); P = 0.03] was a better predictor of CFREM at W52 than CDAI < 150 [OR = 9.3 (0.36-237.1); P = 0.145] and CRP < 2.9 mg/L (0.77-278.0; P = 0.073).

CONCLUSION

The combined monitoring of CDAI, CRP and Fcal after anti-TNF induction therapy is able to predict favorable outcome within one year in patients with CD.

Mechanisms of molecular resistance and predictors of response to biological therapy in inflammatory bowel disease

Biological therapy has led to marked improvements in treatment of patients with inflammatory bowel disease, and an increasing number of drugs has been approved for treatment. However, only a subgroup of patients responds to therapy, highlighting the need to identify biomarkers for therapeutic response to allow personalised medicine in inflammatory bowel disease. Potential markers of response to biological therapy have been identified; however, studies also suggest that changes in the composition of immune cell infiltrates in response to therapeutic pressure lead to molecular resistance to these drugs. For instance, the cytokine interleukin 23 has been identified as a driver of evasion of apoptosis in response to anti-tumour necrosis factor drugs in patients with Crohn's disease, leading to expansion of apoptosis-resistant T cells and drug resistance. In this Review, we examine the concept of molecular resistance to biological therapy and discuss implications for future therapy.

Endoscopic response to tumor necrosis factor inhibitors predicts long term benefits in Crohn’s disease

BACKGROUND

Identifying predictors of therapeutic response is the cornerstone of personalized medicine.

AIM

To identify predictors of long-term mucosal healing (MH) in patients with Crohn’s disease (CD) treated with tumor necrosis factor α (TNF-α) inhibitors.

METHODS

Prospective single center study. Consecutive patients with clinically active CD requiring treatment with a TNF-α inhibitor were included. A baseline segmental CD Endoscopic Index of Severity (CDEIS) ≥ 10 in at least one segment or the presence of ulcerations were required for inclusion. Clinical, biological and endoscopic data were obtained at baseline, weeks 14 and 46. Endoscopic response (ER) was defined as a decrease ≥ 50% from baseline CDEIS and MH as partial CDEIS ≤ 5 in all segments.

RESULTS

Of 62 patients were included. At baseline, median CD Activity Index and CDEIS were 201 and 6.7, respectively with a significant reduction after one year of treatment (53 and 3.0 respectively, P < 0.001). At week 14, 56% of patients achieved ER and 34% MH. At week 46, the corresponding percentages were 52% and 44%. Baseline disease characteristics or biomarkers did not predict MH. A decrease from baseline CDEIS at week 14 of at least 80% was the best predictor of MH at week 46 (59% sensitivity and 91% specificity; area under the curve = 0.778).

CONCLUSION

Clinical and biomarker data are not useful predictors of response to TNF-α inhibitors in CD, whereas ER to induction therapy, defined as 80% reduction in global CDEIS, is a robust predictor of long-term MH. Achievement of this endoscopic endpoint may be considered as a therapeutic target for anti-TNF-α therapy.

Update on C-reactive protein and fecal calprotectin: are they accurate measures of disease activity in Crohn's disease?

'Treat-to-target' paradigms in Crohn's disease (CD) directed at suppressing intestinal inflammation require accurate and reliable measures of disease activity. Although endoscopy has traditionally been considered a gold standard, cost, complexity, resource limitations, and invasiveness are important limitations. Hence, substantial interest exists for non-invasive serum and fecal biomarkers, namely C-reactive protein (CRP) and fecal calprotectin (FC), in the diagnosis, monitoring, and treatment of CD. Areas covered: We review the evidence for using serum CRP and FC in distinguishing patients with CD from those with irritable bowel syndrome, categorizing disease activity among patients with an established diagnosis of CD, predicting the likelihood of treatment response, identifying asymptomatic patients in medically or surgically induced remission who are at risk for disease relapse, and as treatment targets. Expert commentary: Accurate interpretation of CRP and FC is dependent on several factors including the clinical context, the performance characteristics of the assay, the specified test cut-offs, and the pre-test probability of disease. Emerging evidence indicates that CRP and FC are valuable adjuncts for the management of CD in specific circumstances described in this review.

Mucosal healing in inflammatory bowel disease: Expanding horizon

Management of inflammatory bowel diseases has witnessed paradigm shift from 5-aminosalicylic acid and glucocorticoids to various immunosuppressant and biological agents. Targets of therapy have also been changed drastically from symptomatic improvement to mucosal, histological healing, and recently transmural healing. Mucosal healing is associated with reduced need of steroid therapy, hospitalization, and surgery. However, whether mucosal healing alters the natural history of disease remains to be proven. Though assessment of mucosal healing is traditionally done by endoscopic examination, newer tests like fecal calprotectin, capsule endoscopy, and magnetic resonance enterography have also shown promising results. Various immunosuppressants and biologicals are the main therapy being used to achieve mucosal healing. This review focuses on the need for achieving mucosal healing, its long-term benefits, various methods and algorithm for diagnosis, and achievement of mucosal healing.

Evolution of treatment targets in Crohn's disease

Crohn's disease is a chronic relapsing and remitting inflammatory disorder of the gastrointestinal tract, associated with significantly morbidity due to both symptoms and complications that have a considerable detrimental impact on a patient's quality of life. An early treat to target approach with disease modifying agents has been shown to significantly improve long term outcomes, demonstrated by a number of therapeutic targets in a number of modalities. This review will outline the current treatment targets and measures of disease burden in Crohn's disease.

Clinical disease activity and endoscopic severity correlate poorly in children newly diagnosed with Crohn's disease

BACKGROUND AND AIMS

Treatment goals in Crohn's disease (CD) have evolved to target mucosal healing. There is now a drive to determine if noninvasive measures can adequately identify the attainment and persistence of this goal. Currently, data describing the relationship between clinical indices and endoscopic appearance in pediatric CD are sparse. Our aim was to compare endoscopic severity with the weighted Pediatric Crohn's Disease Activity Index (wPCDAI) in children with newly diagnosed CD.

METHODS

All children aged ≤17 years newly diagnosed with CD enrolled in an inception cohort at sites of the Canadian Children Inflammatory Bowel Disease Network were eligible. Clinical disease activity at presentation was evaluated by the wPCDAI and conventional biochemical parameters. Severity of disease at ileocolonoscopy was assessed by the simple endoscopic score for CD (SES-CD), with segmental subscores noted. We evaluated the association of SES-CD and disease activity markers using the Pearson test of correlation, the Spearman rank coefficient, and linear regression models.

RESULTS

Two hundred eighty patients from 11 centers were included in the analysis. The median wPCDAI score was 60 (interquartile range, 40-80; 53% severe). Median SES-CD was 16 (interquartile range 10-22; 51% severe). The wPCDAI correlated weakly with SES-CD (r = .39, P < .001). Examination of the individual components that contribute to the wPCDAI demonstrated weak correlation with the SES-CD for all items apart from stooling (moderate correlation, r = .50, P < .001). Routine blood tests did not correlate well with the SES-CD. In regression models, variation in clinical symptoms accounted for most of the variation in both the wPCDAI and SES-CD, with no additional benefit from routine blood tests.

CONCLUSIONS

In children with newly diagnosed CD, wPCDAI correlates poorly with endoscopic disease activity. As treatment paradigms evolve to target mucosal healing, clinical markers should not be used in isolation to determine disease activity.

Loss of response to scheduled infliximab therapy for Crohn's disease in adults: A systematic review and meta-analysis

OBJECTIVE

To determine the potential predictors of loss of response (LOR) to infliximab (IFX) maintenance therapy for adult patients with Crohn's disease (CD).

METHODS

We searched for English-language articles published between 1990 and March 2017 in PubMed, Embase, and the Cochrane Library. After identifying eligible studies, data extraction was performed independently by two reviewers. The potential prognostic variables were identified and dichotomized for meta-analysis. Based on the heterogeneity among study variables, random-effects models was used in our meta-analysis.

RESULTS

Twenty-six studies met our eligibility criteria and consolidated drug response data were obtained from 3212 patients. The pooled rate of LOR to IFX maintenance therapy with a median follow-up of 1.1 years was 34%. The incidence of LOR to IFX therapy was increased in CD patients with perianal lesions (odds ratio [OR] 1.69, 95% confidence interval [CI] 1.04-2.75, P = 0.03), colon involvement (OR 2.56, 95% CI 1.20-5.50, P = 0.02) and younger age at CD onset (standardized mean difference -0.79, 95% CI -1.41 to -0.18, P = 0.01).

CONCLUSIONS

The meta-analysis estimates the incidence of LOR among adult CD patients undergoing IFX therapy is 34%. The presence of perianal lesions, younger age at CD onset, and involvement of the colon are relative risk factors of LOR in CD patients received scheduled IFX maintenance therapy.

Response to treatment is more important than disease severity at diagnosis for prediction of early relapse in new-onset paediatric Crohn's disease

BACKGROUND

Paediatric Crohn's disease is characteried by frequently relapsing disease which may lead to hospitalisations and complications.

AIM

To develop predictive models for early relapse following first remission.

METHODS

The GROWTH CD prospective inception cohort was designed to predict risk for early disease relapse and poor outcomes. Newly diagnosed children underwent endoscopies and imaging. They were phenotyped and followed at scheduled visits through 78 weeks for relapses. Twenty-eight dichotomous and continuous variables were assessed at baseline and week 12, including phenotype, inflammatory markers, disease activity (PCDAI) and other markers. Clinical relapses defined as PCDAI >10 after remission were recorded using a relapse form. Logistic regression & risk modelling was performed.

RESULTS

We enrolled 282 eligible patients of whom 178 (63.6%) patients achieved steroid free remission by week 12. Disease complications developed in 22/76(29%) of patients with relapse compared to 20/206 (9.7%) without relapse (P = 0.01). Multivariable analysis demonstrated that while variables from age/gender at diagnosis were not predictive, week 12 variables including PCDAI >5 (P = 0.02), CRP >20 mg/L (P = 0.02), and faecal calprotectin >400 µg/g (P = 0.03) as optimal cut-offs were associated with increased risk of relapse. A prediction model for patients in remission including gender, age, week 12 PCDAI, calprotectin and CRP had sensitivity 43%, specificity 92%, PPV 78%, NPV 71% for relapse.

CONCLUSIONS

Early relapses were associated with a higher risk for disease complications at followup. Relapse prediction based on week 12 disease activity or inflammation is superior to prediction using data from diagnosis.

Systematic review: predictive biomarkers of therapeutic response in inflammatory bowel disease-personalised medicine in its infancy

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by substantial heterogeneity in treatment response. With an expanding number of therapeutic agents, identifying optimal treatment at the patient level remains a major challenge.

AIM

To systematically review the available literature on predictive biomarkers of therapeutic response in IBD.

METHODS

An electronic literature search was performed on 30 January 2018 using MEDLINE, EMBASE and the Cochrane Library. Retrospective, prospective, uncontrolled and controlled studies reporting on biomarkers predicting therapeutic response in paediatric and adult IBD populations were eligible for inclusion. The methodological quality of the included studies was assessed using the QUIPS tool. Due to anticipated heterogeneity and limited data, a qualitative, rather than quantitative, assessment was planned.

RESULTS

Of the 10 638 citations identified, 92 articles met the inclusion criteria. Several potential DNA, mRNA and protein markers were evaluated as predictive biomarkers. Most studies focused on predicting response to anti-TNF agents. Substantial between-study heterogeneity was identified with respect to both the biomarkers studied and the definition of response. None of the included studies received a low risk of bias rating for all six domains. Currently, none of the biomarkers is sufficiently predictive for clinical use.

CONCLUSIONS

The search for predictive biomarkers is still in its infancy and current evidence is limited. Future research efforts should take into account the high patient heterogeneity within prospective trials with objective response assessment. Predictive models will most likely comprise a combination of several molecular markers from integrated omics-levels and clinical characteristics.

How to predict response to anti-tumour necrosis factor agents in inflammatory bowel disease

Anti-tumor necrosis factor (TNF) agents have changed the therapeutic approach to inflammatory bowel disease (IBD). However, a considerable proportion of patients either do not primarily respond or lose response to treatment. Despite the long-standing experience in the use of these drugs, still there is the need of identifying the possible predictors of efficacy. Areas covered: We critically review the current knowledge on predictors of response to anti-TNF therapy - both those available in clinical practice and those still under investigation. Multiple factors are involved in treatment success, including disease phenotype and severity, adherence to medications, and pharmacogenomic, pharmacokinetic, and immunologic factors. Literature search was conducted in PubMed using keywords 'inflammatory bowel disease,' 'Crohn's disease,' and 'ulcerative colitis,' matched with 'antitumor necrosis factor,' 'biologic therapy,' 'clinical response,' 'predictors,' and 'efficacy,' Relevant articles were selected for review. Expert commentary: While the role of several factors in clinical practice is clearly established, other investigational markers have been proposed, mostly in small studies, yet for many of them little external validation exists. Therapeutic drug monitoring is emerging as a pivotal strategy to guide decisions in clinical practice. In the near future, novel markers could improve our ability to direct treatment and personalize therapy.

The Role of Biomarkers in Clinical Trials of Inflammatory Bowel Disease

Clinical trials require valid outcome measures to assess the therapeutic benefit of investigational agents. Recently, regulatory authorities have mandated the use of patient-reported outcomes in combination with an objective measure of disease activity as primary outcome measures in inflammatory bowel disease trials. Endoscopy has commonly fulfilled the latter role; however, due to the costs and complexity of these assessments, interest has emerged in the use of noninvasive biomarkers. The role of C-reactive protein, fecal calprotectin, and fecal lactoferrin in clinical research is discussed.

Accounting for Pharmacokinetic Variability of Certolizumab Pegol in Patients with Crohn's Disease

BACKGROUND

Certolizumab pegol is an effective biologic for patients with Crohn's disease (CD). Individual differences in certolizumab pegol apparent clearance (CL/F) affect exposure and possibly efficacy. A previously developed population pharmacokinetic (PK) model did not account for dynamic changes in clinical parameters during therapy.

OBJECTIVE

The aim of this study was to refine the existing PK model to capture the time-varying influence of covariates.

METHODS

Data collected from 2157 Crohn's disease patients in nine studies were analyzed using nonlinear mixed-effects modeling software (NONMEM). Certolizumab pegol concentration-time data were described by a one-compartment PK model with first-order absorption, and one-compartment disposition with linear, time-dependent elimination using antidrug antibody (ADAb) concentration as a continuous variable.

RESULTS

The final dataset consisted of 12,926 analyzable records. Parameter estimates were absorption rate constant 1.83/day, CL/F 0.527 L/day, and apparent volume of distribution (V/F) 8.33 L. ADAb concentration (2.5-214 units/mL) increased the median CL/F by 142-174%. For a typical patient, body weight (46.8-100.5 kg) increased the median CL/F and V/F from 82 to 120%. Albumin (32-48 g/L) decreased and C-reactive protein (0.5-54.0 mg/L) increased the median CL/F from 123 to 85% and from 83 to 113%, respectively. Between-patient variability of CL/F was 19.6%.

CONCLUSIONS

By incorporating time-varying covariates, this population PK model reduces between-patient variability on CL/F estimates, and the relative influence of ADAb can now be assessed. As Crohn's disease patient covariates are often time-dependent, this model is more reflective of patient drug exposure with sustained treatment.

Long-term retention of adalimumab treatment and associated prognostic factors for 1189 patients with Crohn's disease

BACKGROUND AND AIM

There are few studies on the long-term efficacy of adalimumab treatment for patients with Crohn's disease. We have conducted a large, multicenter, retrospective cohort study to evaluate the long-term retention rate and prognostic factors associated with the discontinuation of adalimumab treatment in patients with Crohn's disease.

METHODS

Data were collected from all patients with Crohn's disease who had received at least one induction dose of 160 mg of adalimumab between October 2010 and December 2013 at 41 institutions. The cumulative retention rates of adalimumab treatment following the first administration were estimated using the Kaplan-Meier method. Prognostic factors related to the cumulative retention rates were evaluated by log-rank tests and multivariate Cox regression analysis.

RESULTS

A total of 1189 patients were included in the study. The 1-, 2-, 3-, and 4-year cumulative retention rates of adalimumab were 81%, 72%, 65%, and 62%, respectively. The multivariate Cox regression analysis confirmed female sex, previous infliximab use, perianal disease, concomitant treatment with prednisolone at baseline, higher C-reactive protein levels, and lower albumin levels as significant independent predictors of poor retention rate of adalimumab treatment. Significantly, more female patients than male patients discontinued adalimumab because of adverse events, especially skin reactions, infections, and arthralgia.

CONCLUSIONS

Our data demonstrated a good retention rate of adalimumab in patients with Crohn's disease over a 4-year period. Female sex, perianal disease, concomitant treatment with prednisolone at baseline, previous infliximab use, higher C-reactive protein levels, and lower albumin levels were associated with poor retention of adalimumab treatment.

[Monitoring Disease Activity: How and When?]

Inflammatory bowel disease (IBD) is a chronic, idiopathic inflammatory disease of gastrointestinal tract with waxing and waning clinical course, which may lead to irreversible bowel damage and a loss of bowel function. Cumulative intestinal damage results in complications such as stricture or fistulae, and eventually a large number of IBD patients undergo surgery. Notably, even during remission period (no clinical symptoms), subclinical inflammation often persists and the disease continues to progress. Therefore, the therapeutic target of IBD has been evolving from symptomatic control to mucosal healing to prevent structural intestinal damage. To achieve therapeutic goals in IBD, it is important to optimize therapy according to disease severity and response to treatment. Therefore, monitoring disease activity is recommended throughout the disease course of IBD. Especially strategies to monitor disease beyond symptoms through endoscopy, laboratory markers, and imaging is required.

Biomarker-Based Models Outperform Patient-Reported Scores in Predicting Endoscopic Inflammatory Disease Activity

BACKGROUND

The Crohn's Disease Activity Index (CDAI), a scoring index including patient-reported outcomes (PROs), has known limitations for measuring intestinal inflammatory disease burden. Noninvasive markers of inflammation could prove more accurate than PROs; thus, regulatory authorities are exploring the use of PROs and endoscopic data as coprimary end points in clinical trials. The aim of this study was to assess the predictive ability of individual components of the CDAI, along with biomarker concentrations, to create models for predicting endoscopic disease activity.

METHODS

Between 2004 and 2006, 164 patients with established Crohn's disease (CD) undergoing clinically indicated ileocolonoscopy were recruited. Individual CDAI variables and fecal calprotectin (FC) were selected to explore their predictive accuracy for endoscopic disease activity, with the Simple Endoscopic Score-Crohn's Disease (SES-CD) as the outcome variable. Simple Poisson regression was performed on each variable, and 2 multivariate models were created (PRO-exclusive and PRO+FC [PRO+]). Additional analyses explored the patient-level agreement between models.

RESULTS

Number of liquid stools, abdominal pain, hematocrit (Hct), FC, and high-sensitivity C-reactive protein (hsCRP) correlated significantly with the SES-CD. For the prediction of SES-CD (>7 vs ≤6), the area under the curve (AUC) was 0.81, with 63% and 88% sensitivity and specificity, for the PRO+ model, compared with a 0.56 AUC, with 61% and 55%, respectively, for the PRO model. Intra-individual comparison revealed the PRO+ model to be superior in the prediction of endoscopically active disease.

CONCLUSIONS

The inclusion of biomarkers significantly improved predictive accuracy for endoscopic disease activity compared with PRO-exclusive models.

Long-Term Outcomes of Adalimumab Treatment in 254 Patients with Crohn's Disease: A Hospital-Based Cohort Study from Korea

BACKGROUND AND AIMS

Large-scale studies regarding the long-term outcomes of adalimumab (ADA) treatment in Asian patients with Crohn's disease (CD) are still scarce.

METHODS

We retrospectively analyzed the long-term outcomes of ADA treatment in Korean CD patients who commenced on scheduled ADA treatment at Asan Medical Center between November 2008 and July 2016. Clinical response was defined as maintaining ADA treatment without dose intensification (DI) and/or major abdominal surgery (MAS).

RESULTS

Of the 254 patients who received at least two doses of ADA at 2-week intervals as induction therapy, 250 patients (98.4%) showed an initial favorable response by week 4. Among responders, 243 patients were followed up for longer than 4 weeks and were included for further analysis. The median duration of ADA maintenance therapy was 19.4 months. At the last follow-up, 45 patients (18.5%) required DI after a median of 16.8 months and 31 (12.8%) required MAS after a median of 8.9 months. Finally, 161 patients (66.3%) were still receiving ADA without DI and/or MAS. The cumulative probability of maintaining ADA without DI and/or MAS was 81.1% at 1 year, and 36.5% at 5 years. Secondary loss of response to previous infliximab (P = 0.001) and elevated baseline C-reactive protein at starting ADA treatment (P = 0.008) were identified as independent predictors of a poor response to ADA treatment using multivariate regression analysis.

CONCLUSIONS

The long-term outcome of ADA treatment in a real-life cohort of Korean patients with CD appears to be comparable to that reported in previously published Western studies.