A Matrix-based Model Predicts Primary Response to Infliximab in Crohn's Disease

Predictive biomarkers for anti-TNF alpha therapy in IBD patients

Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition characterized by severe gut inflammation, commonly presenting as Crohn's disease, ulcerative colitis or categorized as IBD- unclassified. While various treatments have demonstrated efficacy in adult IBD patients, the advent of anti-TNF therapies has significantly revolutionized treatment outcomes and clinical management. These therapies have played a pivotal role in achieving clinical and endoscopic remission, promoting mucosal healing, averting disease progression, and diminishing the necessity for surgery. Nevertheless, not all patients exhibit positive responses to these therapies, and some may experience a loss of responsiveness over time. This review aims to present a comprehensive examination of predictive biomarkers for monitoring the therapeutic response to anti-TNF therapy in IBD patients. It will explore their limitations and clinical utilities, paving the way for a more personalized and effective therapeutic approach.

Use of double-balloon endoscopy and an endoscopic scoring system to assess endoscopic remission in isolated small bowel Crohn's disease after treatment with infliximab

Background

It is unclear how clinical and endoscopic factors affect the attainment of endoscopic remission (ER) in patients with small bowel Crohn's disease (SB-CD) who are infliximab-naïve.

Objectives

We aimed to identify the effect of different factors on attaining ER using double-balloon endoscopy (DBE) evaluation.

Design

A single-center retrospective observational study was conducted from 1 January 2018 to 30 November 2022. Among 262 patients who were screened for isolated SB-CD by baseline DBE, 108 patients were assessed for effectiveness during maintenance infliximab therapy by a second DBE evaluation.

Methods

DBE findings before and after infliximab therapy were compared. ER was defined as a simple endoscopic score for CD (SES-CD) below 3, and segmental ER as SES-CD activity of 0. Multivariate regression with calculations of odds ratios (OR) was used to determine the impact of different factors on attaining ER.

Results

In all, 41 patients (38.0%) achieved ER. An elevated C-reactive protein at week 6 was independently associated with a decreased probability of ER [OR: 0.86, 95% confidence interval (CI) = 0.75-0.98, p = 0.03]. Segmental ER of the terminal ileum, rather than the proximal ileum, was associated with a higher rate of ER (60.9% versus 38.2%, p = 0.01). High baseline SES-CD (⩾16) was unrelated to overall ER. For patients with disease in the terminal ileum, those with moderate/severe disease were less likely to attain segmental ER than those with mild disease [adjusted odds ratios (aOR): 0.27, 95% CI: 0.09-0.83, p = 0.02]. A large ulcer in the terminal ileum was associated with a lower rate of segmental ER (aOR: 0.18, 95% CI: 0.06-0.56, p = 0.01).

Conclusion

For infliximab-naïve patients with SB-CD, the overall severity of the endoscopic score was unrelated to attainment of ER. Patients were less likely to attain segmental ER if they had greater endoscopic inflammation or larger ulcers in the terminal ileum.

Precision medicine in inflammatory bowel diseases

Inflammatory bowel diseases comprising Crohn's disease and ulcerative colitis have emerged as global diseases. Multiple distinct therapeutic mechanisms have allowed us to increase our rates of achieving remission and reducing permanent disease-related morbidity. However, there is limited data to inform relative positioning of different therapies. This review will summarize existing literature on use of clinical decision models to inform relative efficacy of one therapeutic mechanism compared to the other given individual patient characteristics. It will also demonstrate the value of serologic, transcriptomic (from biopsies), and microbiome-based biomarkers in identifying which therapy is most likely to work for a given patient. We will review the existing gaps in the literature in this field and suggest a path forward for future studies to better inform patient care, incorporating the principles of precision medicine in the management of inflammatory bowel disease.

Predictive factors of response to infliximab therapy in Brazilian inflammatory bowel disease patients

Background

Biological therapies have revolutionized the treatment of patients with inflammatory bowel disease (IBD). Infliximab (IFX) has been shown to be effective in inducing and maintaining remission in patients with Crohn's disease and ulcerative colitis. However, about one-third of the patients are primary non-responders, and up to half can lose response over time. Hence, it is important to assess which factors are related to treatment failure.

Objectives

We aimed to identify factors predicting clinical and endoscopic remission with IFX treatment during maintenance therapy in a Brazilian IBD referral center.

Design

We conducted a cross-sectional study to describe demographic, clinical, and IBD therapy-related characteristics of IBD patients treated with IFX for at least 6 months in a Brazilian referral center. Subsequently, we evaluated factors associated with clinical and endoscopic remission (primary and secondary outcomes, respectively).

Methods

We used descriptive statistics to summarize the essential demographic and clinical characteristics of the population. The association of sociodemographic and clinical variables with outcomes was analyzed using multivariable logistic regression.

Results

A total of 131 IBD patients (the mean age 41.7 years) were enrolled in this study. Clinical and endoscopic remission were observed in 79.4% and 58.2% of the patients, respectively. In the multivariable analysis, IFX therapy duration and higher albumin levels increased the likelihood of clinical remission, while previous surgery decreased its chance. Prior use of adalimumab and higher C-reactive protein levels reduced the likelihood of endoscopic remission.

Conclusion

In summary, this study has enhanced our understanding of the predictive factors of treatment response to IFX in a well-characterized Brazilian IBD population.

Trial registration

4.254.501 and 2.903.748.

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.

The importance of predicting patient responses to monoclonal antibodies for Crohn's disease

INTRODUCTION

Crohn's disease (CD) is a chronic immune-mediated inflammatory bowel disease that results in relapsing and remitting symptoms but progressive transmural bowel damage leading to significant morbidity. CD results from dysregulation of the immune system related to genetic and environmental factors. While the use of monoclonal antibodies targeting cytokines and adhesion molecules has been shown to improve outcomes in CD patients, their widespread use has been limited due to high costs as well as variable access. Here, we summarize the factors that have been shown to correlate with responsiveness to biologic agents for use in practice.

AREAS COVERED

We summarize the current literature regarding factors that have been shown to influence patient response to various biologic agents including: patient-related factors (e.g. age, gender, weight smoking history); disease-specific factors (e.g. disease duration, location/extension, behavior/phenotype, severity); genetic markers; transcription factors, and the gut microbiome. Finally, we review the utility of prediction models and present data supporting the use of recently developed decision support tools.

EXPERT OPINION

Clinical decision support tools developed by machine learning are currently available for the selection of biologic agents in CD patients. We expect these models to become an integral tool for clinicians in the treatment of CD in the coming years.

The expression IL1B correlates negatively with the clinical response to adalimumab in Crohn's disease patients: An ex vivo approach using peripheral blood mononuclear cells

AIMS

Understanding of the molecular mechanisms of anti-TNFα therapy non-response and reliable biomarkers are essential for personalized medicine in Crohn's disease (CD) patients. Using RNA-seq data adjusted for deconvoluted fractions of peripheral blood cells, we recently described MMD gene, coding for a monocyte to macrophage differentiation factor, as a biomarker of adalimumab (anti-TNFα) therapy response in CD. The results also suggest that cell subtype-specific biomarkers may be superior to those measured in bulk peripheral blood. Here, we used functional cell model to further investigate the role of the monocyte to macrophage differentiation in adalimumab treatment response and evaluate monocyte/macrophage specific expression of the inflammatory cytokines as potential biomarkers for (non)response to adalimumab in CD patients.

MAIN METHODS

The peripheral monocytes of CD patients responsive and non-responsive to adalimumab were isolated, differentiated into macrophages, and exposed to inflammation and concurrent adalimumab therapy in vitro. The results were correlated to the clinical response of the donor patients.

KEY FINDINGS

Correlation is shown of the expression of two macrophage differentiation related genes- CD68 and MMD, with the expression of the inflammatory cytokines TNF, IL1B, IL6 and CXCL8. Monocytes and in vitro differentiated macrophages of adalimumab non-responders express more inflammatory cytokines than those of responders. The biggest difference was in the IL1B expression. Additionally, IL1B expression in the in vitro differentiated macrophages of CD patients correlates negatively with their clinical response to adalimumab.

SIGNIFICANCE

We propose the IL1B expression in the macrophages as a possible biomarker for adalimumab response in CD patients.

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.

Vedolizumab Is Safe and Efficacious for the Treatment of Pediatric-Onset Inflammatory Bowel Disease Patients Who Fail a Primary Biologic Agent

BACKGROUND

Vedolizumab (VDZ) is currently licensed for use in adults for the treatment of inflammatory bowel disease (IBD). We aimed to investigate the clinical course of pediatric-onset IBD following treatment with VDZ as more than a secondary biologic agent. We also evaluated factors associated with secondary loss of response (LOR) and durability of VDZ treatment.

METHODS

Pediatric-onset IBD patients diagnosed at an age younger than 18 years who had received VDZ as more than a secondary biologic agent were included in this retrospective observational study conducted at the Department of Pediatrics of two centers in Korea. Comparative analysis was conducted between groups divided according to the development of secondary LOR during VDZ treatment.

RESULTS

A total of 24 patients comprising 10 patients with Crohn's disease and 14 with ulcerative colitis were included. Of these, 19 were male and 5 were female. The mean age at diagnosis was 14.6 ± 2.5 years. The mean age at initiation of VDZ was 20.5 ± 2.8 years. Nine patients (37.5%) had received two or more biologic agents before starting VDZ. During a median of 0.9 years follow-up from VDZ initiation, 9 patients (37.5%) experienced LOR requiring interval shortening and 4 patients (16.7%) were changed to a different biologic agent. According to multivariate Cox proportional hazard regression analysis, administration of two or more biologic agents before VDZ treatment was the only factor positively associated with LOR (hazard ratio [HR], 5.6; 95% confidence interval [CI], 1.026-30.56; P = 0.047), while LOR was the only factor negatively associated with VDZ durability (HR, 0.003; 95% CI, 0.00-0.08; P = 0.010). No adverse events were observed during treatment with VDZ.

CONCLUSION

VDZ is safe and efficacious for the treatment of pediatric-onset IBD patients failing a primary biologic agent. The durability of VDZ may be enhanced by introducing VDZ earlier in the disease course. Further prospective studies in children are required in the future to validate these findings.

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.

How Do We Predict a Patient's Disease Course and Whether They Will Respond to Specific Treatments?

Gastroenterologists will be all too familiar with the difficult decisions that managing inflammatory bowel disease often presents. How aggressively should I treat this patient? Do I expect them to have a mild or aggressive form of disease? Do they need a biologic? If so, which one? And when should I start it? The reality is that the answers that would be right for one patient might be disastrous for another. The growing therapeutic armamentarium will only make these decisions more difficult, and yet, we have seen how other specialties have begun to use the molecular heterogeneity in their diseases to provide some answers. Here, we review the progress that has been made in predicting the future for any given patient with inflammatory bowel disease-whether that is the course of disease that they will experience or whether or not they will respond to, or indeed tolerate, a particular therapy.

Positioning biologics in the treatment of IBD: A practical guide – Which mechanism of action for whom?

The number of available biological therapies have doubled over the last 10 years and the arrival of novel molecules (interleukin 23p19 inhibitors) is ongoing alongside the development of small molecules. As a result of this vast landscape of treatment, positioning advanced therapies (according to clinical situation, efficacy and safety) is of paramount importance to providing personalized, appropriate IBD treatment.

In this publication the recent available literature is summarized for practical integration into clinical practice including comparative efficacy data, patient and disease demographics. We refer to recent publications and expert opinion in order to facilitate the decision making process of positioning biologicals IBD treatment.

How to Choose the Biologic Therapy in a Bio-Naïve Patient with Inflammatory Bowel Disease

The availability of biologic therapies in inflammatory bowel disease (IBD) is increasing significantly. This represents more options to treat patients, but also more difficulties in choosing the therapies, especially in the context of bio-naïve patients. Most evidence of safety and efficacy came from clinical trials comparing biologics with placebo, with a lack of head-to-head studies. Network meta-analysis of biologics and real-world studies have been developed to solve this problem. Despite the results of these studies, there are also other important factors to consider before choosing the biologic, such as patient preferences, comorbidities, genetics, and inflammatory markers. Given that resources are limited, another important aspect is the cost of biologic therapy, since biosimilars are widely available and have been demonstrated to be effective with a significant decrease in costs. In this review, we summarize the evidence comparing biologic therapy in both Crohn´s disease (CD) and ulcerative colitis (UC) in different clinical situations. We also briefly synthesize the evidence related to predictors of biologic response, as well as the biologic use in extraintestinal manifestations and the importance of the drug-related costs.

Results of the Seventh Scientific Workshop of ECCO: Precision Medicine in IBD-Disease Outcome and Response to Therapy

Inflammatory bowel diseases [IBD] are a heterogeneous spectrum with two extreme phenotypes, Crohn's disease [CD] and ulcerative colitis [UC], which both represent numerous phenotypical variations. Hence, we should no longer approach all IBD patients similarly, but rather aim to rethink clinical classifications and modify treatment algorithms to usher in a new era of precision medicine in IBD. This scientific ECCO workshop aims to provide a state-of-the-art overview on prognostic and predictive markers, shed light on key questions in biomarker development, propose best practices in IBD biomarker development [including trial design], and discuss the potential for multi-omic data integration to help drive further advances to make precision medicine a reality in IBD.

A random forest model predicts responses to infliximab in Crohn's disease based on clinical and serological parameters

BACKGROUND

Infliximab (IFX) has revolutionised the treatment for Crohn's disease (CD) recently, while a part of patients show no response to it at the end of the induction period. We developed a random forest-based prediction tool to predict the response to IFX in CD patients.

METHODS

This observational study retrospectively enrolled the patients diagnosed with active CD and received IFX treatment at the Gastroenterology Department in Xiangya Hospital of Central South University between January 2017 and December 2019. The baseline data were recorded in the beginning and were used as predictor variables to construct models to forecast the outcome of the response to IFX.

RESULTS

Our cohort identified a total of 174 patients finally with a response rate of 29.3% (51/174). The area under the receiver operating characteristic curve (AUC) for the model, based on the random forest was 0.90 (95%CI: 0.82-0.98), compared to the logistic regression model with AUC of 0.68 (95%CI: 0.52-0.85). The optimal cut-off value of the random forest model was 0.34 with the specificity of 0.94, the sensitivity of 0.81 and the accuracy of 0.85. We demonstrated a strong association of IFX response with the levels of complement C3 (C3), high density lipoprotein, serum albumin, Controlling Nutritional Status (CONUT) score and visceral fat area/subcutaneous fat area ratio (VSR).

CONCLUSION

A novel random forest model using the clinical and serological parameters of baseline data was established to identify CD patients with baseline inflammation to achieve IFX response. This model could be valuable for physicians, patients and insurers, which allows individualised therapy.

Nomogram to predict primary non-response to infliximab in patients with Crohn's disease: a multicenter study

BACKGROUND

Infliximab (IFX) is effective at inducing and maintaining clinical remission and mucosal healing in patients with Crohn's disease (CD); however, 9%-40% of patients do not respond to primary IFX treatment. This study aimed to construct and validate nomograms to predict IFX response in CD patients.

METHODS

A total of 343 patients diagnosed with CD who had received IFX induction from four tertiary centers between September 2008 and September 2019 were enrolled in this study and randomly classified into a training cohort (n = 240) and a validation cohort (n = 103). The primary outcome was primary non-response (PNR) and the secondary outcome was mucosal healing (MH). Nomograms were constructed from the training cohort using multivariate logistic regression. Performance of nomograms was evaluated by area under the receiver-operating characteristic curve (AUC) and calibration curve. The clinical usefulness of nomograms was evaluated by decision-curve analysis.

RESULTS

The nomogram for PNR was developed based on four independent predictors: age, C-reactive protein (CRP) at week 2, body mass index, and non-stricturing, non-penetrating behavior (B1). AUC was 0.77 in the training cohort and 0.76 in the validation cohort. The nomogram for MH included four independent factors: baseline Crohn's Disease Endoscopic Index of Severity, CRP at week 2, B1, and disease duration. AUC was 0.79 and 0.72 in the training and validation cohorts, respectively. The two nomograms showed good calibration in both cohorts and were superior to single factors and an existing matrix model. The decision curve indicated the clinical usefulness of the PNR nomogram.

CONCLUSIONS

We established and validated nomograms for the prediction of PNR to IFX and MH in CD patients. This graphical tool is easy to use and will assist physicians in therapeutic decision-making.

A Novel Radiomics Nomogram for the Prediction of Secondary Loss of Response to Infliximab in Crohn's Disease

Purpose

The prediction of the loss of response (LOR) to infliximab (IFX) is crucial for optimizing treatment strategies and shifting biologics. However, a secondary LOR is difficult to predict by endoscopy due to the intestinal stricture, perforation, and fistulas. This study aimed to develop and validate a radiomic nomogram for the prediction of secondary LOR to IFX in patients with Crohn’s disease (CD).

Patients and Methods

A total of 186 biologic-naive patients diagnosed with CD between September 2016 and June 2019 were enrolled. Secondary LOR was determined during week 54. Computed tomography enterography (CTE) texture analysis (TA) features were extracted from lesions and analyzed using LIFEx software. Feature selection was performed by least absolute shrinkage and selection operator (LASSO) and ten-fold cross validation. A nomogram was constructed using multivariable logistic regression, and the internal validation was approached by ten-fold cross validation.

Results

Predictors contained in the radiomics nomogram included three first-order and five second-order signatures. The prediction model presented significant discrimination (AUC, 0.880; 95% CI, 0.816–0.944) and high calibration (mean absolute error of = 0.028). Decision curve analysis (DCA) indicated that the nomogram provided clinical net benefit. Ten-fold cross validation assessed the stability of the nomogram with an AUC of 0.817 and an accuracy of 0.819.

Conclusion

This novel radiomics nomogram provides a predictive tool to assess secondary LOR to IFX in patients with Crohn’s disease. This tool will help physicians decide when to switch therapy.

Development and Validation of an Interleukin-6 Nomogram to Predict Primary Non-response to Infliximab in Crohn's Disease Patients

Background: The primary non-response (PNR) rate of infliximab (IFX) varies from 20 to 46% for the treatment of Crohn’s disease (CD). Detected PNR reduces the improper use of specific treatments. To date, there is hardly any knowledge regarding early markers of PNR. The aim of this study was to evaluate the role of Interleukin-6 (IL-6) as an early predictor of PNR of IFX for the treatment of CD.

Methods: We enrolled 322 bio-naïve patients diagnosed with CD from January 2016 to May 2020. Primary response was determined at week 14. Multivariable logistic regression was used to construct prediction models. Area under the curve (AUC), calibration and decision curve analyses (DCA) were assessed in the validation cohort. GEO data were analyzed to identify potential mechanisms of IL-6 in IFX therapy for CD.

Results: PNR occurred in 31.06% (100 of 322) patients who were assessable at week 14. IL-6 levels significantly decreased after IFX therapy (p < 0.001). The validation model containing IL-6 presented enhanced discrimination with an AUC of 0.908 and high calibration. Decision curve analysis (DCA) indicated that the model added extra predictive value. GEO data confirmed the IL-6 levels were increased in the PNR group and IL-6-related differentially expressed genes (DEGs) were enriched in the inflammatory response.

Conclusions: We concluded that IL-6 may be used as a predictive factor to assess the risk of PNR to IFX therapy.

How to Optimize Treatment With Ustekinumab in Inflammatory Bowel Disease: Lessons Learned From Clinical Trials and Real-World Data

Ustekinumab is a fully human IgG1 monoclonal antibody that has been approved for the treatment of moderate to severe Crohn's disease, and more recently moderate to severe ulcerative colitis. It binds with high affinity to the p40 subunit of human interleukin-12 and 23. This mechanism of action prevents the bioactivity of both interleukins, thus precluding their interaction with the cell surface receptor protein. The pivotal clinical trials (UNITI-1, UNITI-2 and IM-UNITI) demonstrated its clinical efficacy and safety, in naïve patients and also in those previously exposed to immunosuppressants and/or biologics. There is now an extensive experience with its use worldwide, corroborating its favorable profile even in patients with refractory disease. However, the number of medical treatment options available in inflammatory bowel disease are still limited. Hence, we should prioritize the treatments that have a greater probability of response in an individual patient. Our aim was to review and summarize all the available literature regarding the potential predictors of response to ustekinumab that can increase the success rate with this therapy in clinical practice.

Novel bio-genetic predictors of response to biologic treatment in inflammatory bowel diseases

Despite the evolving therapeutic armamentarium, the treatment of IBD patients remains challenging and many patients fail to respond to biologic agents. With the limited yield of clinical factors to predict the outcome of biologic treatments, studies have focused on identifying genetic alterations and circulating or tissue biomarkers to identify patients who are likely to respond to therapy. In this review, we examine the current knowledge and status of genetic, expression biomarkers, and microbiome predictors. The search for genetic predictors has yielded many genetic loci variants, but few were reproducible. Expression studies of putative biomarkers show promising results, especially with TREM1, oncostatin M and TNF biomarkers, but confirmatory studies are warranted. Finally, the microbiome is emerging as an important player with specific taxa and functional pathways differentially abundant and enriched in responders versus non-responders to certain biologics. Integrating different factors into a robust predictive model, which is both reproducible, accurate and affordable, remains the main challenge before these individualized strategies can reach clinical use.

Development of a clinical model to predict secondary non-response of infliximab treatment in Crohn's disease

PURPOSE

Secondary non-response to infliximab (IFX) in patients with Crohn's disease (CD) is so common that prediction of non-response is required to adopt the optimal therapy for an individual patient.

METHODS

The clinical model was constructed in a training cohort. Clinical features, serological parameters, and genetic biomarkers at week 14 IFX therapy were obtained as predictors. Secondary non-response was defined at week 54. Univariate analysis was first performed to eliminate irrelevant predictors with non-response. Then, a logistic regression model was developed by using predictors with P < 0.1 in a univariate analysis. Finally, the model was validated with reference to its discrimination, calibration, and decision curve analysis (DCA).

RESULTS

In a univariate analysis, erythrocyte sedimentation rate (ESR), the previous surgery, disease location, C-reactive protein (CRP), and TNFRSF1B (676 T>G) were found associated with secondary non-response to IFX. Logistic regression analysis with stepwise backward selection P < 0.05 then identified that ESR, the previous surgery, CRP, and TNFRSF1B (676 T>G) could serve as independent predictors, and a clinical model was developed based on the above predictors. Model 2 with TNFRSF1B (676 T>G) incorporated demonstrated more satisfactory discrimination (P = 0.029), better calibration (U P2 > 0.05), and higher clinical value in the validation cohort.

CONCLUSIONS

The study presents a model to predict non-response to IFX in CD, which incorporates previous surgery, ESR, CRP, and TNFRSF1B (676 T>G). This model can be used to help clinicians adjust the therapeutic strategy and CD patients avoid unnecessary exposure to IFX.

Personalizing Treatment in IBD: Hype or Reality in 2020? Can We Predict Response to Anti-TNF?

The advent of anti-TNF agents as the first approved targeted therapy in the treatment of inflammatory bowel disease (IBD) patients has made a major impact on our existing therapeutic algorithms. They have not only been approved for induction and maintenance treatment in IBD patients, but have also enabled us to define and achieve novel therapeutic outcomes, such as combination of clinical symptom control and endoscopic remission, as well as mucosal healing. Nevertheless, approximately one third of treated patients do not respond to initiated anti-TNF therapy and these treatments are associated with sometimes severe systemic side-effects. There is therefore the currently unmet clinical need do establish predictive markers of response to identify the subgroup of IBD patients, that have a heightened probability of response. There have so far been approaches from different fields of IBD research, to descry markers that would empower us to apply TNF-inhibitors in a more rational manner. These markers encompass findings from disease-related and clinical factors, pharmacokinetics, biochemical markers, blood and stool derived parameters, pharmacogenomics, microbial species, metabolic compounds, and mucosal factors. Furthermore, changes in the intestinal immune cell composition in response to therapeutic pressure of anti-TNF treatment have recently been implicated in the process of molecular resistance to these drugs. Insights into factors that determine resistance to anti-TNF therapy give reasonable hope, that a more targeted approach can then be utilized in these non-responders. Here, IL-23 could be identified as one of the key factors determining resistance to TNF-inhibitors. Growing insights into the molecular mechanism of action of TNF-inhibitors might also enable us to derive critical molecular markers that not only mediate the clinical effects of anti-TNF therapy, but which level of expression might also correlate with its therapeutic efficacy. In this narrative review, we present an overview of currently identified possible predictive markers for successful anti-TNF therapy and discuss identified molecular pathways that drive resistance to these substances. We will also point out the necessity and difficulty of developing and validating a diagnostic marker concerning clinically relevant outcome parameters, before they can finally enter daily clinical practice and enable a more personalized therapeutic approach.

Personalised medicine in Crohn's disease

Similar to many immune-mediated diseases, Crohn's disease follows a relapsing-remitting pattern, with a variable disease course and heterogeneous clinical outcomes. Frequency of flare-ups, development of complications, and response to treatment collectively determine the effect on a patient's quality of life, which can vary from minimal disruption to profound disability or death. Despite recent advances in the understanding of complex disease pathogenesis, including for Crohn's disease, management decisions are still typically made using a one-size-fits-all approach. Indeed, the inability to reliably predict clinical outcomes in a way that could guide future therapy represents a major unmet need. Recently, several important insights have been made into the biology underlying outcomes in Crohn's disease. In this Review, we will summarise these insights and discuss how greater understanding of these disease mechanisms can be used to develop clinically useful biomarkers, identify novel approaches to optimise disease control, and help deliver the goal of personalised medicine.

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.

Positioning Therapies in the Management of Crohn's Disease

In the past decade, several new therapies with different mechanisms of action have been approved for the management of moderate to severe Crohn's disease. However, there is limited guidance on optimal positioning of agents as first- or second-line therapies because of the absence of head-to-head trials. Furthermore, given the lack of comparative studies, treatment guidelines have provided limited insight. In this review, we discuss data on key treatment attributes, comparative efficacy and safety, factors predictive of response to each agent, and propose an algorithm for positioning therapies for the management of patients with low-risk and high-risk Crohn's disease.

Usefulness of monitoring antitumor necrosis factor serum levels during the induction phase in patients with Crohn's disease

AIMS

The aims of this study were (a) to know the kinetics of antitumor necrosis factor (TNF) drug serum levels during the induction phase in patients with Crohn's disease; (b) to identify variables associated with these levels; and (c) to assess the relation between these levels and short-term effectiveness in Crohn's disease patients.

METHODS

Patients with Crohn's disease naïve to anti-TNF treatment were prospectively included. Remission was defined as a Crohn's disease activity index (CDAI) score <150 after 14 weeks of treatment. Blood samples were obtained at baseline and at weeks 4, 8, and 14. Adalimumab and infliximab levels were measured, receiver operating characteristic (ROC) curves were constructed, and the area under the ROC curve was calculated.

RESULTS

One-hundred fifty patients with Crohn's disease were included, 79 (53%) received infliximab and 71 (47%) had CDAI > 150 at study entry. At week 14, 52 out of 71 patients with CDAI > 150 at baseline (73%) had clinical remission. There were no differences in infliximab levels between patients with and without remission (8 vs. 9.1 μg/mL, P > 0.05) or with and without response (7 vs. 11 μg/mL, P > 0.05) at week 14. There was a trend to higher levels of adalimumab concentration in responders in comparison with nonresponders (13 vs. 6.7 μg/mL, P = 0.05) and in patients who achieved remission in comparison with nonremitters (13.5 vs. 8.4 μg/mL, P = 0.06). In the multivariate analysis, no variable was predictive of short-term remission, including infliximab and adalimumab serum levels.

CONCLUSION

Determining anti-TNF serum levels during the induction phase is not useful for predicting short-term remission in patients with Crohn's disease.

Serological antibodies and surgery in a population-based inception cohort of Crohn's disease patients - the IBSEN study

Introduction: Serological antibodies have been associated with complicated disease course in Crohn's disease (CD), including the need for surgery.Aim: The aim of this study was to investigate if a panel of relevant antibodies could predict surgery in a prospective population-based cohort of patients with CD.Methods: The population-based IBSEN cohort has been followed prospectively for 20 years. At the 10- and 20-year follow-up, the following panel of serological antibodies was analysed: pANCA, ASCA IgA, ASCA IgG, anti-OmpC, anti-I2, and anti-CBir1. At the 20-year follow-up or until lost to follow-up, all CD-related surgeries were registered.Results: Serum was available from 159 patients at 10-year follow-up and 135 patients at 20-year follow-up. In 113 patients, serum was available at both time points. No significant change of antibody status (positive vs. negative) was found from 10-year to 20-year follow-up. Negative pANCA, positive ASCA IgA and positive ASCA IgG at 10-year follow-up were all individually associated with increased risk for CD-related surgery. There was no association between anti-OmpC, anti-I2 or anti-CBir1 and CD-related surgery. In a multiple regression model including disease location and behaviour, only stricturing or penetrating disease behaviour and negative pANCA remained significantly associated with higher odds for surgery.Conclusion: Positive ASCA IgA and IgG, and negative pANCA were associated with higher odds for CD-related surgery in univariate analysis. Since disease phenotype changes during the disease course, while serological antibodies are stable, our results support the use of pANCA, ASCA IgA and ASCA IgG as prognostic markers in CD.

Are We Ready to Include Prognostic Factors in Inflammatory Bowel Disease Trials?

Inflammatory bowel disease (IBD) is a chronic inflammatory disease characterized by periodic episodes of flares and remission. Treatment is aimed at healing the bowel, to ultimately decrease hospitalization rates, need for surgeries and overall disability. In more recent years, treatment has transitioned from a reactive approach to a more proactive approach focusing on treating disease earlier and preventing complications. The challenge lies in identifying patients who need more intensive treatment early and trying to determine who will respond to which medications. Biomarkers and clinical activity scoring systems can be used to help guide treatment decisions. However, IBDs are very heterogeneous and the significance of these biomarkers can be difficult to discern on an individual basis. Recently, prognostic tools have been developed to aid in determining a patient's prognosis as well as their likelihood to respond to different therapies. Despite this progress, clinical trials have not routinely adopted this approach in their study design. Tools for stratification of disease severity and to personalize treatment choices have the potential to improve our studies both by enriching the patient population and further guiding clinical decision making in practice. This review aims to discuss biomarkers, current prognosticating tools, tools that determine response to therapy and how incorporating these into clinical trials will be beneficial.

Oncostatin M as a new diagnostic, prognostic and therapeutic target in inflammatory bowel disease (IBD)

Introduction: Given the high rate of primary and acquired resistance to current inflammatory bowel disease (IBD) treatments, novel drug targets and biomarkers that aid in therapeutic prediction are eagerly awaited. Furthermore, postponing treatment initiation because of a diagnostic delay profoundly affects patient well-being and overall disease evolution. Among the emerging targets and biomarkers, oncostatin M (OSM) has gained much interest in the past few years.Areas covered: A literature search to June 2019 was performed to identify the most relevant reports on Oncostatin M. The authors summarize the biology of OSM, its role in health and disease, its potential as a diagnostic, prognostic and therapeutic biomarker in the field of IBD and how it might be a drug target of the future.Expert opinion: OSM has diagnostic, prognostic and therapeutic capabilities. High mucosal OSM predicts primary non-response to anti-TNF antibodies. However, one could question whether a single cytokine can capture the complexity and heterogeneity of IBD. Neutralizing OSM in patients with elevated mucosal OSM appears to be attractive and should be considered as a valid option for the first biomarker-stratified, proof-of-concept trial that studies a novel therapeutic compound in IBD.

Impact of therapeutic drug level monitoring on outcomes of patients with Crohn's disease treated with Infliximab: real world data from a retrospective single centre cohort study

BACKGROUND

Therapeutic drug monitoring (TDM) by measuring infliximab (IFX) trough levels and antibodies to infliximab (ATI) is used to optimise treatment in inflammatory bowel disease. We aimed to explore the clinical outcomes of TDM for patients with Crohn's disease on IFX in real life setting.

METHODS

This is a retrospective observational study. Primary outcomes were the clinicians' response to each TDM result and the rate of IFX discontinuation due to secondary loss of response or serious adverse event. Secondary outcomes included the intestinal surgery rate after IFX initiation and remission 6 months after TDM. Multivariate logistic regression was performed to identify factors associated with IFX discontinuation and abdominal surgery.

RESULTS

291 patients were included. 238 (81.8%) patients were tested for TDM at least once during their follow-up with 672 TDM results. 95/238 patients (39.9%) had undetectable levels and 76 (31.9%) had positive ATI at least once. The median infliximab trough level was 3.4 µg/mL. IFX was discontinued in 109 patients (37.5%). 526/672 (78.3%) TDMs results were not followed by altered patient management. Treatment was discontinued in 40 (75.5%) patients never tested for TDM compared with 69 (29.0%) of those tested (p<0.01). Fewer TDM tested patients (29; 12.2%) required intestinal surgery post IFX initiation compared with TDM not-tested (15; 28.3%). Not being TDM tested was independently associated with IFX discontinuation and abdominal surgery.

CONCLUSIONS

IFX discontinuation and intestinal surgery were significantly less frequent with TDM. TDM requested to investigate loss of response resulted in change in patient management.

Molecular Profiling of Inflammatory Bowel Disease: Is It Ready for Use in Clinical Decision-Making?

Inflammatory bowel disease (IBD) is a heterogeneous disorder in terms of age at onset, clinical phenotypes, severity, disease course, and response to therapy. This underlines the need for predictive and precision medicine that can optimize diagnosis and disease management, provide more cost-effective strategies, and minimize the risk of adverse events. Ideally, we can leverage molecular profiling to predict the risk to develop IBD and disease progression. Despite substantial successes of genome-wide association studies in the identification of genetic variants affecting IBD susceptibility, molecular profiling of disease onset and progression as well as of treatment responses has lagged behind. Still, thanks to technological advances and good study designs, predicting phenotypes using genomics and transcriptomics in IBD has been rapidly evolving. In this review, we summarize the current status of prediction of disease risk, clinical course, and response to therapy based on clinical case presentations. We also discuss the potential and limitations of the currently used approaches.

Pre-Treatment Biomarkers of Anti-Tumour Necrosis Factor Therapy Response in Crohn's Disease-A Systematic Review and Gene Ontology Analysis

The most prominent treatment for the serious cases of Crohn’s disease (CD) are biological tumour necrosis factor (TNF) inhibitors. Unfortunately, therapy nonresponse is still a serious issue in ~1/3 of CD patients. Accurate prediction of responsiveness prior to therapy start would therefore be of great value. Clinical predictors have, however, proved insufficient. Here, we integrate genomic and expression data on potential pre-treatment biomarkers of anti-TNF nonresponse. We show that there is almost no overlap between genomic (annotated with tissue-specific expression quantitative trait loci data) and transcription (RNA and protein data) biomarkers. Furthermore, using interaction networks we demonstrate there is little direct interaction between the proposed biomarkers, though a majority do have common interactors connecting them into networks. Our gene ontology analysis shows that these networks have roles in apoptotic signalling, response to oxidative stress and inflammation pathways. We conclude that a more systematic approach with genome-wide search of genomic and expression biomarkers in the same patients is needed in future studies.

Development and Validation of a Scoring System to Predict Outcomes of Vedolizumab Treatment in Patients With Crohn's Disease

BACKGROUND & AIMS

As more treatment options for inflammatory bowel diseases become available, it is important to identify patients most likely to respond to different therapies. We created and validated a scoring system to identify patients with Crohn's disease (CD) who respond to vedolizumab.

METHODS

We collected data from the GEMINI 2 phase 3 trial of patients with active CD treated with vedolizumab for 26 weeks (n = 814) and performed logistic regression analysis to identify factors associated with clinical, steroid-free, and durable remission (derivation set). We used these data to develop a clinical decision support tool, which we validated using data from 366 participants in a separate clinical practice observational cohort of patients with active CD treated with vedolizumab for 26 weeks (the VICTORY cohort). We evaluated the ability of this tool to identify patients in clinical remission or corticosteroid-free remission, or those with mucosal healing (MH), clinical remission with MH, or corticosteroid-free remission with MH after vedolizumab therapy using receiver operating characteristic area under the curve (AUC) analyses. The primary outcome was to develop and validate a list of factors associated with achieving remission by vedolizumab in patients with active CD.

RESULTS

In the derivation analysis, we identified absence of previous treatment with a tumor necrosis factor antagonist (+3 points), absence of prior bowel surgery (+2 points), absence of prior fistulizing disease (+2 points), baseline level of albumin (+0.4 points per g/L), and baseline concentration of C-reactive protein (reduction of 0.5 points for values between 3.0 and 10.0 mg/L and 3.0 points for values >10.0 mg/L) as factors associated with remission. In the validation set, our model identified patients in clinical remission with an AUC of 0.67, patients in corticosteroid-free remission with an AUC of 0.66, patients with MH with an AUC of 0.72, patients in clinical remission with MH with an AUC of 0.73, and patients in corticosteroid-free clinical remission with MH with an AUC of 0.75. A cutoff value of 13 points identified patients in clinical remission after vedolizumab therapy with 92% sensitivity, patients in corticosteroid-free remission with 94% sensitivity, patients with MH with 98% sensitivity, patients with clinical remission and MH with 100% sensitivity, and patients with corticosteroid-free clinical remission with MH with 100% sensitivity.

CONCLUSIONS

We developed and validated a scoring system to identify patients with CD most likely to respond to 26 weeks of vedolizumab therapy. Further studies are needed to optimize its accuracy in select populations and determine its cost-effectiveness.

Induction with Infliximab and a Plant-Based Diet as First-Line (IPF) Therapy for Crohn Disease: A Single-Group Trial

BACKGROUND

Approximately 30% of patients with Crohn disease (CD) are unresponsive to biologics. No previous study has focused on a plant-based diet in an induction phase of CD treatment.

OBJECTIVE

To investigate the remission rate of infliximab combined with a plant-based diet as first-line (IPF) therapy for CD.

METHODS

This was a prospective single-group trial conducted at tertiary hospitals. Subjects included consecutive adults with a new diagnosis (n = 26), children with a new diagnosis (n = 11), and relapsing adults (n = 9) with CD who were naïve to treatment with biologics. Patients were admitted and administered a standard induction therapy with infliximab (5 mg/kg; 3 infusions at 0, 2, and 6 weeks). Additionally, they received a lacto-ovo-semivegetarian diet. The primary end point was remission, defined as the disappearance of active CD symptoms at week 6. Secondary end points were Crohn Disease Activity Index (CDAI) score, C-reactive protein (CRP) concentration, and mucosal healing.

RESULTS

Two adults with a new diagnosis were withdrawn from the treatment protocol because of intestinal obstruction. The remission rates by the intention-to-treat and per-protocol analyses were 96% (44/46) and 100% (44/44), respectively. Mean CDAI score (314) on admission decreased to 63 at week 6 (p < 0.0001). Mean CRP level on admission (5.3 mg/dL) decreased to 0.2 (p < 0.0001). Mucosal healing was achieved in 46% (19/41) of cases.

CONCLUSION

IPF therapy can induce remission in most patients with CD who are naïve to biologics regardless of age or whether they have a new diagnosis or relapse.

Genome-wide association studies in Crohn's disease: Past, present and future

Over the course of the past decade, genome-wide association studies (GWAS) have revolutionised our understanding of complex disease genetics. One of the diseases that has benefitted most from this technology has been Crohn's disease (CD), with the identification of autophagy, the IL-17/IL-23 axis and innate lymphoid cells as key players in CD pathogenesis. Our increasing understanding of the genetic architecture of CD has also highlighted how a failure to suppress aberrant immune responses may contribute to disease development - a realisation that is now being incorporated into the design of new treatments. However, despite these successes, a significant proportion of disease heritability remains unexplained. Similarly, most of the causal variants at associated loci have not yet been identified, and even fewer have been functionally characterised. Because of the inarguable rise in the incidence of CD in regions of the world that previously had low disease rates, GWAS studies will soon have to shift from a largely Caucasian focus to include populations from other ethnic backgrounds. Future studies should also move beyond conventional studies of disease susceptibility into phenotypically driven 'within-cases' analyses in order to explore the role of genetics in other important aspects of disease biology. These studies are likely to include assessments of prognosis and/or response to treatments and may be critical if personalised medicine is ever to become a reality.

Early drug and anti-infliximab antibody levels for prediction of primary nonresponse to infliximab therapy

BACKGROUND

Primary nonresponse, defined as lack of clinical benefit during the induction phase, occurs in up to 30% of IBD patients treated with infliximab. The mechanisms underlying primary nonresponse have not yet been clearly defined.

AIM

To evaluate the association of early (week 2 and week 6) induction infliximab and anti-infliximab antibody levels with primary nonresponse.

METHODS

A retrospective observational case-control study of inflammatory bowel disease patients treated with infliximab and followed at Sheba Medical Center between 2009 and 2016 was performed. Pre-infusion infliximab and antibodies to infliximab (ATI) levels were measured by our previously described drug-tolerant ELISA assay.

RESULTS

Thirty-five primary nonresponders have been identified and matched with 105 primary responders (1:3 ratios). Both week 2 and week 6 infliximab levels were significantly lower among primary nonresponders compared to responders (week 2, 6: median level 7.2, 2.2 μg/mL vs 13.5, 9.5 μg/mL, P = .0019, P < .0001 respectively). Antibodies to infliximab appeared more frequently (either week 2 or 6, 68% vs 28% prevalence, P = .0004) and at higher levels in nonresponders compared to responders (week 2, 6: median ATI 7.3, 10.8 μg/mL-eq vs 3.8, 4.4 μg/mL-eq, P = .005, P = .008 respectively). Moreover, week 2 infliximab levels <6.8 μg/mL (AUC = 0.68, P = .002, sensitivity 50%, specificity 86%) and antibodies to infliximab levels >4.3 μg/mL-eq (AUC = 0.78, P = .0004, sensitivity 77%, specificity 71%) were predictive of primary nonresponse. Among the other clinical and demographic variables, higher baseline ulcerative colitis clinical score, infliximab monotherapy, prior adalimumab therapy and previous Crohn's disease-related surgeries were also associated with an increased risk of primary nonresponse.

CONCLUSIONS

Infliximab levels below 6.8 μg/mL and antibodies to infliximab levels above 4.3 μg/mL-eq before the second infusion are associated with primary nonresponse, especially among Crohn's disease patients.

Population Health Management for Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are chronic and impose significant, multidimensional burdens on patients and health care systems. The increasing prevalence of IBD will only worsen this problem globally-population health management (PHM) strategies are needed to increase quality of care and population health outcomes while reducing health care costs. We discuss the key components of PHM in IBD. Effective implementation of PHM strategies requires accurate identification of at-risk patients and key areas of variability in care. Improving outcomes of the at-risk population requires implementation of a multicomponent chronic care model designed to shift delivery of ambulatory care from acute, episodic, and reactive encounters, to proactive, planned, long-term care. This is achieved through team care of an activated patient with the help of remote monitoring, clinical information systems, and integrated decision support, with accompanying changes in delivery systems. Performance measurement is integral to any PHM strategy. This involves developing and implementing meaningful metrics of different phases of quality of IBD care and measuring them efficiently using modern clinical information systems. Such an integrated framework of PHM in IBD will facilitate the delivery of high-value care to patients.

Anti-Tumour Necrosis Factor Therapy for Paediatric Crohn's Disease: Improved Benefits Through Treatment Optimisation, Deeper Understanding of Its Risks, and Reduced Costs due to Biosimilar Availability

Antibodies directed to tumour necrosis factor-α (TNF-α) are very effective in treating paediatric Crohn's disease (CD). Over the last few years, research has provided important new insights into how to optimise this treatment's effectiveness. Research on predictors for anti-TNF treatment responsiveness has revealed potential markers, but data on their accuracy in paediatric CD patients are lagging behind. Also, new evidence has become available on the safety profile of anti-TNF antibodies that suggests the assumed increased malignancy risk seen in patients on anti-TNF and thiopurine combination treatment may be linked more to thiopurine use and not to anti-TNF treatment. In addition, the early results of CT-P13, an infliximab biosimilar, in CD patients confirm the expected similarity with its originator. Thus, the effectiveness of anti-TNF antibody treatment is slowly improving, its malignancy risk is lower than assumed, and its costs are reduced by the introduction of equally effective biosimilars. Together, these trends allow for a more prominent role for anti-TNF antibodies in future treatment of paediatric CD.

Evolution of cytokines and inflammatory biomarkers during infliximab induction therapy and the impact of inflammatory burden on primary response in patients with Crohn's disease

OBJECTIVE

Primary non-response to infliximab in Crohn's disease is still incompletely understood. Our aim was to further characterize the role of inflammatory burden during infliximab induction therapy.

MATERIALS AND METHODS

We studied a well-characterized cohort of 201 anti-TNF naive Crohn's disease patients treated with infliximab 5mg/kg at week 0, 2, 6 and 14 who had serum samples drawn just before every infusion. All serum samples were analyzed for CRP, albumin, TNF, IFN-γ, IL-6, IL-8, IL-10, infliximab trough concentrations (in-house-developed ELISA) and antibodies to infliximab (HMSA, Prometheus Laboratories Inc., San Diego, CA). Primary non-response was defined as the absence of clinical improvement at week 14.

RESULTS

The incidence of primary non-response to infliximab was 8% (n = 16). IL-8 concentrations at baseline were higher (p = .01) and albumin at week 6 was lower in primary non-responders (p = .01) compared to responders. During induction, IFN-γ and IL-6 concentrations decreased significantly at week 2 and week 6 in responders compared to primary non-responders (p < .05). Serum TNF increased significantly after each infliximab infusion and this increase from week 0 to week 14 was more pronounced in responders (p = .03). Multiple logistic regression identified TNF/CRP ratio at baseline as predictive for primary non-response to infliximab at week 14 (OR 2.8 (95% CI 1.4-5.5; p = .003)).

CONCLUSIONS

In this intensively sampled cohort of Crohn's disease patients, we demonstrate that inflammatory burden is more determining for primary non-response than drug exposure or immunogenicity. Our findings furthermore suggest that the contribution of TNF in inflammation might be higher in primary non-response, contradicting the non-TNF-driven concept.

Genetics of inflammatory bowel disease: beyond NOD2

The study of the genetic underpinnings of inflammatory bowel disease has made great progress since the identification of NOD2 as a major susceptibility gene. Novel genotyping and sequencing technologies have led to the discovery of 242 common susceptibility loci, 45 of which have been fine-mapped to statistically conclusive causal variants; 50 genes associated with very-early-onset inflammatory disease have been identified. The evolving genetic architecture of inflammatory bowel disease has deepened our understanding of its pathogenesis through identification of major disease associated pathways-knowledge that has the potential to indicate novel drug targets or markers for personalised medicine. However, many causal variants have yet to be identified, and a large proportion of missing heritability still needs to be accounted for. In addition, the medical and scientific communities are probably not yet fully harnessing the power of these genetic discoveries.

Considerations, challenges and future of anti-TNF therapy in treating inflammatory bowel disease

INTRODUCTION

Crohn's disease (CD) and ulcerative colitis (UC) are chronic disabling conditions. Monoclonal antibody therapy directed against tumor necrosis factor-alpha (anti-TNF) has revolutionized the care of patients with inflammatory bowel disease (IBD).

AREAS COVERED

Considerations before starting anti-TNF therapy are highlighted: the best time to start with anti-TNF therapy, either alone or in combination with an immunomodulator, the choice of an anti-TNF agent and the contra-indications to anti-TNF therapy. Primary nonresponse and secondary loss of response are discussed. De-escalating therapy, the role of therapeutic drug monitoring and the use of biosimilars, are handled. Finally, the future directions of anti-TNF therapy are emphasized.

EXPERT OPINION

Anti-TNF therapy remains the cornerstone in the treatment of IBD. When initiating long-term therapy, safety and cost issues are of great importance. The therapeutic armamentarium in the treatment of IBD is rapidly growing. Therefore, the challenge is to optimize the use and refine the exact position of anti-TNF therapy in the near future, with personalized medicine as the ultimate goal.

Effectiveness of anti-TNFα drugs in patients with Crohn's disease who do not achieve remission with their first anti-TNFα agent

BACKGROUND

Anti-TNF treatment is effective for Crohn's disease (CD); however, some patients did not achieve remission with these drugs.

AIMS

To evaluate the short-term effectiveness of a second anti-TNF in CD patients who did not achieve remission with the first one and to assess its durability.

METHODS

Patients who did not achieve remission with their first anti-TNF were included. The short-term response of the second anti-TNF was assessed, the long-term response was evaluated in patients who achieved remission (Kaplan-Meier). Cox-regression was performed to identify predictors of loss of efficacy.

RESULTS

In all, 118 CD patients received a second anti-TNF after primary failure of the first. The first anti-TNF was discontinued because of non-response in 54% of patients and partial response in 46%. Fifty-one percent of patients achieved remission in the short-term. The probability of remission was lower in patients for whom the drug indication was perianal disease (OR=0.3, 95% CI=0.1-0.7, P=0.005). The dose was increased in 33% of patients, and 37% achieved/regained remission. The probability of maintaining remission was 76%, 68% and 64% at 12, 18 and 24 months, respectively.

CONCLUSIONS

Approximately half of the patients achieved remission with a second anti-TNF after primary failure of the first, this strategy was less effective in patients with perianal disease.