Predictors of response to infliximab in patients with Crohn's disease

Clinical and Biochemical Factors Associated with Infliximab Pharmacokinetics in Paediatric Patients with Inflammatory Bowel Disease

Monitoring infliximab (IFX) concentrations is crucial for optimizing IFX therapy in children with inflammatory bowel diseases (IBDs) who show low response rates due to inadequate drug exposure. Substantial variation occurs in IFX trough concentrations in paediatric patients. Objectives: This study aimed to investigate IFX pharmacokinetics (PK) in children with IBD during both the induction phase and maintenance phases and to identify covariates associated with IFX PK. Methods: This single-centre retrospective cohort study was conducted at an academic children's hospital. Data was extracted from paediatric IBD patients receiving IFX between January 2018 and October 2023 and included demographic-, clinical- and laboratory parameters collected from electronic health records. Linear mixed model analysis was performed to investigate associations between these parameters and IFX trough concentrations. Target attainment [≥15 μg/mL in induction or 5-10 μg/mL in maintenance phase] of the IFX dosing regimens was evaluated. Results and Conclusions: A total of 115 children (417 unique IFX concentrations) were included. Multivariate analysis revealed significant positive associations between IFX and albumin concentrations (β = 0.388, p = 0.010) and IFX concentrations with dose (β = 6.534, p < 0.001), and an inversion association between IFX concentrations and treatment phase (β = -4.922, p < 0.001). During the induction and maintenance phases, 57.2% and 30.6% of IFX concentrations were subtherapeutic, respectively. A systematic search of studies investigating factors influencing IFX concentrations was concurrently performed. Our findings were critically compared against existing literature to assess relevant clinical and biochemical determinants of IFX PK in children with IBD. Our findings highlight the need for personalized dosing strategies in pediatric IBD patients, particularly during the induction phase. By implementing therapeutic drug monitoring (TDM) and considering clinical and biochemical factors, clinicians can implement more personalized strategies, potentially improving treatment efficacy and reducing the risk of treatment failure or adverse effects. This approach could lead to better target attainment, potentially enhancing clinical outcomes and minimizing premature switching to other therapies.

Prediction of early remission after infliximab in Crohn's disease using baseline microbiome and metabolomics

To characterize the microbiome and metabolic profile in Crohn's disease (CD) patients with different outcome after infliximab (IFX) treatment. The clinical data of a cohort of 35 patients with moderate-to-severe CD admitted at Jinling hospital between Oct 2022 and Dec 2023 were collected. Stool samples at baseline were collected to perform 16SrRNA and ITS2 sequencing and LC-MS untargeted metabolomics. Of these, seven discontinued IFX and underwent surgery during the induction period, and 28 received IFX at weeks 0, 2, and 6, each administered intravenously. Clinical remission was assessed based on the clinical symptoms and HBI at baseline and week 14. Baseline microbial richness and evenness was not significantly different between remission and non-remission group. The taxonomic community analysis identified decrease of Ruminococcus, Lachnoclostridium, Akkermansia in bacterial community and decrease of Asterotremella and Wallemia in fungal community in the non-remission group. LC-MS analysis showed that histamine, creatinine and L-proline significantly increased in remission group, while androsterone, berberine and episterol significantly decreased. The combined prediction model of histamine, androsterone, and episterol demonstrated a high predictive value of remission in patients after IFX treatment (AUC=0.898, p<0.001). Together, these data might facilitate a priori determination of optimal therapeutics for CD patients.

Assessing Progression of Biologic Therapies Based on Smoking Status in Patients With Crohn's Disease

BACKGROUND

Active smoking is a well-established risk factor for developing Crohn's disease (CD) and negatively impacts overall disease progression. Patients who start or continue smoking after CD diagnosis are at risk for poor outcomes, higher therapeutic requirements, and have higher rates of relapse. However, it remains unclear if the exposure to smoking leads to increased sequencing through treatment therapies, especially biologics.

METHODS

The Study of Prospective Adult Research Cohort with IBD (SPARC IBD) registry has been collecting patient-reported outcomes data in real-time, as well as laboratory, endoscopic, and pathologic samples from 17 tertiary referral centers since 2016. In this study, we conducted a retrospective review of the SPARC clinical registry collected between December 2016 and January 2021 from 1 participating site, the University of Maryland School of Medicine's Inflammatory Bowel Disease Program. A total of 619 patients were enrolled in the SPARC IBD database. Four hundred twenty-five patients with CD were included for initial review of completeness of data; of these, 144 patients were excluded due to missing data on smoking status and/or biologic treatment, resulting in a final cohort of 281 patients. We collected and analyzed baseline demographic and clinical characteristics. The final cohort was categorized into 3 exposure groups: current, former, and never smokers. Our outcome of interest was number biologics used, categorized into 3 groups: 0, 1, or ≥2 biologics.

RESULTS

One hundred seventy-two never smokers, 70 former smokers, and 39 current smokers were identified. Current, former, and never smokers had no statistically significant differences in number of biologics used (ie, biologic sequencing). However, statistically significant independent risk factors for increased sequencing of biologics were identified. These risk factors included female sex, ileocolonic disease location, younger age at diagnosis, and prolonged disease duration; none of these factors remained significant in adjusted analyses.

CONCLUSION

To date, this is the first study assessing the association of smoking and sequencing of biologics. Although current or former smokers were not found to sequence through more biologics when compared with never smokers, smoking is a well-established risk factor for poor health outcomes, and efforts should be made to counsel patients to quit. Further, additional research must be done to stratify risk to patients based on amount of tobacco exposure.

Prevalence of Immunomodulator Use as Combination Therapy With Vedolizumab or Ustekinumab in Inflammatory Bowel Disease

INTRODUCTION

The benefit of adding an immunomodulator to vedolizumab and ustekinumab remains unclear and may compromise the safety of these biologics. We evaluated the prevalence and predictors of immunomodulator use with vedolizumab or ustekinumab in patients with inflammatory bowel disease in a large longitudinal cohort.

METHODS

Clinical information was ascertained from electronic medical records of patients enrolled in TARGET-IBD, a prospective longitudinal observational cohort of patients with inflammatory bowel disease (IBD) at 34 sites. The prevalence of immunomodulator use with vedolizumab, ustekinumab, and antitumor necrosis factor therapies and predictors of immunomodulator use with vedolizumab and ustekinumab were estimated. Rates of combination therapy were additionally stratified by time from drug approval.

RESULTS

Four thousand thirty-nine adults with IBD were identified, of whom 18.8% were treated with vedolizumab and 13.0% were treated with ustekinumab. Combination therapy with vedolizumab and ustekinumab exceeded 30% (30.7% and 36.2%, respectively) and was more likely in those with perianal disease or previous biologic exposure. Age and presence of extraintestinal manifestations did not consistently predict the use of an immunomodulator. Combination therapy decreased in the years after drug approval.

DISCUSSION

Combination therapy with vedolizumab or ustekinumab was common and was associated with perianal disease and greater exposure to other biologics, although the practice is decreasing with time. Further data are needed to determine the efficacy and safety of combination therapy in patients initiating vedolizumab or ustekinumab for IBD.

Apoptosis and inflammatory genes variants in primary non-response to anti-TNF therapy in Crohn's disease patients

Anti-TNF therapy has indeed revolutionized the treatment of Crohn's disease, leading to higher rates of response and remission in patients. However, a significant proportion of 20-40% of patients do not respond to the initial therapy, others experience a secondary loss of response with ongoing treatment. Adverse drug reactions also occur in some patients. The effectiveness of anti-TNF treatment may be influenced by genetic variability, including FCGR3A, ADAM17, TNFRSF1A, TNFRSF1B, FAS, FASL, IL1B, CASP9 , and MIF genes. In this article, we provide an overview of the current knowledge and findings in the pharmacogenetics of anti-TNF drugs in CD focusing on the aspect of apoptosis and inflammatory genes variants in primary non-response. Pharmacogenetic investigations have been conducted to identify genetic markers that can predict response to anti-TNF therapy. However, large multi-center validation studies and multi-loci algorithms development are required to effectively prognose the treatment effect. The identification of predictive markers of response to anti-TNF therapy can help clinicians make informed decisions about treatment options and minimize adverse drug reactions in patients.

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.

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.

Implications of the changing epidemiology of inflammatory bowel disease in a changing world

The epidemiology of inflammatory bowel disease (IBD) has undergone considerable shifts since its emergence in the Western world over a century ago, especially in the last few decades, with increasing global burden of disease. IBD incidence continues to rise in developed countries in all age groups which is contributing to compounding prevalence. Further, IBD incidence is rising sharply in Asia and other recently developed and developing countries. In this review, we discuss the implications of changing trends of IBD epidemiology. First, changing patterns provide insights into IBD causes, as they occur concurrent with shifts in the environment, cultures, and attitudes. Understanding the impact of the environment on IBD risk can help towards prediction and prevention strategies. Second, we must prepare healthcare systems for the rising burden of IBD and address it at various levels towards improving outcomes and health, overall.

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.

Novel Models of Crohn's Disease Pathogenesis Associated with the Occurrence of Mitochondrial Dysfunction in Intestinal Cells

Crohn’s disease remains one of the challenging problems of modern medicine, and the development of new and effective and safer treatments against it is a dynamic field of research. To make such developments possible, it is important to understand the pathologic processes underlying the onset and progression of Crohn’s disease at the molecular and cellular levels. During the recent years, the involvement of mitochondrial dysfunction and associated chronic inflammation in these processes became evident. In this review, we discuss the published works on pathogenetic models of Crohn’s disease. These models make studying the role of mitochondrial dysfunction in the disease pathogenesis possible and advances the development of novel therapies.

Smoking Behaviour Changes After Diagnosis of Inflammatory Bowel Disease and Risk of All-cause Mortality

BACKGROUND AND AIMS

We examined smoking behaviour changes after diagnoses of Crohn's disease [CD] and ulcerative colitis [UC] and evaluated their impact on mortality.

METHODS

Study population included incident CD or UC cases from three cohorts of the Nurses' Health Study [NHS], NHSII, and Health Professionals Follow-up Study. Smoking and other risk factors were prospectively assessed. Smoking behaviour changes were categorised as never, former [i.e., quit smoking before diagnosis], quitters [i.e., quit smoking after diagnosis], and current [i.e., continue smoking after diagnosis]. Follow-up for date and cause of death was completed through linkage to the National Death Index. Cox proportional hazard regression was used to estimate hazard ratios [HRs] and 95% confidence intervals [CIs].

RESULTS

Among 909 eligible CD and UC cases, 45% were never smokers, 38% were past smokers, and 16% were active smokers at the time of diagnosis. Among active smokers, 70% of patients with CD and 44% of patients with UC continued to smoke after diagnosis. In patients with CD, compared with current smokers, the multivariable-adjusted HRs [95% CI] of death were 0.19 [0.10 to 0.38] for never smokers, 0.31 [0.16 to 0.57] for former smokers, and 0.41 [0.18 to 0.93] for quitters. Similarly for UC, compared with current smokers, we observed a reduced risk of mortality for never smokers [HR = 0.23, 95% CI 0.10 to 0.51], former smokers [HR = 0.23, 95% CI 0.11 to 0.48], and quitters [HR = 0.28, 95% CI 0.11 to 0.72].

CONCLUSIONS

In three cohorts of health professionals, a substantial proportion of patients with new diagnosis of CD and UC and history of smoking continued to smoke after diagnosis. Smoking cessation around the time of diagnosis was associated with a significant reduction in mortality.

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.

Approach to the Management of Recently Diagnosed Inflammatory Bowel Disease Patients: A User's Guide for Adult and Pediatric Gastroenterologists

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are chronic, progressive, immune-mediated diseases of adults and children that have no cure. IBD can cause significant morbidity and lead to complications such as strictures, fistulas, infections, and cancer. In children, IBD can also result in growth impairment and pubertal delays. IBD is highly heterogenous, with severity ranging from mild to severe and symptoms ranging from mild to debilitating. Delay in IBD diagnosis, especially in Crohn's disease, is common and associated with adverse outcomes. Early diagnosis and prompt institution of treatment are the cornerstones for improving outcomes and maximizing health. Early diagnosis requires a low threshold of suspicion and red flags to guide early specialist referral at the primary provider level. Although the armamentarium of IBD medications is growing, many patients will not respond to treatment, and the selection of first-line therapy is critical. Risk stratification of disease severity, based on clinical, demographic, and serologic markers, can help guide selection of first-line therapy. Clinical decision support tools, genomics, and other biomarkers of response to therapy and risk of adverse events are the future of personalized medicine. After starting appropriate therapy, it is important to confirm remission using objective end points (treat to target) with continued control of inflammation with adjustment of therapy using surrogate biomarkers (tight control). Lastly, IBD therapy extends far beyond medications, and other aspects of the overall health and wellbeing of the patient are critical. These include preventive health, nutrition, and psychobehavioral support addressing patients' concerns around complementary therapy and medication adherence, prevention of disability, and ensuring open communication.

Improved Smoking Cessation Rates in a Pharmacist-Led Program Embedded in an Inflammatory Bowel Disease Specialty Medical Home

BACKGROUND

Cigarette smoking is associated with disease progression, poor outcomes, and increased biologic use in Crohn's Disease (CD). In this prospective study, we describe the structure and results of a pharmacist-driven smoking cessation program in an Inflammatory Bowel Disease (IBD) Specialty Medical Home.

METHODS

One pharmacist designed and implemented a collaborative drug therapy management (CDTM) program, which allowed the pharmacist to initiate and modify smoking cessation aids, monitor medication safety and efficacy, and provide behavioral counseling. Crohn's Disease patients who were current smokers and referred to the program were analyzed. Clinical and demographic data, disease activity, and smoking history were collected. The primary outcome was the proportion of patients in the enrolled group and the declined group who quit smoking at least once during the follow-up period. Secondary outcomes include demographic and clinical differences between enrolled and declined patients, and enrolled quitters and non-quitters.

RESULTS

Thirty-two patients were referred to the program and 19 participated. Over a median follow-up period of 305 [264-499] days, 42% (8/19) of enrolled patients quit smoking at least once. Fifteen percent (2/13) of declined patients quit smoking. Patients who continued to smoke had more instances of loss of response to a biologic, need to start a new biologic, or escalation of biologic therapy. The CDTM pharmacist was able to provide all necessary clinical services for smokers enrolled in the program.

CONCLUSIONS

A pharmacist-led smoking cessation program in a specialty medical home is feasible. It may result in successful quit attempts and may optimize IBD medication use.

The impact of tobacco smoking on treatment choice and efficacy in inflammatory bowel disease

Smoking significantly increases the risk of developing and worsens Crohn's disease (CD), yet protects against the development and reduces the severity of ulcerative colitis. It is less clear whether smoking impacts the efficacy of therapeutics in inflammatory bowel disease (IBD). We review the literature regarding the relationship between smoking and the efficacy of medical and surgical therapy in IBD. Smoking is associated with alterations in thiopurine metabolism and may affect time to disease relapse. The outcomes of anti-tumor necrosis factor therapy in active smokers appear neutral with data lacking for newer biologics. Smoking increases the risk of postoperative recurrence in those requiring resection for CD, likely attributable to perturbations of the gut microbiota although further implications of these for disease onset/progression and treatment efficacy remain unclear. Multiple lifestyle and psychosocial confounders are likely under-recognized cofactors in the association between smoking and IBD. Despite the widely promulgated risks associated with cigarette smoking in CD, more incisive data are required to further elucidate the actual relationship between smoking and disease pathways, while accounting for the several negative cofactors prevalent in smokers which cast uncertainty on the magnitude of the direct effect of smoking on disease pathophysiology and the efficacy of therapy.

Passive Smoking Increases the Risk for Intestinal Surgeries in Patients With Crohn's Disease

BACKGROUND

Despite substantial evidence on the negative effect of active smoking, the impact of passive smoking on the course of Crohn's disease (CD) remains largely unclear. Our aim was to assess passive smoking as a risk factor for intestinal surgeries in CD.

METHODS

The study was conducted in a university-based, monocentric cohort of 563 patients with CD. Patients underwent a structured interview on exposure to passive and active smoking. For clinical data, chart review was performed. Response rate was 84%, leaving 471 cases available for analysis. For evaluation of the primary objective, which was the impact of exposure to passive smoking on the risk for intestinal surgery, only never actively smoking patients were included.

RESULTS

Of 169 patients who never smoked actively, 91 patients (54%) were exposed to passive smoking. Exposed patients were more likely to undergo intestinal surgery than nonexposed patients (67% vs 30%; P < 0.001). Multivariate Cox regression analysis revealed that passive smoking was an independent risk factor for intestinal surgeries (hazard ratio, 1.7; 95% CI, 1.04-2.9; P = 0.034) after adjustment for ileal disease at diagnosis (hazard ratio, 2.9; 95% CI, 1.9-4.5; P < 0.001) and stricturing or penetrating behavior at diagnosis (hazard ratio, 1.9; 95% CI, 1.2-3.1; P = 0.01). Passive smoking during childhood was a risk factor for becoming an active smoker in later life (odds ratio, 2.2; 95% CI, 1.5-3.2; P < 0.001).

CONCLUSION

Passive smoking increases the risk for intestinal surgeries in patients with CD.

Smoking May Reduce the Effectiveness of Anti-TNF Therapies to Induce Clinical Response and Remission in Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Cigarette smoking worsens prognosis of Crohn's disease [CD]. We conducted a systematic review and meta-analysis to examine the association between smoking and induction of clinical response or remission with anti-tumour necrosis factor [TNF] therapy.

METHODS

MEDLINE, EMBASE, PubMed, and Cochrane CENTRAL [June 2019] were searched for studies reporting the effect of smoking on short-term clinical response and remission to anti-TNF therapy [≤16 weeks following the first treatment] in patients with CD. Risk ratios [RR] with 95% confidence intervals [CI] were calculated using random-effects models.

RESULTS

Eighteen observational studies and three randomised controlled trials [RCT] were included. Current smokers and non-smokers [never or former] had similar rates of clinical response [observational studies RR: 0.96; 95% CI: 0.88, 1.05; RCTs RR: 1.09; 95% CI: 0.84, 1.41]. When restricted to studies clearly defining the smoking exposure, smokers treated with anti-TNF were less likely to achieve clinical response than non-smokers [smokers defined as having ≥5 cigarettes/day for ≥6 months RR: 0.63; 95% CI: 0.48, 0.83; lifetime never smokers vs ever smokers excluding former smokers RR: 0.81; 95% CI: 0.71, 0.93]. Current smokers were also less likely to achieve clinical remission in observational studies [RR: 0.75; 95% CI: 0.57, 0.98], though this association was not seen in RCTs [RR: 1.04; 95% CI: 0.89, 1.21].

CONCLUSIONS

Smoking is significantly associated with a reduction in the ability of infliximab or adalimumab to induce short-term clinical response and remission when pooling studies where smoking status was clearly defined. When patients with CD are treated with highly effective therapy, including anti-TNF agents, concurrent smoking cessation may improve clinical outcomes.

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.

Is Polymorphism in the Apoptosis and Inflammatory Pathway Genes Associated With a Primary Response to Anti-TNF Therapy in Crohn's Disease Patients?

Anti-tumor necrosis factor (TNF) therapy is used for the induction and maintenance of remission in Crohn’s disease (CD) patients. However, primary nonresponders to initial treatment constitute 20%–40% of cases. The causes of this phenomenon are still unknown. In this study, we aimed to determine the genetic predictors of the variable reactions of CD patients to anti-TNF therapy. Using long-range PCR libraries and the next-generation sequencing (NGS) method, we performed broad pharmacogenetic studies including a panel of 23 genes (TNFRSF1A, TNFRSF1B, CASP9, FCGR3A, LTA, TNF, FAS, ADAM17, IL17A, IL6, MMP1, MMP3, S100A8, S100A9, S100A12, TLR2, TLR4, TLR9, CD14, IL23R, IL23, IL1R, and IL1B) in a group of 107 diagnosed and clinically characterized CD patients following anti-TNF therapy. In the studied group, we indicated, in total, 598 single nucleotide variants for all analyzed genomic targets. Twelve patients (11.2%) did not respond to the induction therapy, which was associated with alleles in 11 loci located in FCGR3A (rs7539036, rs6672453, rs373184583, and rs12128686), IL1R (rs2041747), TNFRSF1B (rs5746053), IL1B (rs1071676, rs1143639, rs1143637, and rs1143634), and FAS (rs7896789) genes. After multiple comparison corrections, the results were not statistically significant, however for nonresponders the alleles distribution for those loci presented large differences and specified scheme compared to responders and populations. These findings require further investigation in an independent larger cohort before introducing them for a clinical setting, however, we identified an interesting direction. Polymorphism of the FCGR3A, IL1R, TNFRSF1B, IL1B, and FAS genes could be a predictor of the primary response to anti-TNF therapy in CD patients.

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.

Novel Pharmacological Therapy in Inflammatory Bowel Diseases: Beyond Anti-Tumor Necrosis Factor

Inflammatory bowel diseases (IBDs) are chronic conditions of the gastrointestinal tract in which dysregulated immune responses cause persistent inflammation of the gut mucosa. Biologic therapy with anti-TNF blockers has revolutionized the therapeutic management of IBD for their remarkable efficacy and potential impact on disease course and for many years has represented the sole treatment option for patients refractory or intolerant to conventional therapy. In recent years, more molecules, both biologically and chemically synthetized, have been developed as potential therapeutic options for IBD that target different molecular pathways aside from TNF blockade, and which have been proposed as targets for novel drugs. This is particularly relevant for the present, as well as future, management of IBD, considering that some patients are refractory to anti-TNF. This review will summarize the pharmacological options, either currently available or in the pipeline, for market approval to treat IBD, besides anti-TNF strategies, based on their mechanism(s) of action. We will also analyze the current evidence for effectiveness and safety, as well as offer perspective, regarding the potential implementation for such therapies in the future.

Predicting (side) effects for patients with inflammatory bowel disease: The promise of pharmacogenetics

Inflammatory bowel disease (IBD) is a chronic and heterogeneous intestinal inflammatory disorder. The medical management of IBD aims for long-lasting disease remission to prevent complications and disease progression. Early introduction of immunosuppression forms the mainstay of medical IBD management. Large inter-individual variability in drug responses, in terms of both efficacy and toxicity, leads to high rates of therapeutic failure in the management of IBD. Better patient stratification is needed to maximize patient benefit and minimize the harm caused by adverse events. Pre-treatment pharmacogenetic testing has the potential to optimize drug selection and dose, and to minimize harm caused by adverse drug reactions. In addition, optimizing the use of cheap conventional drugs, and avoiding expensive ineffective drugs, will lead to a significant reduction in costs. Genetic variation in both TPMT and NUDT15, genes involved in thiopurine metabolism, is associated to an increased risk of thiopurine-induced myelosuppression. Moreover, specific HLA haplotypes confer risk to thiopurine-induced pancreatitis and to immunogenicity to tumor necrosis factor-antagonists, respectively. Falling costs and increased availability of genetic tests allow for the incorporation of pre-treatment genetic tests into clinical IBD management guidelines. In this paper, we review clinically useful pharmacogenetic associations for individualized treatment of patients with IBD and discuss the path from identification of a predictive pharmacogenetic marker to implementation into IBD clinical care.

Influence of previous corticosteroid treatment on the efficacy and safety of infliximab therapy in Crohn disease

To determine the effect of prior corticosteroid treatment on the results of infliximab (IFX) therapy in patients with Crohn disease (CD).Patients with CD treated with at least 3 IFX infusions between March 2009 and April 2017 were divided into steroid group (n = 43) and nonsteroid group (n = 22) and analyzed retrospectively.The cumulative probabilities of clinical remission and response to IFX at weeks 14, 30, 54, and 78 were higher in the steroid group, though this difference was not statistical significant. At the mean interval of 11.7 months following the initiation of IFX treatment, the mucosal healing rate was significantly higher in the steroid group (71.0% vs 22.2%, P < .01). There was no statistical difference in the incidence of adverse reactions between the 2 groups.In CD, patients with prior corticosteroid treatment may increase the response rate to IFX therapy.

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.

Identifying demographic, social and clinical predictors of biologic therapy effectiveness in psoriasis: a multicentre longitudinal cohort study

Background

Biologic therapies have revolutionized the treatment of moderate‐to‐severe psoriasis. However, for reasons largely unknown, many patients do not respond or lose response to these drugs.

Objectives

To evaluate demographic, social and clinical factors that could be used to predict effectiveness and stratify response to biologic therapies in psoriasis.

Methods

Using a multicentre, observational, prospective pharmacovigilance study (BADBIR), we identified biologic‐naive patients starting biologics with outcome data at 6 (n = 3079) and 12 (n = 3110) months. Associations between 31 putative predictors and outcomes were investigated in univariate and multivariable regression analyses. Potential stratifiers of treatment response were investigated with statistical interactions.

Results

Eight factors associated with reduced odds of achieving ≥ 90% improvement in Psoriasis Area and Severity Index (PASI 90) at 6 months were identified (described as odds ratio and 95% confidence interval): demographic (female sex, 0·78, 0·66–0·93); social (unemployment, 0·67, 0·45–0·99); unemployment due to ill health (0·62, 0·48–0·82); ex‐ and current smoking (0·81, 0·66–0·99 and 0·79, 0·63–0·99, respectively); clinical factors (high weight, 0·99, 0·99–0·99); psoriasis of the palms and/or soles (0·75, 0·61–0·91); and presence of small plaques only compared with small and large plaques (0·78, 0·62–0·96). White ethnicity (1·48, 1·12–1·97) and higher baseline PASI (1·04, 1·03–1·04) were associated with increased odds of achieving PASI 90. The findings were largely consistent at 12 months. There was little evidence for predictors of differential treatment response.

Conclusions

Psoriasis phenotype and potentially modifiable factors are associated with poor outcomes with biologics, underscoring the need for lifestyle management. Effect sizes suggest that these factors alone cannot inform treatment selection.

What's already known about this topic?

Biologic therapy used in the treatment of moderate‐to‐severe psoriasis differs in its effectiveness across patients.

Previous research has indicated that patients with a higher body mass index, who smoke or who have smoked, and with a lower baseline Psoriasis Area and Severity Index (PASI) are less likely to have a good outcome with biologic therapy for the treatment of moderate‐to‐severe psoriasis.

What does this study add?

This large‐scale study in a real‐world setting confirms that weight, smoking status and baseline PASI are associated with effectiveness of biologic therapy.

There is evidence that non‐white ethnicity, female sex, unemployment, psoriasis of the palms and soles and the presence of small chronic plaques are associated with poor outcomes with biologics.

There is some evidence that men have a comparatively worse response to etanercept, relative to adalimumab, than women. Otherwise, most factors do not appear to be predictors of differential treatment response.

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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.

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.

Visceral Fat Is Associated With Mucosal Healing of Infliximab Treatment in Crohn's Disease

BACKGROUND

Visceral fat is the pathogenesis of Crohn's disease and is associated with disease status.

OBJECTIVE

This study aimed to evaluate the effect of the visceral fat on mucosal healing in patients with Crohn's disease after infliximab induction therapy DESIGN:: This was a retrospective study.

SETTINGS

The study was conducted in a tertiary referral hospital.

PATIENTS

Between 2011 and 2017, 97 patients with Crohn's disease with the presence of ulcers underwent infliximab therapy.

MAIN OUTCOME MEASURES

We studied them retrospectively. Mucosal healing was the end point. Patients composed 2 groups: mucosal healing and no mucosal healing. Univariate, multivariate, and receiver operating characteristic curve analyses determined the predictive value of the visceral fat area.

RESULTS

Univariate analysis showed a statistically significant difference in the smoking history between the groups. Mucosal healing rates after infliximab were lower among active smokers (p = 0.022). Healed patients had significantly less visceral fat area before therapy (47.76 ± 4.94 vs 75.88 ± 5.55; p = 0.000) and a lower mesenteric fat index (0.52 ± 0.04 vs 0.89 ± 0.07; p = 0.000). There was no significant difference in the subcutaneous fat area (87.39 ± 5.01 vs 93.31 ± 6.95; p = 0.500). Multivariate analysis showed that only visceral fat area (OR = 0.978 (95% CI, 0.964-0.992); p = 0.002) and smoking history (OR = 0.305 (95% CI, 0.089-0.996); p = 0.041) were independent factors for mucosal healing. Receiver operating characteristic curve analysis showed predictive cutoff values of 61.5 cm and 0.62 for visceral fat area and mesenteric fat index.

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

There was an association between increased visceral fat area and attenuated mucosal healing after infliximab therapy in biologically naive patients with Crohn's disease, indicating a need for earlier increased infliximab doses among patients with increased visceral fat. See Video Abstract at http://links.lww.com/DCR/A590.

Evidence-based clinical practice guidelines for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disorder involving mainly the intestinal tract, but possibly other gastrointestinal and extraintestinal organs. Although etiology is still uncertain, recent knowledge in pathogenesis has accumulated, and novel diagnostic and therapeutic modalities have become available for clinical use. Therefore, the previous guidelines were urged to be updated. In 2016, the Japanese Society of Gastroenterology revised the previous versions of evidence-based clinical practice guidelines for ulcerative colitis (UC) and Crohn's disease (CD) in Japanese. A total of 59 clinical questions for 9 categories (1. clinical features of IBD; 2. diagnosis; 3. general consideration in treatment; 4. therapeutic interventions for IBD; 5. treatment of UC; 6. treatment of CD; 7. extraintestinal complications; 8. cancer surveillance; 9. IBD in special situation) were selected, and a literature search was performed for the clinical questions with use of the MEDLINE, Cochrane, and Igaku Chuo Zasshi databases. The guidelines were developed with the basic concept of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Recommendations were made using Delphi rounds. This English version was produced and edited based on the existing updated guidelines in Japanese.

Inflammatory bowel disease: towards a personalized medicine

The management of inflammatory bowel disease (IBD) has been transformed over the last two decades by the arrival of tumor necrosis factor (TNF) antagonist agents. Recently, alternative drugs have been approved, directed at leukocyte-trafficking molecules (vedolizumab) or other inflammatory cytokines (ustekinumab). New therapeutics are currently being developed in IBD and represent promising targets as they involve other mechanisms of action (JAK molecules, Smad 7 antisense oligonucleotide etc.). Beyond TNF antagonist agents, these alternative drugs are needed for early-stage treatment of patients with aggressive IBD or when the disease is resistant to conventional therapy. Personalized medicine involves the determination of patients with a high risk of progression and complications, and better characterization of patients who may respond preferentially to specific therapies. Indeed, more and more studies aim to identify factors predictive of drug response (corresponding to a specific signaling pathway) that could better manage treatment for patients with IBD. Once treatment has started, disease monitoring is essential and remote patient care could in some circumstances be an attractive option. Telemedicine improves medical adherence and quality of life, and has a positive impact on health outcomes of patients with IBD. This review discusses the current application of personalized medicine to the management of patients with IBD and the advantages and limits of telemedicine in IBD.

Body mass index influences infliximab post-infusion levels and correlates with prospective loss of response to the drug in a cohort of inflammatory bowel disease patients under maintenance therapy with Infliximab

Introduction

Infliximab is an effective treatment for inflammatory bowel disease (IBD). Studies differ regarding the influence of body mass index (BMI) on the response to infliximab, with the majority of studies indicating that increased BMI may be associated with a poorer response to Infliximab. However, the pharmacokinetic mechanisms causing this have not yet been reported.

Aims

Examine the correlation between BMI/immunosuppressant use with clinical response, trough and post-infusion levels of infliximab, tumour necrosis factor-α(TNF-α) and anti-drug antibodies(ATI), and determine if these factors can predict future response.

Methods

We collected serum from 24 patients receiving Infliximab before and 30 minutes following infusion. Clinical parameters were collected retrospectively and prospectively. ELISA measurements of infliximab, TNF-α and ATI were performed.

Results

We confirmed that patients with higher infliximab trough levels have a better response rate and that patients with an elevated BMI display a higher rate of loss of response (20%). Patients with a higher BMI had elevated post-infusion levels of infliximab. Additionally, the ratio of IFX/TNF-α trough levels correlated with clinical response to the following infusion.

Conclusion

This study confirms that an elevated BMI is associated with a poorer response to infliximab. For the first time, we describe that a higher BMI correlates with higher post-infusion levels, however this does not correlate with a higher rate of response to the drug, suggesting that circulating drug levels do not correlate with tissue levels. Furthermore, in our small cohort of patients, we identified a possible predictive marker of future response to treatment which may be used to guide dose escalation and predict non-response to infliximab.

The role of smoking and alcohol behaviour in the management of inflammatory bowel disease

In the era of increasing use of immunosuppressive and biologic therapy for inflammatory bowel disease, environmental influences remain important independent risk factors to modify the course of the disease, affect the need for surgery and recurrence rates post-surgical resection. The effect of smoking on inflammatory bowel disease has been established over the decades, however the exact mechanism of how smoking affects remains as area of research. Alcohol is also among the socio-environmental factors which has been recognised to cause a flare of symptoms in inflammatory bowel disease patients. Nonetheless, the exact relation to date is not fully understood, and various paradoxical results from different studies are still a point of controversy.

Can We Predict the Efficacy of Anti-TNF-α Agents?

The use of biologic agents, particularly anti-tumor necrosis factor (TNF)-α, has revolutionized the treatment of inflammatory bowel diseases (IBD), modifying their natural history. Several data on the efficacy of these agents in inducing and maintaining clinical remission have been accumulated over the past two decades: their use avoid the need for steroids therapy, promote mucosal healing, reduce hospitalizations and surgeries and therefore dramatically improve the quality of life of IBD patients. However, primary non-response to these agents or loss of response over time mainly due to immunogenicity or treatment-related side-effects are a frequent concern in IBD patients. Thus, the identification of predicting factors of efficacy is crucial to allow clinicians to efficiently use these therapies, avoiding them when they are ineffective and eventually shifting towards alternative biological therapies with the end goal of optimizing the cost-effectiveness ratio. In this review, we aim to identify the predictive factors of short- and long-term benefits of anti-TNF-α therapy in IBD patients. In particular, multiple patient-, disease- and treatment-related factors have been evaluated.

[Second Korean Guidelines for the Management of Crohn's Disease]

Crohn's disease (CD) is a chronic, progressive, and disabling inflammatory bowel disease (IBD) with an uncertain etiopathogenesis. CD can involve any site of the gastrointestinal tract from the mouth to the anus, and is associated with serious complications, such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower compared with those in Western countries, but they have been rapidly increasing during the recent decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies have been applied for the treatment of this disease. Concerning CD management, there have been substantial discrepancies among clinicians according to their personal experience and preference. To suggest recommendable approaches to the diverse problems of CD and to minimize the variations in treatment among physicians, guidelines for the management of CD were first published in 2012 by the IBD Study Group of the Korean Association for the Study of the Intestinal Diseases. These are the revised guidelines based on updated evidence, accumulated since 2012. These guidelines were developed by using mainly adaptation methods, and encompass induction and maintenance treatment of CD, treatment based on disease location, treatment of CD complications, including stricture and fistula, surgical treatment, and prevention of postoperative recurrence. These are the second Korean guidelines for the management of CD and will be continuously revised as new evidence is collected.

ACG Clinical Guideline: Preventive Care in Inflammatory Bowel Disease

Recent data suggest that inflammatory bowel disease (IBD) patients do not receive preventive services at the same rate as general medical patients. Patients with IBD often consider their gastroenterologist to be the primary provider of care. To improve the care delivered to IBD patients, health maintenance issues need to be co-managed by both the gastroenterologist and primary care team. Gastroenterologists need to explicitly inform the primary care provider of the unique needs of the IBD patient, especially those on immunomodulators and biologics or being considered for such therapy. In particular, documentation of up to date vaccinations are crucial as IBD patients are often treated with long-term immune-suppressive therapies and may be at increased risk for infections, many of which are preventable with vaccinations. Health maintenance issues addressed in this guideline include identification, safety and appropriate timing of vaccinations, screening for osteoporosis, cervical cancer, melanoma and non-melanoma skin cancer as well as identification of depression and anxiety and smoking cessation. To accomplish these health maintenance goals, coordination between the primary care provider, gastroenterology team and other specialists is necessary.

Second Korean guidelines for the management of Crohn's disease

Crohn's disease (CD) is a chronic, progressive, and disabling inflammatory bowel disease (IBD) with an uncertain etiopathogenesis. CD can involve any site of the gastrointestinal tract from the mouth to the anus, and is associated with serious complications, such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower compared with those in Western countries, but they have been rapidly increasing during the recent decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies have been applied for the treatment of this disease. Concerning CD management, there have been substantial discrepancies among clinicians according to their personal experience and preference. To suggest recommendable approaches to the diverse problems of CD and to minimize the variations in treatment among physicians, guidelines for the management of CD were first published in 2012 by the IBD Study Group of the Korean Association for the Study of Intestinal Diseases. These are the revised guidelines based on updated evidence, accumulated since 2012. These guidelines were developed by using mainly adaptation methods, and encompass induction and maintenance treatment of CD, treatment based on disease location, treatment of CD complications, including stricture and fistula, surgical treatment, and prevention of postoperative recurrence. These are the second Korean guidelines for the management of CD and will be continuously revised as new evidence is collected.

Biomarkers in Search of Precision Medicine in IBD

The completion of the human genome project in 2003 represented a major scientific landmark, ushering in a new era with hopes and expectations of fresh insights into disease mechanisms and treatments. In inflammatory bowel disease (IBD), many important discoveries soon followed, notably the identification of >200 genetic susceptibility loci and characterization of the gut microbiome. As "big data", driven by advances in technology, becomes increasingly available and affordable, individuals with IBD and clinicians alike yearn for tangible outcomes from the promise of "precision medicine"-precise diagnosis, monitoring, and treatment. Here, we provide a commentary on the prospects and challenges of precision medicine and biomarkers in IBD. We focus on the three key areas where precision IBD will have the most impact: (1) disease susceptibility, activity, and behavior; (2) prediction of drug response and adverse effects; and (3) identification of subphenotypic mechanisms to facilitate drug discovery and selection of new treatments in IBD.

Crohn's Disease: Evolution, Epigenetics, and the Emerging Role of Microbiome-Targeted Therapies

Crohn's disease (CD) is a chronic, systemic, immune-mediated inflammation of the gastrointestinal tract. Originally described in 1932 as non-caseating granulomatous inflammation limited to the terminal ileum, it is now recognized as an expanding group of heterogeneous diseases defined by intestinal location, extent, behavior, and systemic extraintestinal manifestations. Joint diseases, including inflammatory spondyloarthritis and ankylosing spondylitis, are the most common extraintestinal manifestations of CD and share more genetic susceptibility loci than any other inflammatory bowel disease (IBD) trait. The high frequency and overlap with genes associated with infectious diseases, specifically Mendelian susceptibility to mycobacterial diseases (MSMD), suggest that CD may represent an evolutionary adaptation to environmental microbes. Elucidating the diversity of the enteric microbiota and the protean mucosal immune responses in individuals may personalize microbiome-targeted therapies and molecular classifications of CD. This review will focus on CD's natural history and therapies in the context of epigenetics, immunogenetics, and the microbiome.

Relationship of Body Mass Index to Clinical Outcomes after Infliximab Therapy in Patients with Crohn's Disease

BACKGROUND & AIMS

There are conflicting data for the role of obesity in Crohn's disease (CD) and the effect on long-term clinical outcomes is poorly studied. Some evidence suggests obesity is associated with diminished responsiveness to biological agents, especially anti-tumour necrosis factor antibodies.

METHODS

We aimed to examine the influence of body mass index (BMI) on the response to infliximab in CD in a retrospective analysis. The outcomes of interest within 12 months were: (1) Composite loss of response (CD-related flare or surgery; LOR); (2) any CD-related surgery (CDRS); and (3) CD-related intestinal resectional surgery (CDRIS).

RESULTS

A total of 388 patients were included. The mean BMI was 24.2kg/m(2) [± standard deviation (SD) 5.1]. Of the 388 patients, 137 (35.4%) were overweight (BMI: 25-29.9kg/m(2)) or obese (BMI: ≥30kg/m(2))-160 (41.6%) patients had LOR during the 12 months follow-up; 121 (31.4%) required CDRS, and 109 (28.2%) required CDRIS. Multivariate analysis showed that increasing BMI (per unit, kg/m(2) increase) reduced the risk of LOR [odds ratio (OR): 0.98], CDRS (OR: 0.95), and CDRIS (OR: 0.95). Rates for all outcomes were higher, but not significantly so, in the extreme categories (underweight and obese) and lower in the underweight categories compared with normal BMI. Exclusion of the obese category of patients strengthened this relationship.

CONCLUSIONS

Body mass index at first infusion of infliximab has a non-linear relationship with outcomes at 12 months. The worst outcomes are at the extremes of weight (underweight and obese categories). Increasing BMI is associated with a modest reduction in risk of LOR, CDRS, and CDRIS within 12 months, increasing with the exclusion of the obese category.

Optimizing Treatment with TNF Inhibitors in Inflammatory Bowel Disease by Monitoring Drug Levels and Antidrug Antibodies

BACKGROUND

Biological tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory bowel disease and redefined treatment goals to include mucosal healing. Clinicians are faced with challenges such as inadequate responses, treatment failures, side effects, and high drug costs. The objective is to review optimization of anti-TNF therapy by use of personalized treatment strategies based on circulating drug levels and antidrug antibodies (Abs), i.e. therapeutic drug monitoring (TDM). Furthermore, to outline TDM-related pitfalls and their prevention.

METHODS

Literature review.

RESULTS

Circulating anti-TNF drug trough level is a marker for the pharmacokinetics (PK) of TNF inhibitors. Because of a number of factors, including antidrug antibodies, PK varies between and within patients across time leading to variable clinical outcomes. Differences in intestinal inflammatory phenotype influencing the pharmacodynamic (PD) responses to TNF inhibitors also affect treatment outcomes. As an alternative to handling anti-TNF-treated patients by empiric strategies, TDM identifies underlying PK and PD-related reasons for treatment failure and aids decision making to secure optimal clinical and economic outcomes. Although promising, evidence does not the support use of TDM to counteract treatment failure in quiescent disease. Use of TDM is challenged by methodological biases, difficulties related to differentiation between PK and PD problems, and temporal biases due to lack of chronology between changes in PK versus symptomatic and objective disease activity manifestations. Biases can be accommodated by knowledgeable interpretation of results obtained by validated assays with clinically established thresholds, and by repeated assessments over time using complimentary techniques.

CONCLUSIONS

TDM-guided anti-TNF therapy at treatment failure has been brought from bench to bedside.

[Smoking, smoking cessation and Crohn's disease]

CONTEXT

Smoking whose prevalence is higher in patients with Crohn's disease (CD) worsens its evolution. Ulcerative colitis mostly affect non- or ex-smokers; smoking may improve the course of the disease.

OBJECTIVES

Systematic literature review of data on the relationship between smoking, smoking cessation and Crohn'disease.

DOCUMENTARY SOURCES

Medline, on the period 1980-2015 with the keywords "Crohn's disease" or "inflammatory bowel disease" and "smoking" or "smoking cessation"; limits "Title/Abstract"; the selected languages were English or French.

STUDY SELECTION

Among 1315 articles, 168 abstracts have given rise to a dual reading to select 69 studies (case-control, retrospective, reviews or meta-analysis). Data were extracted using a reading gate.

RESULTS

Smoking increases the risk of complications, recurrences and resort of surgery, corticosteroids or immunosuppressants. These deleterious effects are more common in women. Stopping smoking improves the course of the disease and represents an essential component of its management.

LIMITS

Heterogeneity of the studies collected according to the type, population characteristics, definition of smoking status and the validation of smoking cessation.

CONCLUSION

Smokers suffering from CD must routinely be made aware of the disadvantages of smoking, benefits of abstinence and helped to quit smoking.

Diffusion-weighted magnetic resonance enterocolonography in predicting remission after anti-TNF induction therapy in Crohn's disease

BACKGROUND

Diffusion-weighted magnetic resonance entero-colonography (DW-MREC) with no rectal distension and with no bowel cleansing is accurate to assess inflammatory activity in ileocolonic Crohn's disease (CD).

AIM

To study DW-MREC parameters as predictors of remission (CDAI < 150 and CRP < 5mg/L) after anti-TNF induction therapy.

METHODS

Forty consecutive CD patients were prospectively and consecutively included. All the patients underwent DW-MREC with apparent diffusion coefficient (ADC) and MaRIA calculation before starting anti-TNF. Mean ADC was defined as the mean of the segmental ADC.

RESULTS

Twenty patients (50.0%) experienced remission at W12. Low mean ADC (2.05 ± 0.22 vs 1.89 ± 0.25, p = 0.03) and high total MaRIA (39.2 ± 16.6 vs 51.7 ± 18.2, p = 0.03) were predictive of remission at W12. Using a ROC curve, we determined a mean ADC of 1.96 as predictive cut-off of remission at W12 (AUC = 0.703 [0.535-0.872]) with sensitivity, specificity, positive predictive value and negative predictive value of 70.0%, 65.0%, 66.7% and 68.4%, respectively. In multivariate analysis, mean ADC < 1.96 (OR = 4.87, 95% CI [1.04-22.64]) and total MaRIA > 42.5 (OR = 5.11, 95% CI [1.03-25.37]), reflecting high inflammatory activity, were predictive of remission at week 12.

CONCLUSIONS

DW-MREC using quantitative parameters i.e. ADC, is useful in detecting and assessing inflammatory activity but also to predict efficacy of anti-TNF induction therapy in CD.

Impact of patient characteristics on the clinical efficacy of mongersen (GED-0301), an oral Smad7 antisense oligonucleotide, in active Crohn's disease

BACKGROUND

In a phase 2 study, mongersen, an oral antisense oligonucleotide targeting Smad7, was effective in inducing clinical remission in approximately 60% of patients with active Crohn's disease (CD).

AIM

In a post hoc analysis to evaluate those patient disease characteristics that may have influenced the efficacy and safety of mongersen therapy.

METHODS

Patients with steroid-dependent/resistant, active CD were randomised to mongersen 10, 40 or 160 mg/day or placebo for 2 weeks; patients were followed for 10 weeks. Clinical remission [Crohn's Disease Activity Index (CDAI) score <150] and clinical response (CDAI score reduction ≥100 points) were assessed at weeks 2, 4 and 12 for these subgroups: disease duration <5/≥5 years, human serum C-reactive protein (hsCRP) <3/≥3 mg/L, and CDAI at baseline ≤260/>260. Additional patient baseline and disease characteristics were explored.

RESULTS

Clinical remission and response rates were significantly higher in patients receiving mongersen 40 and 160 mg/day but not 10 mg/day vs. placebo and independent of disease duration and hsCRP. Patients with baseline CDAI ≤260 had significantly higher remission rates with 40 and 160 mg/day. In patients with baseline CDAI >260, remission rates were statistically greater with 160 mg/day and numerically better with 40 mg/day vs. placebo. Adverse event rates were similar across treatment groups. Mongersen was safe and well tolerated.

CONCLUSIONS

Patients with higher CDAI scores achieved clinical remission most frequently with the highest mongersen dose. Disease duration and baseline human serum C-reactive protein did not appear to significantly impact efficacy of mongersen in this study (EudraCT Number: 2011-002640-27.).

Systematic review: predicting and optimising response to anti-TNF therapy in Crohn's disease - algorithm for practical management

BACKGROUND

Nonresponse and loss of response to anti-TNF therapies in Crohn's disease represent significant clinical problems for which clear management guidelines are lacking.

AIM

To review the incidence, mechanisms and predictors of primary nonresponse and secondary loss of response to formulate practical clinical algorithms to guide management.

METHODS

Through a systematic literature review, 503 articles were identified which fit the inclusion criteria.

RESULTS

Primary nonresponse to anti-TNF treatment affects 13-40% of patients. Secondary loss of response to anti-TNF occurs in 23-46% of patients when determined according to dose intensification, and 5-13% of patients when gauged by drug discontinuation rates. Recent evidence suggests that the mechanisms underlying primary nonresponse and secondary loss of response are multifactorial and include disease characteristics (phenotype, location, severity); drug (pharmacokinetic, pharmacodynamic or immunogenicity) and treatment strategy (dosing regimen) related factors. Clinical algorithms that employ therapeutic drug monitoring (using anti-TNF tough levels and anti-drug antibody levels) may be used to determine the underlying cause of primary nonresponse and secondary loss of response respectively and guide clinicians as to which patients are most likely to respond to anti-TNF therapy and help optimise drug therapy for those who are losing response to anti-TNF therapy.

CONCLUSIONS

Nonresponse or loss of response to anti-TNF occurs commonly in Crohn's disease. Clinical algorithms utilising therapeutic drug monitoring may establish the mechanisms for treatment failure and help guide the subsequent therapeutic approach.

Infliximab for the treatment of Crohn's disease: efficacy and safety in a Chinese single-center retrospective study

BACKGROUND AND AIM

Information describing the efficacy and safety of infliximab (IFX) for Crohn's disease (CD) in China is limited. The aim of this study was to report response rates, relapse rates after IFX-induced remission, and adverse events, and identify factors associated with relapse in a cohort of CD patients treated with IFX in a Chinese center.

PATIENTS AND METHODS

Clinical data of CD patients treated with two or more infusions of IFX from July 2010 to February 2013 at Nanfang Hospital (Guangzhou, China) were retrieved and analyzed retrospectively. Primary measurements were clinical response rate and relapse rate during 30 weeks of follow-up. Overall adverse events and risk factors related to IFX were evaluated.

RESULTS

A total of 70 CD patients were finally included. The clinical response rate was 98.6% at week 2, 97% at week 6, 92.5% at week 14, 84.9% at week 22, and 84.1% at week 30. The remission rate was 55.7% at week 2, 94% at week 6, 92.5% at week 14, 82.7% at week 22, and 77.3% at week 30. Relapse began following the third infusion. The relapse rate was 3.23% at week 6, 6.12% at week 14, 10.53% at week 22, and 8.82% at week 30. Adverse events related to IFX occurred in 32.6% of patients; most were mild and transient. Univariate analysis showed that sex was a significant predictor of clinical relapse.

CONCLUSION

IFX is an effective and safe treatment for CD in Chinese patients. Sex may be an independent predictor of relapse.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.