Efficacy and Safety of Infliximab Therapy and Predictors of Response in Korean Patients with Crohn's Disease: A Nationwide, Multicenter Study

(Re-)introduction of TNF antagonists and JAK inhibitors in patients with previous tuberculosis: a systematic review

BACKGROUND

Tuberculosis (TB) is a common complication associated with treatment with tumour necrosis factor (TNF) antagonists and Janus kinase (JAK) inhibitors. However, there is uncertainty about the risk of TB relapse in patients with TB and comorbidities requiring treatment with these agents.

OBJECTIVES

To assess the risk of TB relapse in patients (re-)started on TNF antagonists or JAK inhibitors.

METHODS

Systematic review.

DATA SOURCES

PubMed and Cochrane Library databases until 11 December 2023.

STUDY ELIGIBILITY CRITERIA

Randomized control trials, prospective and retrospective cohort studies, case reports and case series.

PARTICIPANTS

Patients with current or previous TB who were (re-)started on TNF antagonists or JAK inhibitors.

INTERVENTIONS

(Re-)introduction of TNF antagonists and JAK inhibitors.

ASSESSMENT OF RISK OF BIAS

All studies meeting entry criteria were included regardless of quality.

METHODS OF DATA SYNTHESIS

Categorical data are presented as frequencies and percentages. For non-normally distributed aggregated data, we calculated the pooled weighted median with 95% CI. For individual patient data, the median and interquartile range (IQR) were calculated.

RESULTS

Of 5018 articles screened for eligibility, 67 publications reporting on 368 TB patients who (re-)initiated treatment with TNF antagonists for underlying diseases were included. The median age was 42.5 years (95% CI: 40.4-42.5) and the proportion of female patients was 36.6% (n = 74) of patients whose sex was reported. A total of 14 patients (3.8%, 95% CI: 2.1-6.3%) developed TB relapse after a median of 8.5 months (interquartile range, 6.8-14.8 months) following (re-)initiation of anti-TNF treatment. Furthermore, among 251 articles screened for eligibility, 11 reports on TB patients who were (re-)started on JAK inhibitors for underlying diseases were identified. The median age was 62 years (interquartile range, 48.5-68.5 years) and 45.5% (n = 5) were female. Only one patient (9.1%; 95% CI: 0.2-41.3%) had TB reactivation 10 months after starting treatment with ruxolitinib. In addition, 94 patients who were treated with TNF antagonists and two patients temporarily treated with JAK inhibitors for the prevention or treatment of paradoxical reactions were analysed. None of the publications reported microbiological failure or worsening of TB-related symptoms.

CONCLUSIONS

(Re-)initiation of TNF antagonists and JAK inhibitors may be relatively safe in patients with current or previous TB and the need for further treatment of underlying diseases.

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.

Crohn’s disease: Why the ileum?

Crohn’s disease (CD) is an inflammatory bowel disease characterized by immune-mediated flares affecting any region of the intestine alternating with remission periods. In CD, the ileum is frequently affected and about one third of patients presents with a pure ileal type. Moreover, the ileal type of CD presents epidemiological specificities like a younger age at onset and often a strong link with smoking and genetic susceptibility genes. Most of these genes are associated with Paneth cell dysfunction, a cell type found in the intestinal crypts of the ileum. Besides, a Western-type diet is associated in epidemiological studies with CD onset and increasing evidence shows that diet can modulate the composition of bile acids and gut microbiota, which in turn modulates the susceptibility of the ileum to inflammation. Thus, the interplay between environmental factors and the histological and anatomical features of the ileum is thought to explain the specific transcriptome profile observed in CD ileitis. Indeed, both immune response and cellular healing processes harbour differences between ileal and non-ileal CD. Taken together, these findings advocate for a dedicated therapeutic approach to managing ileal CD. Currently, interventional pharmacological studies have failed to clearly demonstrate distinct response profiles according to disease site. However, the high rate of stricturing disease in ileal CD requires the identification of new therapeutic targets to significantly change the natural history of this debilitating disease.

Comparison of the Persistence of Anti-TNF Agents and Ustekinumab in Patients with Crohn’s Disease: A Study Based on the Korean National Database

Background: Biologics play an important role in the treatment of moderate to severe Crohn’s disease (CD). Ustekinumab was approved for such patients in the Republic of Korea on 1 December 2018. Therefore, we need to compare the efficacy of ustekinumab and anti-TNF inhibitors. Methods: We compared one-year persistence rates between anti-TNF inhibitors and ustekinumab in moderate-to-severe CD patients using Korean National Health Insurance Service data from 1 December 2016 to 30 November 2021. We also analysed the risk factors for the non-persistence of biologics. Results: The one-year persistence rates with index therapy in bio-naïve and bio-experienced patients were 87.7% and 69.7% for infliximab (p < 0.001), 85.1% and 72.8% for adalimumab (p < 0.001), and 92.1% and 89.8% for ustekinumab (p = 0.333), respectively. The risk factors for non-persistence were older age, non-use of an immune modulator, and previous biologic exposure in both the infliximab and adalimumab groups. The one-year persistence rate of ustekinumab was higher than that of anti-TNF inhibitors in bio-naïve patients (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.35–0.81; p = 0.003) and bio-experienced patients (HR 0.32; 95% CI 0.22–0.45; p < 0.001). Conclusions: Ustekinumab was superior in bio-naïve CD patients compared to anti-TNF inhibitors. However, the follow-up time was relatively short; further studies should continuously collect and analyse data.

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.

Personalized medicine in inflammatory bowel disease: Perspectives on Asia

Inflammatory bowel diseases are chronic, relapsing inflammatory disorders of the gastrointestinal tract with variable disease courses and complications, which in some cases can result in significant morbidities and disabilities. Etiologies remain unclear due to complex interactions between genetic and environmental factors. Considering the heterogeneity of inflammatory bowel diseases, personalized approaches in diagnosing and managing affected patients would be beneficial in maximizing treatment efficacies and minimizing adverse events. Personalized medicine may also help to stratify patients with a high risk of progression and inflammatory bowel disease-related complications and identify sub-phenotypic mechanisms to facilitate drug discovery and the development of new treatments. In Asia, with a rapidly increasing incidence and prevalence of inflammatory bowel diseases, studies have shown that patients of Asian ethnicity differ from their Western counterparts in terms of genetic and clinical aspects of inflammatory bowel diseases. Therefore, personalized medicine may differ for patients of Asian ethnicity with inflammatory bowel diseases. We reviewed and summarized current evidence concerning personalized medicine for the diagnosis and management of patients with inflammatory bowel diseases and its possible role from an Asian perspective.

Treatments of inflammatory bowel disease toward personalized medicine

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disease characterized by intestinal inflammation and epithelial injury. For the treatment of IBD, 5-aminosalicylic acids, corticosteroids, immunomodulators, and biologic agents targeting tumor necrosis factor (TNF)-α, α4β7-integrin, and interleukin (IL)-12/23 have been widely used. Especially, anti-TNF-α antibodies are the first biologic agents that presently remain at the forefront. However, 10-30% of patients resist biologic agents, including anti-TNF-α agents (primary non-responder; PNR), and 20-50% of primary responders develop treatment resistance within one year (secondary loss of response; SLR). Nonetheless, the etiologies of PNR and SLR are not clearly understood, and predictors of response to biologic agents are also not defined yet. Numerous studies are being performed to discover prediction markers of the response to biologic agents, and this review will introduce currently available therapeutic options for IBD, biologics under investigation, and recent studies exploring various predictive factors related to PNR and SLR.

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.

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.

Sex matters: impact on pathogenesis, presentation and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD), as do most chronic inflammatory disorders, displays unique features and confers different risk factors in male and female patients. Importantly, sex-based differences in IBD exist for epidemiological incidence and prevalence among different age groups, with men and women developing distinct clinical symptoms and disparity in severity of disease. In addition, the presentation of comorbidities in IBD displays strong sex differences. Notably, particular issues exclusive to women's health, including pregnancy and childbirth, require specific considerations in female patients with IBD of childbearing age that can have a substantial influence on clinical outcomes. This Review summarizes the latest findings regarding sex-based differences in the epidemiology, clinical course, comorbidities and response to current therapies in patients with IBD. Importantly, the latest basic science discoveries in this area of investigation are evaluated to provide insight into potential mechanisms underlying the influence of sex on disease pathogenesis, as well as to design more personalized and efficacious care, in patients with IBD.

Real-world cost-effectiveness associated with infliximab maintenance therapy for moderate to severe Crohn’s disease in China

BACKGROUND

Infliximab was the first approved biologic treatment for moderate to severe Crohn’s disease (MS-CD) in China. However, the cost-effectiveness of infliximab maintenance therapy (IMT) for MS-CD relative to conventional maintenance therapy remained unclarified. 

AIM

To assess the cost-effectiveness of IMT for MS-CD in Chinese patients from the perspective of Chinese public insurance payer.

METHODS

A cohort of MS-CD patients managed in a Chinese tertiary care hospital was created to compare IMT with conventional maintenance therapy (CMT) for clinical outcomes and direct medical costs over a 1-year observation time using conventional regression analyses. A decision-analytic model with the generated evidence was constructed to assess the cost-effectiveness of IMT relative to CMT using reimbursed medical costs. 

RESULTS

Based on the included 389 patients, IMT was associated with significantly higher disease remission chance [odds ratio: 4.060, P = 0.003], lower risk of developing new complications (odds ratio: 0.527, P = 0.010), higher utility value for quality of life (coefficient 0.822, P = 0.008), and lower total hospital costs related to disease management (coefficient -0.378, P = 0.008) than CMT. Base-case cost-effectiveness analysis estimated that IMT could cost Chinese health insurance payers ¥55260 to gain one quality-adjusted life year (QALY). The cost-effectiveness of IMT was mainly driven by the estimate of quality of life, treatment efficacy of maintenance therapy, mortality risk associated with active disease, and unit price of infliximab. The probability that IMT was cost-effective at a willingness-to-pay threshold of three times gross domestic product [2018 Chinese gross domestic product per capita (GDPPC)] was 86.4%. 

CONCLUSION

IMT significantly improved real-world health outcomes and cost the Chinese public health insurance payers less than one GDPPC to gain one QALY in Chinese MS-CD patients. 

Biosimilars in inflammatory bowel disease

The advent of biologics has changed outcomes in many chronic conditions, including inflammatory bowel disease (IBD). Biologics have been used for the induction and remission of ulcerative colitis and Crohn's disease for almost two decades and are effective in patients who used to fail conventional treatment with steroids, immunomodulators. The use of biologics in the treatment of IBD has increased over the last few years, partly due to the rise in its incidence and the use of biologics as a first-line treatment in severe disease as well as in complicated diseases like penetrating/fistulating Crohn's disease. However, their use is associated with a significant burden to the society with respect to healthcare costs, resulting in the premature discontinuation of therapy in some patients, leading to exacerbations and complications. The introduction of biosimilars a decade ago seems to be a promising approach to reducing the costs related to therapy. Since their introduction, numerous studies conducted in adults and some in children show the efficacy of biosimilars with a similar side-effect profile to biologics. This review discusses the history of biosimilars in the treatment of IBD, enumerates several such studies and discusses the possibility of using biosimilars in the future.

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.

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.

Biologic Use Patterns and Predictors for Non-persistence and Switching of Biologics in Patients with Inflammatory Bowel Disease: A Nationwide Population-Based Study

BACKGROUND

Data on real-life patterns of biologic use for inflammatory bowel disease (IBD) are scarce.

AIMS

We aimed to examine the patterns of biologic use and the factors associated with non-persistence and switching of biologics in Korean IBD patients.

METHODS

Using National Health Insurance claims, we collected data on patients who were diagnosed with IBD and exposed to biologics between 2010 and 2016.

RESULTS

Among 1838 patients with Crohn's disease (CD), 1237 and 601 started with infliximab and adalimumab, respectively. Among 1125 patients with ulcerative colitis (UC), 774, 294, and 57 initiated infliximab, adalimumab, and golimumab, respectively. Rates of non-persistence and switching were higher in UC than in CD. One- and 3-year non-persistence rates were 14.2% and 26.5% in CD and 35.4% and 53.4% in UC, respectively. One- and 3-year switching rates were 3.7% and 10.1% in CD and 15.6% and 22.0% in UC, respectively. In both CD and UC, infliximab and adalimumab initiators showed similar persistence rates, whereas adalimumab initiators had a higher risk of switching than infliximab initiators. In UC, golimumab initiators had a higher risk of non-persistence and switching than infliximab initiators. Steroid use at biologic initiation was associated with an increased risk of non-persistence and switching in both CD and UC. UC patients who started biologic treatment at tertiary hospitals were more likely to continue treatment than those who started at general hospitals/community hospitals/clinics.

CONCLUSIONS

In real-world clinical practice settings, discontinuation of biologics occurred frequently in IBD patients, and switching of biologics was common in UC patients.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Obesity and response to anti-tumor necrosis factor-α agents in patients with select immune-mediated inflammatory diseases: A systematic review and meta-analysis

OBJECTIVES

We sought to evaluate the association between obesity and response to anti-tumor necrosis factor-α (TNF) agents, through a systematic review and meta-analysis.

METHODS

Through a systematic search through January 24, 2017, we identified randomized controlled trials (RCTs) or observational studies in adults with select immune-mediated inflammatory diseases-inflammatory bowel diseases (IBD), rheumatoid arthritis (RA), spondyloarthropathies (SpA), psoriasis and psoriatic arthritis (PsA)-treated with anti-TNF agents, and reporting outcomes, stratified by body mass index (BMI) categories or weight. Primary outcome was failure to achieve clinical remission or response or treatment modification. We performed random effects meta-analysis and estimated odds ratios (OR) and 95% confidence interval (CI).

RESULTS

Based on 54 cohorts including 19,372 patients (23% obese), patients with obesity had 60% higher odds of failing therapy (OR,1.60; 95% CI,1.39-1.83;I2 = 71%). Dose-response relationship was observed (obese vs. normal BMI: OR,1.87 [1.39-2.52]; overweight vs. normal BMI: OR,1.38 [1.11-1.74],p = 0.11); a 1kg/m2 increase in BMI was associated with 6.5% higher odds of failure (OR,1.065 [1.043-1.087]). These effects were observed across patients with rheumatic diseases, but not observed in patients with IBD. Effect was consistent based on dosing regimen/route, study design, exposure definition, and outcome measures. Less than 10% eligible RCTs reported outcomes stratified by BMI.

CONCLUSIONS

Obesity is an under-reported predictor of inferior response to anti-TNF agents in patients with select immune-mediated inflammatory diseases. A thorough evaluation of obesity as an effect modifier in clinical trials is warranted, and intentional weight loss may serve as adjunctive treatment in patients with obesity failing anti-TNF therapy.

Improvement of psychological status after infliximab treatment in patients with newly diagnosed Crohn's disease

BACKGROUND

Patients with newly diagnosed Crohn's disease (CD) are associated with impaired physical and psychological well-being. These psychological characteristics are dynamic with the course of disease and could be influenced by medical treatment. Infliximab is effective and widely used in moderate-to-severe CD patients. The aim of this study was to evaluate the improvement of psychological status after infliximab treatment in patients with newly diagnosed CD.

METHODS

Newly diagnosed moderate-to-severe CD patients were prospectively enrolled in our study. Infliximab 5 mg/kg was administered at weeks 0, 2, 6, 14, 22, and 30. Outcomes including disease severity, illness perceptions, coping strategies, anxiety, depression, and quality of life (QoL) were measured at baseline, week 14, and week 30.

RESULTS

Eighty-two patients completed our study. The rates of clinical remission at weeks 14 and 30 were 59/82 (72.0%) and 58/82 (70.7%), respectively. Patients who achieved clinical remission at weeks 14 and 30 significantly improved in illness perceptions (P<0.001 and <0.001), maladaptive coping (P=0.005 and 0.004), anxiety (P<0.001 and <0.001), depression (P=0.004 and 0.004), and QoL (P<0.001 and <0.001). However, emotion-focused coping and problem-focused coping remained unchanged. For infliximab nonresponders, no significant changes were seen in illness perceptions, coping strategies, anxiety, depression, or QoL at week 14 or 30.

CONCLUSION

Effective infliximab treatment not only led to clinical remission in patients with newly diagnosed moderate-to-severe CD but also improved their psychological status including illness perceptions, maladaptive coping, anxiety, depression, and QoL.

Patterns and predictors of long-term retention of inflammatory bowel or rheumatoid disease patients on innovator infliximab: an analysis of a Canadian prescriptions claims database

BACKGROUND

Long-term effectiveness is an important factor when considering treatment decisions.

OBJECTIVE

To determine the long-term retention patterns of Canadian inflammatory bowel disease (IBD) and rheumatologic disease (RD) patients, including rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, treated with innovator infliximab (IFX) and to assess the impact of year-over-year cumulative IFX exposure on retention in both patient populations.

PATIENTS AND METHODS

This analysis used a Canadian longitudinal prescription claims database to measure retention on IFX over a period of 5 years. Twelve-month unadjusted odds ratios of retention by time on IFX were calculated for the overall cohort, and within-group comparisons evaluated differences according to age, sex, region, insurance coverage, use of concomitant immunosuppressant therapy, indication (RD cohort only), and previous biologic experience. Between-group analyses compared unadjusted 5-year retention among the same variables. Variables that were independently associated with longer retention on IFX were identified using multivariable regression.

RESULTS

Seven thousand eight hundred and six IBD patients and 2,935 RD patients on stable treatment with IFX were included in the analysis. Sixty-nine percent of IBD patients and 66% of RD patients were retained on IFX after 1 year and 33% and 29%, respectively, were retained after 5 years. Moreover, the probability of being retained on IFX significantly increased with cumulative time on IFX. Independent predictors of 5-year retention included sex, region, and type of insurance coverage among IBD patients and region, type of insurance, prior biologic therapy, and specific indication among RD patients. Patients with IBD were 17% more likely to be retained on IFX over 5 years compared to patients with RD.

CONCLUSION

Real-world Canadian IBD and RD patients on IFX have good overall long-term treatment retention. Previous duration of IFX treatment predicts better future retention, and this knowledge could help inform treatment decisions when patients have been stable on IFX treatment for varying periods of time.

Pathogenesis of Inflammatory Bowel Disease and Recent Advances in Biologic Therapies

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disorder with an unknown etiology. IBD is composed of two different disease entities: Crohn's disease (CD) and ulcerative colitis (UC). IBD has been thought to be idiopathic but has two main attributable causes that include genetic and environmental factors. The gastrointestinal tract in which this disease occurs is central to the immune system, and the innate and the adaptive immune systems are balanced in complex interactions with intestinal microbes under homeostatic conditions. However, in IBD, this homeostasis is disrupted and uncontrolled intestinal inflammation is perpetuated. Recently, the pathogenesis of IBD has become better understood owing to advances in genetic and immunologic technology. Moreover, new therapeutic strategies are now being implemented that accurately target the pathogenesis of IBD. Beyond conventional immunesuppressive therapy, the development of biological agents that target specific disease mechanisms has resulted in more frequent and deeper remission in IBD patients, with mucosal healing as a treatment goal of therapy. Future novel biologics should overcome the limitations of current therapies and ensure that individual patients can be treated with optimal drugs that are safe and precisely target IBD.