Smoking and immunomodulators do not influence the response or duration of response to infliximab in Crohn's disease

Choosing Therapy for Moderate to Severe Crohn's Disease

The availability of approved therapies for Crohn's disease has significantly increased over the past decade. To choose the appropriate therapy for the patient, ideally head to head studies, and data on positioning could help the provider individualize the decision. Due to the paucity of head-to-head trial data, we turn to network meta-analysis and real-world studies to help guide our treatment choices. Ultimately, the best approach is to consider each patient on an individual basis, taking into consideration the characteristics of their disease, individual risk factors, extra-intestinal manifestations, co-morbid conditions, patient age, cost, and personal preferences. In this review, we summarize the evidence comparing biologic as well as small molecule therapies for the treatment of moderate-to-severe Crohn's disease. We have summarized the evidence in relation to factors such as efficacy, fistulizing disease, pregnancy, infection risk, and co-existing conditions.

The Optimal Management of Fistulizing Crohn’s Disease: Evidence beyond Randomized Clinical Trials

Fistulizing Crohn’s disease (FCD) remains the most challenging aspect of treating patients with CD. FCD can occur in up to 30% of patients with CD and may lead to significant disability and impaired quality of life. The optimal treatment strategies for FCD require a multidisciplinary approach, including a combined medical and surgical approach. The therapeutic options for FCD are limited due to sparse evidence from randomized clinical trials (RCTs). The current recommendations are mainly based on post hoc analysis from RCTs, real-world clinical studies and expert opinion. There is variation in everyday clinical practice amongst gastroenterologists and surgeons. The evidence for anti-tumor necrosis factor therapy is the strongest in the treatment of FCD. However, long-term fistula healing can be achieved in only 30–50% of patients. In recent years, emerging data in the advent of therapeutic modalities, including the use of new biologic agents, therapeutic drug monitoring, novel surgical methods and mesenchymal stem cell therapy, have been shown to improve outcomes in achieving fistula healing. This review summarizes the existing literature on current and emerging therapies to provide guidance beyond RCTs in managing FCD.

Approach to medical therapy in perianal Crohn's disease

Perianal Crohn's disease remains a challenging condition to treat and can have a substantial negative impact on quality of life. It often requires combined surgical and medical interventions. Anti-tumor necrosis factor (anti-TNF) therapy, including infliximab and adalimumab, remain preferred medical therapies for perianal Crohn's disease. Infliximab has been shown to be efficacious in improving fistula closure rates in randomized controlled trials. Clinicians can be faced with a number of questions relating to the optimal use of anti-TNF therapy in perianal Crohn's disease. Specific issues include evaluation for the presence of perianal sepsis, the treatment target of therapy, the ideal time to commence treatment, whether additional medical therapy should be used in conjunction with anti-TNF therapy, and the duration of treatment. This article will discuss key studies which can assist clinicians in addressing these matters when they are considering or have already commenced anti-TNF therapy for the treatment of perianal Crohn's disease. It will also discuss current evidence regarding the use of vedolizumab and ustekinumab in patients who are failing to achieve a response to anti-TNF therapy for perianal Crohn's disease. Lastly, new therapies such as local injection of mesenchymal stem cell therapy will be discussed.

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.

Patient's profiling for therapeutic management of inflammatory bowel disease: a tailored approach

Introduction: Several biological drugs and a new small molecule are available for the treatment of Crohn's disease and ulcerative colitis. However, to date, no reliable predictors of response to treatment have yet been identified. Areas covered: We focused on studies evaluating the therapeutic management of patients with chronic inflammatory bowel diseases in order to identify any predictive factors of response to drugs and to guide therapeutic decisions based on patient and disease characteristics. Expert opinion: The heterogeneity of literature data, the main retrospective nature of the scientific evidence, and the lack of comparative head-to-head trials are the most relevant limitations for identifying factors predicting drug response. In the near future, a personalized approach to patients with chronic inflammatory diseases will be based on patient's profile to define not only the best drug to use, but also the appropriate follow-up, and the possibility of home care.

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.

Strategies to Optimize Anti-tumor Necrosis Factor Therapy for Perianal Fistulizing Crohn's Disease: A Systematic Review

Tumor necrosis factor (TNF) antagonists are considered the cornerstone therapy for fistulizing perianal Crohn's disease (PCD), yet a substantial proportion of patients fail to achieve healing. Therefore, we reviewed the evidence for strategies to enhance the efficacy of TNF antagonists for PCD. A systematic search of electronic databases through July 2018 was performed to identify studies that assessed the effectiveness of TNF antagonists combined with another medical or surgical intervention for PCD; or assessed the association between anti-TNF serum concentrations and fistula healing. Twelve studies compared anti-TNF therapy alone versus a combined approach: four with surgery, three with antibiotics, and five with immunomodulators. Only two studies, both with antibiotics, were rated high quality. The addition of antibiotics to anti-TNF therapy resulted in significantly higher rates of fistula response and healing in one study, and a trend toward reduction in fistula drainage in the other. Three of four studies found higher rates of fistula healing when surgery was combined with TNF antagonists. In contrast, one of five studies found a trend toward higher rates of fistula healing in patients treated concomitantly with immunomodulators. Five observational studies assessed the association between anti-TNF concentration and fistula healing. Higher infliximab serum concentrations were consistently associated with fistula healing. In conclusion, few high-quality studies assessing strategies to optimize anti-TNF therapy for PCD exist. Although antibiotics, possibly surgery, and higher serum infliximab concentrations appear to improve fistula healing, future prospective studies are needed to determine the optimal treatment strategy.

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

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

The role of 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.

Predicting durable response or resistance to antitumor necrosis factor therapy in inflammatory bowel disease

Monoclonal antibodies to tumor necrosis factor (TNF) have become a mainstay of the therapeutic armamentarium in inflammatory bowel disease (IBD) over the last 15 years. Although highly effective, primary and secondary nonresponse are common and associated with poor clinical outcomes and significant costs. Multiple clinical, genetic and immunopharmacological factors may impact the response to anti-TNFs. Early stratification of IBD patients by the expected risk of therapeutic failure during the induction and maintenance phases of treatment may allow for treatment optimization and potentially optimal short- and long-term outcomes. The aim of this review is to summarize the current data concerning the potential predictors of therapeutic success and failure of anti-TNFs in IBD.

Predictors of response to infliximab in paediatric perianal Crohn's disease

BACKGROUND

It is reported that 27-54% of paediatric patients with perianal Crohn's disease (CD) do not respond to infliximab (IFX).

AIM

To identify predictors of response to IFX in paediatric perianal CD.

METHODS

A retrospective cohort study of 101 paediatric patients treated with IFX between 2000 and 2011 for perianal CD in 22 French hospitals of the GETAID pédiatrique network was performed. Response was monitored after induction therapy and at 1 year. Complete response was defined by closure of all fistulas and complete healing of ulcers. Associations between baseline characteristics and (i) 1-year response and (ii) time of first relapse among initial responders were tested by logistic regression and Cox model respectively.

RESULTS

Eighty-nine patients (88%) responded to induction therapy (36 partial/53 complete). At 1 year, 76 patients (75%) were responders (22 partial/54 complete). Predictors of 1-year response were: number of fistulas ≤1 (OR: 3.76, 95% CI: 1.20-11.77, P = 0.03) and baseline Harvey-Bradshaw index <5 (OR: 3.72, 95% CI: 1.10-12.60, P = 0.03). Predictors of relapse among initial responders were: CD duration <10 months (OR: 3.31, 95% CI: 1.34-8.19, P = 0.0097) and number of fistulas >1 (OR: 2.79, 95% CI: 1.12-6.95, P = 0.028). Combined therapy with an immunomodulator was not associated with 1-year response or time of relapse.

CONCLUSION

Those patients with perianal Crohn's disease have better outcomes if they have less fistulas, a low baseline Harvey-Bradshaw Index or a longer duration of Crohn's disease.

Who should receive biologic therapy for IBD?: The rationale for the application of a personalized approach

The therapeutic approach in inflammatory bowel disease has evolved to target end-organ inflammation to heal intestinal mucosa and avoid structural damage. Objective therapeutic monitoring is required to achieve this goal. Earlier intervention with biologic therapy has been shown, indirectly, to be associated with higher clinical response and remission rates. A personalized approach to risk stratification with consideration of key clinical factors and inflammatory biomarker concentrations is recommended when deciding whether or not to start a patient on biologic therapy.

Clinical use and mechanisms of infliximab treatment on inflammatory bowel disease: a recent update

The pathogenesis and treatment of inflammatory bowel disease (IBD) have been recently advanced, while it is still challenged with high morbidity and poor prognosis. Infliximab, a monoclonal antibody of tumor necrosis factor (TNF), has emerged as an efficient treatment with many clinical benefits such as quick disease activity reduction and IBD patient life quality improvement. However, the biological effects of infliximab on IBD need to be elucidated. This paper reviewed the clinical use and recently advanced biological action of infliximab on IBD. By forming the stable complex with the soluble or the membrane form of TNF in fluid environment or on cell surface of immune cell, fibroblast, endothelium, and epithelium, infliximab quenches TNF activity and performs the important biological actions which lead to amelioration and remission of immune responses. The mechanisms of infliximab treatment for IBD were intensively discussed. The recent advances on two topics including predictors and side effects of infliximab treatment were also reviewed.

Impact of environmental and dietary factors on the course of inflammatory bowel disease

Besides their possible effects on the development of inflammatory bowel disease (IBD), some environmental factors can modulate the clinical course of both ulcerative colitis (UC) and Crohn’s disease (CD). This review is mainly devoted to describing the current knowledge of the impact of some of these factors on the outcome of IBD, with special emphasis on smoking and diet. Although the impact of smoking on the susceptibility to develop CD and UC is firmly established, its influence on the clinical course of both diseases is still debatable. In CD, active smoking is a risk factor for postoperative recurrence. Beyond this clinical setting, smoking cessation seems to be advantageous in those CD patients who were smokers at disease diagnosis, while smoking resumption may be of benefit in ex-smokers with resistant UC. The role of dietary habits on the development of IBD is far from being well established. Also, food intolerances are very frequent, but usually inconsistent among IBD patients, and therefore no general dietary recommendations can be made in these patients. In general, IBD patients should eat a diet as varied as possible. Regarding the possible therapeutic role of some dietary components in IBD, lessons should be drawn from the investigation of the primary therapeutic effect of enteral nutrition in CD. Low-fat diets seem to be particularly useful. Also, some lipid sources, such as olive oil, medium-chain triglycerides, and perhaps omega-3 fatty acids, might have a therapeutic effect. Fermentable fiber may have a role in preventing relapses in inactive UC.

Predicting response to Anti-TNF Agents for the treatment of crohn's disease

The arrival of anti-tumor necrosis factor (TNF) agents has led to a dramatic improvement in the care of patients with Crohn's disease. Since these medications do not work in everyone, and are associated with rare, but serious side effects, we want to selectively treat patients who have the highest chance of responding. A number of variables have been studied to determine their association with response to anti-TNF agents. Clinical parameters include patient characteristics, smoking status and disease phenotype, and biologic markers include C-reactive protein, serum TNF levels and immune responses to microbial antigens. More recently, research has focused on genetics to identify polymorphisms associated with treatment response. Results from individual studies of these factors have not yet allowed for solid clinical applicability. However, further work in this area along with multivariate clinical prediction modeling may soon allow us to deliver 'personalized medicine' by predicting individualized treatment response in patients with Crohn's disease.

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

BACKGROUND

Adalimumab is a fully human monoclonal antibody targeting tumour necrosis factor with proven efficacy in the treatment of Crohn's disease (CD).

AIM

To investigate the predictors of medium-term clinical efficacy and mucosal healing during adalimumab therapy, in patients with CD, in specialised centres approved for biological therapy in Hungary.

METHODS

Data capture of the 201 CD patients was standardised and prospective (male/female: 112/89, median age: 33.0 years, duration: 8 years). Previous infliximab therapy had been administered in 48% of patients, concomitant steroids in 41%, azathioprine in 69% and combined therapy in 27% of patients.

RESULTS

Overall clinical response and remission rates at 24 weeks were 78% and 52%, respectively; at 52 weeks were 69% and 44%, respectively. Endoscopic improvement and healing were achieved in 43% and 24% of patients. In a logistic regression model, clinical efficacy and CRP at week 12, need for combined immunosuppression at induction, shorter disease duration and smoking were identified as independent predictors for 12-month clinical outcome, whereas CRP at week 12, clinical remission at week 24, inflammatory parameters and nonsmoking were associated to endoscopic improvement/healing. Intensification to weekly dosing was needed in 16% of patients. Parallel azathioprine therapy and clinical remission at week 12 were inversely associated with dose escalation.

CONCLUSIONS

Clinical efficacy and normalised CRP at week 12 (early deep clinical remission) are associated with medium-term clinical efficacy and mucosal healing during adalimumab therapy, whereas need for combined immunosuppression at induction and smoking status are predictors for non-response. Parallel azathioprine therapy may decrease the probability for dose escalation.

[Predictors of efficacy, mucosal healing and dose intensification during the first year of adalimumab therapy in patients with luminal and fistulizing Crohn's disease. National data from Hungary]

Adalimumab is a fully human monoclonal antibody targeting tumor necrosis factor with proven efficacy in the treatment of Crohn's disease in clinical trials. The aim of the present study was to investigate the predictors of medium term clinical efficacy and mucosal healing during adalimumab therapy in patients with Crohn's disease in specialized centers approved for biological therapy in Hungary.

METHODS

Data of 201 Crohn's disease patients were prospectively captured (male/female: 112/89, median age: 24 years, duration: 8 years). Previous infliximab therapy was given in 97 (48.3%) patients, concomitant steroids in 41.3% and azathioprine in 69.2% (combined: 26.4%) of patients.

RESULTS

Overall clinical response and remission rates at 24 and 52 weeks were 78% and 52%, and 69.4% and 44.4%, respectively. Endoscopic improvement and healing was achieved in 43.1% and 23.6%, respectively. In a logistic regression model, clinical efficacy and normalized C-reactive protein at week 12, need for combined immunosuppression at induction, shorter disease duration and smoking were identified as independent predictors for 12-month clinical outcome, while normalized C-reactive protein at week 12, clinical remission at week 24, frequency of previous relapses and smoking were associated to endoscopic improvement/healing. Dose intensification to weekly dosing was needed in 16.4%. Parallel azathioprine therapy and clinical remission at week 12 was inversely associated to dose escalation to weekly dosing.

CONCLUSION

Clinical efficacy and normalized C-reactive protein at week 12, need for combined immunosuppression, luminal disease and smoking are predictors for medium term clinical efficacy/mucosal healing during adalimumab therapy, while parallel azathioprine therapy may decrease the probability for dose escalation.

Management of Crohn's disease in smokers: is an alternative approach necessary?

Inflammatory bowel disease is a chronic condition with a pathogenic background that involves both genetic and environmental factors. Although important progress has been made regarding the former in the last decade, scarce knowledge is available for the latter. In this sense, smoking remains the most important environmental factor in IBD. Active smoking increases the risk of developing Crohn's disease (CD). Moreover, CD patients who start or continue smoking after disease diagnosis are at risk for poorer outcomes such as higher therapeutic requirements and disease-related complications, as compared to those patients who quit smoking or who never smoked. However, the harmful effect of active smoking is not uniform in all patients or in all clinical scenarios. Interventions designed to facilitate smoking cessation may impact the course of the disease. In this article, the available evidence of the deleterious effects of smoking on CD is reviewed in detail, and alternative therapeutic approaches to CD in smokers are proposed.

Use of biological molecules in the treatment of inflammatory bowel disease

The introduction of biological agents (i.e. antitumour necrosis factor-α and anti-integrin treatments) for the treatment of inflammatory bowel disease (IBD) [i.e. Crohn's disease (CD) and ulcerative colitis] has led to a substantial change in the treatment algorithms and guidelines, especially in CD. However, many questions still remain about the true efficacy and the best treatment regimens. Thus, a need for further treatment options still exists as up to 40% of IBD patients treated with the presently available biologicals do not have positive clinical responses. Better patient selection might maximize the clinical benefit for those in most need of an effective therapy to avoid disabling disease whilst also minimizing the complications associated with therapy. Further, the 'trough-level strategy' may help clinicians to optimize therapy and to avoid loss of response and/or immunogenicity. The idea behind this dosage regimen is that correct dosing must ensure that the patient's lowest level of drug concentration (i.e. the trough level) occurring just before the next drug administration is high enough for the full effect to be seen. Controversy continues regarding the appropriate use of biologicals; therefore, in this review, we focus on considerations that might lead to a more rational strategy for antitumour necrosis factor-α agents in IBD, emphasizing the situations in which the risks may outweigh the benefits. Finally, the need for an appropriate strategy for stopping biological treatment is discussed.

Smoking status and response to thiopurines in steroid-dependent inflammatory bowel disease

BACKGROUND

The influence of smoking on inflammatory bowel disease (IBD) susceptibility and on its clinical course is well known, but not its impact on drug efficacy. The aim of this study was to evaluate the response to thiopurines in patients with steroid-dependent IBD according to their smoking habits.

METHODS

The medical records of 163 IBD patients (103 Crohn's disease [CD], 60 ulcerative colitis [UC]) in whom thiopurines were started because of steroid-dependency were reviewed. Therapeutic response was defined by steroid-free clinical remission for at least 6 months after 12 months of starting thiopurines. Clinical data and smoking status at diagnosis, at the time thiopurines were started, and during the follow-up were registered.

RESULTS

A therapeutic response was obtained in 72% of CD and 61% of UC patients. Smoking habits did not influence the rate of response to thiopurines, the need for rescue therapies, or the development of penetrating/stricturing complications (CD) or proximal progression (UC). However, CD responders who continued smoking required new courses of steroids more often during follow-up. No influence of smoking was found when these outcomes were analyzed depending on gender or disease location. In the multivariate analysis, smoking status was the only predictive factor of drug tolerance.

CONCLUSIONS

Active smoking does not influence the response to thiopurines in steroid-dependent IBD, but may decrease the likelihood of drug tolerance.

The London Position Statement of the World Congress of Gastroenterology on Biological Therapy for IBD with the European Crohn's and Colitis Organization: when to start, when to stop, which drug to choose, and how to predict response?

The advent of biological therapy has revolutionized inflammatory bowel disease (IBD) care. Nonetheless, not all patients require biological therapy. Selection of patients depends on clinical characteristics, previous response to other medical therapy, and comorbid conditions. Availability, reimbursement guidelines, and patient preferences guide the choice of first-line biological therapy for luminal Crohn's disease (CD). Infliximab (IFX) has the most extensive clinical trial data, but other biological agents (adalimumab (ADA), certolizumab pegol (CZP), and natalizumab (NAT)) appear to have similar benefits in CD. Steroid-refractory, steroid-dependent, or complex fistulizing CD are indications for starting biological therapy, after surgical drainage of any sepsis. For fistulizing CD, the efficacy of IFX for inducing fistula closure is best documented. Unique risks of NAT account for its labeling as a second-line biological agent in some countries. Patients who respond to induction therapy benefit from systematic re-treatment. The combination of IFX with azathioprine is better than monotherapy for induction of remission and mucosal healing up to 1 year in patients who are naïve to both agents. Whether this applies to other agents remains unknown. IFX is also effective for treatment-refractory, moderate, or severely active ulcerative colitis. Patients who have a diminished or loss of response to anti-tumor necrosis factor (TNF) therapy may respond to dose adjustment of the same agent or switching to another agent. Careful consideration should be given to the reasons for loss of response. There are insufficient data to make recommendations on when to stop anti-TNF therapy. Preliminary evidence suggests that a substantial proportion of patients in clinical remission for >1 year, without signs of active inflammation can remain in remission after stopping treatment.

Randomised clinical trial: certolizumab pegol for fistulas in Crohn's disease - subgroup results from a placebo-controlled study

BACKGROUND

Treatment options for fistulizing Crohn's disease (CD) are limited.

AIM

To examine whether fistula closure is maintained at week 26 following treatment with certolizumab pegol.

METHODS

Patients with draining fistulas at baseline from PRECiSE 2 (n = 108) received open-label induction with certolizumab pegol 400 mg at weeks 0 (baseline), 2 and 4. Response was defined as ≥100-point decrease from baseline in the Crohn's Disease Activity Index. Nonresponders (50/108) were excluded. At week 6, responders with draining fistulas (N = 58) were randomised to certolizumab pegol 400 mg (n = 28) or placebo (n = 30) every 4 weeks across weeks 8-24. Fistula closure was evaluated throughout the study, with a final assessment at week 26.

RESULTS

The majority of patients (55/58) had perianal fistula. At week 26, 36% of patients in the certolizumab pegol group had 100% fistula closure compared with 17% of patients receiving placebo (P = 0.038). Protocol-defined fistula closure (≥50% closure at two consecutive post-baseline visits ≥3 weeks apart) was not statistically significant (P = 0.069) with 54% and 43% of patients treated with certolizumab pegol and placebo achieving this end point, respectively.

CONCLUSION

Continuous treatment with certolizumab pegol improves the likelihood of sustained perianal fistula closure compared with placebo.

Impact of concomitant immunomodulator use on long-term outcomes in patients receiving scheduled maintenance infliximab

The long-term benefits of combining scheduled infliximab with concomitant immunomodulators [azathioprine or 6-mercaptopurine (6-MP)] in patients with Crohn's disease are unclear. Historical cohort followed for 5 years after initiation of infliximab for active Crohn's disease. Data were available on 123 patients who received scheduled maintenance infliximab infusions, for up to 5 years after initiation of infliximab. Clinical remission rates in the entire cohort were 73% (82/113) at 1 year, 65% (65/100) at 2 years, and 58% (21/36) at 5 years. Remission rates with maintenance infliximab were significantly improved in those receiving concomitant immunomodulators at 1 year (86% versus 68%, P = 0.03), but not at 2 years (80% versus 72%, P = 0.4). In a multivariate logistic regression model, concomitant immunomodulator use was not associated with a significantly improved odds ratio of remission in patients on maintenance infliximab [odds ratio (OR) 1.1, 95% confidence intervals (CI) 0.9-1.2, P = 0.9]. The risk of surgery was significantly reduced in those receiving immunomodulators at the commencement of maintenance infliximab (OR 0.3, 95% CI 0.1-0.7, P = 0.01), but not in patients who continued maintenance concomitant therapy (OR 0.4, 95% CI 0.1-1.5, P = 0.1). The combination of maintenance infliximab and an immunomodulator produced modest improvements in outcomes beyond maintenance infliximab alone in this cohort.

[Markers of the course of inflammatory bowel disease treated with immunomodulators or biological agents]

Immunosuppressive or biological treatment in patients with inflammatory bowel disease can modify the natural history of their disease, although these treatments are not universally effective and can have severe adverse effects. Attempts have been made to identify predictive factors of response to the various therapeutic options in order to aid the choice of the most appropriate therapeutic alternative in each patient. The possibility of modifying any one of these predictive factors would be of great interest since it would provide the opportunity to alter the course of the disease. Epidemiological, biological, clinical, endoscopic, radiological, genetic and even proteomic markers have been studied, in addition to others related to the disease itself or to specific treatments. The present article briefly discusses the real use of each of these markers and the evidence supporting their utility.

Effects of active and passive smoking on disease course of Crohn's disease and ulcerative colitis

BACKGROUND

Smoking is a remarkable risk factor for inflammatory bowel disease (IBD), aggravating Crohn's disease (CD) while having beneficial effects on ulcerative colitis (UC). We studied the effects of active and passive smoking in Dutch IBD patients.

METHODS

A questionnaire focusing on cigarette smoke exposure was sent to 820 IBD patients. Returned questionnaires were incorporated into a retrospective chart review, containing details about disease behavior and received therapy.

RESULTS

In all, 675 IBD patients (380 [56%] CD and 295 [44%] UC) responded. At diagnosis there were 52% smokers in CD, 41% in the general population, and 28% in UC. The number of present smokers in CD is lower than in the general population (26% versus 35%). No detrimental effects of active smoking on CD were observed, but passive smokers needed immunosuppressants and infliximab more frequently than nonpassive smokers. Active smoking had beneficial effects on UC, indicated by reduced rates of colectomy, primary sclerosing cholangitis, and backwash-ileitis in active smokers compared to never smokers, and higher daily cigarette dose correlated with less extensive colitis and a lower need for therapy. Furthermore, smoking cessation after diagnosis was detrimental for UC patients, indicated by increased needs for steroids and hospitalizations for patients that stopped smoking after compared to before the diagnosis.

CONCLUSIONS

Active smoking is a risk factor for CD, but does not affect the outcome; passive smoking is detrimental for the outcome of CD patients. In UC, active smoking shows dose-dependent beneficial effects. Our data suggest that passive smoking is a novel risk factor for CD.

Does smoking reduce infliximab's effectiveness against Crohn's disease?

Crohn's disease (CD) is an idiopathic inflammatory bowel disease and has no known cure. CD symptoms are treated using an array of medicines, including biological agents such as infliximab. However, infliximab therapy is expensive; therefore, identifying variables that can help predict response to infliximab is worthwhile. The present article reviews the impact of tobacco smoking on the efficacy of infliximab in CD. Earlier studies have speculated that smoking has a negative effect on the response to infliximab in CD, but the current literature is largely unable to identify a significant relationship between the two. Although smoking is known to have a negative effect on the course of CD, as well as other organ systems, presently, a CD patient's smoking status should not influence treatment decisions regarding infliximab therapy.

Canadian Association of Gastroenterology Clinical Practice Guidelines: The use of tumour necrosis factor-alpha antagonist therapy in Crohn's disease

BACKGROUND

Guidelines regarding the use of infliximab in Crohn's disease were previously published by the Canadian Association of Gastroenterology in 2004. However, recent clinical findings and drug developments warrant a review and update of these guidelines.

OBJECTIVE

To review and update Canadian guidelines regarding the use of tumour necrosis factor-alpha antibody therapy in both luminal and fistulizing Crohn's disease.

METHODS

A consensus group of 25 voting participants developed a series of recommendation statements that addressed pertinent clinical questions and gaps in existing knowledge. An iterative voting and feedback process was used in advance of the consensus meeting in conjunction with a systematic literature review to refine the voting statements. These statements were brought to a formal consensus meeting held in Montreal, Quebec (March 2008), wherein each statement underwent discussion, reformulation, voting and subsequent revision until group consensus was obtained (at least 80% agreement).

OUTCOME

The 47 voting statements addressed three themes: induction therapy, maintenance therapy and safety issues. As a result of the iterative process, 23 statements achieved consensus and were submitted for publication.

CONCLUSION

In the past five years, tumour necrosis factor-alpha antagonist therapy has become a cornerstone in the management of moderate-to-severe Crohn's disease refractory to conventional treatment algorithms. The evidentiary base supporting the use of these drugs in Crohn's disease is substantial and strengthened by results from longterm clinical and molecular studies. However, significant gaps in knowledge exist, particularly with regard to treatment failure. Confidence in the safety of these drugs is increasing, provided that therapy is administered in a clinical setting in which potential complications can be readily recognized and treated.

Long-term durability of Crohn's disease treatment with infliximab

BACKGROUND

There is a paucity of data providing insight into the durability of Crohn's disease treatment with infliximab for periods longer than 12 months. Our aim was to assess the long-term durability of infliximab therapy.

MATERIALS AND METHODS

A total of 198 Crohn's patients under a maintenance regimen with infliximab, with at least a 30-month follow-up, were evaluated retrospectively. Long-term response maintenance was estimated using Kaplan-Meier analysis. The effect of specific variables was calculated using logistic regression and proportional hazard regression analyses.

RESULTS

Maintenance of response rates at 72 months was estimated to be 66.4% for initial responders and 58.2% for all patients treated. Concurrent immunomodulators enhanced response maintenance in all patients treated, particularly if started >3 months before the initiation of infliximab therapy. Smoking significantly decreased the maintenance of response in initial responders.

CONCLUSIONS

Infliximab treatment of Crohn's disease is reasonably durable beyond 12 months. Concurrent immunosuppressive therapy may increase - and smoking may decrease - long-term response maintenance.

Infliximab dose intensification in Crohn's disease

BACKGROUND

Crohn's disease (CD) patients who lose response to infliximab may benefit from an increase in dose or decrease in interval between infusions. The aims of this study were to determine the proportion of CD patients who require dose intensification and factors associated with dose intensification.

METHODS

All CD patients who received at least 8 doses of infliximab at the University of Pittsburgh infusion center were included in an analysis to determine the need for dose intensification. Dose intensification was defined as either an increase in infliximab dose, a decrease in interval, or both. Factors were analyzed for association with dose intensification during follow-up.

RESULTS

Between 2002 and 2005 there were 108 CD patients who received at least 8 infliximab doses. At 30 months from initial infusion, 69.1% were event-free from an interval decrease, 48.5% from a dose increase, and 45.7% from any dose intensification. Of the 54 patients who received dose intensification, 75.9% were able to regain response and remained on infliximab. The 30-month event-free rates did not differ by whether the patient had received prior infliximab therapy (P=0.49), had a lapse of more than 6 months between infusions (P=0.75), or were on concomitant immunomodulators (P=0.82).

CONCLUSIONS

A significant proportion of CD patients on long-term infliximab treatment lose response and require an increase in dose and/or decrease in infusion interval. The majority of these patients regain response with dose intensification. Every-8-week maintenance infusions and concomitant immunomodulators did not alter the rate of infliximab dose intensification.

Mode of function of biological anti-TNF agents in the treatment of inflammatory bowel diseases

TNF-alpha has been identified as a major mediator in the pathophysiology of inflammation. Anti-TNF agents, either as a neutralising antibody or a soluble TNF receptor, have markedly influenced the clinical management of several chronic inflammatory disorders. Whereas it seems likely that neutralisation of soluble and membrane-bound TNF might be a key mechanism of any anti-TNF agent, the potential of the anti-TNF antibody infliximab to induce lymphocyte/monocyte apoptosis in Crohn's disease has been considered an additional important mechanism. Other potential mode of actions include induction of the anti-inflammatory cytokines IL-10 or TGF-beta via retrograde signalling or induction of a certain subset of regulatory T cells. Certolizumab, a pegylated fully human anti-TNF monoclonal antibody also effective in Crohn's disease, lacks the capacity to induce apoptosis. Therefore, the capacity to induce apoptosis and neutralisation of TNF alone are insufficient to explain clinical efficacy of anti-TNF agents in human inflammatory bowel diseases.

Does cigarette smoking influence the phenotype of Crohn's disease? Analysis using the Montreal classification

OBJECTIVES

The clinical subclassification of Crohn's disease by phenotype has recently been reevaluated. We have investigated the relationships between smoking habit, age at diagnosis, disease location, and progression to stricturing or penetrating complications using the Montreal classification.

METHODS

408 patients (157 male, median age 29.4 yr) were assessed. Data were collected on smoking habit, age at diagnosis, anatomical distribution, and disease behavior. Follow-up data were available on all patients (median 10 yr).

RESULTS

At diagnosis, ex-smokers (N = 53) were older than nonsmokers (N = 177) or current smokers (N = 178, medians 43.2 vs 28.3 or 28.9 yr, respectively, P < 0.001). Disease location differed according to smoking habit at diagnosis (chi(2)= 24.1, P= 0.02) as current smokers had less colonic (L2) disease than nonsmokers or ex-smokers (30%vs 45%, 50%, respectively). In univariate Kaplan-Meier survival analysis, smoking habit at diagnosis was not associated with time to development of stricturing disease, internal penetrating disease, perianal penetrating disease, or time to first surgery. Patients with isolated colonic (L2) disease were slower to develop strictures (P < 0.001) or internal penetrating disease (P= 0.001) and to require surgery (P < 0.001). Cox models with smoking habit as time-dependent covariates showed that, relative to ileal (L1) location of disease, progression to stricturing disease was less rapid for patients with colonic (L2) disease (HR 0.140, P < 0.001), but not independently affected by smoking habit. Progression to surgery was also slower for colonic (L2) than ileal (L1) disease location (HR 0.273, P < 0.001), but was independent of smoking habit.

CONCLUSIONS

Smoking habit was associated with age at diagnosis and disease location in Crohn's disease, while disease location was associated with the rate of development of stricturing complications and requirement for surgery. The pathogenic basis of these observations needs to be explained.

Infliximab in the treatment of Crohn's disease: predictors of response in an Italian multicentric open study

BACKGROUND

Almost 20% of patients with active Crohn's disease are refractory to conventional therapy. Infliximab is a treatment of proven efficacy in this group of patients and it is not clear which variables predict a good response. AIMS.: To evaluate the role of infliximab looking at the predictors of response in a large series of patients with Crohn's disease.

PATIENTS AND METHODS

Five hundred and seventy-three patients with luminal refractory Crohn's disease (Crohn's Disease Activity Index (CDAI)>220-400) (312 patients) or with fistulising disease (190 patients) or both of them (71 patients) were treated with a dose of 5 mg/kg in 12 Italian referral centres. The primary endpoints of the study were clinical response and clinical remission for luminal refractory and fistulising disease. We evaluated at univariable and multivariable analysis the following variables: number of infusions, sex, age at diagnosis, smoking habit, site of disease, previous surgery, extraintestinal manifestations and concomitant therapies, and type of fistulas.

RESULTS

Patients with luminal refractory disease: 322 patients (84.1%) had a clinical response and 228 (59.5%) reached clinical remission. Patients with fistulising disease: 187 patients (72%) had a reduction of 50% of the number of fistulas and in 107 (41%) a total closure of fistulas was observed. For luminal disease, single infusion (OR 0.49, 95% CI 0.28-0.86) and previous surgery (OR 0.53, 95% CI 0.30-0.93) predicted a worse response for fistulising disease. Other fistulas responded worse than perianal fistulas (OR 0.57, 95% CI 0.303-1.097).

CONCLUSION

In Crohn's disease infliximab is effective in luminal refractory and in fistulising disease. A single infusion and previous surgery predicted a worse response in luminal disease whereas perianal fistulas predicted a better response than other type of fistulas.

Genetic Testing in Crohn Disease

Inflammatory bowel disease (IBD), with its two subforms of Crohn disease and ulcerative colitis, is a polygenic disease that manifests due to environmental trigger factors on the background of a complex genetic predisposition. The first risk gene underlying susceptibility to Crohn disease has been identified as CARD15 (located on chromosome 16q12, encoding NOD2). Three single nucleotide polymorphisms in the leucine rich region (LRR) of this gene are strongly and independently associated with Crohn disease susceptibility and explain up to 20% of the total genetic predisposition for Crohn disease. These variants have been consistently replicated as associated with a particular sub-phenotype characterized by small bowel (ileum) involvement and early age at onset. Presently, genetic testing for the CARD15 variants has only a modest relevance in clinical practice. The most attractive use of genetic testing is for the prediction of response to therapy. Most therapies only show efficacy in subgroups of patients and no clinical parameters are available to distinguish, prior to therapy, whether the patients will be responders or non-responders, or if the patients will experience adverse effects. The pharmacogenetic basis of toxicity is well known for azathioprine: several thiopurine methyltransferase (TPMT) polymorphisms that are associated with reduced activity of this thiopurine drug metabolizing enzyme result in cytotoxic and immunosuppressive adverse effects of azathioprine. Genetic screening, which has found its way into routine clinical diagnostics, allows the identification of the patients who will not tolerate a standard dose of the drug. The extensive search for genetic predictors of response to the anti-tumor necrosis factor treatment with infliximab, which results in a remission rate of 30-40%, has, however, failed to identify a variation associated with a differential response.