Predictors of response to infliximab in luminal Crohn's disease

Low muscle mass is associated with efficacy of biologics in Crohn's disease

BACKGROUND

Low muscle mass (LMM) can be a frequent complication in Crohn's disease (CD). We attempted to explore the effect of LMM on the efficacy of biologics in patients with CD.

METHODS

The retrospective cohort study included moderate-to-severe CD patients treated with infliximab or ustekinumab, and appendicitis patients as control. The skeletal muscle area (SMA) of L3 was assessed to evaluate the patients' muscle mass. After propensity score matching, the impact of LMM on drug efficacy was assessed in CD patients.

RESULTS

A total of 269 patients with CD and 172 appendicitis patients were included. The CD group had lower skeletal muscle density and BMI, and a higher risk of developing LMM than the control group. BMI (OR = 0.48, p < 0.001) and previous use of biologics (OR = 2.94, p = 0.019) were found to be independently associated with LMM. LMM was found to be associated with a decrease in clinical response (at weeks 8-14), clinical remission (at weeks 8-14, 24-30 and 52) and biochemical remission (at week 52). At weeks 24-30 and 52, LMM was independently associated with loss of response (LOR). We found LMM could be a predictor of lower clinical remission at week 30, lower clinical remission at week 52 and a higher LOR rate at week 30 in infliximab. While in ustekinumab, LMM was associated with lower endoscopic remission at week 24, biochemical remission at week 52 and a higher LOR rate at weeks 24 and 52.

CONCLUSIONS

The prevalence of LMM was higher in the CD group compared to the control group. For CD patients with LMM, the efficacy of infliximab and ustekinumab was relatively poor in both the short-term and long-term.

Serum TGF-β1 and CD14 Predicts Response to Anti-TNF-α Therapy in IBD

Background

Tumor necrosis factor-alpha (TNF-α) agonists revolutionized therapeutic algorithms in inflammatory bowel disease (IBD) management. However, approximately every third IBD patient does not respond to this therapy in the long term, which delays efficient control of the intestinal inflammation.

Methods

We analyzed the power of serum biomarkers to predict the failure of anti-TNF-α. We collected serum of 38 IBD patients at therapy prescription and 38 weeks later and analyzed them with relation to therapy response (no-, partial-, and full response). We used enzyme-linked immunosorbent assay to quantify 16 biomarkers related to gut barrier (intestinal fatty acid-binding protein, liver fatty acid-binding protein, trefoil factor 3, and interleukin (IL)-33), microbial translocation, immune system regulation (TNF-α, CD14, lipopolysaccharide-binding protein, mannan-binding lectin, IL-18, transforming growth factor-β1 (TGF-β1), osteoprotegerin (OPG), insulin-like growth factor 2 (IGF-2), endocrine-gland-derived vascular endothelial growth factor), and matrix metalloproteinase system (MMP-9, MMP-14, and tissue inhibitors of metalloproteinase-1).

Results

We found that future full-responders have different biomarker profiles than non-responders, while partial-responders cannot be distinguished from either group. When future non-responders were compared to responders, their baseline contained significantly more TGF-β1, less CD14, and increased level of MMP-9, and concentration of these factors could predict non-responders with high accuracy (AUC = 0.938). Interestingly, during the 38 weeks, levels of MMP-9 decreased in all patients, irrespective of the outcome, while OPG, IGF-2, and TGF-β1 were higher in non-responders compared to full-responders both at the beginning and the end of the treatment.

Conclusions

The TGF-β1 and CD14 can distinguish non-responders from responders. The changes in biomarker dynamics during the therapy suggest that growth factors (such as OPG, IGF-2, and TGF-β) are not markedly influenced by the treatment and that anti-TNF-α therapy decreases MMP-9 without influencing the treatment outcome.

Biosimilars in Pediatric Inflammatory Bowel Diseases: A Systematic Review and Real Life-Based Evidence

Background: Many pediatric inflammatory bowel disease (IBD) patients are now using biosimilars of anti-tumor necrosis factor-α (TNF-α), with increasing trends in recent years. This study reviewed all available data regarding the use of biosimilars in children with IBD. Methods: PubMed, Google Scholar, Scopus, and CENTRAL databases were searched through keywords; inflammatory bowel diseases, Crohn's disease, ulcerative colitis, biosimilar and child were combined using "AND" and "OR." Original research articles involving pediatric patients receiving one of the biosimilar medications based on the anti-TNF-α biologic drugs approved for pediatric IBD treatment, independently from efficacy and drug response, were included. Results: Nine studies were included in the evidence synthesis. CT-P13 was the biosimilar used in all studies. Four studies assessed the induction effectiveness of CT-P13. Clinical response and remission rates of biosimilar treatment were 86-90% and 67-68%, respectively, and they were not significantly different to the originator group. Five prospective studies on patients elected to switch from originator IFX to CT-P13 yielded similar results. Adverse events related to CT-P13 were mostly mild. The most frequently reported were upper respiratory tract infections. The switch from the originator had no significant impact on immunogenicity. Conclusion: The current review showed reported CT-P13 effectiveness as measured by clinical response and/or remission rates after induction or during maintenance and suggest that there is no significant difference with that of the originator IFX. Further studies are warranted, including clinical, and pharmacovigilance studies.

Ileal and colonic Crohn'´s disease: Ddoes location makes a difference in therapy efficacy?

Within the IBD entity of Crohn's disease, there is currently no differentiation between ileal and colonic manifestation for recruitment of patients in clinical trials, well-powered analysis of study results or therapeutic decisions in daily clinical practice. However, there is accumulating evidence from epidemiological, genetic, microbial, immunological, and clinical characteristics that clearly indicate that ileal Crohn's disease represents a distinct disease entity, which differentiates itself from colonic Crohn's disease. This is also reflected by lower efficacy of targeted therapies in isolated ileal compared to colonic Crohn's disease. The distinct site-specific mechanisms that drive heightened non-response in ileal disease need to be analysed in-depth in the future, to enable optimized therapy in the individual Crohn's disease patient.

Location is important: differentiation between ileal and colonic Crohn's disease

Crohn's disease can affect any part of the gastrointestinal tract; however, current European and national guidelines worldwide do not differentiate between small-intestinal and colonic Crohn's disease for medical treatment. Data from the past decade provide evidence that ileal Crohn's disease is distinct from colonic Crohn's disease in several intestinal layers. Remarkably, colonic Crohn's disease shows an overlap with regard to disease behaviour with ulcerative colitis, underlining the fact that there is more to inflammatory bowel disease than just Crohn's disease and ulcerative colitis, and that subtypes, possibly defined by location and shared pathophysiology, are also important. This Review provides a structured overview of the differentiation between ileal and colonic Crohn's disease using data in the context of epidemiology, genetics, macroscopic differences such as creeping fat and histological findings, as well as differences in regard to the intestinal barrier including gut microbiota, mucus layer, epithelial cells and infiltrating immune cell populations. We also discuss the translation of these basic findings to the clinic, emphasizing the important role of treatment decisions. Thus, this Review provides a conceptual outlook on a new mechanism-driven classification of Crohn's disease.

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.

Advances in Therapeutic Drug Monitoring in Biologic Therapies for Pediatric Inflammatory Bowel Disease

In the current era of treat-to-target strategies, therapeutic drug monitoring (TDM) has emerged as a potential tool in optimizing the efficacy of biologics for children diagnosed with inflammatory bowel disease (IBD). The incorporation of TDM into treatment algorithms, however, has proven to be complex. "Proactive" TDM is emerging as a therapeutic strategy due to a recently published pediatric RCT showing a clear benefit of "proactive" TDM in anti-TNF therapy. However, target therapeutic values for different biologics for different disease states [ulcerative colitis (UC) vs. Crohn's disease (CD)] and different periods of disease activity (induction vs. remission) require further definition. This is especially true in pediatrics where the therapeutic armamentarium is limited, and fixed weight-based dosing may predispose to increased clearance leading to decreased drug exposure and subsequent loss of response (pharmacokinetic and/or immunogenic). Model-based dosing for biologics offers an exciting insight into dose individualization thereby minimizing the chances of losing response. Similarly, point-of-care testing promises real-time assessment of drug levels and individualized decision-making. In the current clinical realm, TDM is being used to prolong drug durability and efficacy and prevent loss of response. Ongoing innovations may transform it into a personalized tool to achieve optimal therapeutic endpoints.

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.

Biosimilar infliximab in paediatric inflammatory bowel disease: Efficacy, immunogenicity and safety

WHAT IS KNOWN AND OBJECTIVE

Based on extrapolation, biosimilar infliximab (IFX) was approved to treat inflammatory bowel disease (IBD). The first studies in adults have shown similar efficacy and safety in comparison with reference drug. The aim of this review was to collect and evaluate all the literature data regarding the use of biosimilar IFX in paediatric IBD.

METHODS

This article reviewed efficacy, immunogenicity and safety profile of biosimilar IFX in IBD paediatric patients through a comprehensive search of the published literature.

RESULTS AND DISCUSSION

Eight papers were extracted and critically reviewed. Four paediatric studies (prospective, n = 3; retrospective, n = 1) assessed the induction efficacy of the biosimilar IFX. Clinical response and remission rates reported were 86%-90% and 67%-68%, respectively. No significant difference in clinical response and remission rates between the reference and biosimilar IFX groups was found at follow-up (range: 3-13 months). Similar findings were shown in the prospective studies (n = 4) conducted on patients elected to switch from reference IFX to its biosimilar. The most frequently reported adverse events (AEs) of biosimilar IFX were mild upper respiratory tract infections. Taking into account of all AEs coming from published data, biosimilar IFX seems to be as safe as its originator. Immunogenicity has not been significantly impacted by the switch from the reference drug.

WHAT IS NEW AND CONCLUSION

To date, treatment with (or switch to) biosimilar IFX in paediatric patients with IBD have been successful, without affecting efficacy, immunogenicity or safety. However, further studies are warranted, including clinical trials and pharmacovigilance studies.

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.

A nomogram for predicting the response to exclusive enteral nutrition in adult patients with isolated colonic Crohn's disease

BACKGROUND

Isolated colonic Crohn's disease (cCD) responds less well to induction therapy with exclusive enteral nutrition (EEN) compared with ileal or ileocolonic disease in adult patients; therefore, we aimed to identify the factors that influence the response to EEN and develop a predictive nomogram model to optimize the use of EEN in cCD patients.

MATERIALS AND METHODS

Eighty-five cCD patients treated with EEN as first-line therapy at our center between 1 June 2012 and 30 June 2018 were retrospectively analyzed as the primary cohort. The primary endpoint was clinical remission after EEN therapy. Potential predictive factors for the efficacy of EEN were assessed by univariate and multivariate analyses, and a nomogram to predict the response to EEN therapy in cCD patients was designed. Another 19 cCD patients were retrospectively included in the validation cohort to verify the accuracy of the nomogram model.

RESULTS

The clinical remission rates for the primary cohort and validation cohort were 52.9% and 47.4%, respectively. Pancolitis was the greatest contributor to the risk of failure to respond to EEN [odds ratio (OR) = 4.896; 95% confidence interval (CI) = 1.223-19.607; p = 0.025], lean body mass index (LBMI), colonic lesion features, simple endoscopic scores for Crohn's disease, C-reactive protein before treatment and ∆prealbumin were also related to the efficacy of EEN in cCD. The nomogram model showed robust discrimination, with an area under the receiving operating characteristic curve of 0.906.

CONCLUSION

Several predictive factors for response to EEN therapy in cCD adult patients were identified, and a promising nomogram that can predict the effect of EEN in cCD was developed.

Biological Therapy in Pediatric Inflammatory Bowel Disease: A Systematic Review

The incidence of inflammatory bowel disease (IBD) has increased steadily worldwide, both in adult and in children; approximately 25% of IBD patients are diagnosed before the age of 18. The natural history of IBD is usually more severe in children than in adults, and can be associated with linear growth impairment, delayed puberty onset, reduced bone mass index, malnutrition, and the need for surgery. Biological therapies, especially blocking tumor necrosis factor-α (TNFα), have radically modified the treatment strategies and disease course of IBD in children. In particular, drugs such as Infliximab and Adalimumab are routinely used in the treatment of pediatric IBD. The role of Infliximab and Adalimumab in the management of pediatric IBD has been recently updated in the Consensus guidelines of ECCO/ESPGHAN. Data regarding short-term and long-term efficacy and safety of these drugs in children, and the effects of "top-down" and "step-up" strategies, are lacking. In this paper, the authors will review current indications, efficacy, and safety of biological therapy in pediatric IBD patients, evaluating all articles published after ECCO/ESPGHAN guidelines publication. The authors carried out a systematic search through MEDLINE through PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) Embase, CINAHL, Cochrane Library, and gray literature, from January 2013 to January 2016. Anti-TNFα has been shown to be effective and safe to maintain remission and to achieve mucosal healing. Multicenter trials based on large sample size cohorts are needed to better clarify long-term efficacy of anti-TNFα and the real incidence of treatment-related complications in pediatric IBD.

Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

The genetics of isolated colonic Crohn's disease place it approximately midway between Crohn's disease with small intestinal involvement and UC, making a case for considering it as a separate condition. We have therefore systematically reviewed its epidemiology, pathophysiology and treatment. Key findings include a higher incidence in females (65%) and older average age at presentation than Crohn's disease at other sites, a mucosa-associated microbiota between that found in ileal Crohn's disease and UC, no response to mesalazine, but possibly better response to antitumour necrosis factor than Crohn's disease at other sites. Diagnostic distinction from UC is often difficult and also needs to exclude other conditions including ischaemic colitis, segmental colitis associated with diverticular disease and tuberculosis. Future studies, particularly clinical trials, but also historical cohorts, should assess isolated colonic Crohn's disease separately.

Long-Term Outcomes of Infliximab Treatment in 582 Korean Patients with Crohn's Disease: A Hospital-Based Cohort Study

BACKGROUND AND AIMS

To date, no large-scale studies have evaluated long-term outcomes of infliximab (IFX) treatment in Korean patients with Crohn's disease (CD).

METHODS

We analyzed long-term clinical responses to IFX in 582 Korean CD patients who received scheduled IFX treatments at Asan Medical Center. Clinical responses were defined as maintaining IFX without major abdominal surgery (MAS) or dose intensification.

RESULTS

Between February 2002 and July 2015, a total of 11,990 IFX infusions were administered to 582 Korean patients with CD over a median period of 36 months. At the end of follow-up, 316 (54.3 %) were still receiving IFX without MAS (71 patients, 12.2 %) or dose intensification (86 patients, 14.8 %). IFX was stopped in 109 (18.7 %) patients because of a loss of response (48 patients, 8.2 %), adverse events (30 patients, 5.2 %), or patient preferences or problems with reimbursement (31 patients, 5.3 %). The cumulative survival for maintenance of IFX without MAS or dose intensification was 89.0, 75.9, 68.3, and 50.8 % at 1, 2, 3, and 5 years, respectively. Multivariate regression analysis identified older age at the initiation of IFX (≥40 years, P = 0.006) and a longer disease duration (≥3 years, P = 0.020) as independent positive predictors of a poorer response to IFX.

CONCLUSIONS

The long-term efficacy of IFX in a large, real-life cohort of Korean patients with CD appears to be similar to that in previously published Western studies. Our findings support the early use of IFX to obtain better clinical outcomes.

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.

Smoking and early infliximab response in Crohn’s disease: a meta-analysis

BACKGROUND

Infliximab is used to treat moderate to severe Crohn’s disease (CD), but its efficacy varies. Although cigarette smoking worsens CD, its impact on the infliximab response is unknown. We conducted a systematic review and meta-analysis of clinical trials to determine the effect of smoking on the induction response to infliximab.

METHODS

A systematic search was performed of MEDLINE, EMBASE, CINAHL, the Cochrane central register of controlled trials, the Cochrane IBD Group Specialized Trials Register for publications, and abstracts from major conferences from January 1996 to December 2010. Random effects meta-analysis using the Mantel–Haenszel method was conducted. Heterogeneity across studies was assessed using the Q statistic, the I2 statistic, and τ2.

RESULTS

We identified 12 articles; four were excluded due to use of non-validated scoring systems.The remaining eight included a total of 1658 patients, with 649 active smokers. Luminal response was assessed by the Crohn’s Disease Activity Index in four studies (three of which included fistula response) and the Harvey–Bradshaw index in two (both including fistula response), and two studies examined only the fistula response. The relative risk for response to infliximab among smokers was 0.99 (95% CI 0.88–1.11) (τ2 = 0.0143). Analyses of the five studies examining both inflammatory and fistulizing CD were similar to the analysis of all eight studies. The pooled relative risk was 0.92 (95% CI 0.80–1.06) (τ2 = 0.0154).

CONCLUSION

Though smoking worsens CD, this meta-analysis does not show a negative effect of smoking on initial response to infliximab. This must be viewed in the proper context, as long-term maintenance of response may yet be influenced by smoking status.

Role for therapeutic drug monitoring during induction therapy with TNF antagonists in IBD: evolution in the definition and management of primary nonresponse

: Primary nonresponse and primary nonremission are important limitations of tumor necrosis factor (TNF) antagonists, occurring in 10% to 40% and 50% to 80% of patients with inflammatory bowel disease, respectively. The magnitude of primary nonresponse differs between phase III clinical trials and cohort studies, indicating differences, e.g., in definition, patient population or blinding. The causes of nonresponse can be attributed to the drug (pharmacokinetics, immunogenicity), the patient (genetics, disease activity), the disease (type, location, severity), and/or the treatment strategy (dosing regimen, combination therapy). Primary nonresponse has been attributed to "non-TNF-driven disease" which is an overly simplified and potentially misleading approach to the problem. Many patients with primary nonresponse could successfully be treated with dose optimization during the induction phase or switching to another TNF antagonist. Therefore, primary nonresponse is frequently not a non-TNF-driven disease. Recent studies from rheumatoid arthritis and preliminary data from inflammatory bowel disease evaluating therapeutic drug monitoring have suggested that early measurement of drug and anti-drug antibody concentrations could help to define primary nonresponse and rationalize patient management of this problem. Moreover, a modeling approach including pharmacological parameters and patient-related covariants could potentially be predictive for response to the treatment. We describe an overview of this evolution in thinking, underpinned by previous findings, and assess the potential role of early measurement of drug and antidrug antibody concentrations in the definition and management of primary nonresponse.

Long-term safety of immunomodulators in pediatric inflammatory diseases

The medical management of chronic inflammatory disorders in children, including mainly inflammatory bowel diseases and rheumatic diseases, has evolved dramatically over recent years with the advent of disease-modifying drugs such as immunomodulators and biological agents capable of interrupting the inflammatory cascade underlying these disorders. These agents are generally administered in patients who are refractory to conventional therapies. However, there is growing support that their use in the initial phases of these disorders, especially in pediatric patients, could interrupt and cease the inflammatory process. Thus, the aims of therapy have transitioned from symptomatic control to the achievement of deeper remission, including the healing of the inflammatory lesions combined with symptomatic remission. Therefore, more patients are currently receiving immunomodulators or biologics, frequently in addition to corticosteroids. Immunosuppression due to these therapies increases safety concerns, particularly regarding the risk of infections and malignancies. The available literature highlights how the combination of more than one of these therapies, especially if the combination includes corticosteroids, amplifies the risk of severe opportunistic infections. Otherwise, the infections described are mainly mild. Regarding malignancies, the overall risk associated with treatment appears non-significant in pediatric populations, but an appropriate benefit/risk assessment is recommended prior to the introduction of aggressive treatments such as immunomodulants and biologics. The background cancer risk related to the disease itself remains an issue. Protracted follow-up programs are needed, and the results from international multicenter registries are awaited to better understand the true risk related to therapy of these pediatric populations.

Biological therapy in a pediatric Crohn disease population at a referral center

OBJECTIVE

The antitumor necrosis factor α (TNFα) antibodies infliximab and adalimumab are effective in inducing and maintaining remission in pediatric patients with Crohn disease (CD). The aim of the study was to evaluate the long-term efficacy and safety of biological therapy in pediatric patients with CD followed at a referral center.

METHODS

This work is a retrospective observational study enrolling patients with CD treated with infliximab or adalimumab beyond the induction protocol. The patients' data were collected from the unit's IBD database (maximum follow-up evaluation after 36 months of treatment). The efficacy was evaluated by the Pediatric Crohn Disease Activity Index score and by analysis of the cumulative probability of continuing therapy; the safety was assessed in terms of adverse events.

RESULTS

We enrolled 78 patients; the mean therapy duration was 27.2 ± 16.7 months, and the mean age at enrollment was 15 ± 3.1 years. The Kaplan-Meier analysis showed a cumulative probability of continuing therapy of 81%, 54%, and 33% at 1, 2, and 3 years, respectively, from the introduction of therapy. No association between the patients' baseline characteristics and the long-term outcome was found. The evaluation of the concomitant therapy with immunomodulators and anti-TNFα therapy versus anti-TNFα alone did not show a different outcome. No serious adverse events were recorded.

CONCLUSIONS

The study indicates that biological therapy is effective and safe in pediatric patients with CD in a longer follow-up period. The response to treatment was not influenced by the patients' baseline characteristics or by the immunomodulator association.

Advances in the medical management of paediatric IBD

IBD includes two classic entities, Crohn's disease and ulcerative colitis, and a third undetermined form (IBD-U), characterized by a chronic relapsing course resulting in a high rate of morbidity and impaired quality of life. Children with IBD are vulnerable in terms of growth failure, malnutrition and emotional effects. The aims of therapy have now transitioned from symptomatic control to the achievement of mucosal healing and deep remission. This type of therapy has been made possible by the advent of disease-modifying drugs, such as biologic agents, which are capable of interrupting the inflammatory cascade underlying IBD. Biologic agents are generally administered in patients who are refractory to conventional therapies. However, there is growing support that such agents could be used in the initial phases of the disease, typically in paediatric patients, to interrupt and cease the inflammatory process. Until several years ago, most therapeutic programmes in paediatric patients with IBD were borrowed from adult trials, whereas paediatric studies were often retrospective and uncontrolled. However, guidelines on therapeutic management of paediatric IBD and controlled, prospective, randomized trials including children with IBD have now been published. Here, the current knowledge concerning treatment options for children with IBD are reported. We also highlight the effectiveness and safety of new therapeutic advances in these paediatric patients.

Predictors of adalimumab dose escalation in patients with Crohn's disease at a tertiary referral center

BACKGROUND

Pivotal trials for adalimumab (ADA) demonstrated effectiveness versus placebo for induction and maintenance of remission in moderate to severely active Crohn's disease (CD). Although the approved maintenance regimen in the U.S. is 40 mg subcutaneously every 14 days, some patients require dose-escalation ([DE] either an increase in the delivered dose or decrease in the interval of treatment). Our objective was to determine which patient-, disease-, and therapy-related factors were associated with DE in CD patients treated with ADA.

METHODS

This retrospective medical record review of patients included all patients treated with ADA for CD at the University of Chicago Inflammatory Bowel Disease Center between 2003 and 2008. Patient-related factors, disease-related factors, and therapy-related factors were analyzed. Survival and logistic regression analyses were performed.

RESULTS

In all, 75 patients treated with ADA between December 2003 and June 2008 were identified. Thirty-one subjects (41%) required DE (32% male, median age 37.6, median disease duration 22.7 years) after a median 20 weeks of therapy (range 2-75). Patient-, clinical-, and therapy-related factors were similar between DE and non-DE. Need for DE was predicted by a family history of inflammatory bowel disease (IBD) (P = 0.0187). Time to DE was predicted by male gender, isolated colonic disease, and smoking history (all P < 0.05); however, only male gender was an independent predictor of time to DE.

CONCLUSIONS

In all, 41% of CD patients required ADA DE, with shorter time to DE in smokers, men, and patients with isolated colonic disease. Patients, caregivers, and insurers should anticipate DE when utilizing ADA in CD.

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.

Systematic review: steroid withdrawal in anti-TNF-treated patients with inflammatory bowel disease

BACKGROUND

The increasing awareness of increased risk for opportunistic infections when combining several immunosuppressant drugs led to new treatment goals for inflammatory bowel disease including limited use of steroids.

AIM

To conduct a systematic review to establish figures for steroid withdrawal in anti-TNF treated inflammatory bowel disease-patients.

METHODS

Medline was searched using the search-terms Ulcerative Colitis (UC) [Mesh], Crohn Disease (CD) [Mesh], IBD [Mesh], crohn, colitis, IBD and steroid sparing, all combined with infliximab and adalimumab. We selected English-language publications that addressed the effect of anti-TNF on steroid withdrawal. Studies had to assess patients with luminal CD or UC. Numbers of patients who were able to withdraw steroids were calculated.

RESULTS

Six studies could be included; five reporting on infliximab and one on adalimumab. Studies were heterogeneously designed. Overall, in the adult population, up to 38% of the patients were able to withdraw corticosteroids during infliximab therapy. In the paediatric population, up to 75% of the patients were able to withdraw corticosteroids during infliximab therapy.

CONCLUSIONS

Although a consensus on the definition of steroid-sparing is lacking, approximately two-thirds of the inflammatory bowel disease-patients are unable to withdraw corticosteroid treatment during anti-TNF therapy.

[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.

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.

Loss of response and requirement of infliximab dose intensification in Crohn's disease: a review

OBJECTIVES

To review the frequency with which infliximabloses its effect and dose "intensification" is required for Crohn's disease treatment.

METHODS

Bibliographical searches were performed in MEDLINE, and European (ECCO) and American (DDW) Congresses. Studies evaluating loss of efficacy and requirement of infliximab dose intensification-defined either as an increase of the infliximab dose (generally from 5 mg/kg to 10 mg/kg) or as a decrease in the frequency of infusion (to as often as every 4 weeks)-in Crohn's disease patients were included.

RESULTS

Sixteen studies evaluating the incidence of loss of response to infliximab in Crohn's disease patients were found. A total of 2,236 patients were included (the majority of them receiving a three-dose induction regimen at weeks 0, 2, and 6, followed by maintenance therapy every 8 weeks), providing 6,284 patient-years of follow-up. The mean percentage of patients with loss of infliximab response was 37%. However, as the follow-up time varied markedly among studies, the risk of losing response to infliximab is better expressed as the incidence of this complication per patient-year of follow-up. Therefore, the annual risk for loss of infliximab response was calculated to be 13% per patient-year.

CONCLUSIONS

A variable but relevant proportion of Crohn's disease patients on long-term infliximab treatment lose response. This may be interpreted in two different but compatible ways: a positive view, highlighting that infliximab therapy is relatively durable, with the majority of patients predicted to continue infliximab treatment at least during the first year; or a negative view, interpreting that a significant proportion of Crohn's disease patients-more than 10% per patient-year of infliximab treatment-on long term will lose response and will require an increase in dose and/or decrease in infusion interval.

Therapeutic options in acute severe ulcerative colitis

Ulcerative colitis is a relapsing-remitting inflammatory disease affecting the colon and is associated with considerable morbidity. In acute severe attacks, there continues to be an associated mortality rate of 1-2%, even in specialist units. During an acute severe exacerbation, approximately two-thirds of patients will respond to intravenous corticosteroid therapy, the accepted first-line therapy in such cases. For steroid-refractory patients, options are limited to surgery (colectomy) or second-line agents, such as ciclosporin or infliximab, used in an attempt to salvage the colon. Considerable debate exists over the optimal management of such patients. During the last decade, an increased understanding of the pathogenesis of inflammatory bowel disease has led to the rapid development of other biological agents, such as basiliximab and visilizumab. Novel methods, such as leucopheresis, have been studied and other established immunomodulatory agents, such as tacrolimus, have also been suggested. The purpose of this review is to highlight some of the areas of recent development in the treatment of acute severe ulcerative colitis and review important safety data, with a particular emphasis on biological agents.

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.

Careful patient selection may improve response rates to infliximab in inflammatory bowel disease

BACKGROUND AND AIM

The use of infliximab in the treatment of Crohn's disease (CD) is acceptable and appears to be effective in ulcerative colitis (UC). Careful patient selection, resulting in infliximab only for truly refractory inflammatory bowel disease (IBD), may improve its efficacy. The present study aimed to determine if careful patient selection improved infliximab efficacy in IBD.

METHODS

CD or UC/IBD unclassified patients (Montreal classification) were considered for infliximab treatment only after failure of disease control with conventional therapies and confirmation of active disease. Patients with purely luminal IBD received a single infliximab dose. Patients with fistulizing disease (with or without luminal disease) received infliximab at 0, 2 and 6 weeks. Changes to Harvey Bradshaw (HBI) for inflammatory CD and Colitis Activity Index (CAI) for UC/IBDU were used to determine the response and remission rates. In fistulizing CD, a remission was sustained cessation of drainage and resolution of the fistula. Response was correlated to inflammatory marker levels.

RESULTS

Seventy IBD patients were treated. In CD, 85.2% (46/54) had active luminal and 40.7% (22/54) had fistulizing disease. In luminal CD, at 8 weeks a single infliximab dose induced remission in 75% (24/32) of patients compared to 92.9% (13/14) after infliximab at 0, 2 and 6 weeks. Fistulizing disease responded in 77.2% (17/22) and remitted in 50% (11/22) of patients at 8 weeks. In UC/IBDU, 75% (12/16) responded and 43.8% (7/16) of patients were in remission at 8 weeks.

CONCLUSION

Careful patient selection may improve infliximab's efficacy and clinical remission appears greater after induction with three infliximab doses in CD. Clinical efficacy is suggested for UC/IBDU.

Effectiveness of concomitant immunosuppressive therapy in suppressing the formation of antibodies to infliximab in Crohn's disease

BACKGROUND

Episodic infliximab (IFX) treatment is associated with the formation of antibodies to IFX (ATIs) in the majority of patients, which can lead to infusion reactions and a shorter duration of response. Concomitant use of immunosuppressives (IS) reduces the risk of ATI formation.

AIMS AND METHODS

To investigate which of the IS-that is, methotrexate (MTX) or azathioprine (AZA)-is most effective at reducing the risk of ATI formation, a multicentre cohort of 174 patients with Crohn's disease, treated with IFX in an on-demand schedule, was prospectively studied. Three groups were studied: no IS (n = 59), concomitant MTX (n = 50) and concomitant AZA (n = 65). ATI and IFX concentrations were measured in a blinded manner at Prometheus Laboratories before and 4 weeks after each infusion.

RESULTS

ATIs were detected in 55% (96/174) of the patients. The concomitant use of IS therapy (AZA or MTX) was associated with a lower incidence of ATIs (53/115; 46%) compared with patients not taking concomitant IS therapy (43/59; 73%; p<0.001). The incidence of ATIs was not different for the MTX group (44%) compared with the AZA group (48%). Patients not taking IS therapy had lower IFX levels (median 2.42 microg/ml (interquartile range (IQR) 1-10.8), maximum 21 microg/ml) 4 weeks after any follow-up infusion than patients taking concomitant IS therapy (median 6.45 microg/ml (IQR 3-11.6), maximum 21 microg/ml; p = 0.065), but there was no difference between MTX or AZA. In patients who developed significant ATIs >8 microg/ml during follow-up, the IFX levels 4 weeks after the first infusion were retrospectively found to be significantly lower than in patients who did not develop ATIs on follow-up or had inconclusive ATIs.

CONCLUSION

Concomitant IS therapy reduces ATI formation associated with IFX treatment and improves the pharmacokinetics of IFX. There is no difference between MTX and AZA in reducing these risks. ATI profoundly influences the pharmacokinetics of IFX. The formation of ATIs >8 microg/ml is associated with lower serum levels of IFX already at 4 weeks after its first administration.

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.

American gastroenterological association consensus development conference on the use of biologics in the treatment of inflammatory bowel disease, June 21-23, 2006

The American Gastroenterological Association (AGA) convened a panel of gastroenterologists expert in the area of inflammatory bowel disease (IBD) that developed this consensus statement based on expert presentations of current scientific knowledge about IBD and through subsequent group discussion. This statement reflects the panel's assessment of medical knowledge available when written. Thus, readers should view this statement in the context of data that will accumulate after its creation. The opinions, conclusions, and recommendations expressed in this report are those of the consensus panel members and may or may not reflect the official opinion of the American Gastroenterological Association Institute. The conference upon which this report is based was funded through an unrestricted educational grant from Abbott Laboratories. Abbott Laboratories representatives did not attend the conference, nor did they participate in any way in the development of this report.

Efficacy of infliximab in Crohn's disease. Results of a retrospective multicenter study with a 15-month follow-up

OBJECTIVES

To evaluate prescription practices and response to infliximab treatment for Crohn's disease (CD).

PATIENTS AND METHODS

The files of CD patients treated with at least one infusion of infliximab treated in gastroenterology units belonging to university teaching hospitals of the Parisian hospitals group (Assistance Publique-Hôpitaux de Paris (AP-HP) during the year 2000 were analyzed retrospectively.

RESULTS

One hundred and thirty-seven patients (36.0 +/- 12.7 years, 92 females) from 12 centers were studied. Indication for treatment was fistulae or perianal disease in 39% of patients, active Crohn's disease in 45% and mixed conditions in 16%. Mean follow-up was 15.2 +/- 7.2 months. The overall response rate was 85%. No predictive factor of sustained remission could be identified. The mean time to relapse was to 3.9 +/- 3.1 months. Thirty-eight patients were on maintenance therapy at the end of the follow up; 37% exhibiting progressive lost of response to treatment. Immunosuppressive therapy was added to infliximab in 78% of cases but response to infliximab was not modified by addition of immunosuppressive drugs. Adverse events, most frequently minor, were noted in 23% of the patients.

CONCLUSION

This retrospective study confirms the efficacy and safety of infliximab in CD.