Natalizumab in Crohn's disease: results from a US tertiary inflammatory bowel disease center

Biologics: how far can they go in Crohn’s disease?

Crohn’s disease is a chronic gastrointestinal inflammatory disorder, characterized by episodes of relapsing and remitting flares. As the disease mechanism becomes better elucidated, there is a significant increase in the number of available biologic therapies. This article summarizes and synthesizes current Food and Drug Administration-approved biological therapy for Crohn’s disease and examines the positioning of medical therapy as emerging biologics break onto the market.

Anti-Integrins for the Treatment of Inflammatory Bowel Disease: Current Evidence and Perspectives

Leukocyte trafficking to the gastrointestinal tract is recognized to play a role in the pathogenesis of inflammatory bowel disease (IBD). Integrins are expressed on immune cells and interact with cell adhesion molecules (CAM) to mediate leukocyte trafficking. Blockade of the gut-tropic integrin α4β7 and its subunits has been exploited as a therapeutic target in IBD. Natalizumab (anti-α4) is approved for moderate to severe Crohn's disease (CD), but its use is limited due to potential risk of progressive multifocal leukoencephalopathy. Vedolizumab (anti-α4β7) is approved for the treatment of ulcerative colitis (UC) and CD. It is the most widely used anti-integrin therapy in IBD and has been shown to be effective in both induction and maintenance therapy, with a favorable safety profile. Several models incorporating clinical, genetic, immune, gut microbial, and vitamin D markers to predict response to vedolizumab in IBD have been developed. Etrolizumab (anti-β7) blocks leukocyte trafficking via α4β7 and cell adhesion via αEβ7 integrins. Large phase 3 clinical trials evaluating efficacy of etrolizumab in the induction and maintenance of patients with IBD are underway. Other investigational anti-integrin therapies include abrilumab (anti-α4β7 IgG2), PN-943 (orally administered and gut-restricted α4β7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α4), and ontamalimab (anti-MAdCAM-1 IgG).

Mechanism-Based Treatment Strategies for IBD: Cytokines, Cell Adhesion Molecules, JAK Inhibitors, Gut Flora, and More

Background

Although TNF inhibitors revolutionized the therapy of inflammatory bowel disease (IBD), we have been reaching a point where other therapies with different mechanisms of action are necessary. A rising number of elderly IBD patients with contraindications to established therapies and a growing group of patients losing response to anti-TNF therapy compel us to find safer, better-tolerated, and, ideally, personalized treatment options. However, in order to choose the right drug to fit a patient, it is indispensable to understand the pathomechanism involved in IBD.

Summary

The aim of this review is to explain the inflammatory signaling pathways in IBD and how to inhibit them with current and future therapeutic approaches. Next to biologic agents targeting inflammatory cytokines (anti-TNF agents, anti-IL-12/-23 agents, and specific inhibitors of IL-23), biologics blocking leukocyte trafficking to the gut (anti-integrin antibodies) are available nowadays. More recently, small molecules inhibiting the JAK-STAT pathway (JAK inhibitors) or preventing lymphocyte trafficking (sphingosine-1-phosphate modulators) have been approved or are under investigation. Furthermore, modifying the microbiota has potential therapeutic effects on IBD, and autologous hematopoietic or mesenchymal stem cell transplantation may be considered for a highly selected group of IBD patients.

Key Message

Physicians should understand the different mechanisms of action of the potential therapies for IBD to select the right drug for the right patient.

Real-world evidence on adherence, persistence, switching and dose escalation with biologics in adult inflammatory bowel disease in the United States: A systematic review

WHAT IS KNOWN AND OBJECTIVE

The application of biologics to treat inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is well established. Our aim was to characterize the most recent five years of data on rates of adherence, persistence, switching and dose escalations with biologics used to treat IBD in the United States.

METHODS

We systematically reviewed electronic databases MEDLINE, MEDLINE In-Process, EMBASE and Cochrane Library for 2012-2017 as well as conference proceedings for 2016-2017 published in English.

RESULTS AND DISCUSSION

Of 449 records identified, 41 met all screening criteria. Published studies varied greatly in methodology, data sources, population studied, follow-up time and endpoint definitions, preventing meaningful comparisons across studies. Based on studies using a medication possession rate threshold of <80% or <86%, 38%-77% of patients were found non-adherent to biologics. Discontinuation within the first 3 months occurred in 0%-25% of patients in six studies; 7%-65% discontinued by 12 months in 13 studies. Among all patients who initiated an index biologic, the switch rate to another biologic ranged from 4.5% to 20% in 6 studies. Dose escalations were reported in only four studies; 8%-35% of patients had their dose escalated within the first year of therapy.

WHAT IS NEW AND CONCLUSION

This study demonstrates variability in study design and methodology to assess adherence, persistence, switching and dose escalation with biologics among adults with IBD in the United States. Our findings suggest that real-world biologic use may be suboptimal and indicate new therapies and/or additional patient support may be needed.

A real-world, long-term experience on effectiveness and safety of vedolizumab in adult patients with inflammatory bowel disease: The Cross Pennine study

BACKGROUND

Real-life data on vedolizumab effectiveness in inflammatory bowel disease (IBD) are still emerging. Data on the comparative safety of the gut selective profile are of particular interest.

AIMS

To assess clinical outcome and safety in IBD patients treated with vedolizumab.

METHODS

We retrospectively collected data of patients treated with vedolizumab at eight UK hospitals (August 2014-January 2018). Clinical response and remission at 14 and 52 weeks evaluated through Physician Global Assessment (PGA) and adverse events were recorded. Possible predictors of clinical response were examined.

RESULTS

Two hundred and three IBD patients (mean treatment 16 ± 8 months) were included. Of these, 135 patients (mean age 40.6 ± 16.0 years; F:M 1.9:1) had CD and 68 (mean age 44.5 ± 18.1 years; F:M 1:1.2) had UC. According to PGA, 106/135 (78.5%) CD and 62/68 (91.2%) UC patients (p = 0.02) had a clinical response/remission at 14 weeks, whereas 76/119 (63.9%) CD and 52/63 (82.5%) UC patients (p < 0.01) showed a sustained response or remission at 52 weeks, with a high adherence rate (97%). No predictors of clinical response were found. The cumulative incidence of infectious diseases was 11.9 per 100 person-years.

CONCLUSION

Vedolizumab is an effective therapy for inducing and maintaining remission of IBD, with better results for UC, and with a good safety profile.

Use of Anti-Tumor Necrosis Factors and Anti-Integrins in the Treatment of Crohn's Disease

In patients with Crohn's disease (CD), anti-tumor necrosis factor (TNF) therapy is efficacious for the induction and maintenance of clinical remission, mucosal healing, reducing rates of surgery and hospitalizations, and improving health-related quality of life. The decision between anti-TNFs and anti-integrins as first-line treatment in CD depends on disease severity, safety concerns, and prescription coverage. Given the existing data on long-term outcomes and safety, anti-TNFs are often preferred to anti-integrins. Additional clinical experience and preferably prospective, head-to-head studies will be important to determine whether vedolizumab should be considered more often for first-line therapy in CD.

Natalizumab in the treatment of Crohn's disease patients

INTRODUCTION

Amongst the available therapies for moderate to severe Crohn's disease (CD) patients who are refractory to conventional therapy, anti-TNF blockers are the most effective biological treatment option. However, many patients experience a primary or secondary non-response to anti-TNF therapy, creating the need for alternative biological drugs that target different mechanisms of action and inflammatory pathways. Natalizumab, the first non-anti-TNF biological drug to be approved for treatment of CD patients, is a recombinant humanized antibody that targets the α₄-subunit of both α₄β₁ and α₄β₇ integrins, thus preventing activated leukocyte homing to the intestinal mucosa. Areas covered: This article summarizes the pathophysiological background and the efficacy and safety data of natalizumab, as well as the regulatory issues surrounding it. Expert opinion: Natalizumab represents an effective therapy for refractory CD patients. However, the rare but serious event of progressive multifocal leukoencephalopathy occurrence has compromised its widespread use. The subsequent advent of more specific anti-integrin drugs (i.e. vedolizumab) that carry a more favorable safety profile further reduces the clinical indications for natalizumab. The regulatory process for natalizumab distribution and monitoring in the US may provide a forum for discussion on how to optimally manage use of drugs that offer clinical benefits to patients, while minimizing associated risks.

Neurological Complications of Gastrointestinal Disease

There is a growing interest in the extraintestinal manifestations of common pediatric gastrointestinal diseases, such as inflammatory bowel disease and celiac disease. This article specifically focuses on the neurological symptoms that manifest because of these disorders and their treatments. Many neurological symptoms have been reported in association with these diseases, including neuropathy, myopathy, ataxia, headache, and seizures, among others. It is currently believed that these neurological symptoms are largely overlooked by practitioners and could be a red flag for earlier diagnosis. However, additional research, especially in the pediatric population, is warranted to further elaborate on the causality and pathophysiology of these neurological symptoms.

Vedolizumab Effectiveness and Safety Over the First Year of Use in an IBD Clinical Practice

BACKGROUND AND AIMS

Vedolizumab inhibits leucocyte vascular adhesion and migration into the gastrointestinal tract through α4β7 integrin blockade. This agent became available in mid-2014 for the treatment of moderate to severe Crohn's disease (CD) and UC (UC). The aim of this study was to assess the patterns of use, effectiveness and safety of vedolizumab in an inflammatory bowel disease (IBD) clinical practice.

METHODS

Patients beginning vedolizumab were enrolled with informed consent. A prospective cohort was followed with laboratory, disease activity and quality-of-life assessments made during infusion visits up to week 14. Duration of vedolizumab use, mucosal healing and safety were analysed retrospectively for all patients not captured in the prospective component of this study.

RESULTS

One hundred and two patients started vedolizumab, with 51 patients (30 CD, 21 UC) followed prospectively. The CD patients exhibited a significant decrease in Crohn's Disease Activity Index (p = 0.04) and Harvey-Bradshaw index (p < 0.01) by week 14. The UC patients demonstrated improved partial Mayo scores at weeks 6 (p < 0.01) and 14 (p < 0.001). Ninety percent of all CD and UC patients remained on vedolizumab up to week 14. IBD-related quality of life was improved by week 6 in CD and UC cohorts (p = 0.02 and p < 0.01 respectively). Colectomy for lack of response and systemic histoplamosis were notable reasons for early discontinuation of vedolizumab, which was otherwise well tolerated.

CONCLUSIONS

Vedolizumab was efficacious and a high percentage of patients continued this therapy beyond induction dosing. Observed safety signals may be attributed to the refractory IBD disease state of this early-adopting clinical cohort.

Prevalence of Antibodies Against JC Virus in Patients With Refractory Crohn's Disease and Effects of Natalizumab Therapy

BACKGROUND & AIMS

Natalizumab, a humanized antibody against the α4 integrin subunit, effectively induces and maintains remission in patients with Crohn's disease (CD) refractory to conventional treatments. Progressive multifocal leukoencephalopathy is a rare but fatal brain infection caused by John Cunningham (JC) virus and has been associated with natalizumab use. We assessed the prevalence of and risk factors for antibodies to JC virus in serum of patients with refractory CD who were candidates for, or already were receiving, natalizumab. We also assessed the effects of natalizumab treatment of these patients.

METHODS

In a retrospective study, we analyzed clinical charts from 191 patients with CD (74 males; mean age, 38.7 y; mean duration of disease, 14.9 y) tested for serum JC virus antibody from December 2012 through May 2014 at 2 medical centers in the United States. We calculated JC virus antibody prevalence and compared the characteristics of patients who tested negative vs those who tested positive, to identify risk factors. We also assessed the rate of subsequent natalizumab use, surgery, and seroconversion during natalizumab therapy.

RESULTS

A total of 129 of the patients (67.5%) tested positive for serum JC virus antibody. Multivariate analysis showed that past use of thiopurine was a risk factor for testing positive for JC virus antibody (odds ratio, 7.8; 95% confidence interval, 2.0-30.4; P = .003). Twenty-two of the patients who tested negative for JC virus antibody (35.5%) and 16 of the 129 patients who tested positive (12.4%) had been treated with natalizumab. Cox regression analysis determined that natalizumab use was the only factor associated with avoiding subsequent surgery (hazard ratio, 0.23; 95% confidence interval, 0.06-0.98). Seroconversion (from testing negative to positive for JC virus antibody) occurred in 1 of the 22 patients (4.5%) who initially tested negative during natalizumab therapy.

CONCLUSIONS

The prevalence of CD patients exposed to JC virus is comparable with that of the general population. In this retrospective study, prior thiopurine use was associated with an increased risk for testing positive for JC virus antibody. Natalizumab use reduced the risk of subsequent surgery.

What to Do When Biologic Agents Are Not Working in Inflammatory Bowel Disease Patients

Anti-tumor necrosis factor α and anti-integrin biologic therapies are effective for induction and maintenance of remission in moderate to severe ulcerative colitis and Crohn's disease. However, clinicians face many challenges in determining the best course of action when a patient does not respond or loses response to a biologic therapy. When patients are found to have continued active inflammation despite having undergone biologic therapy, the first determination should be whether this represents a primary nonresponse to the drug's mechanism of action or a secondary loss of response due to inadequate drug levels and/or antibody formation to the drug. Primary nonresponders may respond to a drug with a different mechanism of action. Secondary loss of response may be addressed through strategies such as dose escalation or addition of an immunosuppressant. Future options may include changing to a therapy targeting other mechanisms of immune modulation.

Where are we heading to in pharmacological IBD therapy?

After a relatively long time of failed developments and negative clinical trials in pharmacological inflammatory bowel disease (IBD) therapy we now phase a time of a great number of successful studies and new therapy principles that will most likely make it into clinical practice. This will change the landscape of IBD therapy in future markedly. Many new therapeutic principles have been developed and old ones that seemed to have failed such as anti-sense technology suddenly now provide promising results. Some initially promising therapies will need further development or have failed such as Trichuris suis ova therapy (but not helminth therapy in general), CCR9 targeted therapies or recombinant IL-10. In contrast anti-leukocate trafficking therapies appear to be quite promising. Vedolizumab is the first in class anti-integrin antibody that was approved for the therapy of CD and UC recently. Other anti-integrin antibodies and small molecule adhesion inhibitors will most likely be approved in the next years for IBD therapy. Tofacitinib, a small molecule JAK inhibitor, is a promising candidate for the treatment of UC. Phosphatidylcholine may be a future option for patients with 5-ASA refractory UC or 5-ASA intolerance. The preliminary data for Mongersen, a Smad7 antisense oligonucleotide, are promising despite some concerns about long term effect of TGFβ induction. Anti IL6 strategies will hopefully be further evaluated keeping in mind the caveat of a lack of CRP induction in anti-IL6 treated patients. Stem cell transplantation will become an option for patients that have experienced failure of established medications. Fecal microbiota transplantation and also perhaps combined probiotic therapy is a field that will be evaluated in more detail in the near future especially for UC patients. Based on these new developments treatment algorithms need to be updated. This review will reflect these current developments and give a perspective for future IBD therapy.

Dehydro-β-proline Containing α4β1 Integrin Antagonists: Stereochemical Recognition in Ligand-Receptor Interplay

A novel class of dehydro-β-proline-containing peptidomimetics, designed to be effective as α4β1 integrin ligands, has been developed on the basis of the fundamental requirements for the interactions of these transmembrane receptors with bioactive ligands. Dehydro-β-proline ring has been synthesized through an original pathway, involving ring closing metathesis of a diallylamino derivative. The synthesized products showed to be effective and selective as α4β1 integrin antagonists and displayed IC50 values in the nanomolar range in cell adhesion inhibition assays and in VCAM-1-induced phosphorylation of extracellular-signal-regulated kinases. Significant activity was observed also toward the homologous integrin α4β7, while they did not display any activity toward selected members of β1, β2, and β3 families. A strong dependence on the stereochemistry of the heterocyclic central core could be observed. The great importance of α4β1 integrin in chronic inflammatory and autoimmune diseases suggests a possible exploitation of these ligands as lead compounds for therapeutic tools development.

From historical perspectives to modern therapy: a review of current and future biological treatments for Crohn's disease

Crohn's disease (CD) is a debilitating, systemic inflammatory disorder with both gastrointestinal and extraintestinal manifestations. Its existence predates modern medicine, but its precise etiology remains incompletely understood. Most authorities suggest a multifactorial pathogenesis owing to a mixture of genetic disorders, immunologic dysregulation, microbiota disequilibrium and environmental influences. Of these factors, the overactive immunologic response seen in CD appears to be the most promising target of medical therapy. Biological agents comprise a relatively new class of drugs that can induce and maintain remission in moderate to severe CD, as well as in ulcerative colitis. This review will provide an overview of CD, its history, clinical features, pathophysiology, and treatment options focusing on current and future biological agents with an emphasis on drug development, dosage and administration.

Use of a third anti-TNF after failure of two previous anti-TNFs in patients with inflammatory bowel disease: is it worth it?

BACKGROUND

Some patients with inflammatory bowel disease (IBD) never respond or lose their response to a second anti-TNF.

AIM

To review the efficacy and safety of a third anti-TNF after failure of two previous anti-TNFs. Methods. Bibliographical searches in PubMed for studies evaluating infliximab, adalimumab, or certolizumab as the third anti-TNF in IBD patients whose two previous anti-TNF treatments had failed.

RESULTS

Two retrospective studies with a small sample size and limited follow up evaluated the effectiveness of a third anti-TNF patients whose two previous anti-TNFs had failed. The arguments for this switching strategy are as follows: a)favorable--albeit limited--efficacy (in the study by Allez et al., clinical response was observed in 51% of patients at week 20; and in the study by de Silva et al., over 50% of patients remained on the third anti-TNF at 1 year); b)the eventual response to the third anti-TNF is relatively quick; c) no other medical options have been approved for IBD treatment; d)the only alternative options are surgery, compassionate use with non-anti-TNFs, and clinical trials. However, there are also arguments against the prescription of a third anti-TNF: a)lack of experience, since the few available studies are limited by their small sample size; b)the relatively low response in the long term (mainly due to loss of response); c) and finally, and most importantly, the risk of severe adverse events.

CONCLUSION

The delicate balance between pros and cons means the use of a third anti-TNF after failure of two previous agents should be considered only in patients with no other therapeutic options. Decisions should be taken on an individual basis.

Management of arthropathy in inflammatory bowel diseases

The most common extra-intestinal manifestation in patients with inflammatory bowel disease (IBD) is articular involvement, with a prevalence ranging between 17% and 39%. It is frequently characterized by an involvement of the axial joints but may also be associated with peripheral arthritis. The target of therapy in the management of arthritis associated with IBD is to reduce the inflammation and prevent any disability and/or deformity. This requires active cooperation between gastroenterologist and rheumatologist. The treatment of axial involvement has focused on the combination of exercise with nonsteroidal anti-inflammatory drugs. Immunomodulators have been efficacious in patients with peripheral arthritis and other extra-intestinal manifestations, but they are not effective for the treatment of axial symptoms of spondylitis. Tumor necrosis factor (TNF) α inhibitors have been proven to be highly effective in the treatment of IBD patients which are steroid-dependent or refractory to conventional therapy and in patients with associated articular manifestations. The treatment of peripheral involvement and/or enthesitis and/or dactylitis is based on local steroid injections, while sulfasalazine and/or low doses of systemic steroids may be useful in case of inadequate response to intra-articular steroids. Sulfasalazine induces only a little improvement in peripheral arthritis. Immunomodulators such as methotrexate, azathioprine, cyclosporine and leflunomide show their efficacy in some patients with peripheral arthritis and other extra-intestinal components. TNF-α inhibitors should be considered the first-line therapeutic approach when moderate-to-severe luminal Crohn's disease or ulcerative colitis is associated with polyarthritis. The aim of this review is to provide a fair summary of current treatment options for the arthritis associated with IBD.

Vedolizumab as a Treatment for Crohn's Disease and Ulcerative Colitis

The management of Crohn's disease and ulcerative colitis has become increasingly complex. With the current utilization of immunosuppressive therapies earlier in the disease course for patients presenting with moderate to severe disease, there is a great need for additional biologic agents targeting inflammatory mediators other than anti-tumor necrosis factor-α (anti-TNF) agents. Although anti-TNF agents have positively impacted the treatment of inflammatory bowel disease, many patients can lose their response or develop intolerance to these agents over time through the formation of antidrug antibodies. Furthermore, a sizeable percentage of patients are primary nonresponders to anti-TNF drugs. Vedolizumab (Entyvio, Takeda Pharmaceuticals), a monoclonal antibody to the α4β7 integrin, inhibits gut lymphocyte trafficking and has been demonstrated to be an effective and safe agent for the treatment of both Crohn's disease and ulcerative colitis. This article reviews the clinical trial evidence and rationale for the use of vedolizumab in moderate to severe Crohn's disease and ulcerative colitis.

A medicoeconomic review of early intervention with biologic agents in the treatment of inflammatory bowel diseases

The treatment of inflammatory bowel disease with standard therapy fails to control the disease in many patients. Biologic therapy has an increasing role in altering the natural history of Crohn’s disease and ulcerative colitis, and is improving patient prognosis. However, indications for treatment and issues with drug costs and value for money remain unclear. Also, when to perform early intervention with biologic agents is at present unclear. We performed an extensive literature search and review to address these issues. The biologics provide better care for many patients. The choice of biologic agent, the indications for its use, the switch between agents, and the considerations of cost are outlined, with a view to guiding the treating physician in managing these cases. Outstanding issues and anticipated future developments are defined.

Translational research and efficacy of biologics in Crohn's disease: a cautionary tale

In the last several years many biologic agents for Crohn's disease have been developed. Due to their unique molecular specificity biologics are de facto indicators of the ultimate significance of the molecule targeted by the biologic itself. Here, we have reviewed many clinical studies that have used biologics for Crohn's disease. Their results show that despite potentially sound theoretical mechanisms of action and some initially promising data, most biologics - with few notable exceptions - have failed. Pharmacologic, study design or patient-related issues might explain these findings in some studies. However in many cases clinical failure of biologics might highlight the complexity of in vivo events and the potential deficiencies of current experimental settings. Hence, these observations call for new and efficient ways of predicting drug efficacy in clinical trials based on bench research. Conceivably, computer-based pathogenetic models could be used to simulate and predict clinical studies results in vivo.

Adverse events in IBD: to stop or continue immune suppressant and biologic treatment

Crohn's disease and ulcerative colitis affect an increasing number of patients. A variety of medical options exist for the treatment of these diseases including immune suppressants and biologic therapies. Unfortunately, these agents are associated with adverse events ranging from mild nuisance symptoms to potentially life-threatening complications including infections and malignancies. This review discusses adverse events associated with azathioprine, mercaptopurine, and methotrexate as well as anti-TNF-α and anti-integrin antibodies. In addition, adverse events associated with combination therapy are discussed as are clinical scenarios in which it may be reasonable to discontinue or de-escalate drug therapy. It is the responsibility of the treating gastroenterologist to effectively communicate the benefits and risks of therapy with patients; this review offers strategies that may assist providers in communicating risk with patients in addition to offering our perspective on whether modification or cessation of therapy can be considered.

Inflammatory bowel disease: An increased risk factor for neurologic complications

Only a very few systematic studies have investigated the frequency of neurologic disorders in patients with Crohn’s disease (CD) and ulcerative colitis (UC), which are the two main types of inflammatory bowel disease (IBD). Results have been inconsistent and variable, owing to differences in case-finding methods and evaluated outcomes in different studies. The most frequent neurologic manifestations reported in CD and UC populations are cerebrovascular disease (with either arterial or venous events), demyelinating central nervous system disease, and peripheral neuropathy (whether axonal or demyelinating); however, the literature describes numerous nervous system disorders as being associated with IBD. The pathogenesis of nervous system tissue involvement in IBD has yet to be elucidated, although it seems to be related to immune mechanisms or prothrombotic states. The recently-introduced tumor necrosis factor (TNF) inhibitors have proven successful in controlling moderate to severe IBD activity. However, severe neurologic disorders associated with TNF inhibitors have been reported, which therefore raises concerns regarding the effect of anti-TNF-α antibodies on the nervous system. Although neurological involvement associated with IBD is rarely reported, gastroenterologists should be aware of the neurologic manifestations of IBD in order to provide early treatment, which is crucial for preventing major neurologic morbidity.

Endoscopic therapy in inflammatory bowel diseases (with videos)

Endoscopic therapies are important modalities in the treatment of IBD, adjunct to medical and surgical approaches. These therapeutic techniques are particularly useful in the management of IBD-associated or IBD surgery–associated strictures, fistulas, and sinuses and colitis-associated neoplasia. Although the main focus of endoscopic therapies in IBD has been on balloon stricture dilation and ablation of adenoma-like lesions, new endoscopic approaches are emerging, including needle-knife stricturotomy, needle-knife sinusotomy, endoscopic stent placement, and fistula tract injection. Risk management of endoscopy-associated adverse events is also evolving. The application of endoscopic techniques in novel ways in the treatment of IBD is just beginning and will likely expand rapidly in the near future.

Mucosal healing is associated with improved long-term outcome of maintenance therapy with natalizumab in Crohn's disease

BACKGROUND

Natalizumab is an efficacious agent for induction and maintenance of remission in patients with Crohn's disease (CD) who have failed anti-tumor necrosis factor agents. We aimed to assess the impact of endoscopic severity and mucosal healing on the long-term outcome of natalizumab treatment in CD.

METHODS

We retrospectively assessed endoscopic severity according to the Simple Endoscopic Score for Crohn's Disease in patients with CD who received natalizumab therapy. The degree of endoscopic severity before natalizumab treatment and mucosal healing after treatment and their correlation with long-term outcome were studied.

RESULTS

Thirty-two patients with CD (15 male, median age 32.5 years) receiving natalizumab underwent at least 1 colonoscopy before or during natalizumab treatment. All patients had previously failed immunomodulator(s), and 31 failed anti-tumor necrosis factor agent(s). Mean duration of natalizumab treatment was 14.1 months. Baseline Simple Endoscopic Score for CD was categorized into quartiles, and those with a greater score were less likely to respond to treatment as assessed by Kaplan-Meier survival analysis (n = 32, log-rank test, P = 0.0055). Mucosal healing (decrease of Simple Endoscopic Score for CD of >70%) was achieved in 11 of 26 patients (42.3%), and this was correlated with an improved long-term outcome (log-rank test, P = 0.0063).

CONCLUSIONS

The degree of endoscopic inflammation correlates to response to natalizumab and maintenance of remission. These findings provide prognostic information for patient management decisions.

Efficacy and safety of natalizumab in Crohn's disease patients treated at 6 Boston academic hospitals

BACKGROUND

Despite trials demonstrating its efficacy, many physicians harbor concerns regarding the use of natalizumab in the treatment of patients with refractory Crohn's disease (CD). The purpose of this study was to perform a descriptive analysis of a series of CD patients not currently enrolled in a clinical trial.

METHODS

A retrospective case review of patients treated with natalizumab at 6 sites in Massachusetts: Boston Medical Center, Beth Israel Deaconess Medical Center, Brigham & Women's Hospital, Lahey Clinic, Massachusetts General Hospital, and UMass Medical Center.

RESULTS

Data on 69 CD patients on natalizumab were collected. At the start of treatment, patients' disease duration was 12 years. A high proportion of patients were women (68%), presented with perianal disease (65%) and upper gastrointestinal tract involvement (14%). Prior nonbiologic therapies were steroids (96%), thiopurines (94%), antibiotics (74%), methotrexate (58%), and at least two anti-tumor necrosis factor agent failures (81%). Sixty-nine percent (44 of 64 patients) with available medical evaluation had a partial or complete clinical response. Loss of response was 13% after an average of 1 year of treatment. Adverse events were infusion reactions, headaches, fever, and infections. No case of progressive multifocal leukoencephalopathy was observed.

CONCLUSIONS

In our clinical experience outside the context of a clinical trial, natalizumab is largely reserved for CD patients with extensive ileocolonic disease who have failed conventional immunosuppressants and of at least 2 anti-tumor necrosis factor agents. This drug is, however, well tolerated and offers significant clinical improvement for more than a year in one-third of these difficult-to-treat CD patients.