Biological agents for ulcerative colitis: hypes and hopes

Procyanidin A1 alleviates DSS-induced ulcerative colitis via regulating AMPK/mTOR/p70S6K-mediated autophagy

Ulcerative colitis (UC) is a recurrent chronic inflammatory disease. The symptom of UC is mainly diarrhea including bloody stools. Increasing evidence has suggested that procyanidin A1 (PCA1) exerts an anti-inflammatory effect in several diseases. However, the role of PCA1 in UC is still a mystery. In our study, we explored the effect of PCA1 in dextran sulfate sodium (DSS)-induced UC mice and lipopolysaccharide (LPS)-stimulated HT-29 and IEC-6 cells. Then, cell proliferation, apoptosis, the production of proinflammatory cytokines, and autophagy-related markers were determined. Furthermore, the AMPK/mTOR/p70S6K signaling pathway was assayed by Western blot assay. In in vivo study, we found that PCA1 administration alleviated DSS-induced UC, as evidenced by reducing weight loss, clinical scores, colon weight/length ratio, histological damage, proinflammatory cytokines, and apoptosis. Moreover, we showed that the expression of Beclin-1 and LC3II/I ratio was increased, whereas the level of p62 was decreased after PCA1 treatment in vivo. Meanwhile, the reduced AMP/ATP ratio, enhanced expression of p-AMPK, and decreased p-p70S6K and p-mTOR levels indicate the activation of AMPK/mTOR/p70S6K signaling pathway. In in vitro study, PCA1 promoted cell proliferation and inhibited cell apoptosis in LPS-stimulated HT-29 and IEC-6 cells. Pro-inflammatory cytokines and autophagy-related factors exhibited the same trend as in in vivo results. Mechanically, PCA1 activated the AMPK/mTOR/p70S6K signaling pathway. The treatment with an AMPK inhibitor compound C significantly reversed the anti-inflammatory effect of PCA1 in LPS-stimulated cells. Taken together, these data indicated that PCA1 alleviated UC through induction of AMPK/mTOR/p70S6K-mediated autophagy.

Interfering With Inflammation: Heterogeneous Effects of Interferons in Graft-Versus-Host Disease of the Gastrointestinal Tract and Inflammatory Bowel Disease

The intestine can be the target of several immunologically mediated diseases, including graft-versus-host disease (GVHD) and inflammatory bowel disease (IBD). GVHD is a life-threatening complication that occurs after allogeneic hematopoietic stem cell transplantation. Involvement of the gastrointestinal tract is associated with a particularly high mortality. GVHD development starts with the recognition of allo-antigens in the recipient by the donor immune system, which elicits immune-mediated damage of otherwise healthy tissues. IBD describes a group of immunologically mediated chronic inflammatory diseases of the intestine. Several aspects, including genetic predisposition and immune dysregulation, are responsible for the development of IBD, with Crohn’s disease and ulcerative colitis being the two most common variants. GVHD and IBD share multiple key features of their onset and development, including intestinal tissue damage and loss of intestinal barrier function. A further common feature in the pathophysiology of both diseases is the involvement of cytokines such as type I and II interferons (IFNs), amongst others. IFNs are a family of protein mediators produced as a part of the inflammatory response, typically to pathogens or malignant cells. Diverse, and partially paradoxical, effects have been described for IFNs in GVHD and IBD. This review summarizes current knowledge on the role of type I, II and III IFNs, including basic concepts and controversies about their functions in the context of GVHD and IBD. In addition, therapeutic options, research developments and remaining open questions are addressed.

Efficacy And Safety Of Adalimumab Biosimilar (Exemptia) In Moderate-To-Severe Steroid-Refractory Ulcerative Colitis Patients: Real-Life Outcomes In Resource-Constrained Setting At 24-Weeks Follow-Up

Background

Adalimumab (ADA) is approved for the management of lcerative colitis (UC) not responding to conventional therapy. Use of biologics in resource-constrained settings is very challenging. Currently, real-life data on the safety and efficacy of ADA biosimilar (Exemptia) in steroid-refractory UC patients are limited.

Aim and objectives

To assess the efficacy and safety of ADA biosimilar (Exemptia) to treat steroid-refractory difficult-to-treat UC patients in a resource-constrained Indian setting at 24-weeks follow-up.

Materials and methods

This was a retrospective single-center study to evaluate the efficacy and safety of ADA biosimilar (Exemptia) in steroid-refractory UC patients. All the eligible patients who received induction dose of 160 mg at week 0, 80 mg at week 2 and 40 mg at week 4 and 40 mg every 4 weeks as maintenance regimen from 01 September 2017 to 31 Jan 2019 were retrospectively included in this single-center analysis. Those patients who had shown sub-optimal response at 12 weeks received 40 mg every 2 weeks as maintenance therapy. Outcomes in terms of clinical remission, clinical response and mucosal healing were evaluated in the short term at 12 weeks and 24 weeks.

Results

Twenty-five patients were retrospectively included between the time period of 1 September 2017 to 31 July 2018 with a mean age of 35 years. ADA biosimilar was effective in inducing clinical remission in 16% patients at 12 and 24 weeks, clinical response was seen in 48% at week 12 and 44% at week 24. The mean baseline total Mayo score (TMS) for all patients was 10.16 which decreased to a mean score of 5.72 at 12 weeks and 5.52 at 24 weeks with therapy with the decrease of the score being statistically significant both at 12 and 24 weeks (p<0.05). Two patients (8%) developed pulmonary tuberculosis (TB). ADA biosimilar frequency was accelerated to once in 2 weeks in 14 (56%) patients who did not show an optimal response at 12 weeks. Of these 14 patients, 5 were responders and 9 were non-responders at 12 weeks. At 24 weeks, 6 patients showed clinical response and 7 were non-responders, while one patient had developed TB.

Conclusion

ADA biosimilar (Exemptia) therapy is a safe and cost-effective alternative to original biologics in difficult-to-treat UC patients in resource-constrained Indian setting with comparable efficacy. Maintenance therapy at four weekly intervals can be considered in those patients who have shown an early clinical response at 12 weeks to minimize costs, but more studies are needed to confirm the same.

Reduced CD27-IgD- B Cells in Blood and Raised CD27-IgD- B Cells in Gut-Associated Lymphoid Tissue in Inflammatory Bowel Disease

The intestinal mucosa in inflammatory bowel disease (IBD) contains increased frequencies of lymphocytes and a disproportionate increase in plasma cells secreting immunoglobulin (Ig)G relative to other isotypes compared to healthy controls. Despite consistent evidence of B lineage cells in the mucosa in IBD, little is known of B cell recruitment to the gut in IBD. Here we analyzed B cells in blood of patients with Crohn's disease (CD) and ulcerative colitis (UC) with a range of disease activities. We analyzed the frequencies of known B cell subsets in blood and observed a consistent reduction in the proportion of CD27^-IgD^- B cells expressing all Ig isotypes in the blood in IBD (independent of severity of disease and treatment) compared to healthy controls. Successful treatment of patients with biologic therapies did not change the profile of B cell subsets in blood. By mass cytometry we demonstrated that CD27^-IgD^- B cells were proportionately enriched in the gut-associated lymphoid tissue (GALT) in IBD. Since production of TNFα is a feature of IBD relevant to therapies, we sought to determine whether B cells in GALT or the CD27^-IgD^- subset in particular could contribute to pathology by secretion of TNFα or IL-10. We found that donor matched GALT and blood B cells are capable of producing TNFα as well as IL-10, but we saw no evidence that CD27^-IgD^- B cells from blood expressed more TNFα compared to other subsets. The reduced proportion of CD27^-IgD^- B cells in blood and the increased proportion in the gut implies that CD27^-IgD^- B cells are recruited from the blood to the gut in IBD. CD27^-IgD^- B cells have been implicated in immune responses to intestinal bacteria and recruitment to GALT, and may contribute to the intestinal inflammatory milieu in IBD.

Identification of New Potential Therapies for Colitis Amelioration Using an Appendicitis-Appendectomy Model

The appendix contains copious lymphoid tissue and is constantly exposed to gut flora. Appendicitis followed by appendectomy (AA), when done at a young age, prevents or significantly ameliorates inflammatory bowel diseases (IBDs) in later life. Inflammatory bowel disease comprises Crohn's disease and ulcerative colitis. Our unique murine AA model is the only existing experimental model of AA. Herein, the appendiceal pathology closely resembles the pathological features of human appendicitis. Our AA model protects against experimental colitis in an age-, bacteria- and antigen-dependent manner. Appendicitis-appendectomy performed in the most proximal colon curbs T helper 17 (Th17) cell activity, diminishes autophagy, modulates interferon activity-associated molecules, and suppresses endothelin vasoactivity-mediated immunopathology in the most distal colon. These changes induced by AA contribute to limiting colitis pathology. Manipulating and modulating various aspects of these pathways, pathophysiology, and molecular interactions will assist the development of novel therapeutic options to manage IBD. Competitive inhibition of the Th17 cell recruitment factor CCL20 or the chemokine CCL17 with antibodies, combinatorial peptides, or small molecules may limit colitic pathology. The chemokines CCL5 and CXCL11 could be investigated as potential therapies. Inhibition of the autophagy-associated molecules VPS15, LAMP2, LC3A, XBP1, or ULK1 may decrease colitic pathology. Curtailing endothelin-activity may decrease colitic impact. The antiproliferative, immunomodulatory molecules IFIT1, IFIT2, IFIT3, and IFI44 may have direct therapeutic value in ameliorating colitis. The molecules IRF4, IRF8, IRF2BP1, IFRD1, and IFRD2 are potentially good target molecules to competitively inhibit towards curbing colitis.

Efficacy and safety of the adalimumab biosimilar Exemptia as induction therapy in moderate-to-severe ulcerative colitis

BACKGROUND/AIMS

Data on the efficacy and safety of the adalimumab biosimilar Exemptia are limited.

METHODS

Patients with moderate-to-severe active steroid-refractory ulcerative colitis (UC) treated at Dayanand Medical College and Hospital, India were offered cyclosporine A, biologicals or biosimilars, or surgery. A retrospective analysis was conducted on patients who were treated with the adalimumab biosimilar, Exemptia. These patients were administered an induction dosing schedule of 160 mg Exemptia at week 0, 80 mg at week 2, and then 40 mg every other week from week 4 to 8. The clinical response and remission were assessed at week 8 using Mayo score.

RESULTS

A total of 29 patients (62.1% male; mean age, 34.9 ± 9.7 years) with moderate-to-severe steroid-refractory active UC (mean disease duration, 6.3±5.1 years; pancolitis in 9 patients [31.1%]; left-sided colitis in 20 patients [68.9%]) were treated with the Exemptia induction dosing schedule. The mean Mayo score at presentation was 8.2±1.4. At week 8, clinical response was observed in 7 patients (24.1%), whereas clinical remission was observed only in 1 patient (3.5%). Among the non-responders (n=21), 4 patients required colectomy, 1 died, 1 was lost to follow-up, 10 were offered fecal microbiota transplant, 3 were administered infliximab, and 2 patients were administered cyclosporine and tacrolimus, respectively. Four patients (13.8%) developed extrapulmonary tuberculosis.

CONCLUSIONS

The adalimumab biosimilar Exemptia has limited efficacy for the attainment of clinical response and remission in moderate-to-severe steroid-refractory UC, with a significant risk of acquisition or reactivation of tuberculosis in developing countries such as India.

Gastrointestinal neuroendocrine peptides/amines in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic recurrent condition whose etiology is unknown, and it includes ulcerative colitis, Crohn’s disease, and microscopic colitis. These three diseases differ in clinical manifestations, courses, and prognoses. IBD reduces the patients’ quality of life and is an economic burden to both the patients and society. Interactions between the gastrointestinal (GI) neuroendocrine peptides/amines (NEPA) and the immune system are believed to play an important role in the pathophysiology of IBD. Moreover, the interaction between GI NEPA and intestinal microbiota appears to play also a pivotal role in the pathophysiology of IBD. This review summarizes the available data on GI NEPA in IBD, and speculates on their possible role in the pathophysiology and the potential use of this information when developing treatments. GI NEPA serotonin, the neuropeptide Y family, and substance P are proinflammatory, while the chromogranin/secretogranin family, vasoactive intestinal peptide, somatostatin, and ghrelin are anti-inflammatory. Several innate and adaptive immune cells express these NEPA and/or have receptors to them. The GI NEPA are affected in patients with IBD and in animal models of human IBD. The GI NEPA are potentially useful for the diagnosis and follow-up of the activity of IBD, and are candidate targets for treatments of this disease.

Anti-inflammatory effects of novel AP-1 and NF-κB inhibitors in dextran-sulfate-sodium-induced colitis in rats

The aim of the present study was to elucidate the anti-inflammatory effects of the two novel anti-inflammatory substances, 3-[(dodecylthiocarbonyl)-methyl]-glutarimide (DTCM-G) and dehydroxymethylepoxyquinomicin (DHMEQ), on DSS-induced colitis in rats. For this purpose, rats with dextran sulfate sodium (DSS)-induced colitis were randomly divided into 3 groups with 10 animals in each group as follows: i) the control group, which received 0.5 ml of 0.5% carboxymethyl cellulose (CMC; vehicle), ii) rats that received DTCM-G (20 mg/kg body weight in 0.5% CMC; the DTCM-G group), and iii) rats that received DHMEQ (15 mg/kg body weight in 0.5% CMC; the DHMEQ group). The animals were sacrificed after the 5-day treatment period, and tissue samples were taken from their colons and sectioned for histological evaluation. The tissue sections were stained with hematoxylin and eosin, and immunostained for leukocytes, lymphocytes, macrophages/monocytes and mast cells. The disease activity index (DAI), histological grading of colitis, and densities of several types of submucosal immune cells were compared between the controls, and the DTCM-G and DHMEQ groups. The DAI values were significantly lower in both the DTCM-G and DHMEQ groups than in the control group. The total scores for the histological grading of colitis were also significantly lower in the DTCM-G and DHMEQ groups than in the control group. The submucosal densities of leucocytes, lymphocytes, macrophages/monocytes and mast cells were significantly lower in the DTCM-G and DHMEQ groups than in the control group. Our findings indicate that the anti-inflammatory and anticancer effects of DTCM-G and DHMEQ, and the absence of any associated toxicity render them excellent therapeutic candidates for clinical use in the treatment of colitis.

Combination of Azathioprine and Aminosalicylate Treatment Prevent Risk of Cardiovascular Disease in Women with Ulcerative Colitis by Reducing Inflammation

Background

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with involvement of the immune system. Chronic inflammatory diseases have been associated with increased risk of cardiovascular disease (CVD) but few studies have assessed this risk in patients with UC and the influence of drug treatment. Thus, we evaluated the risk of development of CVD in women with UC in clinical remission, considering the drug treatment.

Material/Methods

Twenty-one women with UC participated in this study: 12 used aminosalicylates (ASA group) and 9 used azathioprine added to aminosalicylates (AZA+ASA group). The healthy control group was matched for age. We evaluated blood pressure, body composition, and biochemical and immunological parameters.

Results

Compared to the respective control group, the UC groups showed expansion of body fat and less lean body mass. Blood pressure, pro-inflammatory cytokines, nitric oxide, C reactive protein, erythrocyte sedimentation rate (ESR), and anti-oxidized LDL antibodies were higher in UC groups. Only AZA+ASA group showed increased anti-inflammatory cytokines (IL-10 and TGF-β). Framingham scores showed higher risk of CVD in UC groups. UC groups were compared and women treated with azathioprine showed reduction of total protein, globulin, ESR, and lymphocytes, with increased IL-6, TNF, IL-10, and TGF-β.

Conclusions

Our data suggest that women with UC in clinical remission have a higher risk for development of atherosclerosis and CVD when compared to the control group, while women treated with azathioprine seem more protected than those treated only with aminosalicylates, due to better regulation of the inflammatory process.

Inflammatory bowel disease therapies discontinued between 2009 and 2014

INTRODUCTION

New therapeutic approaches are currently under development, which consider the fundamental mechanisms involved in the pathogenesis of inflammatory bowel disease (IBD). The disease is associated with inflamed intestinal and colonic mucosa in response to the dysregulated immune system.

AREAS COVERED

The aim of this article is to review drugs that have been designed for the treatment of IBD and discontinued between 2009 and 2014. Herein, nine molecules with different mechanisms of action are under review. Brodalumab, daclizumab, elubrixin and vatelizumab were withdrawn from the Phase II trial due to the lack of efficacy. Abatacept was not significantly superior to the placebo in the rate of remission and its Phase III trials were stopped. CNDO-210 and Catridecacog were discontinued due to safety concerns and lack of efficacy, respectively. Finally, NU-206 and alkaline phosphatase also ceased in development during Phase I and II tests.

EXPERT OPINION

The development in our knowledge and understanding of the pathophysiology of IBD and the identification of key objectives for the future play significant roles in IBD therapeutic development. Furthermore, well-planned clinical trials with concise measures of efficacy and safety are required to better decide whether to extend or terminate the development process. Some anti-inflammatory cytokines such as IL-2, IL-12, IL-17, IL-18, IL-23 and INF-γ could garner more attention in the future.

Modulation of interferon activity-associated soluble molecules by appendicitis and appendectomy limits colitis-identification of novel anti-colitic targets

The therapeutic efficacy of interferons (IFNs) in ulcerative colitis is minimal. However, IFN activity-associated molecules have been inadequately investigated. Appendicitis and appendectomy (AA), when done while young, protect against colitis development later. Our novel murine AA model protects against colitis. This therapeutic target-identifying study enumerates IFN activity-associated molecules involved in this protection. Mice with 2 laparotomies were controls (sham-sham/SS). Distal colons were harvested (4 AA-group colons and 4 SS-group colons). Microarray-analysis/reverse transcriptase-polymerase chain reaction-validation was done from RNA from each (3-days/28-days-post-AA). Gene set enrichment analysis (GSEA) software was used to analyze distal colonic gene sets associated with 46 IFN activity-related genes. More AA-upregulated gene sets were associated with IFIT1, IFIT2, IFIT3, IRF7, IFI35, and IFI44 (False Discovery Rate-FDR <5% and P<0.001), although only IFIT1, IFIT2, IFIT3, and IFI44 showed individual gene upregulation (P<0.05). More AA-downregulated gene sets were associated with IRF1, IRF2, IRF4, IRF8, IRF9, IRF2BP1, IFRD1, IFRD2, and IFIH1 (FDR <5%/P<0.001); although only IRF2BP1 showed individual gene downregulation (P<0.05). There was significant upregulation (P<0.05) of IFNZ; and downregulation of IRF2BP2 and IFI30, despite no major associated GSEA differences. IFIT1, IFIT2, IFIT3, and IFI44, with profound AA-induced individual/GSEA upregulation, and their immunomodulatory/ antiproliferative activity, are the best molecules to investigate therapeutic potential. IRF4, IRF8, IRF2BP1, IFRD1, and IFRD2, owing to their profound AA-induced gene set downregulation, and because of their diverse lymphocytic activity, are good targets to competitively inhibit or to treat with exogenous products in knockout animals.

Grape seed extract reduces the severity of selected disease markers in the proximal colon of dextran sulphate sodium-induced colitis in rats

BACKGROUND

Grape seed extract (GSE) constitutes a rich source of procyanidins. GSE has been demonstrated to exert encouraging anti-inflammatory and anti-ulcer properties in experimental settings, although its effects on inflammation of the colon remain undefined.

AIM

To determine the effects of GSE in a rat model of dextran sulphate sodium (DSS) for ulcerative colitis.

METHODS

Male Sprague-Dawley rats were gavaged daily (days 0-10) with GSE (400 mg/kg). Ulcerative colitis was induced by substituting DSS (2 % w/v) for drinking water from days 5-10. A sucrose breath test was performed on day 11 to determine small bowel function and intestinal tissues were collected for histological analyses. Statistical analysis was by one-way or repeated-measures ANOVA and p < 0.05 was considered significant.

RESULTS

Compared to DSS-treated controls, GSE significantly decreased ileal villus height (14 %; p < 0.01) and mucosal thickness (13 %; p < 0.01) towards the values of normal controls. GSE reduced qualitative histological severity score (p < 0.05) in the proximal colon, although no significant effect was evident in the distal colon. However, GSE failed to prevent DSS-induced damage to the crypts of both colonic regions. Administration of GSE did not negatively impact metabolic parameters, nor did it induce any deleterious gastrointestinal side effects in healthy animals.

CONCLUSIONS

GSE decreased the severity of selected markers of DSS-induced colitis in the distal ileum and proximal colon, suggesting the potential as an adjuvant therapy for the treatment of ulcerative colitis. Future studies of GSE should investigate alternative delivery methods and treatment regimens, further seeking to identify the individual bioactive factors.

Pro-Inflammatory Signaling by IL-10 and IL-22: Bad Habit Stirred Up by Interferons?

Interleukin (IL)-10 and IL-22 are key members of the IL-10 cytokine family that share characteristic properties such as defined structural features, usage of IL-10R2 as one receptor chain, and activation of signal transducer and activator of transcription (STAT)-3 as dominant signaling mode. IL-10, formerly known as cytokine synthesis inhibitory factor, is key to deactivation of monocytes/macrophages and dendritic cells. Accordingly, pre-clinical studies document its anti-inflammatory capacity. However, the outcome of clinical trials assessing the therapeutic potential of IL-10 in prototypic inflammatory disorders has been disappointing. In contrast to IL-10, IL-22 acts primarily on non-leukocytic cells, in particular epithelial cells of intestine, skin, liver, and lung. STAT3-driven proliferation, anti-apoptosis, and anti-microbial tissue protection is regarded a principal function of IL-22 at host/environment interfaces. In this hypothesis article, hidden/underappreciated pro-inflammatory characteristics of IL-10 and IL-22 are outlined and related to cellular priming by type I interferon. It is tempting to speculate that an inherent inflammatory potential of IL-10 and IL-22 confines their usage in tissue protective therapy and beyond that determines in some patients efficacy of type I interferon treatment.

Adalimumab in ulcerative colitis: ready for prime time

Ulcerative colitis is one of the two main types of inflammatory bowel disease and is a chronic condition with a significant impact on health-related quality of life. For many patients, currently available treatment options do not provide adequate efficacy or are poorly tolerated. Efforts to identify new agents for the treatment of ulcerative colitis have focused mainly on targeting tumour necrosis factor α, a pro-inflammatory cytokine believed to play a pivotal role in the initiation and progression of the disease. Until recently, there was only one anti-tumour necrosis factor α agent approved for treatment of ulcerative colitis, infliximab, although there were several other such agents approved for the related condition, Crohn's disease, including adalimumab. This year (2012), adalimumab has been approved by the European Medicines Agency for the treatment of ulcerative colitis. Here, the current evidence regarding use of adalimumab in the treatment of ulcerative colitis is reviewed, with results indicating that adalimumab has compelling efficacy in the treatment of moderate-to-severe ulcerative colitis.

Ulcerative colitis: immune function, tissue fibrosis and current therapeutic considerations

BACKGROUND

Ulcerative colitis (UC) is a complex disease in which the interaction of genetic, environmental and microbial factors drives chronic intestinal inflammation that finally leads to extensive tissue fibrosis.

DISCUSSION

The present review discusses the current knowledge on genetic susceptibility, especially of the IL-12/IL-23 pathway, the pathophysiologic role of the involved cytokines (e.g. IL-13, IL-23, TGFβ1) and immune cells (e.g. T cells, epithelial cells, fibroblasts) in UC followed by an overview on actual therapeutic considerations. These future therapies will target selectively the involved cell types by blocking their activation and its downstream signalling, by inhibiting their migration to the inflamed site and by anti-cytokine strategies. This may avoid-when initiated in time-the perpetuation of the inflammatory mechanisms thus preventing fibrosis. With respect to animal models that have guided the most productive efforts for understanding human inflammatory bowel disease, these will be shortly discussed in the respective context.

Ulcerative colitis: immune function, tissue fibrosis and current therapeutic considerations

BACKGROUND

Ulcerative colitis (UC) is a complex disease in which the interaction of genetic, environmental and microbial factors drives chronic intestinal inflammation that finally leads to extensive tissue fibrosis.

DISCUSSION

The present review discusses the current knowledge on genetic susceptibility, especially of the IL-12/IL-23 pathway, the pathophysiologic role of the involved cytokines (e.g. IL-13, IL-23, TGFβ1) and immune cells (e.g. T cells, epithelial cells, fibroblasts) in UC followed by an overview on actual therapeutic considerations. These future therapies will target selectively the involved cell types by blocking their activation and its downstream signalling, by inhibiting their migration to the inflamed site and by anti-cytokine strategies. This may avoid-when initiated in time-the perpetuation of the inflammatory mechanisms thus preventing fibrosis. With respect to animal models that have guided the most productive efforts for understanding human inflammatory bowel disease, these will be shortly discussed in the respective context.

Investigational new drugs in the treatment of inflammatory bowel disease: a review

The unraveling of the immuno-pathobiology of inflammatory bowel disease (IBD) in the past three decades has ushered in a new era of translational medicine. The biotechnology revolution has resulted in a paradigm shift in how clinicians view and treat IBD. Anti-tumor necrosis factor (TNF)-α strategies using infliximab and adalimumab currently dominate the therapeutic arena. Better understanding of how these biologicals work is driving the quest for loftier therapeutic goals of achieving mucosal healing, sustaining deep remission, and even modifying the natural history of IBD. However, not all patients respond to anti-TNF drugs. Immune-mediated adverse reactions and loss of efficacy with time also limit their use. There are many investigational drugs undergoing active clinical trials. Many have not fulfilled their early promises but some are potentially making the transition from bench to trial and to the bedside in the near future. Clinicians and investigators need to underpin our excitement with caution for the unknown long-term consequences of modulating cytokines and selective adhesion molecules in human. Here we provide an overview of investigational new drugs and other therapeutic strategies currently undergoing clinical trials in IBD.