AJM300 (carotegrast methyl), an oral antagonist of α4-integrin, as induction therapy for patients with moderately active ulcerative colitis: a multicentre, randomised, double-blind, placebo-controlled, phase 3 study

Comprehensive overview of novel chemical drugs for ulcerative colitis: focusing on phase 3 and beyond

INTRODUCTION

Despite the growing number of highly efficacious biologics and chemical drugs for ulcerative colitis (UC), steroid-free disease control is still difficult to achieve in subgroups of patients due to refractoriness, adverse events, primary or secondary failure. New treatments are therefore still required in order to optimize clinical management of patients with UC.

AREAS COVERED

The efficacy and safety of both currently available and newly developed small molecules have been summarized. The PubMed database and clinicaltrials.gov were considered in order to search for phase 2b and 3 trials on new chemical drugs for UC. The study drugs reviewed included Janus kinases (JAK) and sphingosine-1-phosphate receptor (S1Pr) inhibitors, α4 integrin antagonist, and micro-RNA-124 upregulators.

EXPERT OPINION

Rapidity of onset, low immunogenicity, and safety are the main characteristics of small molecules currently available or under evaluation for treatment patients with UC. Among the currently available chemical drugs, the selective JAK and the S1Pr inhibitors are characterized by a good safety profile combined with the ability to induce clinical remission in UC. A relatively low frequency of endoscopic improvement and healing currently appears associated with their use, being higher in UC patients treated with S1Pr inhibitor Etrasimod. Overall, additional new safe and effective drugs are still required in order to optimize disease control in a larger majority of UC patients.

Consistent efficacy outcomes between phase 2 and phase 3 trials in Crohn's disease or ulcerative colitis in adults: a meta-analysis

INTRODUCTION

The approval of novel biologic agents and small molecules for the treatment of Crohn's disease (CD) and ulcerative colitis (UC) is dependent on phase 3 randomized controlled trials (RCTs). However, these trials sometimes fail to achieve the expected efficacy outcomes observed in phase 2 trials.

METHODS

We conducted a systematic review of RCTs that evaluated biologic agents and small molecules using paired regimens in both phase 2 and phase 3. We searched Medline, EMBASE, and Cochrane databases up until February 13, 2024. The revised Cochrane tool was utilized to assess the risk of bias. A generalized linear mixed-effects model (GLMM) was employed to estimate the odds ratios (ORs) for efficacy outcomes in phase 2 trials compared to phase 3.

RESULTS

We identified a total of 23 trials with 10 paired regimens for CD and 30 trials with 11 paired regimens for UC. The GLMM analysis revealed that phase 2 CD trials had higher outcomes measured by the Crohn's Disease Activity Index (CDAI) by 9-13% without statistical significance: CDAI-150: OR, 1.12 (95% CI 0.83-1.51, p = 0.41); CDAI-100: OR, 1.09 (95% CI 0.88-1.35, p = 0.40); or CDAI-70: OR, 1.13 (95% CI 0.61-2.08, p = 0.66). For UC, two efficacy outcomes were estimated to be equally reported in phase 2/phase 3 pairs: clinical remission: OR, 1.00 (95% CI 0.83-1.20, p = 0.96); endoscopic improvement: OR, 0.98 (95% CI 0.83-1.15, p = 0.79). However, the rate of clinical response was underestimated in phase 2 by 19%: OR, 0.81 (95% CI 0.70-0.95, p = 0.03). The inclusion criterion for the type of Mayo score for UC had a significant interaction with the study phase to influence the difference in clinical response (p = 0.002).

CONCLUSIONS

Our findings suggest that the main efficacy outcomes for CD and UC remain consistent between phase 2 and phase 3 trials, except for UC response rates. The efficacy data obtained from phase 2 trials can be considered reliable for the design of subsequent phase 3 trials.

REGISTRATION

PROSPERO (CRD42023407947).

Clinical outcomes of patients with remitting ulcerative colitis after discontinuation of indigo naturalis

Indigo naturalis is an effective treatment for ulcerative colitis. However, long-term use of indigo naturalis causes adverse events, such as pulmonary hypertension. The natural history of patients with ulcerative colitis who discontinued indigo naturalis after induction therapy is unknown. Moreover, the clinical features of patients who relapsed within 52 weeks after the discontinuation of indigo naturalis are unclear. This study aimed to assess the clinical outcomes of patients with ulcerative colitis after discontinuation of indigo naturalis and to identify potential markers responsible for relapse. This single-center retrospective study investigated the follow-up of 72 patients who achieved a clinical response 8 weeks after indigo naturalis treatment. We observed relapse in patients with ulcerative colitis after the discontinuation of indigo naturalis. We analyzed the factors predicting long-term outcomes after discontinuation of indigo naturalis. Relapse was observed in 24%, 57%, and 71% of patients at 8, 26, and 52 weeks, respectively. There were no predictive markers in patients who relapsed within 52 weeks after the discontinuation of indigo naturalis. The ulcerative colitis relapse rate after indigo naturalis discontinuation was high. Follow-up treatment is required after the discontinuation of indigo naturalis in patients with ulcerative colitis.

Novel and emerging drugs for the treatment of Crohn's disease: a review of phase II and III trials

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease characterized by unpredictable flare-ups and periods of remission. While several therapeutic options, such as anti-tumor necrosis factor (TNF), anti-integrin, and interleukin (IL) 12/23 inhibitors, as well as IL-23 and Janus kinase (JAK) inhibitors, have been approved for CD treatment, a substantial number of patients fail to respond adequately or experience a loss of response over time. In recent years, the scientific community has been actively investigating novel agents to address these challenges and improve the management of CD.

AREAS COVERED

This comprehensive narrative review provides an overview of recent developments in CD treatment, summarizing phase 2 and phase 3 clinical trial data. We delve into the clinical efficacy and safety profiles of emerging therapies, encompassing JAK inhibitors, IL-23 inhibitors, anti-adhesion molecules, S1P1 receptor modulators, and combined targeted treatments.

EXPERT OPINION

The armamentarium of CD therapeutic agents is constantly expanding. We analyze pivotal findings from phase 2 and phase 3 CD treatment trials. We also underscore the existing gaps in therapy and the paramount role of ongoing research and innovation in CD management.

Targeting T-cell integrins in autoimmune and inflammatory diseases

The recruitment of T cells to tissues and their retention there are essential processes in the pathogenesis of many autoimmune and inflammatory diseases. The mechanisms regulating these processes have become better understood over the past three decades and are now recognized to involve temporally and spatially specific interactions between cell-adhesion molecules. These include integrins, which are heterodimeric molecules that mediate in-to-out and out-to-in signalling in T cells, other leukocytes, and most other cells of the body. Integrin signalling contributes to T-cell circulation through peripheral lymph nodes, immunological synapse stability and function, extravasation at the sites of inflammation, and T-cell retention at these sites. Greater understanding of the contribution of integrin signalling to the role of T cells in autoimmune and inflammatory diseases has focused much attention on the development of therapeutics that target T-cell integrins. This literature review describes the structure, activation, and function of integrins with respect to T cells, then discusses the use of integrin-targeting therapeutics in inflammatory bowel disease, multiple sclerosis, and psoriasis. Efficacy and safety data from clinical trials and post-marketing surveillance are presented for currently approved therapeutics, therapeutics that have been withdrawn from the market, and novel therapeutics currently in clinical trials. This literature review will inform the reader of the current means of targeting T-cell integrins in autoimmune and inflammatory diseases, as well as recent developments in the field.

Comparison between washed microbiota transplantation and infliximab: Medical cost during long-term management in patients with inflammatory bowel disease

BACKGROUND

Both infliximab (IFX) and fecal microbiota transplantation (FMT) have shown the efficacy for inflammatory bowel disease (IBD). However, there has no head-to-head study on the cost-value of the such treatments on IBD. This study aimed to compare the medical costs using IFX and the new method of FMT (washed microbiota transplantation [WMT]) in the long-term management for IBD under the current health economic condition in China.

METHODS

Patients with IBD who underwent initial WMT via upper gastrointestinal endoscopy, mid-gut tube, or colonic transendoscopic enteral tubing at a university hospital between April 2013 and August 2021 and achieved the long-term sustainment with WMT or WMT combined with mesalazine until August 2022 were recruited in the real-world. The costs and hospitalizations were analyzed among two therapies mentioned above and IFX standard therapy. The charge of WMT was stable in the long term at our center, and the charge of IFX came from virtual statistics publicized by China Healthcare Security.

RESULTS

Sixty eligible patients with IBD were included in the study. The long-term costs of patients using WMT monotherapy annually or per hospitalization were lower than those on WMT combined with mesalazine, respectively ( p < 0.001, respectively). The cumulative costs of IFX at the time of 0.52 and 0.85 years exceeded that of the above WMT, respectively ( p < 0.001, respectively). Besides, patients on WMT monotherapy paid 51.1 k CNY annually in the nonsustain phase but cut down the costs by 7.2 k CNY and duration of hospitalization by 5.1 days per hospitalization when reaching the goal of sustainment.

CONCLUSION

This study demonstrated that WMT could dramatically reduce the cost and duration of hospitalizations in the long-term sustainment in the current Chinese IBD cohort. Compared with IFX, WMT could be a good way for the patients with IBD achieving long-term sustainment and saving medical costs.

Upadacitinib Plus Intensive Granulocyte and Monocyte Adsorptive Apheresis for Ulcerative Colitis Achieved Ulcer Healing for Pyoderma Gangrenosum

A 44-year-old woman who had been diagnosed with ulcerative colitis (UC) at 22 years old was diagnosed with severe flare-up of UC based on endoscopic findings associated with new-onset active pyoderma gangrenosum (PG) on both lower legs after she decided to discontinue UC treatment. Systemic treatment with intravenous prednisolone at 30 mg/day had achieved insufficient response to UC and PG, resulting in a diagnosis of corticosteroid-refractory UC and PG. Combination therapy with upadacitinib at 45 mg/day plus intensive granulocyte and monocyte adsorptive apheresis (GMA) was started to achieve clinical remission of UC. Ten weeks after starting this combination therapy, clinical improvement of UC was achieved with PG ulcer healing on both lower legs. A combination of upadacitinib plus intensive GMA may offer an effective therapeutic option for patients with active PG in addition to UC but has yet to be approved for induction or maintenance treatment of PG worldwide. PG is a dermatological involvement in UC patients that requires attention.

Understanding the molecular mechanisms of anti-trafficking therapies and their clinical relevance in inflammatory bowel disease

In patients with inflammatory bowel disease (IBD), a combination of dysbiosis, increased intestinal permeability, and insufficient regulatory responses facilitate the development of chronic inflammation, which is driven by a complex interplay between the mucosal immune system and the environment and sustained by immune priming and ongoing cellular recruitment to the gut. The localization of immune cells is mediated by their expression of chemokine receptors and integrins, which bind to chemokines and adhesion molecules, respectively. In this article, we review the mechanisms of action of anti-trafficking therapies for IBD and consider clinical observations in the context of the different mechanisms of action. Furthermore, we discuss the evolution of molecular resistance to anti-cytokines, in which the composition of immune cells in the gut changes in response to treatment, and the potential implications of this for treatment sequencing. Lastly, we discuss the relevance of mechanism of action to combination therapy for IBD.

Emerging oral drug options for ulcerative colitis

INTRODUCTION

Despite the availability of a variety of therapeutic compounds and improved management strategies, one-third of UC patients with moderate-to-severe disease do not benefit from the existing treatments or experience drug-related side effects. This has boosted intensive research focusing on the development of new drugs for UC therapy. This article aims to summarize the available evidence on oral drugs, which are now being explored in clinical trials or are ready to enter the clinics.

AREAS COVERED

From May 15 to June 11, we searched on PubMed using the keywords 'oral drugs ulcerative colitis,' 'ulcerative colitis clinical trials,' 'UC phase 2 and 3 trials' excluding case reports, case series, phase 1 and 4 studies, and studies about approved therapies.

EXPERT OPINION

The findings discussed in this article suggest that the future treatment of UC patients will be probably characterized by the possibility of using various small-molecule drugs. All these new compounds, even those belonging to the same class, differ in terms of efficacy and safety. Identification of predictors of response could help optimize the efficacy and safety of these treatments, thus improving resource allocation through a pretreatment stratification of patients.

Research progress on intestinal tissue-resident memory T cells in inflammatory bowel disease

Tissue-resident memory T (TRM) cells are a recently discovered subpopulation of memory T cells that reside in non-lymphoid tissues such as the intestine and skin and do not enter the bloodstream. The intestine encounters numerous pathogens daily. Intestinal mucosal immunity requires a balance between immune responses to pathogens and tolerance to food antigens and symbiotic microbiota. Therefore, intestinal TRM cells exhibit unique characteristics. In healthy intestines, TRM cells induce necessary inflammation to strengthen the intestinal barrier and inhibit bacterial translocation. During intestinal infections, TRM cells rapidly eliminate pathogens by proliferating, releasing cytokines, and recruiting other immune cells. Moreover, certain TRM cell subsets may have regulatory functions. The involvement of TRM cells in inflammatory bowel disease (IBD) is increasingly recognized as a critical factor. In IBD, the number of pro-inflammatory TRM cells increases, whereas the number of regulatory subgroups decreases. Additionally, the classic markers, CD69 and CD103, are not ideal for intestinal TRM cells. Here, we review the phenotype, development, maintenance, and function of intestinal TRM cells, as well as the latest findings in the context of IBD. Further understanding of the function of intestinal TRM cells and distinguishing their subgroups is crucial for developing therapeutic strategies to target these cells.

Novel pharmacological developments in the management of paediatric inflammatory bowel disease: Time for guideline update - A narrative review

AIM

The incidence of paediatric inflammatory bowel disease (IBD) continues to increase in both adults and children across the globe, with more than one third of the patients not responding to anti-tumour necrosis factor biologics and immune modulators. This narrative review provides an overview of novel pharmacological developments in the management of paediatric IBD, including new biological therapies.

METHODS

A PubMed Medline search was performed to include randomised controlled trials, retrospective and prospective observational studies, and relevant case reports of children with IBD published between 2018 and January 2023. Guidelines and protocols from relevant paediatric and adult gastroenterology societies, such as the European Society for Paediatric Gastroenterology, Hepatology and Nutrition and the European Crohn's and Colitis Organisation, were also included. Non-pharmacological treatments including therapeutic diets and faecal microbiota transplantation were outside the scope of this work.

RESULTS

Early real-world evidence suggests that newer biologics and small molecules, such as anti-integrins, interleukin-12 and/or interleukin-23 inhibitors, Janus kinase and signal transducer and activator of transcription proteins inhibitors, are safe and effective in adult patients with IBD, with promising growing evidence for paediatric IBD.

CONCLUSION

While many developments have been achieved with novel pharmacological treatments to manage IBD, ongoing research is required to confirm their effectiveness and safety in the paediatric age. Extending the licence of novel treatments to children will be crucial to tackle the increasing loss of response to conventional treatments. International guidelines will require timely updating to incorporate novel treatments within the existing protocols.

IL-3 receptor signalling suppresses chronic intestinal inflammation by controlling mechanobiology and tissue egress of regulatory T cells

IL-3 has been reported to be involved in various inflammatory disorders, but its role in inflammatory bowel disease (IBD) has not been addressed so far. Here, we determined IL-3 expression in samples from patients with IBD and studied the impact of Il3 or Il3r deficiency on T cell-dependent experimental colitis. We explored the mechanical, cytoskeletal and migratory properties of Il3r -/- and Il3r +/+ T cells using real-time deformability cytometry, atomic force microscopy, scanning electron microscopy, fluorescence recovery after photobleaching and in vitro and in vivo cell trafficking assays. We observed that, in patients with IBD, the levels of IL-3 in the inflamed mucosa were increased. In vivo, experimental chronic colitis on T cell transfer was exacerbated in the absence of Il-3 or Il-3r signalling. This was attributable to Il-3r signalling-induced changes in kinase phosphorylation and actin cytoskeleton structure, resulting in increased mechanical deformability and enhanced egress of Tregs from the inflamed colon mucosa. Similarly, IL-3 controlled mechanobiology in human Tregs and was associated with increased mucosal Treg abundance in patients with IBD. Collectively, our data reveal that IL-3 signaling exerts an important regulatory role at the interface of biophysical and migratory T cell features in intestinal inflammation and suggest that this might be an interesting target for future intervention.

A Comparison of Treatment Effect Sizes in Matched Phase 2 and Phase 3 Trials of Advanced Therapeutics in Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

INTRODUCTION

Phase 2 trials are fundamental to the rational and efficient design of phase 3 trials. We aimed to determine the relationship of treatment effect size estimates from phase 2 and phase 3 clinical trials on advanced therapeutics in inflammatory bowel disease.

METHODS

MEDLINE, EMBASE, CENTRAL, and the Cochrane library were searched from inception to December 19, 2022, to identify paired phase 2 and 3 placebo-controlled induction studies of advanced therapeutics for Crohn's disease (CD) and ulcerative colitis (UC). Treatment effect sizes were expressed as a risk ratio (RR) between the active arm and placebo arm. For the same therapeutics, RRs from phase 2 trials were divided by the RR from phase 3 trial to quantify the relationship of effect sizes between phases.

RESULTS

Twenty-two studies (9 phase 2 trials, 13 phase 3 trials) were included for CD and 30 studies (12 phase 2 trials, 18 phase 3 trials) for UC. In UC (pooled RR 0.72; 95% confidence interval: 0.58-0.86; RR <1 indicates smaller treatment effect sizes in phase 2 trials), but not CD (pooled RR 1.01; 95% confidence interval: 0.84-1.18), phase 2 trials systematically underestimated treatment effect sizes for the primary endpoint compared with phase 3 trials. The underestimation was observed for clinical, but not endoscopic, endpoints in UC.

DISCUSSION

Treatment effect sizes for the primary and clinical endpoints were similar across clinical trial phases in CD, but not UC, where only endoscopic endpoints were comparable. This will help inform clinical development plans and future trial design.

Questionnaire Survey for Inflammatory Bowel Disease Patients in Japan; A Web-Based Japan, Crohn's Disease, Ulcerative Colitis, Patients Survey

Background/Aims

The prevalence of inflammatory bowel disease (IBD) in Japan has been increasing. We aimed to clarify the symptoms of patients with IBD in Japan using an internet-based questionnaire survey.

Methods

Overall, 805 patients with IBD were asked to complete an internet-based questionnaire addressing their history of disturbances in daily activities, prevalence of fecal urgency, incontinence, and treatment preferences.

Results

Responses were obtained from 447 patients with IBD (mean age: 54 years; 70% were men), comprising 363 patients with ulcerative colitis (UC), and 84 with Crohn's disease (CD). Notably, 16% of patients with UC and 35% with CD took over 1 year until the diagnosis of IBD, and 5% of patients with CD visited more than 5 medical institutions. Patients with CD were more likely to experience disturbances in their diet, work, travel, and outings than those with UC. Fecal urgency and incontinence were significantly more frequent in patients with CD than in those with UC (72% vs. 44%, and 50% vs. 26%, respectively). In contrast, 26% of the men and 37% of women with IBD had constipation. Acid reflux, sleep disorders, and depressive symptoms were present in approximately 30% of the patients. Oral administration was preferred.

Conclusions

Patients with IBD in Japan experience more severe disturbances in their daily activities, and these are more severe in those with CD than those with UC. In addition to fecal urgency and incontinence, care is required for constipation, acid reflux, sleep disorders, and depressive symptoms.

Systematic review with meta-analysis: Medical therapies for treatment of ulcerative proctitis

BACKGROUND

Ulcerative proctitis (UP) is a common highly symptomatic form of ulcerative colitis that can be difficult to treat.

AIM

To assess the efficacy of medical treatments for UP.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL on 23 November 2022 for randomised controlled trials (RCTs) of medical therapy for adults with UP. Primary outcomes included induction and maintenance of clinical remission. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for each outcome.

RESULTS

We included 53 RCTs (n = 4096) including 46 induction studies (n = 3731) and seven maintenance studies (n = 365). First-line therapies included topical 5-aminosalicylic acid (5-ASA), conventional corticosteroids, budesonide, and oral 5-ASA. Therapy for refractory UP included topical tacrolimus and small molecules. Topical 5-ASA was superior to placebo for induction (RR 2.72, 95% CI 1.94-3.82) and maintenance of remission (RR 2.09, 95% CI 1.26-3.46). Topical corticosteroids were superior to placebo for induction of remission (RR 2.83, 95% CI 1.62-4.92). Topical budesonide was superior to placebo for induction of remission (RR 2.34, 95% CI 1.44-3.81). Combination therapy with topical 5-ASA and topical corticosteroids was superior to topical monotherapy with either agent. Topical tacrolimus was superior to placebo. Etrasimod was superior to placebo for induction (RR 4.71, 95% CI 1.2-18.49) and maintenance of remission (RR 2.08, 95% CI 1.31-3.32).

CONCLUSIONS

Topical 5-ASA and corticosteroids are effective for active UP. Topical 5-ASA may be effective for maintenance of remission. Tacrolimus may be effective for induction of remission. Etrasimod may be effective for induction and for maintenance of remission. Trials should include UP to expand the evidence base for this under-represented population.

From the updated landscape of the emerging biologics for IBDs treatment to the new delivery systems

Inflammatory bowel diseases (IBDs) treatments have shifted from small-molecular therapeutics to the oncoming biologics. The first-line biologics against the moderate-to-severe IBDs are mainly involved in antibodies against integrins, cytokines and cell adhesion molecules. Besides, other biologics including growth factors, antioxidative enzyme, anti-inflammatory peptides, nucleic acids, stem cells and probiotics have also been explored at preclinical or clinical studies. Biologics with variety of origins have their unique potentials in attenuating immune inflammation or gut mucosa healing. Great advances in use of biologics for IBDs treatments have been archived in recent years. But delivering issues for biologic have also been confronted due to their liable nature. In this review, we will focus on biologics for IBDs treatments in the recent publications; summarize the current landscapes of biologics and their promise to control disease progress. Alternatively, the confronted challenges for delivering biologics will also be analyzed. To combat these drawbacks, some new delivering strategies are provided: firstly, designing the functional materials with high affinity toward biologics; secondly, the delivering vehicle systems to encapsulate the liable biologics; thirdly, the topical adhering delivery systems as enema. To our knowledge, this review is the first study to summarize the updated usage of the oncoming biologics for IBDs, their confronted challenges in term of delivery and the potential combating strategies.

Emerging Therapies for Ulcerative Colitis: Updates from Recent Clinical Trials

Ulcerative colitis (UC) is a chronic and progressive inflammatory disorder that affects the colon. The advent of advanced therapies such as biologic agents and small molecules has revolutionized the management of UC. Despite the expanding therapeutic armamentarium of advanced therapies to treat UC, the overall net remission rates and durability of currently available agents are relatively low. This highlights the need for further drug development and more innovative clinical trial design. There are currently multiple emerging agents in the pipeline for the management of UC. This includes agents with alternative routes of administration such as oral or subcutaneous tumor necrosis factor inhibitors or novel mechanisms of action such as toll-like receptor 9 (TLR9) agonist cobitolimod and phosphodiesterase 4 inhibitor apremilast. In this review, we will highlight novel and emerging advanced therapies currently in the pipeline for the management of UC.

Inflammatory Bowel Disease: Emerging Therapies and Future Treatment Strategies

Inflammatory bowel disease (IBD) is a term used to represent a group of chronic, relapsing inflammatory disorders of the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC) are the two major clinical forms. The global incidence and prevalence of IBD have increased over the last 2-4 decades. Despite the specific etiopathogenesis of IBD still being unknown, it is widely recognized that immunological, genetic, and environmental factors are implicated. A greater understanding of the multiple signaling pathways involved has led to the development of biologic therapies in the last two decades. Although these treatments have dramatically transformed the course of IBD, there is not a definitive cure and available therapies may cause adverse events (AEs), limiting their use, or have an inadequate effect in some patients. In this context, emerging therapies addressing new specific pathogenetic mechanisms have shown promising efficacy and safety data in early clinical trials. The purpose of this review is to highlight the available clinical trial data for these new drugs, such as more preferential JAK inhibitors, anti-IL-23 antibodies, sphingosine-1-phosphate receptor modulators, anti-integrin therapies, and other small molecules that are currently under research. We will emphasize the potential significance of these agents in shaping future treatment options.

An update on the safety of long-term vedolizumab use in inflammatory bowel disease

INTRODUCTION

Vedolizumab (Entyvio) is a humanized monoclonal antibody that disrupts the interaction between α4β7 integrin on circulating T-lymphocytes and MAdCAM-1 on the vascular endothelium to prevent their egress to sites of gut inflammation. It has proven therapeutic efficacy for the treatment of moderate-to-severe Crohn's disease, ulcerative colitis, and pouchitis.

AREAS COVERED

This narrative review assesses the safety profile of vedolizumab from the registration trial programs, open-label extension studies, observational real-world data, and pooled safety analyses. This includes an evaluation of the long-term overall safety in special populations typically underrepresented in clinical trials.

EXPERT OPINION

Vedolizumab is an effective therapy for inflammatory bowel disease with a well-established safety profile. No unexpected long-term safety signals have been identified. Safety data in pregnancy, in pediatric and elderly populations, in patients undergoing surgery, and in patients with a prior history of cancer are reassuring. Due to its safety merits, we propose that vedolizumab is an excellent candidate for advanced combination treatment with an anti-cytokine approach using another biologic or novel small molecule inhibitor. This is important in patients with medically refractory IBD, in patients at high risk of developing disease-related complications, or in patients with concomitant uncontrolled immune-mediated inflammatory diseases.

Novel Small Molecules in IBD: Current State and Future Perspectives

Biologicals have dominated the therapeutic scenery in inflammatory bowel diseases (IBDs), namely ulcerative colitis (UC) and Crohn's disease (CD), for the past 20 years. The development of tofacitinib was the starting point for an era of small molecules after the era of biologicals. These new agents may challenge the use of biological agents in the future. They share properties that appeal to both patients and physicians. Low production costs, a lack of immunogenicity, and ease of use are only some of their benefits. On the other hand, patients and their physicians must manage the potential side effects of small molecules such as JAK inhibitors or S1P1R modulators. Here, we present agents that have already entered the clinical routine and those that are still being investigated in clinical trials.

Breaking through the therapeutic ceiling of inflammatory bowel disease: Dual-targeted therapies

Emerging biologics and small-molecule drugs have changed the clinical status quo of inflammatory bowel disease (IBD). However, current treatments remain at a standstill in terms of response and remission in many cases. Accumulating evidence indicates that dual-targeted therapy (DTT) could be promising in overcoming the existing ceiling of IBD treatment. However, data on the efficacy and safety of DTT on Crohn's disease and ulcerative colitis are still limited or insufficient. Moreover, there is a lack of studies delineating the mechanisms of DTT. Given that various targeted drugs have different targets among the extensive redundant inflammatory networks, DTT could result in various outcomes. In this review, we have summarized the current data on the safety, effectiveness, and clinical development status of novel targeted drugs related to refractory IBD, and have explored the mechanism of action of therapy. We have categorized therapeutic agents into "Therapeutic Agents Targeting Cellular Signaling Pathways" and "Therapeutic Agents Targeting Leukocyte Trafficking" based on the different therapeutic targets, and also by classifying therapeutic agents targeting the cellular signaling pathways into "JAK-dependent" and "JAK-independent," and placed the existing drug combinations into 3 categories based on their mechanisms, namely, overlapping, synergistic, and complementary effects. Lastly, we have proposed the possible mechanisms of DTT to conceive a theoretical framework for clinical decision-making and further drug development and research from an IBD standpoint.

The role of Th17 cells in inflammatory bowel disease and the research progress

Th17 cells play an important role in the abnormal immune response in inflammatory bowel disease (IBD) and are involved in the development and progression of inflammation and fibrosis. An increasing amount of data has shown that gut microbes are important parts of intestinal immunity and regulators of Th17 cellular immunity. Th17 cell differentiation is regulated by intestinal bacteria and cytokines, and Th17 cells regulate the intestinal mucosal immune microenvironment by secreting cytokines, such as IL-17, IL-21, and IL-26. Solid evidence showed that, regarding the treatment of IBD by targeting Th17 cells, the therapeutic effect of different biological agents varies greatly. Fecal bacteria transplantation (FMT) in the treatment of IBD has been a popular research topic in recent years and is safe and effective with few side effects. To further understand the role of Th17 cells in the progression of IBD and associated therapeutic prospects, this review will discuss the progress of related research on Th17 cells in IBD by focusing on the interaction and immune regulation between Th17 cells and gut microbiota.

Targeting integrin pathways: mechanisms and advances in therapy

Integrins are considered the main cell-adhesion transmembrane receptors that play multifaceted roles as extracellular matrix (ECM)-cytoskeletal linkers and transducers in biochemical and mechanical signals between cells and their environment in a wide range of states in health and diseases. Integrin functions are dependable on a delicate balance between active and inactive status via multiple mechanisms, including protein-protein interactions, conformational changes, and trafficking. Due to their exposure on the cell surface and sensitivity to the molecular blockade, integrins have been investigated as pharmacological targets for nearly 40 years, but given the complexity of integrins and sometimes opposite characteristics, targeting integrin therapeutics has been a challenge. To date, only seven drugs targeting integrins have been successfully marketed, including abciximab, eptifibatide, tirofiban, natalizumab, vedolizumab, lifitegrast, and carotegrast. Currently, there are approximately 90 kinds of integrin-based therapeutic drugs or imaging agents in clinical studies, including small molecules, antibodies, synthetic mimic peptides, antibody-drug conjugates (ADCs), chimeric antigen receptor (CAR) T-cell therapy, imaging agents, etc. A serious lesson from past integrin drug discovery and research efforts is that successes rely on both a deep understanding of integrin-regulatory mechanisms and unmet clinical needs. Herein, we provide a systematic and complete review of all integrin family members and integrin-mediated downstream signal transduction to highlight ongoing efforts to develop new therapies/diagnoses from bench to clinic. In addition, we further discuss the trend of drug development, how to improve the success rate of clinical trials targeting integrin therapies, and the key points for clinical research, basic research, and translational research.

Gut immune cell trafficking: inter-organ communication and immune-mediated inflammation

Immune cell trafficking is a complex and tightly regulated process that is indispensable for the body's fight against pathogens. However, it is also increasingly acknowledged that dysregulation of cell trafficking contributes to the pathogenesis of immune-mediated inflammatory diseases (IMIDs) in gastroenterology and hepatology, such as inflammatory bowel disease and primary sclerosing cholangitis. Moreover, altered cell trafficking has also been implicated as a crucial step in the immunopathogenesis of other IMIDs, such as rheumatoid arthritis and multiple sclerosis. Over the past few years, a central role of the gut in mediating these disorders has progressively emerged, and the partly microbiota-driven imprinting of particular cell trafficking phenotypes in the intestine seems to be crucially involved. Therefore, this Review highlights achievements in understanding immune cell trafficking to, within and from the intestine and delineates its consequences for immune-mediated pathology along the gut-liver, gut-joint and gut-brain axes. We also discuss implications for current and future therapeutic approaches that specifically interfere with homing, retention, egress and recirculation of immune cells.

Improving IBD outcomes in the era of many treatment options

Clinical trials of the IL-23p19 antibodies guselkumab and risankizumab have demonstrated that they are safe and effective for induction and maintenance of remission in moderately to severely active Crohn’s disease^1–3.

A phase III trial of the novel Janus kinase inhibitor upadacitinib demonstrated its efficacy in patients with moderately to severely active ulcerative colitis who either had or had not previously received biologic therapy⁵.

A phase III trial of the oral integrin α4 inhibitor carotegrast methyl (AJM300) demonstrated its efficacy as an induction therapy in mildly to moderately active ulcerative colitis; the drug is now approved for clinical use in Japan⁶.

Head-to-head comparison of adalimumab and ustekinumab in moderately to severely active Crohn’s disease in the SEAVUE study showed that their efficacy is similar⁸.

New and Emerging Treatments for Inflammatory Bowel Disease

BACKGROUND

The specific etiopathogenesis of inflammatory bowel disease (IBD) is still unknown. Although the conventional anti-inflammatory or immunomodulatory drugs relatively nonspecific to pathogenesis have been quite useful in many cases, elucidating the pathogenesis has gradually facilitated developments of disease-specific therapies for refractory cases in the last 2 decades.

SUMMARY

With a greater understanding of the multiple overactive signaling pathways of the gut mucosal immune response and enhanced leukocyte trafficking, several biological agents or small molecule drugs following the first novel biologic, anti-tumor necrosis factor α (anti-TNFα), have been developed against several modes of action including adhesion molecules, sphingosine-1-phospate receptors, cytokines (IL-12/23, TL1A, and IL-36), Janus kinase (JAK), and phosphodiesterase. Although preceding biological agents have dramatically changed the IBD treatment strategy, many patients still require alternative therapies due to failure or side effects. Newer treatments are now expected to be provided for better efficacy with an improved adverse event profile. In addition, translational studies have highlighted the new therapeutic concepts' potential, including modulation of host-microbiome interactions, stem therapy for perianal fistula, regulation of fibrosis, regulation of the gut-brain axis, and control of previously less targeted immune cells (B cells and innate lymphoid cells). This paper comprehensively reviewed not only the latest already or shortly available therapies but also emerging promising treatments that will be hopefully established in the future for IBD.

KEY MESSAGES

Many kinds of new treatments are available, and promising treatments with new perspectives are expected to emerge for refractory IBD in the future.

Landscape of new drugs and targets in inflammatory bowel disease

Although the therapeutic armamentarium of Inflammatory bowel diseases (IBD) physicians has expanded rapidly in recent years, a proportion of patients remain with a suboptimal response to medical treatment due to primary no response, loss of response or intolerance to currently available drugs. Our growing knowledges of IBD pathophysiology has led to the development of a multitude of new therapies over time, which may, 1 day, be able to address this unmet medical need. This review aims to provide physicians an update of emerging therapies in IBD by focusing on drugs currently in phase 3 clinical trials. Among the most promising molecules are anti-IL-23, JAK-inhibitors, anti-integrins and S1P modulators. While the results in terms of efficacy and safety are fairly clear for some classes, the question of safety remains more uncertain for other classes. Molecules at a more preliminary stage of development (phase 1 and 2), one of which may 1 day offer an optimal benefit-risk ratio, will also be presented as well as their respective mechanisms of action.

Tackling Inflammatory Bowel Diseases: Targeting Proinflammatory Cytokines and Lymphocyte Homing

Inflammatory bowel diseases (IBDs) are characterized by chronic inflammatory disorders that are a result of an abnormal immune response mediated by a cytokine storm and immune cell infiltration. Proinflammatory cytokine therapeutic agents, represented by TNF inhibitors, have developed rapidly over recent years and are promising options for treating IBD. Antagonizing interleukins, interferons, and Janus kinases have demonstrated their respective advantages in clinical trials and are candidates for anti-TNF therapeutic failure. Furthermore, the blockade of lymphocyte homing contributes to the excessive immune response in colitis and ameliorates inflammation and tissue damage. Factors such as integrins, selectins, and chemokines jointly coordinate the accumulation of immune cells in inflammatory regions. This review assembles the major targets and agents currently targeting proinflammatory cytokines and lymphatic trafficking to facilitate subsequent drug development.

Carotegrast Methyl: First Approval

Carotegrast methyl (Carogra^®) is a small-molecule α4 integrin antagonist being developed by EA Pharma (formerly Ajinomoto Pharmaceuticals) and Kissei Pharmaceutical for the treatment of ulcerative colitis. The active metabolite of carotegrast methyl exerts an anti-inflammatory effect by blocking the interaction of α4β1 or α4β7 integrins and their ligands, VCAM-1 and MAd-CAM-1, thereby inhibiting the adhesion of inflammatory cells, including T cells, to vascular endothelial cells and extravasation into inflammatory sites. In March 2022, carotegrast methyl received its first approval in Japan for the treatment of moderate ulcerative colitis in patients who had inadequate response to 5-aminosalicylic acid. This article summarizes the milestones in the development of carotegrast methyl leading to this first approval for the treatment of moderate ulcerative colitis.

IBD therapeutics: what is in the pipeline?

Inflammatory bowel disease (IBD) is an idiopathic long-term relapsing and remitting disorder including ulcerative colitis and Crohn's disease. The aim of therapy is to induce and maintain remission. Anti-TNF therapies dramatically improved clinical outcomes but primary failure or secondary loss is a common problem as well as potential side effects potentially limiting efficacy and long-term use. The advent of new targeted agents with the potential for greater safety is welcomed in IBD and offers the potential for different agents as the disease becomes refractory or even combination therapies to maximise effectiveness without compromising safety in the future. More data are required to understand the best positioning in pathways and longer-term safety effects.