Natalizumab for active Crohn's disease

Efficacy and Safety of the Anti-mucosal Addressin Cell Adhesion Molecule-1 Antibody Ontamalimab in Patients with Moderate-to-Severe Ulcerative Colitis or Crohn's Disease

BACKGROUND AND AIMS

Ontamalimab is a fully human immunoglobulin G2 monoclonal antibody against mucosal addressin cell adhesion molecule-1, developed as treatment for inflammatory bowel disease.

METHODS

Six phase 3, multicentre, randomised, double-blind, placebo-controlled clinical trials compared efficacy and safety of ontamalimab [25 mg and 75 mg once every 4 weeks] with placebo in patients with moderate-to-severe ulcerative colitis or Crohn's disease [two induction studies and one re-randomised maintenance study per condition]. This clinical trial programme was discontinued in 2020 for reasons unrelated to drug safety/efficacy; Crohn's disease studies are described in the Supplementary data.

RESULTS

The induction [12-week] and maintenance [52-week] studies included 659 and 366 randomised patients, respectively. More patients who received ontamalimab induction than placebo achieved the primary endpoint of clinical remission at Week 12 [25 mg, 18.5% vs 15.8%, p = 0.617, 27.0% vs 12.5%, p = 0.027; 75 mg, 29.8% vs 15.8%, p = 0.018, 29.5% vs 12.5% p = 0.014]; significantly more patients who received ontamalimab maintenance therapy than placebo achieved Week 52 clinical remission [25 mg, 53.5% vs 8.2%, p <0.001; 75 mg, 40.2% vs 12.8%, p <0.001]. Endoscopic improvement was generally significantly different vs placebo [induction: 25 mg, 27.8% vs 21.1%, p = 0.253, 35.1% vs 12.5%, p = 0.001; 75 mg, 41.1% vs 21.1%, p = 0.002, 33.9% vs 12.5%, p = 0.003; maintenance: 25 mg, 56.3% vs 9.6%, p <0.001; 75 mg, 48.8% vs 15.1%, p <0.001]. Adverse event rates were similar between ontamalimab and placebo groups.

CONCLUSIONS

Ontamalimab 75 mg was effective, with no safety concerns, as induction and maintenance therapy for patients with moderate-to-severe ulcerative colitis. [NCT03259334; NCT03259308; NCT03290781; NCT03559517; NCT03566823; NCT03627091].

Potential therapeutic options for celiac Disease: An update on Current evidence from Gluten-Free diet to cell therapy

Celiac disease (CD) is a chronic autoimmune enteropathy and multifactorial disease caused by inappropriate immune responses to gluten in the small intestine. Weight loss, anemia, osteoporosis, arthritis, and hepatitis are among the extraintestinal manifestations of active CD. Currently, a strict lifelong gluten-free diet (GFD) is the only safe, effective, and available treatment. Despite the social burden, high expenses, and challenges of following a GFD, 2 to 5 percent of patients do not demonstrate clinical or pathophysiological improvement. Therefore, we need novel and alternative therapeutic approaches for patients. Innovative approaches encompass a broad spectrum of strategies, including enzymatic degradation of gluten, inhibition of intestinal permeability, modulation of the immune response, inhibition of the transglutaminase 2 (TG2) enzyme, blocking antigen presentation by HLA-DQ2/8, and induction of tolerance. Hence, this review is focused on comprehensive therapeutic strategies ranging from dietary approaches to novel methods such as antigen-based immunotherapy, cell and gene therapy, and the usage of nanoparticles for CD treatment.

Update for surgeons on novel induction treatments for acute severe inflammatory bowel disease associated colitis

BACKGROUND

The landscape of biologic agents for the treatment of inflammatory bowel disease (IBD) associated colitis is rapidly evolving, requiring surgeons to be up-to-date as part of multi-disciplinary, evidence-based care. An update on novel therapies used to induce remission in IBD-associated colitis is presented.

METHODS

A systematic search through Ovid MEDLINE and CENTRAL using a combination of MeSH terms and Boolean operators was conducted.

RESULTS

One thousand and twenty articles from which 38 articles were selected for inclusion in this review. Novel agents were trialled as 4th or 5th line treatment following conventional treatment failure. Rates of serious adverse effects were low. Janus kinase (JAK) inhibitors (upadacitinib and tofacitinib) were efficacious in inducing remission in ulcerative colitis, and IL-23p19 inhibitors (mirikizumab, guselkumab, and risankizumab) in Crohn's colitis. Evidence was limited for other drug classes.

CONCLUSION

JAK-inhibitors and IL-23p19 inhibitors were found to be the most effective agents for inducting remission following failure of standard of care treatment. A significant proportion of patients did not respond, highlighting the inherent challenge in optimizing treatment for moderate to severe IBD-associated colitis. More robust study designs and comparator trials are required.

Restricting CAR T Cell Trafficking Expands Targetable Antigen Space

Chimeric antigen receptor (CAR) T cells are an effective treatment for some blood cancers. However, the lack of tumor-specific surface antigens limits their wider use. We identified a set of surface antigens that are limited in their expression to cancer and the central nervous system (CNS). We developed CAR T cells against one of these antigens, LINGO1, which is widely expressed in Ewing sarcoma (ES). To prevent CNS targeting, we engineered LINGO1 CAR T cells lacking integrin α4 (A4ko), an adhesion molecule essential for migration across the blood-brain barrier. A4ko LINGO1 CAR T cells were efficiently excluded from the CNS but retained efficacy against ES. We show that altering adhesion behavior expands the set of surface antigens targetable by CAR T cells.

A Narrative Review of Cytokine Networks: Pathophysiological and Therapeutic Implications for Inflammatory Bowel Disease Pathogenesis

Inflammatory bowel disease (IBD) is a lifelong inflammatory immune mediated disorder, encompassing Crohn's disease (CD) and ulcerative colitis (UC); however, the cause and specific pathogenesis of IBD is yet incompletely understood. Multiple cytokines produced by different immune cell types results in complex functional networks that constitute a highly regulated messaging network of signaling pathways. Applying biological mechanisms underlying IBD at the single omic level, technologies and genetic engineering enable the quantification of the pattern of released cytokines and new insights into the cytokine landscape of IBD. We focus on the existing literature dealing with the biology of pro- or anti-inflammatory cytokines and interactions that facilitate cell-based modulation of the immune system for IBD inflammation. We summarize the main roles of substantial cytokines in IBD related to homeostatic tissue functions and the remodeling of cytokine networks in IBD, which may be specifically valuable for successful cytokine-targeted therapies via marketed products. Cytokines and their receptors are validated targets for multiple therapeutic areas, we review the current strategies for therapeutic intervention and developing cytokine-targeted therapies. New biologics have shown efficacy in the last few decades for the management of IBD; unfortunately, many patients are nonresponsive or develop therapy resistance over time, creating a need for novel therapeutics. Thus, the treatment options for IBD beyond the immune-modifying anti-TNF agents or combination therapies are expanding rapidly. Further studies are needed to fully understand the immune response, networks of cytokines, and the direct pathogenetic relevance regarding individually tailored, safe and efficient targeted-biotherapeutics.

Learning CNS immunopathology from therapeutic interventions

Modulation of immune cell trafficking across the blood-brain barrier has not only introduced a therapeutic avenue for multiple sclerosis (MS) but also represents an example of reverse translational medicine. Data from clinical trials of drugs such as natalizumab and fingolimod have revealed the involvement of different compartments in relapsing versus non-relapsing MS immune biology, contributed to our understanding of central nervous system (CNS) immune surveillance, and stimulated new fields of research. Here, we discuss the results of these trials, as well as patient biomaterial-based scientific projects, and how both have informed our understanding of CNS immunopathology.

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.

Natalizumab Treatment Induces Proinflammatory CD4 T Cells Preferentially in the Integrin β7+ Compartment

BACKGROUND AND OBJECTIVES

Natalizumab, a monoclonal humanized antibody targeting integrin α4, inhibits the transmigration of lymphocytes into the CNS by preventing the interaction of integrin α4β1 with V-CAM expressed on brain vascular endothelial cells. Although natalizumab treatment reduces the clinical relapse rate in patients with relapsing-remitting MS, its discontinuation after reactivation of the JC virus is associated with a rebound of the disease in 20% of patients. The mechanisms of this rebound are not elucidated, but natalizumab increases the frequencies of circulating CD4 T cells expressing proinflammatory cytokines as well as the proportion of circulating Th17/Th1 cells (Th1-like Th17 cells). Gut-derived memory CD4 T cells are a population of growing interest in the pathogenesis of MS, but whether and how their properties are affected by natalizumab is not known. Here, we studied the phenotype and cytokine expression profile of circulating gut-derived memory CD4 T cells in patients with relapsing-remitting MS under natalizumab.

METHODS

We identified gut-derived memory CD4 T cells by their expression of integrin β7 and compared their properties and those of integrin β7- memory CD4 T cells across healthy donors and patients with relapsing-remitting MS treated or not with natalizumab. We also compared the capacity of integrin β7- and integrin β7+ CD4 T-cell subsets to transmigrate in vitro across a model of blood-brain barrier.

RESULTS

The proportions of proinflammatory Th17/Th1 cells as well as of IL-17A+IFNγ+ and IL-17A+GM-CSF+ cells were higher in memory CD4 T cells expressing integrin β7 in patients receiving natalizumab compared with healthy donors and patients with relapsing-remitting MS not receiving natalizumab. By contrast, integrin β7 negative memory CD4 T cells only presented a modest increased in their proportion of Th17/Th1 cells under natalizumab. We further observed that integrin β7+ Th17/Th1 cells migrated as efficiently as integrin β7- Th17/Th1 across a monolayer of brain microvascular endothelial cells.

DISCUSSION

Our study shows that circulating integrin β7+ memory CD4 T cells of patients with relapsing-remitting MS under natalizumab are enriched in proinflammatory cells supporting the hypothesis that integrin β7+ memory CD4 T cells could play a pathogenic role in the disease rebound observed at natalizumab discontinuation.

Revisiting JC virus and progressive multifocal leukoencephalopathy

Since its definition 65 years ago, progressive multifocal leukoencephalopathy (PML) has continued to devastate a growing population of immunosuppressed patients despite major advances in our understanding of the causative JC virus (JCV). Unless contained by the immune system, JCV lyses host oligodendrocytes collateral to its life cycle, leading to demyelination, neurodegeneration, and death. Novel treatments have stagnated in the absence of an animal model while current antiviral agents fail to address the now ubiquitous polyomavirus. In this review, we highlight the established pathogenesis by which JCV infection progresses to PML, highlighting major challenges that must be overcome to eliminate the underlying virus and, therefore, the debilitating disease.

Comparison of treatment effect between phase 2 and phase 3 trials in patients with inflammatory bowel disease

BACKGROUND AND AIMS

The accumulation of multiple randomized controlled trials in the field of inflammatory bowel diseases provides an opportunity to compare treatment effects between phase 2 and 3 trials. We aimed to determine whether treatment effects observed in phase 3 investigating biologics and small molecule drugs differed from those in their preceding phase 2 trial.

METHODS

We first performed a review of phase 2 and phase 3 trials enrolling ulcerative colitis (UC) or Crohn's disease (CD) patients. We compared the percent overall success for key endpoints between phases (several phase 3 could be matched to a single phase 2 trial). Then, we compared the percent overall success in the matched phase 2 and 3 trials (ratio 1:1), and performed sensitivity analysis.

RESULTS

We identified 14 phase 2 (8 CD; 6 UC) and 24 phase 3 (13 CD; 11 UC) trials. In CD, the different analyses suggest that the percentage of overall success of clinical remission and clinical response was significantly higher in phase 2 than in phase 3 trials. In UC, the analyses suggest collectively that the percent of treatment effect seemed similar for clinical remission, clinical response and histologic outcomes between phases but with a lower percentage of overall success in phase 2 than in phase 3 trials for endoscopic endpoints.

CONCLUSIONS

In UC, we observed a similar percentage of treatment effect for clinical and histologic outcomes between phase 2 and 3 trials but not for endoscopic outcomes. Whereas in CD, we showed a failure to reproduce similar results between phases. These results may help sponsors in the design of future drug development programs.

Pharmacological Therapy in Inflammatory Bowel Diseases: A Narrative Review of the Past 90 Years

Inflammatory Bowel Diseases had their first peak in incidence in countries in North America, Europe, and Oceania and are currently experiencing a new acceleration in incidence, especially in Latin America and Asia. Despite technological advances, 90 years after the development of the first molecule for the treatment of IBD, we still do not have drugs that promote disease remission in a generalized way. We carried out a narrative review on therapeutic advances in the treatment of IBD, the mechanisms of action, and the challenges facing the therapeutic goals in the treatment of IBD. Salicylates are still used in the treatment of Ulcerative Colitis. Corticosteroids have an indication restricted to the period of therapeutic induction due to frequent adverse events, while technologies with less systemic action have been developed. Most immunomodulators showed a late onset of action, requiring a differentiated initial strategy to control the disease. New therapeutic perspectives emerged with biological therapy, initially with anti-TNF, followed by anti-integrins and anti-interleukins. Despite the different mechanisms of action, there are similarities between the general rates of effectiveness. These similar results were also evidenced in JAK inhibitors and S1p modulators, the last therapeutic classes approved for the treatment of IBD.

Biofilm's Impact on Inflammatory Bowel Diseases

The colon has a large surface area covered with a thick mucus coating. Colon's biomass consists of about 1,012 colony-forming units per gram of feces and 500-1,000 distinct bacterial species. The term inflammatory bowel disease (IBD) indicates the collection of intestinal illnesses in which the digestive system (esophagus, large intestine, mouth, stomach, and small intestine) experiences persistent inflammation. IBD development is influenced by environmental (infections, stress, and nutrition) and genetic factors. The microbes present in gut microbiota help maintain intestinal homeostasis and support immune and epithelial cell growth, differentiation, as well as proliferation. It has been discovered that a variety of variables and microorganisms are crucial for the development of biofilms and mucosal colonization during IBD. An extracellular matrix formed by bacteria supports biofilm production in our digestive system and harms the host's immunological response. Irritable bowel syndrome (IBS) and IBD considerably affect human socioeconomic well-being and the standard of living. IBD is a serious public health issue, affecting millions of people across the globe. The gut microbiome may significantly influence IBS pathogenesis, even though few diagnostic and treatment options are available. As a result, current research focuses more on disrupting biofilm in IBD patients and stresses primarily on drugs that help improve the quality of life for human well-being. We evaluate studies on IBD and bacterial biofilm to add fresh insights into the existing state of knowledge of biofilm formation in IBD, incidence of IBD patients, molecular level of investigations, bacteria that are involved in the formation of biofilm, and present and down the line regimens and probiotics. Planning advanced ways to control and eradicate bacteria in biofilms should be the primary goal to add fresh insights into generating innovative diagnostic and alternative therapy options for IBD.

Recent advances in the treatment of IBD: Targets, mechanisms and related therapies

Inflammatory bowel disease (IBD), as a representative inflammatory disease, currently has multiple effective treatment options available and new therapeutic strategies are being actively explored to further increase the treatment options for patients with IBD. Furthermore, biologic agents and small molecule drugs developed for ulcerative colitis (UC) and Crohn's disease (CD) have evolved toward fewer side effects and more accurate targeting. Novel inhibitors that target cytokines (such as IL-12/23 inhibitors, PDE4 inhibitors), integrins (such as integrin inhibitors), cytokine signaling pathways (such as JAK inhibitors, SMAD7 blocker) and cell signaling receptors (such as S1P receptor modulator) have become the preferred treatment choice for many IBD patients. Conventional therapies such as 5-aminosalicylic acid, corticosteroids, immunomodulators and anti-tumor necrosis factor agents continue to demonstrate therapeutic efficacy, particularly in combination with drug therapy. This review integrates research from chemical, biological and adjuvant therapies to evaluate current and future IBD therapies, highlighting the mechanism of action of each therapy and emphasizing the potential of development prospects.

Most Placebo-Controlled Trials in Inflammatory Bowel Disease were Underpowered Because of Overestimated Drug Efficacy Rates: Results from a Systematic Review of Induction Studies

BACKGROUND AND AIMS

Most pharmaceutical clinical trials for inflammatory bowel disease [IBD] are placebo-controlled and require effect size estimation for a drug relative to placebo. We compared expected effect sizes in sample size calculations [SSCs] to actual effect sizes in IBD clinical trials.

METHODS

MEDLINE, EMBASE, CENTRAL and the Cochrane library were searched from inception to March 26, 2021, to identify placebo-controlled induction studies for luminal Crohn's disease [CD] and ulcerative colitis [UC] that reported an SSC and a primary endpoint of clinical remission/response. Expected effects were subtracted from actual effects, and interquartile ranges [IQRs] for each corresponding median difference were calculated. Linear regression was used to assess whether placebo or drug event rate misspecifications were responsible for these differences.

RESULTS

Of eligible studies, 36.9% [55/149] were excluded because of incomplete SSC reporting, yielding 94 studies [46 CD, 48 UC]. Treatment effects were overestimated in CD for remission (-12.6% [IQR: -16.3 to -1.6%]), in UC for remission (-10.2% [IQR: -16.5 to -5.6%]) and in CD for response (-15.3% [IQR: -27.1 to -5.8%]). Differences observed were due to overestimated drug event rates, whereas expected and actual placebo event rates were similar. A meta-regression demonstrated associations between overestimated treatment effect sizes and several trial characteristics: isolated ileal disease, longer CD duration, extensive colitis [UC], single-centre, phase 2 and no endoscopic endpoint component [UC].

CONCLUSION

Overestimation of IBD therapy efficacy rates resulted in smaller-than-expected treatment effects. These results should be used to inform SSCs and trial design for IBD drug development.

Opportunistic Infections in Patients with Inflammatory Bowel Disease Treated with Advanced Therapies: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND AIMS

Advanced therapies for inflammatory bowel disease [IBD] could potentially lead to a state of immunosuppression with an increased risk of opportunistic infections [OIs]. We aimed to provide an update on the incidence of OIs among adult IBD patients in randomized controlled trials [RCTs] of approved biologics and small-molecule drugs [SMDs]. Also, we aimed to describe OI definitions utilized in RCTs, to ultimately propose a standardized definition.

METHODS

Electronic databases were searched from January 1, 1990, until April 16, 2022. Our primary outcome was incidence rate of overall OIs among IBD patients exposed and unexposed to biologics or SMDs. We also describe specific OIs reported in included trials, as well as definitions of OIs within studies when provided.

RESULTS

Ninety studies were included. The incidence rates of reported OIs were 0.42 and 0.21 per 100 person-years in patients exposed to advanced therapies and placebo, respectively. This was highest for anti-tumour necrosis factors [0.83 per 100 person-years] and Janus kinase inhibitors [0.55 per 100 person-years] and lowest for anti-integrins and ozanimod. On meta-analysis, no increased risk of OIs was observed. None of the studies provided a detailed definition of OIs, or a comprehensive list of infections considered as OIs.

CONCLUSION

Different mechanisms of action may have specific OI profiles. In the absence of a uniform definition of OIs, these estimates are less reliable. We propose a definition to be used in future studies to help provide standardized reporting. When using this definition, we saw significant differences in incidence rates of OIs across mechanisms of action.

Treatment of autoimmunity: The impact of disease-modifying therapies in multiple sclerosis and comorbid autoimmune disorders

More than 10 disease-modifying therapies (DMT) are approved by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for the treatment of multiple sclerosis (MS) and new therapeutic options are on the horizon. Due to different underlying therapeutic mechanisms, a more individualized selection of DMTs in MS is possible, taking into account the patient's current situation. Therefore, concomitant treatment of various comorbid conditions, including autoimmune mediated disorders such as rheumatoid arthritis, should be considered in MS patients. Because the pathomechanisms of autoimmunity partially overlap, DMT could also treat concomitant inflammatory diseases and simplify the patient's treatment. In contrast, the exacerbation and even new occurrence of several autoimmune diseases have been reported as a result of immunomodulatory treatment of MS. To simplify treatment and avoid disease exacerbation, knowledge of the beneficial and adverse effects of DMT in other autoimmune disorders is critical. Therefore, we conducted a literature search and described the beneficial and adverse effects of approved and currently studied DMT in a large number of comorbid autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel diseases, cutaneous disorders including psoriasis, Sjögren´s syndrome, systemic lupus erythematosus, systemic vasculitis, autoimmune hepatitis, and ocular autoimmune disorders. Our review aims to facilitate the selection of an appropriate DMT in patients with MS and comorbid autoimmune diseases.

Clinical remission in paired phase two and three studies in inflammatory bowel disease: a systematic review with meta-analysis

Discrepancies in phase two and three studies can result in significant patient and financial burden, as well as the nonapproval of potentially efficacious drugs. We aimed to determine whether this discrepancy exists for clinical trials in inflammatory bowel disease (IBD). Electronic databases (MEDLINE and Embase) and clinical trial repositories were searched from 1 January 1946 to 12 March 2021, for paired phase two and three studies of advanced therapies for Crohn's disease and ulcerative colitis. The primary outcome was to compare clinical remission rates between paired phase two and three studies for Crohn's disease and ulcerative colitis. Multivariable mixed-model meta-analysis was performed to calculate odds ratios (OR) with 95% confidence intervals (CI). The Cochrane risk-of-bias tool was used to grade the risk of bias. Of 2642 studies, 29 were included. Fifteen were phase three, 11 were phase two, one was phase one/two, and two were phase two/three. There were no differences in clinical remission rates between phase two and three studies for Crohn's disease (OR, 1.07; 95% CI, 0.86-1.34; P = 0.54) and ulcerative colitis (OR, 0.81; 95% CI, 0.48-1.36; P = 0.43). Furthermore, there was a lack of any appreciable differences in study characteristics, inclusion criteria and patient demographics among paired phase two and three studies. Most studies were considered low risk of bias. Overall, paired phase two and three studies demonstrate similar clinical remission rates for advanced therapies in IBD. Whether this applies to newer outcomes, such as endoscopic and mucosal healing remains to be determined.

Controlling in and out - the future of interfering with immune cell trafficking in inflammatory bowel disease

INTRODUCTION

Immune cell trafficking is a key requirement in the pathogenesis of inflammatory bowel diseases. Consistently, therapeutic strategies to target immune cell trafficking have been established and continue to be developed for the treatment of ulcerative colitis and Crohn's disease.

AREAS COVERED

In this review, we briefly summarize the most important checkpoints of intestinal immune cell trafficking and their importance during IBD. Moreover, we provide an overview of associated therapeutic targets and previous as well as current efforts on treatment strategies related to these targets.

EXPERT OPINION

Finally, we comment on potential future developments that might shape the field of immune cell trafficking in the context of IBD.

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.

Etrolizumab-s Does Not Induce Residual Trafficking of Regulatory T Cells

BACKGROUND

Blocking immune cell gut homing via α4β7 integrin with the monoclonal antibody vedolizumab is an established therapeutic strategy in inflammatory bowel disease. However, despite promising preclinical and phase 2 clinical data, the anti-β7 antibody etrolizumab yielded disappointing results in a large phase 3 trial program in UC. Mechanistic explanations are still lacking. We have recently shown that vedolizumab is associated with residual homing of regulatory T (Treg) cells in a certain exposure range and aimed to investigate whether a similar mechanism applies for etrolizumab.

METHODS

We used flow cytometry, competitive dynamic adhesion, and transmigration assays to assess binding of the etrolizumab surrogate (etrolizumab-s) antibody FIB504 to Treg and effector T cells (Teff) and to explore the impact on cell trafficking.

RESULTS

We observed only minimal differences in the binding of etrolizumab-s to Treg and Teff cells. Dynamic adhesion and transmigration of Treg and Teff cells was not substantially differentially affected at relevant concentrations. The β1+ and PI16+ Treg cells were only resistant to etrolizumab-s at low concentrations.

CONCLUSIONS

Etrolizumab does not seem to induce notable residual trafficking of Treg cells. Thus, the Teff overweight in the inflamed gut might persist despite reduced overall T cell recruitment. This might be one piece of the puzzle to explain recent clinical results in phase 3.

A comprehensive review of intravitreal immunosuppressants and biologicals used in ophthalmology

Systemic immunosuppressants and biologicals have been a valuable tool in the treatment of inflammatory diseases and malignancies. The safety profile of these drugs has been debatable, especially in localized systems, such as the eye. This has led to the search for fairly local approaches, such as intravitreal, subconjunctival, and topical route of administration. Immunosuppressants have been used as a second-line drug in patients intolerable to corticosteroids or those who develop multiple recurrences on weaning corticosteroids. Similarly, biologicals have also been used as the next line of therapy, when adequate control of inflammation could not be attained or immunosuppressants were contraindicated to patients. Intravitreal immunosuppressants, such as methotrexate and sirolimus, have been extensively studied in noninfectious posterior uveitis, whereas limited studies have established the efficacy of intravitreal biologicals, such as infliximab and adalimumab. Most of these drugs have shown good safety profile and tolerability in animal studies alone and have not been studied further in human subjects. However, most of the studies in literature are single-case reports or case series which limits the level of evidence. In this comprehensive review, we discuss the mechanism of action, pharmacodynamics, pharmacokinetics, indications, efficacy, and side effects of different intravitreal immunosuppressants and biologicals that have been studied in literature.

Immune Modulation by Antigenic Peptides and Antigenic Peptide Conjugates for Treatment of Multiple Sclerosis

The immune system defends our body by fighting infection from pathogens utilizing both the innate and adaptive immune responses. The innate immune response is generated rapidly as the first line of defense. It is followed by the adaptive immune response that selectively targets infected cells. The adaptive immune response is generated more slowly, but selectively, by targeting a wide range of foreign particles (i.e., viruses or bacteria) or molecules that enter the body, known as antigens. Autoimmune diseases are the results of immune system glitches, where the body's adaptive system recognizes self-antigens as foreign. Thus, the host immune system attacks the self-tissues or organs with a high level of inflammation and causes debilitation in patients. Many current treatments for autoimmune diseases (i.e., multiple sclerosis (MS), rheumatoid arthritis (RA)) have been effective but lead to adverse side effects due to general immune system suppression, which makes patients vulnerable to opportunistic infections. To counter these negative effects, many different avenues of antigen specific treatments are being developed to selectively target the autoreactive immune cells for a specific self-antigen or set of self-antigens while not compromising the general immune system. These approaches include soluble antigenic peptides, bifunctional peptide inhibitors (BPI) including IDAC and Fc-BPI, polymer conjugates, and peptide-drug conjugates. Here, various antigen-specific methods of potential treatments, their efficacy, and limitations will be discussed along with the potential mechanisms of action.

Understanding the Role of LFA-1 in Leukocyte Adhesion Deficiency Type I (LAD I): Moving towards Inflammation?

LFA-1 (Lymphocyte function-associated antigen-1) is a heterodimeric integrin (CD11a/CD18) present on the surface of all leukocytes; it is essential for leukocyte recruitment to the site of tissue inflammation, but also for other immunological processes such as T cell activation and formation of the immunological synapse. Absent or dysfunctional expression of LFA-1, caused by mutations in the ITGB2 (integrin subunit beta 2) gene, results in a rare immunodeficiency syndrome known as Leukocyte adhesion deficiency type I (LAD I). Patients suffering from severe LAD I present with recurrent infections of the skin and mucosa, as well as inflammatory symptoms complicating the clinical course of the disease before and after allogeneic hematopoietic stem cell transplantation (alloHSCT); alloHSCT is currently the only established curative treatment option. With this review, we aim to provide an overview of the intrinsic role of inflammation in LAD I.

Model-Based Meta-Analysis on the Efficacy of Biologics and Small Targeted Molecules for Crohn’s Disease

Information on comparative drug efficacy is of great importance for drug development as well as clinical practice. Up to now, the relative efficacy of biologics and small targeted molecules for Crohn’s disease (CD) remains unclear. The objective of this study was to quantify the relative efficacy of investigational and approved biological treatments for CD measured in Crohn’s Disease Activity Index (CDAI), Inflammatory Bowel Disease Questionnaire (IBDQ), and C-reactive protein (CRP). The analysis dataset was composed of summary-level data from 46 trials, containing 12,846 patients, with treatment of 24 drugs. Six mathematical models with non-parametric placebo estimations were developed to describe the time course and dose–response of six efficacy measures. The effects of covariate were further evaluated. Time–response relationships were found in outcomes measured in CDAI. The patients’ age, disease duration, baseline CDAI, and CRP showed an impact on the efficacy. Model simulations were performed to compare the efficacies across different drugs. The most achievement in clinical remission (defined as CDAI less than 150) and clinical response (defined as the reduction in CDAI for 100 or 70) was observed in the simulation for PF-04236921 and infliximab, respectively. The most improvement in IBDQ was shown in tofacitinib. In general, tumor necrosis factor (TNF)-α inhibitors were the most effective biologics, and the highest efficacy of small targeted molecules was observed in janus kinase (JAK) inhibitors. These findings have important implications for clinical practice in CD.

In vitro and in vivo effects of AVA4746, a novel competitive antagonist of the ligand binding of VLA-4, in B-cell acute lymphoblastic leukemia

Treatment of resistant or recurrent acute lymphoblastic leukemia (ALL) remains a challenge. It was previously demonstrated that the adhesion molecule integrin α4, referred to hereafter as α4, mediates the cell adhesion-mediated drug resistance (CAM-DR) of B-cell ALL by binding to vascular cell adhesion molecule-1 (VCAM-1) on bone marrow stroma. In addition, it was previously observed that the blockade of α4 with natalizumab or inhibition using the small molecule antagonist TBC3486 sensitized relapsed ALL cells to chemotherapy. However, α4-targeted therapy is not clinically available for the treatment of leukemia to date. In the present study, the use of a novel non-peptidic small molecule integrin α4 antagonist, AVA4746, as a potential new approach to combat drug-resistant B-ALL was explored. An in vitro co-culture = model of primary B-ALL cells and an in vivo xenograft model of patient-derived B-ALL cells were utilized for evaluation of AVA4746. VLA-4 conformation activation, cell adhesion/de-adhesion, endothelial tube formation, in vivo leukemia cell mobilization and survival assays were performed. AVA4746 exhibited high affinity for binding to B-ALL cells, where it also efficiently blocked ligand-binding to VCAM-1. In addition, AVA4746 caused the functional de-adhesion of primary B-ALL cells from VCAM-1. Inhibition of α4 using AVA4746 also prevented angiogenesis in vitro and when applied in combination with chemotherapy consisting of Vincristine, Dexamethasone and L-asparaginase, it prolonged the survival of ~33% of the mice in an in vivo xenograft model of B-ALL. These data implicate the potential of targeting the α4-VCAM-1 interaction using AVA4746 for the treatment of drug-resistant B-lineage ALL.

Regulation and Role of αE Integrin and Gut Homing Integrins in Migration and Retention of Intestinal Lymphocytes during Inflammatory Bowel Disease

Adhesion molecules are upregulated in inflamed intestinal mucosa in IBD patients.

Baseline β7 expression does not impact αE induction or gene expression in T cells.

Phospho-SMAD3 is increased in inflamed mucosa in IBD.

Targeting interactions between α4β7 integrin and endothelial adhesion molecule MAdCAM-1 to inhibit lymphocyte migration to the gastrointestinal tract is an effective therapy in inflammatory bowel disease (IBD). Following lymphocyte entry into the mucosa, a subset of these cells expresses αEβ7 integrin, which is expressed on proinflammatory lymphocytes, to increase cell retention. The factors governing lymphocyte migration into the intestinal mucosa and αE integrin expression in healthy subjects and IBD patients remain incompletely understood. We evaluated changes in factors involved in lymphocyte migration and differentiation within tissues. Both ileal and colonic tissue from active IBD patients showed upregulation of ICAM-1, VCAM-1, and MAdCAM-1 at the gene and protein levels compared with healthy subjects and/or inactive IBD patients. β1 and β7 integrin expression on circulating lymphocytes was similar across groups. TGF-β1 treatment induced expression of αE on both β7⁺ and β7⁻ T cells, suggesting that cells entering the mucosa independently of MAdCAM-1/α4β7 can become αEβ7⁺. ITGAE gene polymorphisms did not alter protein induction following TGF-β1 stimulation. Increased phospho-SMAD3, which is directly downstream of TGF-β, and increased TGF-β–responsive gene expression were observed in the colonic mucosa of IBD patients. Finally, in vitro stimulation experiments showed that baseline β7 expression had little effect on cytokine, chemokine, transcription factor, and effector molecule gene expression in αE⁺ and αE⁻ T cells. These findings suggest cell migration to the gut mucosa may be altered in IBD and α4β7⁻, and α4β7⁺ T cells may upregulate αEβ7 in response to TGF-β once within the gut mucosa.

The Multiple Faces of Integrin-ECM Interactions in Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) comprises a series of chronic and relapsing intestinal diseases, with Crohn's disease and ulcerative colitis being the most common. The abundant and uncontrolled deposition of extracellular matrix, namely fibrosis, is one of the major hallmarks of IBD and is responsible for the progressive narrowing and closure of the intestine, defined as stenosis. Although fibrosis is usually considered the product of chronic inflammation, the substantial failure of anti-inflammatory therapies to target and reduce fibrosis in IBD suggests that fibrosis might be sustained in an inflammation-independent manner. Pharmacological therapies targeting integrins have recently shown great promise in the treatment of IBD. The efficacy of these therapies mainly relies on their capacity to target the integrin-mediated recruitment and functionality of the immune cells at the damage site. However, by nature, integrins also act as mechanosensitive molecules involved in the intracellular transduction of signals and modifications originating from the extracellular matrix. Therefore, understanding integrin signaling in the context of IBD may offer important insights into mechanisms of matrix remodeling, which are uncoupled from inflammation and could underlie the onset and persistency of intestinal fibrosis. In this review, we present the currently available knowledge on the role of integrins in the etiopathogenesis of IBD, highlighting their role in the context of immune-dependent and independent mechanisms.

Will the Inducing and Maintaining Remission of Non-biological Agents and Biological Agents Differ for Crohn's Disease? The Evidence From the Network Meta-Analysis

Background: Several drugs currently are available for the treatment of Crohn's disease, including non-biological agents such as anti-inflammatory agents, steroids, immunosuppressive agents, and biologic agents such as anti-tumor necrosis factor (TNF), anti-α4β7 integrin, anti-alpha-4 integrin and anti-interleukin 12/23. However, the choice of treatments for induction and maintenance is still a challenge. The relevant comparison between non-biologic agents and biologic agents is few. In our research, we aimed to help making decisions, as well as providing clinicians and patients with medication references.

Methods: We searched MEDLINE, Embase, and the Cochrane Central Register of controlled trials for relevant randomized controlled trials published through to July 2020 and systematic reviews published from January 2011 to December 2020. Search results were screened by 2 independent reviewers first by title and abstract and then by full text. Disagreements were resolved through discussion with a third reviewer.

Results: 54 randomized controlled trials were included in our analysis. For induction of remission, azathioprine (OR, 3.5; 95% Crl, 1.4–8.9), infliximab (OR, 4.1; 95% Crl, 1.2–16.0), infliximab + azathioprine (OR, 7.0; 95% Crl, 1.2–41.0) and infliximab+ methotrexate (OR, 7.8; 95% Crl, 1.2–65.0) were more effective in first-line therapy than placebo. Adalimumab showed superiority to placebo in second-line therapy, but the range of SD was wide. For maintenance of remission, adalimumab (OR,2.24;95% Crl,1.17–4.76) and azathioprine (OR,2.05; 95% Crl,1.14–3.96) were more effective than placebo. Adalimumab (OR,0.56; 95%Crl,0.27–1.2), budesonide (OR,0.63; 95%Crl,0.26–1.6) and natalizumab (OR,0.65; 95%Crl,0.30–1.4) was associated with less risk of withdrawals when compared with placebo.

Conclusion: For induction of remission, azathioprine, infliximab, and infliximab + azathioprine were more effective in first-line therapy. In second-line therapy, adalimumab was more effective but should be interpreted carefully. For maintenance of remission, adalimumab and azathioprine were more effective. Besides, adalimumab, budesonide, natalizumab had lower withdrawals. Therefore, biological agents were not always better than non-biological agents and they have their own advantages in different treatment methods of Crohn's disease.

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).

Dual targeting of lymphocyte homing and retention through α4β7 and αEβ7 inhibition in inflammatory bowel disease

Anti-integrins are therapeutically effective for inflammatory bowel disease, yet the relative contribution of α4β7 and αEβ7 to gut lymphocyte trafficking is not fully elucidated. Here, we evaluate the effect of α4β7 and αEβ7 blockade using a combination of murine models of gut trafficking and longitudinal gene expression analysis in etrolizumab-treated patients with Crohn's disease (CD). Dual blockade of α4β7 and αEβ7 reduces CD8+ T cell accumulation in the gut to a greater extent than blockade of either integrin alone. Anti-αEβ7 reduces epithelial:T cell interactions and promotes egress of activated T cells from the mucosa into lymphatics. Inflammatory gene expression is greater in human intestinal αEβ7+ T cells. Etrolizumab-treated patients with CD display a treatment-specific reduction in inflammatory and cytotoxic intraepithelial lymphocytes (IEL) genes. Concurrent blockade of α4β7 and αEβ7 promotes reduction of cytotoxic IELs and inflammatory T cells in the gut mucosa through a stepwise inhibition of intestinal tissue entry and retention.

30 Years of Biotherapeutics Development-What Have We Learned?

Since the birth of biotechnology, hundreds of biotherapeutics have been developed and approved by the US Food and Drug Administration (FDA) for human use. These novel medicines not only bring significant benefit to patients but also represent precision tools to interrogate human disease biology. Accordingly, much has been learned from the successes and failures of hundreds of high-quality clinical trials. In this review, we discuss general and broadly applicable themes that have emerged from this collective experience. We base our discussion on insights gained from exploring some of the most important target classes, including interleukin-1 (IL-1), tumor necrosis factor α (TNF-α), IL-6, IL-12/23, IL-17, IL-4/13, IL-5, immunoglobulin E (IgE), integrins and B cells. We also describe current challenges and speculate about how emerging technological capabilities may enable the discovery and development of the next generation of biotherapeutics.

Targeting Immune Cell Trafficking - Insights From Research Models and Implications for Future IBD Therapy

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC) are multifactorial diseases with still unknown aetiology and an increasing prevalence and incidence worldwide. Despite plentiful therapeutic options for IBDs, the lack or loss of response in certain patients demands the development of further treatments to tackle this unmet medical need. In recent years, the success of the anti-α4β7 antibody vedolizumab highlighted the potential of targeting the homing of immune cells, which is now an important pillar of IBD therapy. Due to its complexity, leukocyte trafficking and the involved molecules offer a largely untapped resource for a plethora of potential therapeutic interventions. In this review, we aim to summarise current and future directions of specifically interfering with immune cell trafficking. We will comment on concepts of homing, retention and recirculation and particularly focus on the role of tissue-derived chemokines. Moreover, we will give an overview of the mode of action of drugs currently in use or still in the pipeline, highlighting their mechanisms and potential to reduce disease burden.

The impact of cell type and context-dependent regulatory variants on human immune traits

BACKGROUND

The vast majority of trait-associated variants identified using genome-wide association studies (GWAS) are noncoding, and therefore assumed to impact gene regulation. However, the majority of trait-associated loci are unexplained by regulatory quantitative trait loci (QTLs).

RESULTS

We perform a comprehensive characterization of the putative mechanisms by which GWAS loci impact human immune traits. By harmonizing four major immune QTL studies, we identify 26,271 expression QTLs (eQTLs) and 23,121 splicing QTLs (sQTLs) spanning 18 immune cell types. Our colocalization analyses between QTLs and trait-associated loci from 72 GWAS reveals that genetic effects on RNA expression and splicing in immune cells colocalize with 40.4% of GWAS loci for immune-related traits, in many cases increasing the fraction of colocalized loci by two fold compared to previous studies. Notably, we find that the largest contributors of this increase are splicing QTLs, which colocalize on average with 14% of all GWAS loci that do not colocalize with eQTLs. By contrast, we find that cell type-specific eQTLs, and eQTLs with small effect sizes contribute very few new colocalizations. To investigate the 60% of GWAS loci that remain unexplained, we collect H3K27ac CUT&Tag data from rheumatoid arthritis and healthy controls, and find large-scale differences between immune cells from the different disease contexts, including at regions overlapping unexplained GWAS loci.

CONCLUSION

Altogether, our work supports RNA splicing as an important mediator of genetic effects on immune traits, and suggests that we must expand our study of regulatory processes in disease contexts to improve functional interpretation of as yet unexplained GWAS loci.

The Role of Ninjurin1 and Its Impact beyond the Nervous System

Ninjurin1 (Ninj1) is a double-transmembrane cell surface protein that could promote nerve regeneration in the process of the peripheral nervous system injury and repairment. Nonetheless, the accurate function of Ninj1 in the central nervous system and outside the nervous system is not completely clear. According to the recent studies, we found that Ninj1 is also aberrantly expressed in various pathophysiological processes in vivo, including inflammation, tumorigenesis, and vascular, bone, and muscle homeostasis. These findings suggest that Ninj1 may play an influential role during these pathophysiological processes. Our review summarizes the diverse roles of Ninj1 in multiple pathophysiological processes inside and outside the nervous system. Ninj1 should be considered as an important and novel therapeutic target in certain diseases, such as inflammatory diseases and ischemic diseases. Our study provided a better understanding of Ninj1 in different pathophysiological processes and thereby provided the theoretical support for further research.

Vedolizumab and Extraintestinal Manifestations in Inflammatory Bowel Disease

In Crohn's disease and ulcerative colitis, inflammation is not limited to the digestive tract. Extraintestinal manifestations (EIMs), which affect up to 50% of patients, can substantially impair quality of life. EIMs may parallel luminal disease activity or have an independent course. They most commonly involve the musculoskeletal system (e.g., peripheral or axial arthritis) and skin (e.g., erythema nodosum and pyoderma gangrenosum). Less commonly, the hepatobiliary tract (e.g., primary sclerosing cholangitis [PSC]) and the eye (e.g., episcleritis, scleritis, and uveitis) are involved. Although the pathophysiology of EIMs is poorly understood, they are likely either manifestations of a primary systemic immune disease with variable expression amongst organs, or secondary phenomena to bowel inflammation. Additional pathophysiologic mechanisms may include aberrant lymphocyte homing mediated by ectopic expression of gut-specific chemokines and adhesion molecules, cross-reactivity between microbial and self-antigens, autoantibodies against epitopes shared by the intestine and extraintestinal tissues, elevated serum concentrations of cytokines, and alterations in innate immunity. Many EIMs independent of intestinal disease activity can be successfully treated with tumor necrosis factor (TNF) antagonists. The efficacy of vedolizumab-a monoclonal antibody targeting the α4β7 integrin-for the treatment of EIMs is uncertain, but data are emerging from post hoc analyses of randomized controlled trials, prospective and retrospective cohort studies, and case series. Vedolizumab may be effective in treating EIMs related to luminal disease activity (e.g., type 1 peripheral arthritis and erythema nodosum) but has not shown biochemical improvement in PSC. Its postulated role in the development of de novo EIMs is heavily confounded by the high proportion of patients previously exposed to TNF antagonists; new EIMs could result from TNF antagonist treatment cessation rather than being caused by vedolizumab. A common limitation of clinical studies is the lack of multidisciplinary involvement in the diagnosis and monitoring of EIMs, which may lead to misdiagnosis and overreporting. Future studies should rigorously measure EIMs in parallel with objective measures of luminal disease activity to provide more robust data on the relative efficacy of new drugs, especially as increasing numbers of gut-selective compounds enter clinical development.

An integrin αEβ7-dependent mechanism of IgA transcytosis requires direct plasma cell contact with intestinal epithelium

Efficient IgA transcytosis is critical for the maintenance of a homeostatic microbiota. In the canonical model, locally-secreted dimeric (d)IgA reaches the polymeric immunoglobulin receptor (pIgR) on intestinal epithelium via simple diffusion. A role for integrin αE(CD103)β7 during transcytosis has not been described, nor its expression by intestinal B cell lineage cells. We found that αE-deficient (αE^-/-) mice have a luminal IgA deficit, despite normal antibody-secreting cells (ASC) recruitment, local IgA production and increased pIgR expression. This deficit was not due to dendritic cell (DC)-derived retinoic acid (RA) nor class-switching defects, as stool from RAG^-/- mice reconstituted with αE^-/- B cells was also IgA deficient. Flow cytometric, ultrastructural and transcriptional profiling showed that αEβ7-expressing ASC represent an undescribed subset of terminally-differentiated intestinal plasma cells (PC) that establishes direct cell to cell contact with intestinal epithelium. We propose that IgA not only reaches pIgR through diffusion, but that αEβ7+ PC dock with E-cadherin-expressing intestinal epithelium to directly relay IgA for transcytosis into the intestinal lumen.

Strategies to prevent hemorrhagic transformation after reperfusion therapies for acute ischemic stroke: A literature review

BACKGROUND

Reperfusion therapies by tissue plasminogen activator (tPA) and mechanical thrombectomy (MT) have ushered in a new era in the treatment of acute ischemic stroke (AIS). However, reperfusion therapy-related HT remains an enigma.

AIM

To provide a comprehensive review focused on emerging concepts of stroke and therapeutic strategies, including the use of protective agents to prevent HT after reperfusion therapies for AIS.

METHODS

A literature review was performed using PubMed and the ClinicalTrials.gov database.

RESULTS

Risk of HT increases with delayed initiation of tPA treatment, higher baseline glucose level, age, stroke severity, episode of transient ischemic attack within 7 days of stroke onset, and hypertension. At a molecular level, HT that develops after thrombolysis is thought to be caused by reactive oxygen species, inflammation, remodeling factor-mediated effects, and tPA toxicity. Modulation of these pathophysiological mechanisms could be a therapeutic strategy to prevent HT after tPA treatment. Clinical mechanisms underlying HT after MT are thought to involve smoking, a low Alberta Stroke Program Early CT Score, use of general anesthesia, unfavorable collaterals, and thromboembolic migration. However, the molecular mechanisms are yet to be fully investigated. Clinical trials with MT and protective agents have also been planned and good outcomes are expected.

CONCLUSION

To fully utilize the easily accessible drug-tPA-and the high recanalization rate of MT, it is important to reduce bleeding complications after recanalization. A future study direction could be to investigate the recovery of neurological function by combining reperfusion therapies with cell therapies and/or use of pleiotropic protective agents.

High anti-JCPyV serum titers coincide with high CSF cell counts in RRMS patients

Background:

Progressive multifocal leukoencephalopathy (PML) can in rare cases occur in natalizumab-treated patients with high serum anti-JCPyV antibodies, hypothetically due to excessive blockade of immune cell migration.

Objective:

Immune cell recruitment to the central nervous system (CNS) was assessed in relapsing-remitting multiple sclerosis (RRMS) patients stratified by low versus high anti-JCPyV antibody titers as indicator for PML risk.

Methods:

Cerebrospinal fluid (CSF) cell counts of 145 RRMS patients were quantified by flow cytometry. Generalized linear models were employed to assess influence of age, sex, disease duration, Expanded Disability Status Scale (EDSS), clinical/radiological activity, current steroid or natalizumab treatment, as well as anti-JCPyV serology on CSF cell subset counts.

Results:

While clinical/radiological activity was associated with increased CD4, natural killer (NK), B and plasma cell counts, natalizumab therapy reduced all subpopulations except monocytes. With and without natalizumab therapy, patients with high anti-JCPyV serum titers presented with increased CSF T-cell counts compared to patients with low anti-JCPyV serum titers. In contrast, PML patients assessed before (n = 2) or at diagnosis (n = 5) presented with comparably low CD8 and B-cell counts, which increased after plasma exchange (n = 4).

Conclusion:

High anti-JCPyV indices, which could be indicative of increased viral activity, are associated with elevated immune cell recruitment to the CNS. Its excessive impairment in conjunction with viral activity could predispose for PML development.

Biologics Targeting in the Treatment of Inflammatory Bowel Disease: A Conundrum

Inflammatory bowel disease is a chronic, gastrointestinal disorder which is classified into Crohns’ disease and ulcerative colitis. It has a strong effect on the quality of life and is characterized by chronic periods of exacerbation and remission. It has an unknown etiology but is driven due to excessive immune response in the gut wall. The triggered immune response causes overproduction of proinflammatory cytokines and adhesion molecules. Biological therapies are the monoclonal antibodies that are created in the laboratory to stop certain proteins in the body causing inflammation. These biologics have dramatically changed the therapeutic approach to inflammatory bowel disease. Biologics has three classes: anti-tumor necrosis factor (TNF), anti-integrins, and anti-interleukin (IL) 12/23. This article offers a critical evaluation of the efficacy and safety of biological agents in the management of inflammatory bowel disease. We compared different studies that were available in the PubMed database. All the biologics showed a better clinical response and mucosal healing than placebo. Infliximab has the highest efficacy, but it can make antibodies to infliximab that causes loss of response; then golimumab is effective in these patients. Certolizumab is more effective if it is used as a first-line drug. If corticosteroid and immunomodulator therapy has failed then vedolizumab is effective. As steroid therapy causes major adverse effects and involves the whole body, biological therapy should take over. Still, we need more studies to make biological therapy as a first option in the treatment of inflammatory bowel disease. 

How not to discover a drug - integrins

INTRODUCTION

Integrins are a family of 24 cell adhesion receptors that play a role in the biggest unmet needs in medicine - cardiovascular disease, immunology and cancer. Their discovery promised huge potential for the pharmaceutical industry. Areas covered. Over 35-years since their discovery, there is little to show for the hundreds of billions of dollars of investment in anti-integrin drug discovery programmes. In this review the author discusses the reasons for the failure of this promising class of drugs and the future for this class of drugs. Expert opinion. Within 10-years, there was a plethora of potent, specific anti-integrin molecules and since their discovery, many of these agents have entered clinical trials. The success in discovering these agents was due to recently discovered monoclonal antibody technology. The integrin-recognition domain Arg-Gly-Asp (RGD) provided the basis for discovering small molecule inhibitors to integrins - both cyclic peptides and peptidomimetics. Most agents failed in the Phase III clinical trials and those agents that did make it to the market were plagued with issues of toxicity and limited efficacy and were soon replaced with non-integrin targeting agents. Their failure was due to a combination of poor pharmacokinetics and pharmacodynamics, complicated by the complex pathophysiology of integrins.

Phase II trial of natalizumab with corticosteroids as initial treatment of gastrointestinal acute graft-versus-host disease

The α4ß7 integrin is upregulated on naive and memory T cell subsets in patients who subsequently develop gastrointestinal (GI) acute GVHD. Natalizumab (Tysabri^®, Biogen Inc.) acts against the α4 subunit that mediates homing of lymphocytes to the GI tract. We initiated a phase II study of natalizumab with corticosteroids for initial treatment of acute GI GVHD. In total, 300 mg IV of natalizumab was given, with steroids initiated up to 3 days prior. Twenty-one subjects were treated, median age was 63 years (range 38-74), and 15 (71%) were male. Eighteen (86%) underwent RIC, 15 (71%) received MUD, and all received PBSCs. Overall GVHD at enrollment was grade II in 4 and grade III in 17. The primary endpoint, day 56 GVHD-free survival rate, was attained in 33.3%. The overall response rate at day 28 and 56 was 57% and 52%, respectively. Six of eight CRs were durable for 1 year. Five experienced toxicity possibly related to natalizumab and ten had infections before day 100. 2-year OS was 43% (95% CI 22-62%) and 2-year NRM was 52% (95% CI 29-71%). Natalizumab with corticosteroids as initial treatment of acute GI GVHD is safe, effective, and durable.

Risiken und Chancen von Immuntherapien in Zeiten der Coronavirus-2019-Pandemie

Immuntherapien stellen die essenzielle Grundlage der Behandlung von neuroinflammatorischen Erkrankungen dar. In Zeiten der Coronavirus-2019 (COVID-19)-Pandemie ergibt sich im klinischen Alltag jedoch zunehmend die Frage, ob eine Immuntherapie bei neurologischen Patienten aufgrund des potenziellen Infektionsrisikos eingeleitet, intensiviert, pausiert oder gar beendet werden sollte. Unsicherheit besteht v. a. deshalb, weil verschiedene nationale und internationale Fachgesellschaften diesbezüglich unterschiedliche Empfehlungen veröffentlichten. In diesem Artikel soll ein Überblick über die Wirkmechanismen von Immuntherapien und den daraus abzuleitenden Infektionsrisiken in Bezug auf COVID-19 (durch den Coronavirus verursachte Erkrankung) gegeben werden. Potenzielle Chancen und vorteilhafte Effekte einzelner Substrate in der Akuttherapie von COVID-19 werden diskutiert.

The Emerging Jamboree of Transformative Therapies for Autoimmune Diseases

Standard treatments for autoimmune and autoinflammatory disorders rely mainly on immunosuppression. These are predominantly symptomatic remedies that do not affect the root cause of the disease and are associated with multiple side effects. Immunotherapies are being developed during the last decades as more specific and safer alternatives to small molecules with broad immunosuppressive activity, but they still do not distinguish between disease-causing and protective cell targets and thus, they still have considerable risks of increasing susceptibility to infections and/or malignancy. Antigen-specific approaches inducing immune tolerance represent an emerging trend carrying the potential to be curative without inducing broad immunosuppression. These therapies are based on antigenic epitopes derived from the same proteins that are targeted by the autoreactive T and B cells, and which are administered to patients together with precise instructions to induce regulatory responses capable to restore homeostasis. They are not personalized medicines, and they do not need to be. They are precision therapies exquisitely targeting the disease-causing cells that drive pathology in defined patient populations. Immune tolerance approaches are truly transformative options for people suffering from autoimmune diseases.

Network meta-regression for ordinal outcomes: Applications in comparing Crohn's disease treatments

Crohn's disease (CD) is a life-long condition associated with recurrent relapses characterized by abdominal pain, weight loss, anemia, and persistent diarrhea. In the US, there are approximately 780 000 CD patients and 33 000 new cases added each year. In this article, we propose a new network meta-regression approach for modeling ordinal outcomes in order to assess the efficacy of treatments for CD. Specifically, we develop regression models based on aggregate covariates for the underlying cut points of the ordinal outcomes as well as for the variances of the random effects to capture heterogeneity across trials. Our proposed models are particularly useful for indirect comparisons of multiple treatments that have not been compared head-to-head within the network meta-analysis framework. Moreover, we introduce Pearson residuals and construct an invariant test statistic to evaluate goodness-of-fit in the setting of ordinal outcome data. A detailed case study demonstrating the usefulness of the proposed methodology is carried out using aggregate ordinal outcome data from 16 clinical trials for treating CD.

Population Pharmacokinetics and Pharmacodynamics of Ontamalimab (SHP647), a Fully Human Monoclonal Antibody Against Mucosal Addressin Cell Adhesion Molecule-1 (MAdCAM-1), in Patients With Ulcerative Colitis or Crohn's Disease

Ontamalimab (SHP647) is a fully human, immunoglobulin G₂, antihuman mucosal addressin cell adhesion molecule‐1 (MAdCAM‐1) monoclonal antibody being developed for the treatment of ulcerative colitis (UC) and Crohn's disease (CD). A population pharmacokinetic/pharmacodynamic (PK/PD) analysis was conducted using clinical phase 2 study data to evaluate the PK and PD of ontamalimab following subcutaneous administrations of 7.5, 22.5, 75, and 225 mg every 4 weeks in patients with moderate to severe UC or CD. A total of 440 patients with UC (n = 249; 56.6%) or CD (n = 191; 43.4%) were included in the analysis. A 2‐compartment model with parallel linear and nonlinear elimination adequately characterized concentration‐time profiles of ontamalimab. The apparent clearance and volume of distribution were 0.0127 L/h (0.305 L/day) and 6.53 L, respectively. Apparent clearance and volume of distribution were mainly dependent on baseline albumin and body weight, respectively. No differences in the PK properties of ontamalimab were observed between patients with UC or CD. The presence of antidrug antibodies did not impact the PK of ontamalimab. Nonlinear elimination occurred at very low concentrations and was unlikely to contribute to the elimination half‐life under steady‐state conditions. A linear PK/PD model described the relationship between ontamalimab and free MAdCAM‐1. Minimum concentrations of ontamalimab at steady state following 75 mg every 4 weeks were associated with >95% suppression of circulating free MAdCAM‐1. The PK/PD properties characterized support phase 3 testing in UC and CD.

AJM300, a novel oral antagonist of α4-integrin, sustains an increase in circulating lymphocytes: A randomised controlled trial in healthy male subjects

Aims

AJM300 is an oral antagonist of α4‐integrin that reduces inflammation by blocking leucocyte trafficking. This study aimed to investigate safety, tolerability, pharmacokinetics and pharmacodynamics of AJM300 in healthy male subjects.

Methods

A total of 23 subjects were randomised to receive 240 mg (n = 6), 480 mg (n = 5), 960 mg (n = 6) of AJM300 or the corresponding placebo (n = 2 per group). The study drugs were taken orally 3 times daily after each meal on the first day followed by a 4‐day washout period. Thereafter, multiple‐dose administration was conducted for 6 consecutive days. The pharmacokinetic parameters of AJM300 and its active metabolite (HCA2969) were assessed, and total white blood cells and the differential cell count were used to determine the pharmacodynamic effects. Adverse events (AEs) were also monitored.

Results

The plasma AJM300 and HCA2969 concentration–time curves displayed a triphasic pattern on Day 1 (single‐day administration) and Day 10 (last day of multiple dosing), whereas the concentration of HCA2969 was much higher than that of AJM300. A significant but transient increase in lymphocyte count was observed after AJM300 dosing at all dosages tested compared with the placebo. The increase was sustained over a 24‐h period only at the 960‐mg dosage. In particular, a significant increase in the lymphocyte count compared to placebo (mean, 50.58%; 95% confidence intervals, 20.40–80.76) was observed at the first 960‐mg dose on Day 10. Six (26.1%) subjects reported ≥1 AEs, all of which were mild and resolved spontaneously.

Conclusion

The maximal and 24‐h sustained pharmacodynamic effects were demonstrated at the 960‐mg dosage after oral administration of AJM300 3 times daily for 6 days, which was also found to be safe and well tolerated.

Food Effect on a Single High Dose of Carotegrast Methyl, an Oral Antagonist of α4-Integrin, in Healthy Male Subjects: A Randomised, Placebo-Controlled, Double-Blind Study

Background and Objectives

Carotegrast methyl, a novel prodrug, oral antagonist of α4-integrin, is in development for the treatment of active ulcerative colitis. This randomised, placebo-controlled, double-blind, crossover study evaluated the effect of food on the pharmacokinetics and pharmacodynamics as well as the safety profile after a single dose of carotegrast methyl in healthy male subjects.

Methods

Subjects were randomised to receive a single dose of carotegrast methyl (240, 480 or 960 mg) or placebo in a 6:2 ratio and received the study drug under both fed and fasted conditions separated by an 8-day washout. The pharmacokinetic profiles of carotegrast methyl and its active metabolite, carotegrast, were assessed. The pharmacodynamic profile was evaluated according to a change in the peripheral lymphocyte count. Safety was monitored throughout.

Results

Based on the area under the time curve from zero to the time of the last quantifiable concentration (AUC_last), food reduced systemic exposure to both carotegrast methyl and carotegrast by 21–57% and 5–29%, respectively. The fed-to-fasted ratio of least square means for the increase in the lymphocyte count was almost at unity in each dose, indicating no food effect on pharmacodynamics. The time  ≥ 90% of maximum effect was prolonged dose dependently, suggesting that a 960 mg-dose can provide a long-lasting effect. Reported adverse events were all mild.

Conclusions

Despite the reduced systemic exposure to both carotegrast methyl and carotegrast, food had no effect on the increase in lymphocyte count. A single administration of carotegrast methyl up to 960 mg was found to be safe.

Electronic supplementary material

The online version of this article (10.1007/s40261-019-00879-1) contains supplementary material, which is available to authorized users.

Desperately Seeking Therapies for Cerebral Malaria

Malaria is a deadly infectious disease caused by parasites of the Plasmodium spp. that takes an estimated 435,000 lives each year, primarily among young African children. For most children, malaria is a febrile illness that resolves with time, but in ∼1% of cases, for reasons we do not understand, malaria becomes severe and life threatening. Cerebral malaria (CM) is the most common form of severe malaria, accounting for the vast majority of childhood deaths from malaria despite highly effective antiparasite chemotherapy. Thus, CM is one of the most prevalent lethal brain diseases, and one for which we have no effective therapy. CM is, in part, an immune-mediated disease, and to fully understand CM, it is essential to appreciate the complex relationship between the malarial parasite and the human immune system. In this study, we provide a primer on malaria for immunologists and, in this context, review progress identifying targets for therapeutic intervention.