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Recently, novel biologics or small molecular drugs have been introduced for overcoming the unmet needs associated with anti-tumor necrosis factor α agents for inflammtory bowel disease (IBD) treatment. Among these novel drugs, anti integrin agents block leukocyte trafficking to the intestine by blocking the interaction between integrin and cell adhesion molecules. Vedolizumab (anti-α4β7) is most widely used anti-integrin approved in both ulcerative colitis and Crohn’s disease .It has been shown to be effective in both induction and maintenance therapy with a favorable safety profile due to gut selectivity. Several models incorporating clinical, genetic, immune and gut microbial 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. In addition, the introduction of subcutaneous vedolizumab showed similar efficacy and safety with improved patients’ convenience. 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).

Background: To explore the efficacy and safety of etrolizumab in treating inflammatory bowel disease (IBD) through meta-analysis. Method: A comprehensive exploration encompassed randomized controlled trials examining the efficacy of etrolizumab in treating IBD across PubMed, Embase, Cochrane library, and Web of Science, with a search deadline of 1 December 2023. Quality assessment leaned on the Cochrane manual's risk-of-bias evaluation, while Stata 15 undertook the data analysis. Result: Five randomized controlled studies involving 1682 individuals were finally included, Meta-analysis results suggested that compared with placebo, etrolizumab could improve clinical response (RR = 1.26, 95% CI [1.04–1.51]), clinical remission (RR = 1.26, 95% CI [1.04–1.51]) in IBD patients. Endoscopic alleviate (RR = 2.10, 95% CI [1.56–2.82]), endoscopic improvement (RR = 2.10, 95% CI [1.56–2.82]), endoscopic remission (RR = 2.10, 95% CI [1.56–2.82]), Endoscopic improvement (RR = 1.56, 95% CI [1.30–1.89]), histological remission (RR = 1.62, 95% CI [1.26–2.08]), and did not increase any adverse events (RR = 0.95, 95% CI [0.90–1.01]) and serious adverse events (RR = 0.94, 95% CI [0.68–1.31]). Conclusion: According to our current study, etrolizumab is a promising drug in IBD. [ABSTRACT FROM AUTHOR]

Background: The existing body of scientific literature offers inconclusive findings on the safety and therapeutic effectiveness of etrolizumab (ETR) for the treatment of ulcerative colitis (UC). Objectives: The goal of this meta-analysis is to furnish a comprehensive synthesis of evidence that evaluates the safety and therapeutic effects of ETR in the management of UC. Design: Meta-analysis. Data sources and methods: PubMed, Embase, and Web of science were searched to collect relevant English studies, and the reference lists of eligible studies were manually searched to avoid missing any eligible studies. Outcome measures encompassed clinical response, incidence of adverse events, histological remission, endoscopic remission, endoscopic improvement, and antidrug antibodies. Relevant data were extracted by two independent investigators. Results: The meta-analysis incorporated five eligible studies, involving a total of 1528 patients, with 1015 treated with ETR and 513 with placebo. The pooled analysis indicates that ETR is both effective and safe. The adverse event rates, endoscopic and histological response, as well as overall remission were comparable between the two groups. The monoclonal antibody group had a lower incidence rate of adverse reactions than the placebo group [odds ratio (OR): 0.81; 95% confidence interval (CI): 0.63–1.03; p = 0.09)]. Clinical response was higher in the ETR group than in the placebo group (OR: 1.56; 95% CI: 1.20–2.02; p = 0.0009), and endoscopic improvement was more favorable in the ETR group (OR: 1.88; 95% CI: 1.45–2,45; p < 0.00001). A higher rate of endoscopic remission was found in the ETR group than in the placebo group (OR: 2.48; 95% CI: 1.75–3.50; p < 0.00001); histological remission was significantly higher in the ETR group than in the placebo group (OR: 2.11; 95% CI: 1.55–2.86; p < 0.00001). The placebo group had a lower rate of positive antidrug antibodies (OR: 1.31; 95% CI: 0.79–2.17; p < 0.29), and the incidence of complications was significantly higher in the ETR group compared with the placebo group (OR: 2.05; 95% CI: 1.48–2.83; p < 0.0001). Conclusion: Given the heterogeneity and potential biases in the included studies, gastroenterologists should cautiously tailor drug delivery strategies based on their clinical experience and the unique needs of individual patients. PROSPERO registration: CRD42023396100 [ABSTRACT FROM AUTHOR]

Background: Etrolizumab is a promising drug for treating moderate to severe ulcerative colitis. Aim: The aim of this study was to assess the efficacy and safety of etrolizumab for induction and maintenance of remission in moderate to severe ulcerative colitis. Methods: We searched the following databases: PUBMED, Web of Science, OVID, and SCOPUS from inception to January 15. Inclusion criteria were any phase 2 and 3 clinical trials that compared etrolizumab with a placebo in treating moderate to severe ulcerative colitis, excluding case reports, animal studies, phase 1 trials, and conference abstracts due to duplication. We used RevMan software (5.4) for the meta‐analysis. Results: Five clinical trials were included in our meta‐analysis. The total number of patients included in the study is 1248 patients, 860 patients in the etrolizumab group and 388 patients in the placebo group. In the induction phase, the pooled analyses showed a statistically significant association between etrolizumab and increased clinical remission, and endoscopic remission compared with placebo (risk ratio [RR] = 2.66, 95% confidence interval [CI] = 1.69–4.19, p < 0.0001), and (RR = 2.35, 95% CI = 1.52–3.65, p = 0.0001), respectively. In the maintenance phase, the pooled analyses showed a statistically significant association between etrolizumab and increased histologic remission and endoscopic remission (RR = 2.04, 95% CI = 1.40–2.98, p = 0.0002) and (RR = 1.92, 95% CI = 1.29–2.85, p = 0.001), respectively. No statistically significant difference was observed in adverse events between etrolizumab and placebo in the induction and maintenance phases. Conclusion: Our results show that etrolizumab is an effective and safe drug for the induction and maintenance of clinical remission in moderate to severe ulcerative colitis patients, as proved by histologic and endoscopic findings. Future randomized trials are still needed to compare etrolizumab to the other agents and further establish its value for the practice. Highlights: Our analysis showed that etroliozumab is an effective biologic drug in the induction and maintenance of moderate and severe cases of ulcerative colitis.Etrolizumab is generally a safe drug, as it rarely causes serious adverse effects that would result in the discontinuation of the drug.We did a comprehensive review on the comparison between etrolizumab and the most common biologic agents used in the treatment of moderate and severe ulcerative colitis (infliximab, adalimumab, and vedolizumab). However, our results are inconclusive and future studies should aim to make head‐to‐head comparisons with other biologic drugs for treatment of ulcerative colitis.This is the first meta‐analysis to include phase 2 and phase 3 trials on etrolizumab efficacy versus placebo, so we provide the most recent evidence to affect future clinical decisions, and this article shall be a reference for all future studies.Our analysis included a large number of patients from multi‐international centers, which allows for generalization and increases the credibility of our results. [ABSTRACT FROM AUTHOR]

Background To explore the efficacy and safety of etrolizumab in treating inflammatory bowel disease (IBD) through meta-analysis. Method A comprehensive exploration encompassed randomized controlled trials examining the efficacy of etrolizumab in treating IBD across PubMed, Embase, Cochrane library, and Web of Science, with a search deadline of 1 December 2023. Quality assessment leaned on the Cochrane manual’s risk-of-bias evaluation, while Stata 15 undertook the data analysis. Result Five randomized controlled studies involving 1682 individuals were finally included, Meta-analysis results suggested that compared with placebo, etrolizumab could improve clinical response (RR = 1.26, 95% CI [1.04–1.51]), clinical remission (RR = 1.26, 95% CI [1.04–1.51]) in IBD patients. Endoscopic alleviate (RR = 2.10, 95% CI [1.56–2.82]), endoscopic improvement (RR = 2.10, 95% CI [1.56–2.82]), endoscopic remission (RR = 2.10, 95% CI [1.56–2.82]), Endoscopic improvement (RR = 1.56, 95% CI [1.30–1.89]), histological remission (RR = 1.62, 95% CI [1.26–2.08]), and did not increase any adverse events (RR = 0.95, 95% CI [0.90–1.01]) and serious adverse events (RR = 0.94, 95% CI [0.68–1.31]). Conclusion According to our current study, etrolizumab is a promising drug in IBD.

Background and Aim: Etrolizumab is a gut‐targeted anti‐β7 integrin monoclonal antibody. However, the evidence of etrolizumab efficacy and safety in ulcerative colitis remains inconclusive. Therefore, we aim to evaluate the safety and efficacy of etrolizumab as an induction and maintenance therapy for active moderate to severe ulcerative colitis. Methods: We synthesized randomized controlled studies (RCTs) from MEDLINE, Scopus, EMBASE, PubMed, Web of Science, and Cochrane Library until April 2023. The risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI) was used. The study protocol was registered in PROSPERO with ID: CRD42023437040. Results: Five RCTs with 1849 participants were included. The etrolizumab group had a significant clinical response (RR: 1.28 with 95% CI [1.08, 1.51], P = 0.005), clinical remission rates during the induction phase (RR: 2.47 with 95% CI [1.48, 4.11], P = 0.0005), compared with the placebo group in ulcerative colitis; however, there was no statistically significant difference between the two groups, regarding the corticosteroids‐free remission rate (RR: 1.92 with 95% CI [0.94, 3.92], P = 0.07). Moreover, endoscopic improvement, endoscopic remission, and histologic remission rates were observed more in the etrolizumab group during both the induction and maintenance phases. For safety outcomes, etrolizumab was significantly safer, but any adverse event was higher in the etrolizumab group than in the placebo. Conclusion: Etrolizumab shows its effectiveness as both an induction and maintenance therapy for moderate or severe UC. The findings demonstrate its positive impact on clinical, endoscopic, and histologic remission rates. Regarding safety, other than any side effects, etrolizumab showed a good safety than a placebo. [ABSTRACT FROM AUTHOR]

Abstract Background Etrolizumab is a promising drug for treating moderate to severe ulcerative colitis. Aim The aim of this study was to assess the efficacy and safety of etrolizumab for induction and maintenance of remission in moderate to severe ulcerative colitis. Methods We searched the following databases: PUBMED, Web of Science, OVID, and SCOPUS from inception to January 15. Inclusion criteria were any phase 2 and 3 clinical trials that compared etrolizumab with a placebo in treating moderate to severe ulcerative colitis, excluding case reports, animal studies, phase 1 trials, and conference abstracts due to duplication. We used RevMan software (5.4) for the meta‐analysis. Results Five clinical trials were included in our meta‐analysis. The total number of patients included in the study is 1248 patients, 860 patients in the etrolizumab group and 388 patients in the placebo group. In the induction phase, the pooled analyses showed a statistically significant association between etrolizumab and increased clinical remission, and endoscopic remission compared with placebo (risk ratio [RR] = 2.66, 95% confidence interval [CI] = 1.69–4.19, p

Abstract Background and Aim Etrolizumab is a gut‐targeted anti‐β7 integrin monoclonal antibody. However, the evidence of etrolizumab efficacy and safety in ulcerative colitis remains inconclusive. Therefore, we aim to evaluate the safety and efficacy of etrolizumab as an induction and maintenance therapy for active moderate to severe ulcerative colitis. Methods We synthesized randomized controlled studies (RCTs) from MEDLINE, Scopus, EMBASE, PubMed, Web of Science, and Cochrane Library until April 2023. The risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI) was used. The study protocol was registered in PROSPERO with ID: CRD42023437040. Results Five RCTs with 1849 participants were included. The etrolizumab group had a significant clinical response (RR: 1.28 with 95% CI [1.08, 1.51], P = 0.005), clinical remission rates during the induction phase (RR: 2.47 with 95% CI [1.48, 4.11], P = 0.0005), compared with the placebo group in ulcerative colitis; however, there was no statistically significant difference between the two groups, regarding the corticosteroids‐free remission rate (RR: 1.92 with 95% CI [0.94, 3.92], P = 0.07). Moreover, endoscopic improvement, endoscopic remission, and histologic remission rates were observed more in the etrolizumab group during both the induction and maintenance phases. For safety outcomes, etrolizumab was significantly safer, but any adverse event was higher in the etrolizumab group than in the placebo. Conclusion Etrolizumab shows its effectiveness as both an induction and maintenance therapy for moderate or severe UC. The findings demonstrate its positive impact on clinical, endoscopic, and histologic remission rates. Regarding safety, other than any side effects, etrolizumab showed a good safety than a placebo.

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.

Background: Closing mucosal defects to reach mucosal healing is an important goal of therapy in inflammatory bowel disease (IBD). Among other cells, monocyte‐derived macrophages are centrally involved in such intestinal wound healing. We had previously demonstrated that the anti‐α4β7 integrin antibody vedolizumab blocks the recruitment of non‐classical monocytes as biased progenitors of wound healing macrophages to the gut and delays wound healing. However, although important for the interpretation of disappointing results in recent phase III trials in IBD, the effects of the anti‐β7 antibody etrolizumab on wound healing are unclear so far. Methods: We analyzed the expression of etrolizumab targets on human and mouse monocyte subsets by flow cytometry and assessed their function in adhesion and homing assays. We explored wound‐associated monocyte recruitment dynamics with multiphoton microscopy and compared the effects of etrolizumab and vedolizumab surrogate (‐s) antibodies on experimental wound healing and wound‐associated macrophage abundance. Finally, we investigated wound healing macrophage signatures in the large intestinal transcriptome of patients with Crohn's disease treated with etrolizumab. Results: Human and mouse non‐classical monocytes expressed more αEβ7 integrin than classical monocytes and were a target of etrolizumab‐s, which blocked non‐classical monocyte adhesion to MAdCAM‐1 and E‐Cadherin as well as gut homing in vivo. Intestinal wound healing was delayed on treatment with etrolizumab‐s along with a reduction of peri‐lesional wound healing macrophages. Wound healing macrophage signatures in the colon of patients with Crohn's disease were substantially down‐regulated on treatment with etrolizumab, but not with placebo. Conclusions: Combined blockade of αEβ7 and α4β7 with etrolizumab seems to exceed the effect of anti‐α4β7 treatment on intestinal wound healing, which might help to inform further investigations to understand the recent observations in the etrolizumab phase III trial program. [ABSTRACT FROM AUTHOR]

Abstract Background Closing mucosal defects to reach mucosal healing is an important goal of therapy in inflammatory bowel disease (IBD). Among other cells, monocyte‐derived macrophages are centrally involved in such intestinal wound healing. We had previously demonstrated that the anti‐α4β7 integrin antibody vedolizumab blocks the recruitment of non‐classical monocytes as biased progenitors of wound healing macrophages to the gut and delays wound healing. However, although important for the interpretation of disappointing results in recent phase III trials in IBD, the effects of the anti‐β7 antibody etrolizumab on wound healing are unclear so far. Methods We analyzed the expression of etrolizumab targets on human and mouse monocyte subsets by flow cytometry and assessed their function in adhesion and homing assays. We explored wound‐associated monocyte recruitment dynamics with multiphoton microscopy and compared the effects of etrolizumab and vedolizumab surrogate (‐s) antibodies on experimental wound healing and wound‐associated macrophage abundance. Finally, we investigated wound healing macrophage signatures in the large intestinal transcriptome of patients with Crohn's disease treated with etrolizumab. Results Human and mouse non‐classical monocytes expressed more αEβ7 integrin than classical monocytes and were a target of etrolizumab‐s, which blocked non‐classical monocyte adhesion to MAdCAM‐1 and E‐Cadherin as well as gut homing in vivo. Intestinal wound healing was delayed on treatment with etrolizumab‐s along with a reduction of peri‐lesional wound healing macrophages. Wound healing macrophage signatures in the colon of patients with Crohn's disease were substantially down‐regulated on treatment with etrolizumab, but not with placebo. Conclusions Combined blockade of αEβ7 and α4β7 with etrolizumab seems to exceed the effect of anti‐α4β7 treatment on intestinal wound healing, which might help to inform further investigations to understand the recent observations in the etrolizumab phase III trial program.

Gut-related diseases like ulcerative colitis, Crohn's disease, or colorectal cancer affect millions of people worldwide. It is an ongoing process finding causes leading to the development and manifestation of those disorders. This is highly relevant since understanding molecular processes and signalling pathways offers new opportunities in finding novel ways to interfere with and apply new pharmaceuticals. Memory T cells (mT cells) and their pro-inflammatory properties have been proven to play an important role in gastrointestinal diseases and are therefore increasingly spotlighted. This review focuses on mT cells and their subsets in the context of disease pathogenesis and maintenance. It illustrates the network of regulatory proteins and metabolites connecting mT cells with other cell types and tissue compartments. Furthermore, the crosstalk with various microbes will be a subject of discussion. Characterizing mT cell interactions will help to further elucidate the sophisticated molecular and cellular networking system in the intestine and may present new ideas for future research approaches to control gut-related diseases. [ABSTRACT FROM AUTHOR]

John Gubatan,1 Kian Keyashian,1 Samuel JS Rubin,2,3 Jenny Wang,2 Cyrus A Buckman,2 Sidhartha Sinha1 1Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA; 2Stanford University School of Medicine, Stanford, CA, USA; 3Immunology Program, Stanford University School of Medicine, Stanford, CA, USACorrespondence: John Gubatan Email jgubatan@stanford.eduAbstract: 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 α 4β 7 and its subunits has been exploited as a therapeutic target in IBD. Natalizumab (anti-α 4) 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-α 4β 7) 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-β 7) blocks leukocyte trafficking via α 4β 7 and cell adhesion via αEβ 7 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-α 4β 7 IgG2), PN-943 (orally administered and gut-restricted α 4β 7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α 4), and ontamalimab (anti-MAdCAM-1 IgG).Keywords: anti-integrin, inflammatory bowel disease, ulcerative colitis, Crohn’s disease, vedolizumab, natalizumab, etrolizumab

Tumor necrosis factor (TNF) antagonists are the cornerstone of therapy for moderately to severely active inflammatory bowel disease (IBD). Although our understanding of pharmacokinetics, pharmacodynamics, and treatment optimization for these agents has evolved considerably over the past decade, a substantial majority of individuals fail to respond or lose response to TNF-antagonists over time. A need therefore remains for efficacious treatment options in these patients. Alternative immunological targets have now been identified, and several novel therapeutic agents are in development for IBD. In this review article, we discuss these novel therapeutic agents, with a particular focus on those demonstrated to be efficacious in phase 2 and 3 clinical trials. We further discuss considerations to be made when integrating these agents into routine practice over the next decade.

Introduction: Etrolizumab is a novel, dual-action anti-β7 integrin antibody studied in phase 3 trials in patients with inflammatory bowel disease. An autoinjector (AI) is being developed in parallel to complement the prefilled syringe with needle safety device (PFS-NSD) for subcutaneous (SC) administration in these trials. Here we demonstrate the comparable pharmacokinetics, tolerability, and safety of both devices.Methods: This randomized, open-label, two-part study in healthy participants evaluated the comparability of etrolizumab exposure between the AI and the PFS-NSD. Part 1 (pilot) involved a small number of participants, and initial results were used to finalize the design of the larger part 2 (pivotal) study. In both parts, participants were randomly assigned to receive a single SC dose of etrolizumab 105 mg by AI or PFS-NSD. Randomization was stratified by body weight. Primary pharmacokinetic outcomes were Cmax, AUClast, and AUC0-inf.Results: One hundred and eighty healthy participants (part 1, n = 30; part 2, n = 150) received a single SC dose of etrolizumab by AI or PFS-NSD. Primary pharmacokinetic results from part 1 supported modification of the part 2 study design. Results from part 2 demonstrated that etrolizumab exposure was equivalent between devices, with geometric mean ratios (GMRs) between AI and PFS-NSD of 102% (90% confidence interval [CI] 94.2-111) for Cmax, 98.0% (90% CI 89.3-107) for AUClast, and 97.6% (90% CI 88.6-107) for AUC0-inf. Median tmax and mean terminal t1/2 were also similar between devices. GMRs and 90% CIs of all primary pharmacokinetic parameters were fully contained within the predefined equivalence limits (80-125%).Conclusion: This pharmacokinetic study demonstrated that single SC injections of etrolizumab 105 mg using an AI or a PFS-NSD resulted in equivalent etrolizumab exposure and similar safety and tolerability in healthy participants. Taken together, these results support the use of an AI for etrolizumab administration.Trial Registration: NCT02996019. [ABSTRACT FROM AUTHOR]

Introduction: Etrolizumab is a novel, dual-action, anti-β7 integrin antibody in development for patients with moderate to severe ulcerative colitis or Crohn's disease. Phase 3 studies use a prefilled syringe (PFS) for etrolizumab administration. In parallel, an autoinjector (AI) is being developed to increase delivery options for patients if etrolizumab is approved. Here we describe the overall development strategy and detail the first-in-human study of this AI.Methods: This open-label study of healthy volunteers evaluated the tolerability and usability of the etrolizumab AI under development. The primary endpoint was the proportion of participants with greater than mild pain following injection. Adverse events (AEs) and usage errors were also assessed. Results were reported by injection site (thigh vs abdomen) and needle training (experienced vs naive). Pharmacokinetic (PK) variability between participants was an exploratory endpoint.Results: Thirty participants completed the study; 97% of them did not experience any pain greater than mild, and 50% did not experience any pain at all. Three usage errors were observed, one of which resulted in delivery of a partial dose of etrolizumab. No patterns of usage errors were observed. Mild injection site reactions (ISRs) were reported; all resolved by the end of the study. Participants injecting into the abdomen reported more ISRs than those injecting into the thigh; needle training did not influence AE incidence or severity.Conclusions: Results from this first-in-human study demonstrate that single injections of etrolizumab 105 mg using an AI were well tolerated in healthy volunteers, with transient, mild pain and minimal usage errors. Results from this study also informed the design of a subsequent PK comparability study evaluating exposure of etrolizumab administered by either the PFS or the AI. Overall, the availability of an AI may provide an attractive option for patients desiring a convenient, easy-to-use delivery mechanism for etrolizumab.Trial Registration: NCT02629744. [ABSTRACT FROM AUTHOR]

ObjectiveEtrolizumab (rhuMAb β7, anti-β7, PRO145223) is a humanised monoclonal antibody targeting the β7 subunit of the heterodimeric integrins α4β7 and αEβ7, which are implicated in leucocyte migration and retention in ulcerative colitis (UC). This randomised phase I study evaluated the safety and pharmacology of etrolizumab in patients with moderate to severe UC.DesignIn the single ascending dose (SAD) stage, etrolizumab (0.3, 1.0, 3.0, 10 mg/kg intravenous, 3.0 mg/kg subcutaneous (SC) or placebo) was administered 4:1 (n=25) in each cohort. In the multiple dose (MD) stage, new patients received monthly etrolizumab (0.5 mg/kg SC (n=4), 1.5 mg/kg SC (n=5), 3.0 mg/kg SC (n=4), 4.0 mg/kg intravenous (n=5)) or placebo (n=5). The pharmacokinetics was studied and Mayo Clinic Score evaluated at baseline, day 29 (SAD), and days 43 and 71 (MD).ResultsIn the SAD stage, there were no dose limiting toxicities, infusion or injection site reactions. Two impaired wound healing serious adverse events occurred in two patients receiving etrolizumab. In the MD stage, there were no dose limiting toxicities, and no infusion or injection site reactions. Headache was the most common adverse event, occurring more often in etrolizumab patients. Antietrolizumab antibodies were detected in two subjects. The duration of β7 receptor full occupancy was dose related. A clinical response was observed in 12/18 patients, and clinical remission in 3/18 patients treated with etrolizumab in the MD stage, compared with 4/5 and 1/5 placebo patients, respectively.ConclusionEtrolizumab is well tolerated in moderate to severe UC. Further investigation is warranted.

Introduction: Etrolizumab is a next-generation anti-integrin with dual action that targets two pathways of inflammation in the gut. A robust phase 3 clinical program in ulcerative colitis (UC) and Crohn's disease is ongoing and will evaluate the efficacy and safety of etrolizumab in well-defined patient populations in rigorous trials that include direct head-to-head comparisons against approved anti-tumor necrosis factor alpha agents (anti-TNF). The etrolizumab phase 3 clinical program consists of six randomized controlled trials (RCTs; UC: HIBISCUS I and II, GARDENIA, LAUREL, HICKORY; Crohn's disease: BERGAMOT) and two open-label extension trials (OLEs; UC: COTTONWOOD; Crohn's disease: JUNIPER) evaluating patients with moderately to severely active UC or Crohn's disease.Methods: In the UC RCTs, patients are randomly assigned according to each protocol to receive etrolizumab, adalimumab, infliximab, or placebo. In BERGAMOT, patients are randomly assigned to receive etrolizumab 105 mg, etrolizumab 210 mg, or placebo. The primary outcomes for the UC RCTs are Mayo Clinic score-based clinical response, remission, and clinical remission; for BERGAMOT, the co-primary outcomes are clinical remission (based on abdominal pain and stool frequency) and endoscopic improvement (based on the Simple Endoscopic Score for Crohn's disease). The OLEs will primarily assess long-term efficacy and safety. Secondary and exploratory endpoints include endoscopy, histology, quality of life, and biomarkers at various timepoints.Discussion: The etrolizumab phase 3 clinical program is the largest and most comprehensive in inflammatory bowel disease, enrolling more than 3000 patients. The program explores both induction and maintenance regimens. HIBISCUS I and II and GARDENIA are among the first head-to-head trials in UC against an anti-TNF and are the first registrational trials making that comparison. This program will also help address unanswered clinical questions on evaluation of treatment effects and treatment selection across a range of patients with varying treatment histories using an extensive repository of patient samples and data.Trial Registration: ClinicalTrials.gov: HIBISCUS I (NCT02163759), HIBISCUS II (NCT02171429), GARDENIA (NCT02136069), LAUREL (NCT02165215), HICKORY (NCT02100696), COTTONWOOD (NCT02118584), BERGAMOT (NCT02394028), JUNIPER (NCT02403323). [ABSTRACT FROM AUTHOR]

Background: Anti-integrin therapy is a new frontline strategy in the treatment of inflammatory bowel diseases (IBD). The anti-β7 integrin antibody etrolizumab is currently being investigated for safety and efficacy in Crohn’s disease (CD) and ulcerative colitis (UC) in several phase III trials. Mechanistically, etrolizumab is known to block β7 integrin ligand binding and reduces intestinal trafficking of β7-expressing cells. Etrolizumab blocks β7 integrin ligand binding and reduces β7-positive lymphocyte migration and retention in the inflamed gut mucosa, but the exact mechanisms by which this inhibition occurs are not fully understood.Methods: Cellular effects of etrolizumab or etrolizumab surrogate antibody (etrolizumab-s) were investigated in cell culture models and analyzed by flow cytometry, fluorescence microscopy, ImageStream®, stimulated emission depletion (STED) microscopy and functional dynamic in vitro adhesion assays. Moreover, effects on α4β7 integrin were compared with the pharmacodynamically similar antibody vedolizumab.Results: As demonstrated by several different approaches, etrolizumab and etrolizumab-s treatment led to internalization of β7 integrin. This resulted in impaired dynamic adhesion to MAdCAM-1. Internalized β7 integrin localized in endosomes and re-expression of β7 was dependent on de novo protein synthesis. In vitro etrolizumab treatment did not lead to cellular activation or cytokine secretion and did not induce cytotoxicity. Internalization of α4β7 integrin was increased with etrolizumab compared with vedolizumab.Discussion: Our data suggest that etrolizumab does not elicit secondary effector functions on the single cell level. Integrin internalization may be an important mechanism of action of etrolizumab, which might explain some but not all immunological effects observed with etrolizumab.

Background: Anti-integrin therapy is a new frontline strategy in the treatment of inflammatory bowel diseases (IBD). The anti-β7 integrin antibody etrolizumab is currently being investigated for safety and efficacy in Crohn's disease (CD) and ulcerative colitis (UC) in several phase III trials. Mechanistically, etrolizumab is known to block β7 integrin ligand binding and reduces intestinal trafficking of β7-expressing cells. Etrolizumab blocks β7 integrin ligand binding and reduces β7-positive lymphocyte migration and retention in the inflamed gut mucosa, but the exact mechanisms by which this inhibition occurs are not fully understood. Methods: Cellular effects of etrolizumab or etrolizumab surrogate antibody (etrolizumab-s) were investigated in cell culture models and analyzed by flow cytometry, fluorescence microscopy, ImageStream®, stimulated emission depletion (STED) microscopy and functional dynamic in vitro adhesion assays. Moreover, effects on α4β7 integrin were compared with the pharmacodynamically similar antibody vedolizumab. Results: As demonstrated by several different approaches, etrolizumab and etrolizumab-s treatment led to internalization of β7 integrin. This resulted in impaired dynamic adhesion to MAdCAM-1. Internalized β7 integrin localized in endosomes and re-expression of β7 was dependent on de novo protein synthesis. In vitro etrolizumab treatment did not lead to cellular activation or cytokine secretion and did not induce cytotoxicity. Internalization of α4β7 integrin was increased with etrolizumab compared with vedolizumab. Discussion: Our data suggest that etrolizumab does not elicit secondary effector functions on the single cell level. Integrin internalization may be an important mechanism of action of etrolizumab, which might explain some but not all immunological effects observed with etrolizumab. [ABSTRACT FROM AUTHOR]

Graphical abstract OR: Odd ratio, LCL: Lower Confidence Level, UCL: Upper Confidence Level. Abstract Objectives There is still a need to develop new effective medications for the treatment of ulcerative colitis, particularly for patients who are intolerant or resistant to first line therapies. This article compared the efficacy and safety of etrolizumab and infliximab in moderate to severe ulcerative colitis. Methods This meta-analysis was performed according to the PRISMA statement protocol. A systematic literature search of three major bibliographic databases (Scopus, PubMed, and Cochran) was performed until June 30, 2018. This review included studies that evaluated the efficacy of etrolizumab or infliximab in ulcerative colitis and were placebo controlled randomized trials. Pooled data from each treatment were indirectly compared using Bucher's method. Results Seven trials were sufficiently homogeneous to be used for indirect comparison of the induction phase of the treatment. There were no significant differences in clinical remission and serious adverse events between etrolizumab and infliximab. Moreover, adverse events of etrolizumab were significantly less than those of infliximab. However, further trials are required to compare other parameters of efficacy such as the clinical response and mucosal healing of etrolizumab with infliximab in anti-TNF alpha naïve patients. [ABSTRACT FROM AUTHOR]

Integrins are cell surface receptors with bidirectional signalling capabilities that can bind to adhesion molecules in order to mediate homing of leukocytes to peripheral tissues. Gut-selective leukocyte homing is facilitated by interactions between α4β7 and its ligand, mucosal addressin cellular adhesion molecule-1 [MAdCAM-1], while retention of lymphocytes in mucosal tissues is mediated by αEβ7 binding to its ligand E-cadherin. Therapies targeting gut-selective trafficking have shown efficacy in inflammatory bowel disease [IBD], confirming the importance of leukocyte trafficking in disease pathobiology. This review will provide an overview of integrin structure, function and signalling, and highlight the role that these molecules play in leukocyte homing and retention. Anti-integrin therapeutics, including gut-selective antibodies against the β7 integrin subunit [etrolizumab] and the α4β7 integrin heterodimer [vedolizumab and abrilumab], and the non-gut selective anti-α4 integrin [natalizumab], will be discussed, as well as novel targeting approaches using small molecules. [ABSTRACT FROM AUTHOR]

Abstract: Etrolizumab, a humanized monoclonal antibody, specifically binds to the β7 subunit of the heterodimeric integrins α4β7 and αEβ7. Pharmacokinetic (PK) and pharmacodynamic (PD) data were collected from an etrolizumab phase 1 trial in patients with moderate to severe ulcerative colitis (UC). We developed a mechanism‐based model to simultaneously describe the kinetics of serum etrolizumab concentration and free β7 receptors on circulating intestinal‐homing CD4+ T lymphocytes. Included in the analysis were 38 phase 1 UC patients who received single or 3 monthly doses of etrolizumab intravenously or subcutaneously across a dose range of 0.3 to 10 mg/kg. A quasi–steady‐state target‐mediated drug disposition model was developed to describe the dynamic interaction between serum etrolizumab concentration and free β7 receptors on intestinal‐homing CD4+ T lymphocytes in UC patients. The time profiles of serum etrolizumab and absolute counts of β7+ lymphocytes (expressed as percentage of baseline level) were well described by the quasi–steady‐state target‐mediated drug disposition model. The model was able to characterize the maximum drug occupancy of β7 receptors on intestinal‐homing CD4+ T lymphocytes and the concentration‐dependent duration of occupancy. The 90% effective concentration for etrolizumab to saturate the β7 receptors on intestinal homing CD4+ T cells was 1.3 μg/mL. PK and PD profiles predicted by the model were consistent with observations from a subsequent phase 2 study. In conclusion, an integrated PK/PD model developed in this analysis reasonably described serum etrolizumab PK profiles and the relationship between PK and PD (free β7 receptors on circulating intestinal‐homing CD4+ T lymphocytes) in UC patients. [ABSTRACT FROM AUTHOR]

The number of biologicals for the therapy of immunologically mediated diseases is constantly growing. In contrast to other agents that were previously introduced in rheumatologic or dermatologic diseases and only later adopted for the treatment of inflammatory bowel diseases (IBDs), the field of IBD was ground breaking for the concept of anti-adhesion blockade. Anti-adhesion antibodies selectively target integrins controlling cell homing to the intestine, which leads to reduction of inflammatory infiltration to the gut in chronic intestinal inflammation. Currently, the anti-α4β7-antibody vedolizumab is successfully used for both Crohn’s disease and ulcerative colitis worldwide. In this mini-review, we will summarize the fundamental basis of intestinal T cell homing and explain the molecular groundwork underlying current and potential future anti-adhesion therapies. Finally, we will comment on noteworthy clinical aspects of anti-adhesion therapy and give an outlook to the future of anti-integrin antibodies and inhibitors.

The number of biologicals for the therapy of immunologically mediated diseases is constantly growing. In contrast to other agents that were previously introduced in rheumatologic or dermatologic diseases and only later adopted for the treatment of inflammatory bowel diseases (IBDs), the field of IBD was ground breaking for the concept of anti-adhesion blockade. Anti-adhesion antibodies selectively target integrins controlling cell homing to the intestine, which leads to reduction of inflammatory infiltration to the gut in chronic intestinal inflammation. Currently, the anti-a4ß7-antibody vedolizumab is successfully used for both Crohn's disease and ulcerative colitis worldwide. In this mini-review, we will summarize the fundamental basis of intestinal T cell homing and explain the molecular groundwork underlying current and potential future anti-adhesion therapies. Finally, we will comment on noteworthy clinical aspects of anti-adhesion therapy and give an outlook to the future of anti-integrin antibodies and inhibitors. [ABSTRACT FROM AUTHOR]