Review article: nonclinical and clinical pharmacology, pharmacokinetics and pharmacodynamics of etrolizumab, an anti-β7 integrin therapy for inflammatory bowel disease

Biosimilars versus biological therapy in inflammatory bowel disease: challenges and targeting strategies using drug delivery systems

Inflammatory bowel disease (IBD) is a multifactorial illness with a climbing prevalence worldwide. While biologics are commonly prescribed especially for severe cases, they may worsen patients' outcomes due to financial burden. Consequently, there has been an increased focus on biosimilars to improve overall disease outcomes by maintaining similar efficacy and safety while minimizing the cost of therapy. Infliximab-dyyb was the first biosimilar approved by US-FDA for IBD. Since that, the US-FDA approved 14 biosimilars with different mechanisms of action and different routes of administration for IBD patients (four infliximab biosimilars, nine adalimumab biosimilars, and most recently one ustekinumab biosimilar). It should be noted that more biologics are in the pipeline as golimumab and natalizumab patents are set to expire in the near future, and biosimilars are now in pre-clinical to phase 3 trials. Different studies have evaluated biologics' effectiveness and safety and concluded that the majority of available biosimilars are efficacious and have similar adverse effect profiles compared to their reference biologics. It is worth mentioningthat post-marketing surveillance reports revealed some risks associated with biosimilars which should be taken into consideration in future research and clinical trials to avoid health hazards. Most biologics and biosimilars are administered parenterally which results in several drawbacks such as raised risk of infections, hypersensitivity, autoimmunity, development of malignancies, liver toxicity as well as worsening of heart failure. Several drug delivery systems based on passive and active targeting mechanisms are under active investigation to overcome these limitations. This review sheds light on the emergence of biologics and biosimilars as alternatives in IBD management, the differences between them, challenges and risks, and future perspectives in IBD therapy and new trends in drug delivery systems.

Efficacy and safety of etrolizumab in the treatment of inflammatory bowel disease: a meta-analysis

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.

MAdCAM-1 co-stimulation combined with retinoic acid and TGF-β induces blood CD8+ T cells to adopt a gut CD101+ TRM phenotype

Resident memory T cells (TRMs) help control local immune homeostasis and contribute to tissue-protective immune responses. The local cues that guide their differentiation and localization are poorly defined. We demonstrate that mucosal vascular addressin cell adhesion molecule 1, a ligand for the gut-homing receptor α4β7 integrin, in the presence of retinoic acid and transforming growth factor-β (TGF-β) provides a co-stimulatory signal that induces blood cluster of differentiation (CD8+ T cells to adopt a TRM-like phenotype. These cells express CD103 (integrin αE) and CD69, the two major TRM cell-surface markers, along with CD101. They also express C-C motif chemokine receptors 5 (CCR5) , C-C motif chemokine receptors 9 (CCR9), and α4β7, three receptors associated with gut homing. A subset also expresses E-cadherin, a ligand for αEβ7. Fluorescent lifetime imaging indicated an αEβ7 and E-cadherin cis interaction on the plasma membrane. This report advances our understanding of the signals that drive the differentiation of CD8+ T cells into resident memory T cells and provides a means to expand these cells in vitro, thereby affording an avenue to generate more effective tissue-specific immunotherapies.

Meta-analysis of etrolizumab versus placebo in ulcerative colitis: safety and efficacy outcomes

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.

Etrolizumab as an induction and maintenance therapy for ulcerative colitis: A systematic review and meta-analysis of randomized controlled trials

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.

Inflammatory Bowel Disease: From Conventional Immunosuppression to Biologic Therapy

BACKGROUND

Inflammatory bowel diseases (IBDs) are chronic, recurrent inflammatory diseases with partly understood etiology and pathogenesis. The course of IBD, both ulcerative colitis and Crohn's disease, is characterized by periods of relapse and remission with the possible occurrence of extraintestinal manifestations.

SUMMARY

During the last decades, therapeutic goals in IBD evolved toward endoscopic remission and mucosal healing creating the need for early administration of disease-modifying agents (DMAs). DMAs include conventional immunosuppressants (thiopurines, methotrexate), biologic drugs (anti-TNF, anti-integrin, and anti-IL-12/23 monoclonal antibodies), and small molecules (JAK inhibitors, S1P receptor modulators). Patients with aggressive course of disease and risk factors for poor prognosis should be treated with biologic therapy early, while conventional immunomodulators should be used in those with milder course of disease in the absence of risk factors.

KEY MESSAGES

Challenges in the treatment of IBD patients include the choice of effective yet safe drug and prevention or overcoming loss of response.

Factors contributing to the nonlinear pharmacokinetics of astegolimab: a close examination of potential causes

Aim: This paper describes a case study of an antibody therapeutic targeting a membrane-bound receptor, also present in systemic circulation, as a soluble receptor. During phase I studies of astegolimab, nonlinear pharmacokinetics (PKs) were observed. We investigated the potential contribution of antidrug antibodies, target-mediated drug disposition and assay format. Materials & methods: A more target-tolerant assay was developed, and a subset of phase I samples were evaluated in both free and total PK assay formats. Results & conclusion: Our results demonstrate that there were two main contributors to PK nonlinearity: soluble target interference in the free PK assay, in addition to target-mediated drug disposition. Antidrug antibody status did not significantly impact PK.

Integrin signaling in cancer: bidirectional mechanisms and therapeutic opportunities

Integrins are transmembrane receptors that possess distinct ligand-binding specificities in the extracellular domain and signaling properties in the cytoplasmic domain. While most integrins have a short cytoplasmic tail, integrin β4 has a long cytoplasmic tail that can indirectly interact with the actin cytoskeleton. Additionally, 'inside-out' signals can induce integrins to adopt a high-affinity extended conformation for their appropriate ligands. These properties enable integrins to transmit bidirectional cellular signals, making it a critical regulator of various biological processes.Integrin expression and function are tightly linked to various aspects of tumor progression, including initiation, angiogenesis, cell motility, invasion, and metastasis. Certain integrins have been shown to drive tumorigenesis or amplify oncogenic signals by interacting with corresponding receptors, while others have marginal or even suppressive effects. Additionally, different α/β subtypes of integrins can exhibit opposite effects. Integrin-mediated signaling pathways including Ras- and Rho-GTPase, TGFβ, Hippo, Wnt, Notch, and sonic hedgehog (Shh) are involved in various stages of tumorigenesis. Therefore, understanding the complex regulatory mechanisms and molecular specificities of integrins are crucial to delaying cancer progression and suppressing tumorigenesis. Furthermore, the development of integrin-based therapeutics for cancer are of great importance.This review provides an overview of integrin-dependent bidirectional signaling mechanisms in cancer that can either support or oppose tumorigenesis by interacting with various signaling pathways. Finally, we focus on the future opportunities for emergent therapeutics based on integrin agonists. Video Abstract.

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.

MAdCAM-1 costimulation in the presence of retinoic acid and TGF-β promotes HIV infection and differentiation of CD4+ T cells into CCR5+ TRM-like cells

CD4+ tissue resident memory T cells (TRMs) are implicated in the formation of persistent HIV reservoirs that are established during the very early stages of infection. The tissue-specific factors that direct T cells to establish tissue residency are not well defined, nor are the factors that establish viral latency. We report that costimulation via MAdCAM-1 and retinoic acid (RA), two constituents of gut tissues, together with TGF-β, promote the differentiation of CD4+ T cells into a distinct subset α4β7+CD69+CD103+ TRM-like cells. Among the costimulatory ligands we evaluated, MAdCAM-1 was unique in its capacity to upregulate both CCR5 and CCR9. MAdCAM-1 costimulation rendered cells susceptible to HIV infection. Differentiation of TRM-like cells was reduced by MAdCAM-1 antagonists developed to treat inflammatory bowel diseases. These finding provide a framework to better understand the contribution of CD4+ TRMs to persistent viral reservoirs and HIV pathogenesis.

Etrolizumab as induction and maintenance therapy in patients with moderately to severely active Crohn's disease (BERGAMOT): a randomised, placebo-controlled, double-blind, phase 3 trial

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 monoclonal antibody targeting α4β7 and αEβ7 integrins. We aimed to compare the safety and efficacy of two doses of etrolizumab with placebo in patients with Crohn's disease.

METHODS

BERGAMOT was a randomised, placebo-controlled, double-blind, phase 3 study done at 326 treatment centres worldwide. We included patients aged 18-80 years with moderately to severely active Crohn's disease (Crohn's Disease Activity Index [CDAI] score of 220-480, and a mean daily stool frequency score of ≥6 or a mean daily stool frequency score of >3, and a mean daily abdominal pain score of >1, as well as the presence of active inflammation on screening ileocolonoscopy) who had intolerance, inadequate response, or no response to one or more of corticosteroids, immunosuppressants, or anti-TNF therapy within the past 5 years. BERGAMOT consisted of three induction cohorts (a placebo-controlled, double-blind exploratory cohort [cohort 1]; an active treatment cohort not containing a placebo control [cohort 2]; and a placebo-controlled, double-blind pivotal cohort [cohort 3]) and one maintenance cohort. In induction cohort 3, during the 14-week induction, patients were randomly assigned (2:3:3) to receive matched placebo, 105 mg etrolizumab subcutaneously every 4 weeks (at weeks 0, 4, 8, and 12) or 210 mg etrolizumab subcutaneously (at weeks 0, 2, 4, 8, and 12), stratified by concomitant treatment with oral corticosteroids, concomitant treatment with immunosuppressants, baseline disease activity, and previous exposure to anti-TNF therapy. To preserve masking, all patients received two injections at weeks 0, 4, 8, and 12 and one injection at week 2. Week 14 etrolizumab responders from all cohorts were re-randomly assigned (1:1) to receive 105 mg etrolizumab (etrolizumab maintenance group) or placebo (placebo maintenance group) every 4 weeks for 52 weeks; patients in the induction placebo group underwent a sham re-randomisation to preserve masking. During maintenance, randomisation was stratified by CDAI remission status, concomitant treatment with oral corticosteroids, induction dose regimen, and previous exposure to anti-TNF therapy. All participants and study site personnel were masked to treatment assignment for both induction and maintenance. Co-primary induction endpoints at week 14 (placebo vs 210 mg etrolizumab) were clinical remission (mean stool frequency ≤3 and mean abdominal pain ≤1, with no worsening) and endoscopic improvement (≥50% reduction in Simple Endoscopic Score for Crohn's Disease [SES-CD]). Co-primary maintenance endpoints at week 66 (placebo vs etrolizumab) were clinical remission and endoscopic improvement. Efficacy was analysed using a modified intention-to-treat (mITT) population, defined as all randomised patients who received at least one dose of study drug (induction) and as all patients re-randomised into maintenance who received at least one dose of study drug in the maintenance phase (maintenance). Safety analyses included all patients who received at least one dose of study drug. Maintenance safety analyses include all adverse events occurring in both induction and maintenance. This trial is registered with ClinicalTrials.gov, NCT02394028, and is closed to recruitment.

FINDINGS

Between March 20, 2015, and Sept 7, 2021, 385 patients (209 [54%] male and 326 [85%] white) were randomly assigned in induction cohort 3 to receive placebo (n=97), 105 mg etrolizumab (n=143), or 210 mg etrolizumab (n=145). 487 patients had a CDAI-70 response in any of the induction cohorts and were enrolled into the maintenance cohort, of whom 434 had a response to etrolizumab and were randomly assigned to placebo (n=217) or 105 mg etrolizumab (n=217). At week 14, 48 (33%) of 145 patients in the 210 mg induction etrolizumab group versus 28 (29%) of 96 patients in the placebo induction group were in clinical remission (adjusted treatment difference 3·8% [95% CI -8·3 to 15·3]; p=0·52), and 40 (27%) versus 21 (22%) showed endoscopic improvement (5·8% [-5·4 to 17·1]; p=0·32). At week 66, a significantly higher proportion of patients receiving etrolizumab than those receiving placebo had clinical remission (76 [35%] of 217 vs 52 [24%] of 217; adjusted treatment difference 11·3% [95% CI 2·7-19·7]; p=0·0088) and endoscopic improvement (51 [24%] vs 26 [12%]; 11·5% [4·1-18·8]; p=0·0026). Similar proportions of patients reported one or more adverse events during induction (95 [66%] of 143 in the 105 mg etrolizumab group, 85 [59%] of 145 in the 210 mg etrolizumab group, and 51 [53%] of 96 in the placebo group) and maintenance (189 [87%] of 217 in the etrolizumab group and 190 [88%] of 217 in the placebo group). During induction, the most common treatment-related adverse events were injection site erythema (six [4%] of 143 in the 105 mg etrolizumab group, four [3%] of 145 in the 210 mg etrolizumab group, and none of 96 in the placebo group), and arthralgia (two [1%], one [1%], and four [4%]). In the maintenance cohort, the most common treatment-related adverse events were injection site erythema (six [3%] of 217 in the etrolizumab group vs 14 [6%] of 217 in the placebo: group), arthralgia (five [2%] vs eight [4%]), and headache (five [2%] vs seven [3%]). The most common serious adverse event was exacerbation of Crohn's disease (14 [6%] of 217 patients taking placebo and four [2%] of 217 patients taking 105 mg etrolizumab in the maintenance cohort).

INTERPRETATION

A significantly higher proportion of patients with moderately to severely active Crohn's disease achieved clinical remission and endoscopic improvement with etrolizumab than placebo during maintenance, but not during induction.

FUNDING

F Hoffmann-La Roche.

Dendritic Cell-Triggered Immune Activation Goes along with Provision of (Leukemia-Specific) Integrin Beta 7-Expressing Immune Cells and Improved Antileukemic Processes

Integrin beta 7 (β7), a subunit of the integrin receptor, is expressed on the surface of immune cells and mediates cell-cell adhesions and interactions, e.g., antitumor or autoimmune reactions. Here, we analyzed, whether the stimulation of immune cells by dendritic cells (of leukemic derivation in AML patients or of monocyte derivation in healthy donors) leads to increased/leukemia-specific β7 expression in immune cells after T-cell-enriched mixed lymphocyte culture-finally leading to improved antileukemic cytotoxicity. Healthy, as well as AML and MDS patients' whole blood (WB) was treated with Kit-M (granulocyte-macrophage colony-stimulating factor (GM-CSF) + prostaglandin E1 (PGE1)) or Kit-I (GM-CSF + Picibanil) in order to generate DCs (DC_leu or monocyte-derived DC), which were then used as stimulator cells in MLC. To quantify antigen/leukemia-specific/antileukemic functionality, a degranulation assay (DEG), an intracellular cytokine assay (INTCYT) and a cytotoxicity fluorolysis assay (CTX) were used. (Leukemia-specific) cell subtypes were quantified via flow cytometry. The Kit treatment of WB (compared to the control) resulted in the generation of DC/DC_leu, which induced increased activation of innate and adaptive cells after MLC. Kit-pretreated WB (vs. the control) led to significantly increased frequencies of β7-expressing T-cells, degranulating and intracellular cytokine-producing β7-expressing immune cells and, in patients' samples, increased blast lysis. Positive correlations were found between the Kit-M-mediated improvement of blast lysis (vs. the control) and frequencies of β7-expressing T-cells. Our findings indicate that DC-based immune therapies might be able to specifically activate the immune system against blasts going along with increased frequencies of (leukemia-specific) β7-expressing immune cells. Furthermore, β7 might qualify as a predictor for the efficiency and the success of AML and/or MDS therapies.

Management of inflammatory bowel disease beyond tumor necrosis factor inhibitors: novel biologics and small-molecule drugs

The incidence and prevalence of inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, have increased in Asia and developing countries. In the past two decades, anti-tumor necrosis factor (TNF) agents have revolutionized the treatment of IBD, in part by decreasing the rates of complications and surgery. Although anti-TNF agents have changed the course of IBD, there are unmet needs in terms of primary and secondary non-responses and side effects such as infections and malignancies. Novel biologics and small-molecule drugs have been developed for IBD, and the medical treatment options have improved. These drugs include sphingosine-1-phosphate receptor modulators and anti-integrins to block immune cell migration, and cytokine and Janus kinase inhibitors to block immune cell communications. In this review, we discuss the approved novel biologics and small-molecule drugs, including several of those in the late stages of development, for the treatment of IBD.

Pharmacokinetics, Pharmacodynamics, and Safety of Etrolizumab in Children With Moderately to Severely Active Ulcerative Colitis or Crohn's Disease: Results from a Phase 1 Randomized Trial

BACKGROUND

Etrolizumab, a humanized anti-β7 antibody, has not been studied in children. Here, we evaluate the pharmacokinetics, pharmacodynamics, and safety of etrolizumab in children with inflammatory bowel disease.

METHODS

Patients age 4 to 17 years with moderately to severely active ulcerative colitis or Crohn's disease were randomized 1:1 to receive 1.5mg/kg of etrolizumab subcutaneously every 4 weeks (q4w) or 3.0mg/kg every 8 weeks (q8w) for 16 weeks in this open-label phase 1 trial. Pharmacokinetics, pharmacodynamics, safety, and efficacy were assessed.

RESULTS

Of the 24 patients treated, 21 completed the study. In the groups of 1.5mg/kg q4w and 3.0mg/kg q8w, respectively, mean (SD) maximum concentration (Cmax) was 9.8 (4.86) µg/mL and 18.1 (6.25) µg/mL; and mean (SD) area under the curve within a dosing interval (AUCtau) was 167 (86.9) and 521 (306) μg·day/mL after the last dose. The Cmax increased dose proportionally. The AUC over an 8-week period was slightly higher in the 3.0mg/kg q8w dose group. Median half-life was similar for both dosing regimens. Median numbers of free β7high gut-homing T and B cell subsets declined below 10% of baseline, confirming β7 target engagement and complete/near-complete receptor occupancy. Adverse events were consistent with the safety profile in adults. Approximately 60% of patients achieved a clinical response.

CONCLUSIONS

Etrolizumab showed a dose-proportional increase in Cmax and a slightly greater than dose-proportional increase in AUCtau. Both regimens achieved complete/near-complete β7 receptor occupancy, with a similar relationship to concentration as adults. Etrolizumab was well tolerated and demonstrated clinical activity in children.

Etrolizumab as induction and maintenance therapy for ulcerative colitis in patients previously treated with tumour necrosis factor inhibitors (HICKORY): a phase 3, randomised, controlled trial

BACKGROUND

Etrolizumab is a gut-targeted, anti-β7 integrin, monoclonal antibody. In an earlier phase 2 induction study, etrolizumab significantly improved clinical remission compared with placebo in patients with moderately to severely active ulcerative colitis. We aimed to evaluate the efficacy and safety of etrolizumab in patients with moderately to severely active ulcerative colitis who had been previously treated with anti-tumour necrosis factor (TNF) agents.

METHODS

HICKORY was a multicentre, phase 3, double-blind, placebo-controlled study in adult (18-80 years) patients with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) previously treated with TNF inhibitors. Patients were recruited from 184 treatment centres across 24 countries in North America, South America, Europe, Asia, Oceania, and the Middle East. Patients needed to have an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. In cohort 1, patients received open-label etrolizumab 105 mg every 4 weeks for a 14-week induction period. In cohort 2, patients were randomly assigned (4:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks for the 14-week induction phase. Patients in either cohort achieving clinical response to etrolizumab induction were eligible for the maintenance phase, in which they were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks through to week 66. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants (induction randomisation only), baseline disease activity, week 14 MCS remission status (maintenance randomisation only), and induction cohort (maintenance randomisation only). All patients and study site personnel were masked to treatment assignment. Primary endpoints were remission (Mayo Clinic total score [MCS] ≤2, with individual subscores of ≤1 and a rectal bleeding subscore of 0) at week 14, and remission at week 66 among patients with a clinical response (MCS with ≥3-point decrease and ≥30% reduction from baseline, plus ≥1 point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) at week 14. Efficacy was analysed using a modified intent-to-treat population. Safety analyses included all patients who received at least one dose of study drug during the induction phase. This study is registered at ClinicalTrials.gov, NCT02100696.

FINDINGS

HICKORY was conducted from May 21, 2014, to April 16, 2020, during which time 1081 patients were screened, and 609 deemed eligible for inclusion. 130 patients were included in cohort 1. In cohort 2,479 patients were randomly assigned to the induction phase (etrolizumab n=384, placebo n=95). 232 patients were randomly assigned to the maintenance phase (etrolizumab to etrolizumab n=117, etrolizumab to placebo n=115). At week 14, 71 (18·5%) of 384 patients in the etrolizumab group and six (6·3%) of 95 patients in the placebo group achieved the primary induction endpoint of remission (p=0·0033). No significant difference between etrolizumab and placebo was observed for the primary maintenance endpoint of remission at week 66 among patients with a clinical response at week 14 (27 [24·1%] of 112 vs 23 [20·2%] of 114; p=0·50). Four patients in the etrolizumab group reported treatment-related adverse events leading to treatment discontinuation. The proportion of patients reporting at least adverse event was similar between treatment groups for induction (etrolizumab 253 [66%] of 384; placebo 63 [66%] of 95) and maintenance (etrolizumab to etrolizumab 98 [88%] of 112; etrolizumab to placebo 97 [85%] of 114). The most common adverse event in both groups was ulcerative colitis flare. Most adverse events were mild or moderate. During induction, the most common serious adverse event was ulcerative colitis flare (etrolizumab ten [3%] of 384; placebo: two [2%] of 95). During maintenance, the most common serious adverse event in the etrolizumab to etrolizumab group was appendicitis (two [2%] of 112) and the most common serious adverse events in the etrolizumab to placebo group were ulcerative colitis flare (two [2%] of 114) and anaemia (two [2%] of 114).

INTERPRETATION

HICKORY demonstrated that a significantly higher proportion of patients with moderately to severely active ulcerative colitis who had been previously treated with anti-TNF agent were able to achieve remission at week 14 when treated with etrolizumab compared with placebo; however, there was no significant difference between groups in remission at week 66 among patients with a clinical response at week 14.

FUNDING

F Hoffmann-La Roche.

Etrolizumab versus infliximab for the treatment of moderately to severely active ulcerative colitis (GARDENIA): a randomised, double-blind, double-dummy, phase 3 study

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In a previous phase 2 induction study, etrolizumab significantly improved clinical remission versus placebo in patients with moderately to severely active ulcerative colitis. We aimed to compare the safety and efficacy of etrolizumab with infliximab in patients with moderately to severely active ulcerative colitis.

METHODS

We conducted a randomised, double-blind, double-dummy, parallel-group, phase 3 study (GARDENIA) across 114 treatment centres worldwide. We included adults (age 18-80 years) with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. Patients were required to have had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. Participants were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks or intravenous infliximab 5 mg/kg at 0, 2, and 6 weeks and every 8 weeks thereafter for 52 weeks. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants, and baseline disease activity. All participants and study site personnel were masked to treatment assignment. The primary endpoint was the proportion of patients who had both clinical response at week 10 (MCS ≥3-point decrease and ≥30% reduction from baseline, plus ≥1-point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) and clinical remission at week 54 (MCS ≤2, with individual subscores ≤1); efficacy was analysed using a modified intention-to-treat population (all randomised patients who received at least one dose of study drug). GARDENIA was designed to show superiority of etrolizumab over infliximab for the primary endpoint. This trial is registered with ClinicalTrials.gov, NCT02136069, and is now closed to recruitment.

FINDINGS

Between Dec 24, 2014, and June 23, 2020, 730 patients were screened for eligibility and 397 were enrolled and randomly assigned to etrolizumab (n=199) or infliximab (n=198). 95 (48%) patients in the etrolizumab group and 103 (52%) in the infliximab group completed the study through week 54. At week 54, 37 (18·6%) of 199 patients in the etrolizumab group and 39 (19·7%) of 198 in the infliximab group met the primary endpoint (adjusted treatment difference -0·9% [95% CI -8·7 to 6·8]; p=0·81). The number of patients reporting one or more adverse events was similar between treatment groups (154 [77%] of 199 in the etrolizumab group and 151 [76%] of 198 in the infliximab group); the most common adverse event in both groups was ulcerative colitis (55 [28%] patients in the etrolizumab group and 43 [22%] in the infliximab group). More patients in the etrolizumab group reported serious adverse events (including serious infections) than did those in the infliximab group (32 [16%] vs 20 [10%]); the most common serious adverse event was ulcerative colitis (12 [6%] and 11 [6%]). There was one death during follow-up, in the infliximab group due to a pulmonary embolism, which was not considered to be related to study treatment.

INTERPRETATION

To our knowledge, this trial is the first phase 3 maintenance study in moderately to severely active ulcerative colitis to use infliximab as an active comparator. Although the study did not show statistical superiority for the primary endpoint, etrolizumab performed similarly to infliximab from a clinical viewpoint.

FUNDING

F Hoffmann-La Roche.

Etrolizumab for maintenance therapy in patients with moderately to severely active ulcerative colitis (LAUREL): a randomised, placebo-controlled, double-blind, phase 3 study

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In a previous phase 2 induction study, etrolizumab significantly improved clinical remission versus placebo in patients with moderately to severely active ulcerative colitis. We aimed to evaluate the efficacy and safety of etrolizumab for maintenance of remission in patients with moderately to severely active ulcerative colitis.

METHODS

We conducted a randomised, placebo-controlled, double-blind, phase 3 study (LAUREL) across 111 treatment centres worldwide. We included adults (age 18-80 years) with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. Patients were required to have had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. During open-label induction, participants received subcutaneous etrolizumab 105 mg once every 4 weeks. Participants who had clinical response at week 10 (MCS with ≥3-point decrease and ≥30% reduction from baseline, plus ≥1-point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) proceeded into the double-blind maintenance phase and were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks or matched placebo until week 62. Randomisation was stratified by baseline concomitant treatment with corticosteroids, treatment with immunosuppressants, baseline disease activity, and week 10 remission status. All participants and study site personnel were masked to treatment assignment. The primary endpoint was remission at week 62 (MCS ≤2, with individual subscores ≤1, and rectal bleeding subscore of 0) among patients with a clinical response at week 10, measured in the modified intention-to-treat population (all randomised patients who received at least one dose of study drug). This trial is registered with ClinicalTrials.gov, NCT02165215, and is now closed to recruitment.

FINDINGS

Between Aug 12, 2014, and June 4, 2020, 658 patients were screened for eligibility and 359 were enrolled into the induction phase. 214 (60%) patients had a clinical response at week 10 and were randomly assigned to receive etrolizumab (n=108) or placebo (n=106) in the maintenance phase. 80 (74%) patients in the etrolizumab group and 42 (40%) in the placebo group completed the study through week 62. Four patients in the placebo group did not receive study treatment and were excluded from the analyses. At week 62, 32 (29·6%) of 108 patients in the etrolizumab group and 21 (20·6%) of 102 in the placebo group were in remission (adjusted treatment difference 7·7% [95% CI -4·2 to 19·2]; p=0·19). A greater proportion of patients reported one or more adverse events in the placebo group (82 [80%] of 102) than in the etrolizumab group (70 [65%] of 108); the most common adverse event in both groups was ulcerative colitis (16 [15%] patients in the etrolizumab group and 37 [36%] in the placebo group). Ten (9%) patients in the etrolizumab group and eight (8%) in the placebo group reported one or more serious adverse events. No deaths were reported in either treatment group.

INTERPRETATION

No significant differences were observed between maintenance etrolizumab and placebo in the primary endpoint of remission at week 62 among patients who had a clinical response at week 10. Etrolizumab was well tolerated in this population and no new safety signals were identified.

FUNDING

F Hoffmann-La Roche.

Etrolizumab versus adalimumab or placebo as induction therapy for moderately to severely active ulcerative colitis (HIBISCUS): two phase 3 randomised, controlled trials

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In an earlier phase 2 induction study, etrolizumab significantly improved clinical remission relative to placebo in patients with moderately to severely active ulcerative colitis. The HIBISCUS studies aimed to compare the efficacy and safety of etrolizumab to adalimumab and placebo for induction of remission in patients with moderately to severely active ulcerative colitis.

METHODS

HIBISCUS I and HIBISCUS II were identically designed, multicentre, phase 3, randomised, double-blind, placebo-controlled and active-controlled studies of etrolizumab, adalimumab, and placebo in adult (18-80 years) patients with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. All patients had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. In both studies, patients were randomly assigned (2:2:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks; subcutaneous adalimumab 160 mg on day 1, 80 mg at week 2, and 40 mg at weeks 4, 6, and 8; or placebo. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants, and baseline disease activity. All patients and study site personnel were masked to treatment assignment. The primary endpoint was induction of remission at week 10 (defined as MCS of 2 or lower, with individual subscores of 1 or lower, and rectal bleeding subscore of 0) with etrolizumab compared with placebo. Pooled analyses of both studies comparing etrolizumab and adalimumab were examined for several clinical and endoscopic endpoints. Efficacy was analysed using a modified intent-to-treat population, defined as all randomly assigned patients who received at least one dose of study drug. These trials are registered with ClinicalTrials.gov, NCT02163759 (HIBISCUS I), NCT02171429 (HIBISCUS II).

FINDINGS

Between Nov 4, 2014, and May 25, 2020, each study screened 652 patients (HIBISCUS I) and 613 patients (HIBISCUS II). Each study enrolled and randomly assigned 358 patients (HIBISCUS I etrolizumab n=144, adalimumab n=142, placebo n=72; HIBISCUS II etrolizumab n=143; adalimumab n=143; placebo n=72). In HIBISCUS I, 28 (19·4%) of 144 patients in the etrolizumab group and five (6·9%) of 72 patients in the placebo group were in remission at week 10, with an adjusted treatment difference of 12·3% (95% CI 1·6 to 20·6; p=0·017) in favour of etrolizumab. In HIBISCUS II, 26 (18·2%) of 143 patients in the etrolizumab group and eight (11·1%) of 72 patients in the placebo group were in remission at week 10, with an adjusted treatment difference of 7·2% (95% CI -3·8 to 16·1; p=0·17). In the pooled analysis, etrolizumab was not superior to adalimumab for induction of remission, endoscopic improvement, clinical response, histological remission, or endoscopic remission; however, similar numerical results were observed in both groups. In HIBISCUS I, 50 (35%) of 144 patients in the etrolizumab group reported any adverse event, compared with 61 (43%) of 142 in the adalimumab group and 26 (36%) of 72 in the placebo group. In HIBISCUS II, 63 (44%) of 143 patients in the etrolizumab group reported any adverse event, as did 62 (43%) of 143 in the adalimumab group and 33 (46%) in the placebo group. The most common adverse event in all groups was ulcerative colitis flare. The incidence of serious adverse events in the pooled patient population was similar for etrolizumab (15 [5%] of 287) and placebo (seven [5%] of 144) and lower for adalimumab (six [2%] of 285). Two patients in the etrolizumab group died; neither death was deemed to be treatment related.

INTERPRETATION

Etrolizumab was superior to placebo for induction of remission in HIBISCUS I, but not in HIBISCUS II. Etrolizumab was well tolerated in both studies.

FUNDING

F Hoffmann-La Roche.

Treatment of Inflammatory Bowel Disease: A Comprehensive Review

Inflammatory bowel disease (IBD), as a global disease, has attracted much research interest. Constant research has led to a better understanding of the disease condition and further promoted its management. We here reviewed the conventional and the novel drugs and therapies, as well as the potential ones, which have shown promise in preclinical studies and are likely to be effective future therapies. The conventional treatments aim at controlling symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures and/or surgical resection if necessary. However, a considerable fraction of patients do not respond to available treatments or lose response, which calls for new therapeutic strategies. Diverse therapeutic options are emerging, involving small molecules, apheresis therapy, improved intestinal microecology, cell therapy, and exosome therapy. In addition, patient education partly upgrades the efficacy of IBD treatment. Recent advances in the management of IBD have led to a paradigm shift in the treatment goals, from targeting symptom-free daily life to shooting for mucosal healing. In this review, the latest progress in IBD treatment is summarized to understand the advantages, pitfalls, and research prospects of different drugs and therapies and to provide a basis for the clinical decision and further research of IBD.

Challenges with development of a pharmacokinetics assay to measure a variably glycosylated fusion protein

Aim: Development of recombinant fusion proteins as drugs poses unique challenges for bioanalysis. This paper describes a case study of a glycosylated fusion protein, where variable glycosylation, matrix interference and high sensitivity needs posed unique challenges. Results: Six different assay configurations, across four different platforms were evaluated for measurement of drug concentrations. Two platforms that achieved the assay requirements were Simoa HD-1 and immune-capture LC-MS/MS-based assay. Conclusion: Both, Simoa HD-1 and the mass spectrometry-based methods were able to detect total drug by providing the adequate matrix tolerance, required sensitivity and detection of all the various glycosylated fusion proteins to support clinical sample analysis. The mass spectrometry-based method was selected due to robustness and ease of method transfer.

Emerging therapeutic opportunities for integrin inhibitors

Integrins are cell adhesion and signalling proteins crucial to a wide range of biological functions. Effective marketed treatments have successfully targeted integrins αIIbβ3, α4β7/α4β1 and αLβ2 for cardiovascular diseases, inflammatory bowel disease/multiple sclerosis and dry eye disease, respectively. Yet, clinical development of others, notably within the RGD-binding subfamily of αv integrins, including αvβ3, have faced significant challenges in the fields of cancer, ophthalmology and osteoporosis. New inhibitors of the related integrins αvβ6 and αvβ1 have recently come to the fore and are being investigated clinically for the treatment of fibrotic diseases, including idiopathic pulmonary fibrosis and nonalcoholic steatohepatitis. The design of integrin drugs may now be at a turning point, with opportunities to learn from previous clinical trials, to explore new modalities and to incorporate new findings in pharmacological and structural biology. This Review intertwines research from biological, clinical and medicinal chemistry disciplines to discuss historical and current RGD-binding integrin drug discovery, with an emphasis on small-molecule inhibitors of the αv integrins.

Integrins are key signalling molecules that are present on the surface of subsets of cells and are therefore good potential therapeutic targets. In this Review, Hatley and colleagues discuss the development of integrin inhibitors, particularly the challenges in developing inhibitors for integrins that contain an αv-subunit, and suggest how these challenges could be addressed.

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.

Comparable Pharmacokinetics, Safety, and Tolerability of Etrolizumab Administered by Prefilled Syringe or Autoinjector in a Randomized Trial in Healthy Volunteers

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 C_max, AUC_last, and AUC_0–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 C_max, 98.0% (90% CI 89.3–107) for AUC_last, and 97.6% (90% CI 88.6–107) for AUC_0–inf. Median t_max and mean terminal t_1/2 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.

Microbiota and Drug Response in Inflammatory Bowel Disease

A mutualistic relationship between the composition, function and activity of the gut microbiota (GM) and the host exists, and the alteration of GM, sometimes referred as dysbiosis, is involved in various immune-mediated diseases, including inflammatory bowel disease (IBD). Accumulating evidence suggests that the GM is able to influence the efficacy of the pharmacological therapy of IBD and to predict whether individuals will respond to treatment. Additionally, the drugs used to treat IBD can modualate the microbial composition. The review aims to investigate the impact of the GM on the pharmacological therapy of IBD and vice versa. The GM resulted in an increase or decrease in therapeutic responses to treatment, but also to biotransform drugs to toxic metabolites. In particular, the baseline GM composition can help to predict if patients will respond to the IBD treatment with biologic drugs. On the other hand, drugs can affect the GM by incrementing or reducing its diversity and richness. Therefore, the relationship between the GM and drugs used in the treatment of IBD can be either beneficial or disadvantageous.

Current Trends in the Treatment of Systemic Lupus Erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease in mankind. SLE's downregulation of T and B lymphocytes could cause the development of autoantibodies, which in turn attack cell surface, nuclear, and cytoplasmic molecules, creating immune complexes that harm tissues.

OBJECTIVE

The objective of the present review is to evaluate SLE's present therapeutic policies and raise consciousness about the disease.

METHODS

New therapies are rare for SLE. This is due to the complexity of the disease and its various manifestations. Three techniques are used to develop biological treatments for the illness: B-cell modulation, T-cell regulation and cytokine inhibition. This paper reviews the present trends in SLE therapy.

RESULTS

Each arm of the immune system is a prospective therapeutic development target for this disease; it involves B-cells, T-cells, interferon (IFN) and cytokines. To date, only one of these agents is been approved for use against lupus, belimumab which comes under B-cell therapy. Both the innate and the adaptive immune systems are the objectives. Currently, although there is no full SLE remedy, drug therapy can minimize organ injury and control active disease, which relies on immunosuppressants and glucocorticoids.

CONCLUSION

It is possible to access SLE treatment in the form of T-cell, B-cell and anticytokine therapies. In these therapies, antibodies and antigens interactions play a major part. Another medication for treating SLE is the non-steroidal anti-inflammatory drug such as hydroxychloroquine. Glucocorticoids (GCs) are another antiinflammatory treatment that suppresses the growth of cytokines related to inflammation and prevents the recruitment of leukocyte by reducing endothelial cell permeability.

Network pharmacology strategy for predicting the correlation of Systemic Scleroderma with Vitamin D deficiency

The deficiency of Vitamin D (V_D) is a common symptom of systemic scleroderma (SSc), but the correlation of V_D deficiency and SSc is not completely clear. Therefore, a strategy based on network pharmacology was designed to explore the correlation of V_D deficiency and SSc. After a series of network construction and analysis, 5 integrins were predicated as the kernel targets in the correlation of V_D deficiency and SSc, including ITGA5, ITGA4, ITGB3, ITGB1 and ITGAV. The crucial pathways in which the kernel targets participated were mainly involved in the function of immune, vascular and internal organ. The regulation modules of crucial pathways were closely related to the biological processes in the pathological of SSc. Taken together, the analysis predicted that the deficiency of V_D might affect the pathological of SSc through the mediation of these integrins. Therefore, targeted regulation of these integrins might be an effective therapy against SSc.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

A mutation that blocks integrin α4β7 activation prevents adaptive immune-mediated colitis without increasing susceptibility to innate colitis

Background

β₇ integrins are responsible for the efficient recruitment of lymphocytes from the blood and their retention in gut-associated lymphoid tissues. Integrin α₄β₇ binds MAdCAM-1, mediating rolling adhesion of lymphocytes on blood vessel walls when inactive and firm adhesion when activated, thereby controlling two critical steps of lymphocyte homing to the gut. By contrast, integrin α_Eβ₇ mediates the adhesion of lymphocytes to gut epithelial cells by interacting with E-cadherin. Integrin β₇ blocking antibodies have shown efficacy in clinical management of inflammatory bowel disease (IBD); however, fully blocking β₇ function leads to the depletion of colonic regulatory T (Treg) cells and exacerbates dextran sulfate sodium (DSS)-induced colitis by evoking aberrant innate immunity, implying its potential adverse effect for IBD management. Thus, a better therapeutic strategy targeting integrin β₇ is required to avoid this adverse effect.

Results

Herein, we inhibited integrin α₄β₇ activation in vivo by creating mice that carry in their integrin β₇ gene a mutation (F185A) which from structural studies is known to lock α₄β₇ in its resting state. Lymphocytes from β₇-F185A knock-in (KI) mice expressed α₄β₇ integrins that could not be activated by chemokines and showed significantly impaired homing to the gut. The β₇-F185A mutation did not inhibit α_Eβ₇ activation, but led to the depletion of α_Eβ₇⁺ lymphocytes in the spleen and a significantly reduced population of α_Eβ₇⁺ lymphocytes in the gut of KI mice. β₇-F185A KI mice were resistant to T cell transfer-induced chronic colitis, but did not show an increased susceptibility to DSS-induced innate colitis, the adverse effect of fully blocking β₇ function.

Conclusions

Our findings demonstrate that specific inhibition of integrin α₄β₇ activation is a potentially better strategy than fully blocking α₄β₇ function for IBD treatment.

Perspectives on Current and Novel Treatments for Inflammatory Bowel Disease

New therapeutic strategies in inflammatory bowel disease (IBD) have shifted from symptom control towards treat-to-target algorithms in order to optimize treatment results. The treatment of IBD has evolved with the development of tumor necrosis factor-α inhibitors beyond the conventional therapies. In spite of their long-term effectiveness, many patients do not respond to or cannot sustain treatment with these drugs, which have various side effects. Therefore, the development of new drugs targeting specific pathways in the pathogenesis of IBD has become necessary. Some novel biologics and small molecule drugs have shown potential in IBD clinical trials, providing safe and effective results. In addition, clinicians are now trying to target the dysbiotic microbiome of patients with IBD using fecal microbiota transplantation. New tools such as stem cells have also been developed. The available therapeutic options for IBD are expanding rapidly. In the next few years, physicians will face an unprecedented number of options when choosing the best treatments for patients with IBD. This review provides an overview of recent advances in IBD treatment options.

Human Intestinal Mononuclear Phagocytes in Health and Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a complex immune-mediated disease of the gastrointestinal tract that increases morbidity and negatively influences the quality of life. Intestinal mononuclear phagocytes (MNPs) have a crucial role in maintaining epithelial barrier integrity while controlling pathogen invasion by activating an appropriate immune response. However, in genetically predisposed individuals, uncontrolled immune activation to intestinal flora is thought to underlie the chronic mucosal inflammation that can ultimately result in IBD. Thus, MNPs are involved in fine-tuning mucosal immune system responsiveness and have a critical role in maintaining homeostasis or, potentially, the emergence of IBD. MNPs include monocytes, macrophages and dendritic cells, which are functionally diverse but highly complementary. Despite their crucial role in maintaining intestinal homeostasis, specific functions of human MNP subsets are poorly understood, especially during diseases such as IBD. Here we review the current understanding of MNP ontogeny, as well as the recently identified human intestinal MNP subsets, and discuss their role in health and IBD.

Immune cell trafficking and retention in inflammatory bowel disease: mechanistic insights and therapeutic advances

Intestinal immune cell trafficking has been identified as a central event in the pathogenesis of inflammatory bowel diseases (IBD). Intensive research on different aspects of the immune mechanisms controlling and controlled by T cell trafficking and retention has led to the approval of the anti-α4β7 antibody vedolizumab, the ongoing development of a number of further anti-trafficking agents (ATAs) such as the anti-β7 antibody etrolizumab or the anti-MAdCAM-1 antibody ontamalimab and the identification of potential future targets like G-protein coupled receptor 15. However, several aspects of the biology of immune cell trafficking and regarding the mechanism of action of ATAs are still unclear, for example, which impact these compounds have on the trafficking of non-lymphocyte populations like monocytes and how precisely these therapies differ with regard to their effect on immune cell subpopulations. This review will summarise recent advances of basic science in the field of intestinal immune cell trafficking and discuss these findings with regard to different pharmacological approaches from a translational perspective.

α4β7 integrin inhibitors: a patent review

INTRODUCTION

The α₄β₇ integrin is heterodimeric cell surface receptors expressed on most leukocytes. Mucosal addressing cell adhesion molecule 1(MAdCAM-1) is an exclusive ligand for α₄β₇ integrin. Areas covered: This article will highlight the progress that has been made in the discovery and development of α₄β₇ integrin inhibitors, and their use in the treatment of inflammatory bowel diseases, multiple sclerosis, asthma, hepatic disorders, human immunodeficiency virus, allergic conjunctivitis and type 1 diabetes. Expert opinion: α₄β₇ integrin inhibitors have attracted much interest for their clinical implication. Natalizumab and Vedolizumab are monoclonal antibodies (mAbs) successfully utilized clinically. Natalizumab is a mAbs of α₄-subunit blocking both α₄β₁ and α₄β₇ integrin. Vedolizumab selectively targets the α₄β₇ integrin. Several mAbs are still in the process of research and development. Among these mAbs, etrolizumab selectively against the β₇-subunit and AMG-181 specifically against the α₄β₇ integrin are the most promising anti-α₄β₇ integrin antibodies. Despite the unclear development stage of TR-14035 and R411, several low molecular compounds show bright future of further development, such as AJM300 and CDP323. In addition, results from laboratory data show that peptide inhibitors, such as peptide X, are effective α₄β₇ integrin inhibitors.