Soluble Mucosal Addressin Cell Adhesion Molecule 1 and Retinoic Acid are Potential Tools for Therapeutic Drug Monitoring in Patients with Inflammatory Bowel Disease Treated with Vedolizumab: A Proof of Concept Study

Advancements in Targeted Therapies for the Management of Crohn's Disease: A Comprehensive Review

Crohn's disease (CD) is a complex clinical condition characterized by persistent gastrointestinal inflammation that leads to episodes of flare-ups and subsequent healing. The treatment options for this disease are heterogeneous as its impact on different patients is also different. This study aims to evaluate the effectiveness of recently approved drugs that specifically target certain pathways within cells that are involved in CD pathogenesis. These medicines include biologics like anti-TNF agents, interleukin inhibitors, and small molecule inhibitors; they work by altering the modulation of immune responses and reducing inflammation. These drugs seem promising in terms of inducing remission in moderate to severe CD among various patient populations. Conversely, it is possible to examine how well these drugs perform using gene expression and molecular markers. By understanding these results along with other ongoing trials, personalized medicine can be used more frequently by doctors who will adopt a strategy for an individual patient, maximizing benefits while minimizing adverse effects. There are still some issues that need to be worked out like the high cost associated with these drugs or immunogenicity risk and infectious complications too. In conclusion, there has been a remarkable improvement in CD management over the past decade with customized drugs leading toward a precision medical era. Further understanding of molecular mechanisms implicated in CD pathogenesis and new therapeutic approaches could potentially improve treatment outcomes among affected individuals. This research is crucial in understanding how CD therapeutics are changing, thus facilitating selection by doctors on the most appropriate methods for individualized patient care.

Actions of Retinoic Acid in the Pathophysiology of HIV Infection

The vitamin A metabolite all-trans retinoic acid (RA) plays a key role in tissue homeostasis and mucosal immunity. RA is produced by gut-associated dendritic cells, which are among the first cells encountered by HIV. Acute HIV infection results in rapid reduction of RA levels and dysregulation of immune cell populations whose identities and function are largely controlled by RA. Here, we discuss the potential link between the roles played by RA in shaping intestinal immune responses and the manifestations and pathogenesis of HIV-associated enteropathy and similar conditions observed in SIV-infected non-human primate models. We also present data demonstrating the ability of RA to enhance the activation of replication-competent viral reservoirs from subjects on suppressive anti-retroviral therapy. The data suggest that retinoid supplementation may be a useful adjuvant for countering the pathologic condition of the gastro-intestinal tract associated with HIV infection and as part of a strategy for reactivating viral reservoirs as a means of depleting latent viral infection.

sMAdCAM: IL-6 Ratio Influences Disease Progression and Anti-Viral Responses in SARS-CoV-2 Infection

The role of sMAdCAM, an important gut immune migratory marker, remains unexplored in COVID-19 pathogenesis considering recent studies positing the gut as a sanctuary site for SARS-CoV-2 persistence. Thus, assimilating profiles of systemic inflammatory mediators with sMAdCAM levels may provide insights into the progression of COVID-19 disease. Also, the role of these markers in governing virus specific immunity following infection remains largely unexplored. A cohort (n = 84) of SARS-C0V-2 infected individuals included a group of in-patients (n = 60) at various stages of disease progression together with convalescent individuals (n = 24) recruited between April and June 2020 from Mumbai, India. Follow-up of 35 in-patients at day 7 post diagnosis was carried out. Th1/Th2/Th17 cytokines along with soluble MAdCAM (sMAdCAM) levels in plasma were measured. Also, anti-viral humoral response as measured by rapid antibody test (IgG, IgM), Chemiluminescent Immunoassay (IgG), and antibodies binding to SARS-CoV-2 proteins were measured by Surface Plasmon Resonance (SPR) from plasma. IL-6 and sMAdCAM levels among in-patients inversely correlated with one another. When expressed as a novel integrated marker—sMIL index (sMAdCAM/IL-6 ratio)—these levels were incrementally and significantly higher in various disease states with convalescents exhibiting the highest values. Importantly, sMAdCAM levels as well as sMIL index (fold change) correlated with peak association response units of receptor binding domain and fold change in binding to spike respectively as measured by SPR. Our results highlight key systemic and gut homing parameters that need to be monitored and investigated further to optimally guide therapeutic and prophylactic interventions for COVID-19.

Frequency of Effector Memory Cells Expressing Integrin α4β7 Is Associated With TGF-β1 Levels in Therapy Naïve HIV Infected Women With Low CD4+ T Cell Count

Integrin α₄β₇ expressing CD4⁺ T cells are preferred targets for HIV infection and are thought to be predictors of disease progression. Concurrent analysis of integrin α₄β₇ expressing innate and adaptive immune cells was carried out in antiretroviral (ART) therapy naïve HIV infected women in order to determine its contribution to HIV induced immune dysfunction. Our results demonstrate a HIV infection associated decrease in the frequency of integrin α₄β₇ expressing endocervical T cells along with an increase in the frequency of integrin α₄β₇ expressing peripheral monocytes and central memory CD4⁺ T cells, which are considered to be viral reservoirs. We report for the first time an increase in levels of soluble MAdCAM-1 (sMAdCAM-1) in HIV infected individuals as well as an increased frequency and count of integrin β7Hi CD8⁺ memory T cells. Correlation analysis indicates that the frequency of effector memory CD8⁺ T cells expressing integrin α₄β₇ is associated with levels of both sMAdCAM-1 and TGF-β1. The results of this study also suggest HIV induced alterations in T cell homeostasis to be on account of disparate actions of sMAdCAM-1 and TGF-β1 on integrin α₄β₇ expressing T cells. The immune correlates identified in this study warrant further investigation to determine their utility in monitoring disease progression.

Vedolizumab in Inflammatory Bowel Disease: West versus East

Background

Vedolizumab is a humanized immunoglobulin G1 monoclonal antibody, which binds to α4β7 integrin on T lymphocytes, thus disturbing the interaction with mucosal vascular addressin cell adhesion molecule 1 on the intestinal endothelial cells to interfere with lymphocyte trafficking to the gut.

Summary

Vedolizumab is a safe and effective drug to induce and maintain clinical remission in patients with Crohn's disease (CD) and ulcerative colitis (UC) in both clinical trials and real-world data. Various guidelines recommend vedolizumab as a first- or second-line treatment regimen for steroid-dependent, steroid, or immunomodulator refractory cases of UC and CD; however, it is more effective in anti-TNF-naive patients. The first head-to-head trial (VARSITY trial) comparing the efficacy of vedolizumab to adalimumab has shown better clinical remission and mucosal healing with vedolizumab.

Key Messages

In this review, we have discussed guidelines recommendation of vedolizumab use, as well as its safety data, use in special population, in presence of extraintestinal complications, therapeutic drug monitoring, data from Asian patients, along with other evolving concepts. Because of its excellent safety data and low immunogenicity, vedolizumab is an impressive option for patients with prior malignancy and less chance of reactivation of tuberculosis; however, cost remains an issue.

Biomarkers are associated with clinical and endoscopic outcomes with vedolizumab treatment in Crohn's disease

BACKGROUND

Vedolizumab, an α4β7 integrin antagonist, is an effective therapy for Crohn's disease (CD). Biomarkers are needed to guide therapy and predict outcomes. This study evaluated biomarker concentrations and outcomes in patients with CD undergoing vedolizumab treatment.

METHODS

Sera at weeks 0, 2, 6, 14, and ⩾26 were collected from vedolizumab-treated, refractory CD patients. Concentrations of soluble (s)-Vascular Cell Adhesion Molecule (VCAM)-1, s-Intercellular Cell Adhesion Molecule (ICAM)-1, s-Mucosal Addressin Cell Adhesion Molecule (MAdCAM)-1, and s-α4β7 integrin were evaluated for associations with achieving endoscopic remission.

RESULTS

A total of 22 patients with CD were included. In all patients, s-MAdCAM-1 decreased significantly and s-α4β7 increased compared with baseline. s-VCAM-1 and s-ICAM-1 changed differentially in patients who achieved remission. At week 6, median s-VCAM-1 (859.6 ng/ml versus 460.3 ng/ml, p = 0.03) and s-ICAM-1 (545.7 ng/ml versus 286.2 ng/ml, p = 0.03) concentrations were higher in patients who achieved endoscopic remission compared with those who did not, and similar differences were observed for s-ICAM-1 concentrations in patients who achieved clinical remission, compared with those who did not (669.1 ng/ml versus 291.0 ng/ml, p = 0.04). Week 14 s-α4β7 concentrations were lower in patients who achieved endoscopic remission, compared with those who did not (7.5 ng/ml versus 17.6 ng/ml, p = 0.020).

CONCLUSION

In all vedolizumab-treated CD patients, s-MAdCAM-1 decreased significantly and s-α4β7 increased. However, higher concentrations of s-ICAM-1 and s-VCAM-1 at week 6 and lower concentrations of s-α4β7 at week 14 differentiated patients who achieved endoscopic remission. These findings may help identify early predictors of response to vedolizumab treatment in patients with CD. Further validation in less refractory CD patients is needed.

Therapeutic Drug Monitoring of Biologics During Induction to Prevent Primary Non-Response

Biologic therapies have revolutionized the management of inflammatory bowel disease [IBD], but primary and secondary non-responses occur in a significant proportion of patients. Therapeutic drug monitoring [TDM] now has an established role in the treatment algorithm for managing secondary loss of response to anti-tumour necrosis factor [anti-TNF] agents during maintenance therapy. Data to support the use of TDM in the management of secondary loss of response to vedolizumab and ustekinumab are emerging. The potential to prevent primary non-response to biologic agents during induction is of equal, and potentially greater, clinical importance. Again, most data supporting the use of 'proactive' TDM during induction pertains to the use of anti-TNF agents, but signals of efficacy for the use of TDM during induction with other biologic classes are now appearing. This review aims to summarize data on the use of TDM during induction to prevent pharmacokinetic primary non-response to all three classes of biologic therapy currently available for the treatment of IBD.

Vedolizumab in the treatment of inflammatory bowel disease: evolving paradigms

Inflammatory bowel diseases, comprising Crohn's disease (CD) and ulcerative colitis (UC), are chronic, relapsing and remitting immune-mediated inflammatory diseases affecting the gastrointestinal tract. Vedolizumab is the first licensed drug in a group of 'gut-selective' biological agents used to treat inflammatory bowel diseases. The GEMINI registrational trials established the efficacy of vedolizumab for the induction and maintenance of remission in both CD and UC, with the most favourable results in tumour necrosis factor (TNF)-antagonist-naive patients. In recent years, a wealth of 'real-world' data has emerged supporting positive clinical, endoscopic and histological outcomes in patients treated with vedolizumab (VDZ) as well as reassuring safety data. More recently, the results of the first head-to-head trials of VDZ and TNF antagonists have been reported, as well as the results of a number of studies exploring the role of therapeutic drug monitoring with VDZ. This review brings together data reported on VDZ to date, including from the GEMINI trials, real-world data and emerging studies regarding therapeutic drug monitoring and immunogenicity. The safety profile of VDZ is also reviewed. Evolving treatment paradigms are explored, including data regarding the role of VDZ in perianal CD, post-operative complications and recurrence, extraintestinal manifestations and pregnancy.

A product review of vedolizumab in inflammatory bowel disease

Vedolizumab is a monoclonal antibody to the α4β7 integrin that selectively reduces intestinal lymphocyte trafficking, thereby providing a safe and effective treatment option for patients with inflammatory bowel disease (IBD). This product review outlines the unique mechanism of vedolizumab in addition to efficacy, safety, pharmacokinetic and pharmacodynamic data from clinical trials, observational studies and meta-analyses. Vedolizumab has been shown to be effective as a first- or second-line induction and maintenance therapy in both ulcerative colitis (UC) and Crohn's disease (CD). Prolonged induction therapy may increase efficacy, particularly in tumor necrosis factor-alpha-exposed CD patients. To date, no drug-specific safety signals have been identified. In addition to the presence of an apparent exposure-response relationship, vedolizumab has demonstrated consistent pharmacodynamic effects on α4β7, mucosal vascular addressin cell adhesion molecule 1 and other cell adhesion molecules. Future efforts should focus on identifying predictive biomarkers capable of guiding personalized IBD treatment with vedolizumab.