Review article: emerging drug therapies in inflammatory bowel disease

Population Pharmacokinetics and Exposure-Response Relationships of Etrolizumab in Patients with Moderately-to-Severely Active Crohn's Disease

This study aimed to characterize the pharmacokinetics (PK) of etrolizumab, an IgG1-humanized monoclonal anti-β7 integrin antibody, and assess its exposure-response (ER) relationship for key clinical outcomes in patients with moderately-to-severely active Crohn's disease. ER analyses were based on data from Phase 3 BERGAMOT trial, which evaluated etrolizumab at 105 or 210 mg during induction phase and 105 mg during maintenance phase. Population pharmacokinetic analysis was performed to characterize etrolizumab PK and identify influential covariates. ER analyses were conducted at end of induction and maintenance for clinical remission, endoscopic improvement, and endoscopic remission. ER modeling was performed using logistic regression, and full covariate model was used to examine the impact of baseline covariates on clinical outcomes. Pharmacokinetics of etrolizumab was best characterized using a two-compartment model with first-order absorption, demonstrating a time-dependent decrease in clearance. Typical maximum reduction of clearance was 22.0% (95% CI: 20.5%-23.5%) with onset half-life of 3.45 (95% CI: 2.84-4.04) weeks. Baseline body weight, albumin, and C-reactive protein were the most impactful covariates for etrolizumab exposure. Based on population PK results, trough concentration at Week 4 of induction was selected as exposure metric. Etrolizumab exposure-response slope was significant (P < .05) for clinical remission, endoscopic improvement, and endoscopic remission final models in maintenance phase, but none of final ER models of induction phase. For all induction ER endpoints, tumor necrosis factor (TNF)-naive patients had significantly higher probability of a favorable outcome at end of induction compared to TNF-experienced patients. In summary, exposure-response was more evident at end of maintenance than at end of induction.

Molecular Hydrogen Therapy: Mechanisms, Delivery Methods, Preventive, and Therapeutic Application

Molecular hydrogen (H2), recognized as the smallest gas molecule, is capable of permeating cellular membranes and diffusing throughout the body. Due to its high bioavailability, H2 is considered a therapeutic gas for the treatment of various diseases. The therapeutic efficacy of hydrogen is contingent upon factors such as the administration method, duration of contact with diseased tissue, and concentration at targeted sites. H2 can be administered exogenously and is also produced endogenously within the intestinal tract. A comprehensive understanding of its delivery mechanisms and modes of action is crucial for advancing hydrogen medicine. This review highlights H₂'s mechanisms of action, summarizes its administration methods, and explores advancements in treating intestinal diseases (e.g., inflammatory bowel disease, intestinal ischemia-reperfusion, colorectal cancer). Additionally, its applications in managing other diseases are discussed. Finally, the challenges associated with its clinical application and potential solutions are explored. We propose that current delivery challenges faced by H2 can be effectively addressed through the use of nanoplatforms; furthermore, interactions between hydrogen and gut microbiota may provide insights into its mechanisms for treating intestinal diseases. Future research should explore the synergistic effects of H2 in conjunction with conventional therapies and develop personalized treatment plans to achieve precision medicine.

S1PR4-dependent effects of Etrasimod on primary human myeloid immune cell activation

Background

Sphingosine-1-phosphate (S1P) and its five receptors S1PR1-5 play an essential role in the migration, differentiation and activation of various immune cells. Several S1PR modulators with distinct selectivity have been recently approved for the treatment of various inflammatory diseases. Among those are Ozanimod, an S1PR1/5 modulator approved for the treatment of ulcerative colitis and multiple sclerosis, and Etrasimod, an S1PR1/4/5 modulator approved for the treatment of ulcerative colitis. Chronic autoinflammatory diseases such as the inflammatory bowel diseases (IBDs) Crohn's disease and ulcerative colitis are characterized by an abundance of disease-propagating immune cells in the gastrointestinal tract. Since currently available treatment options such as biologics provide a sometimes inadequate treatment response, one alternative strategy to treat IBDs is the use of S1P receptor modulators.

Objective

We aimed to investigate if targeting S1PR4 affects the impact of Etrasimod on the activation of primary human immune cells, and to elucidate the mode of action of Etrasimod on S1PR4.

Methods

Primary human macrophages, plasmacytoid dendritic cells and neutrophils were pretreated with S1P, Etrasimod (S1PR1/4/5), Ozanimod (S1PR1/5), Siponimod (S1PR1/5), CYM 50308 (S1PR4 agonist) and CYM 50358 (S1PR4 antagonist), and then stimulated with Zymosan A, ODN 2336 and PMA, respectively. We measured cytokine and chemokine production by macrophages and plasmacytoid dendritic cells via CBA/Legendplex, and survival and activation markers for neutrophils via flow cytometry. Confocal microscopy of S1PR-expressing CHO-K1 cell lines was used to study receptor internalization.

Results

We found that signaling induced by S1P, Etrasimod and the S1PR4 agonist attenuates CCL20 and CXCL5 production by Zymosan-stimulated macrophages, and these findings were confirmed by S1PR4 knockdown. Additionally, S1PR4 was involved in the regulation of IFN-α production by ODN2336-stimulated plasmacytoid dendritic cells. Lastly, both Etrasimod and the S1PR4 agonist reduced the activation level of PMA-stimulated neutrophils. Regarding receptor dynamics, we show that Etrasimod induces internalization of S1PR4.

Conclusion

Taken together, our data show that S1PR4 takes on an essential role in the regulation of various immunological functions, and that Etrasimod can act as a superagonist/functional antagonist of S1PR4.

Orally Bioavailable BRD4 BD1 Inhibitor ZL0516 Effectively Suppresses Colonic Inflammation in Animal Models of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), a chronic, progressive, and recurrent gastrointestinal inflammatory disorder, poses a significant threat to global health and exerts an adverse effect on the quality of life. Currently, there is a lack of effective therapies for IBD. Developing novel targeted therapies for IBD, particularly orally effective therapeutics, is a vital need for IBD patients. Herein, we first demonstrate that BRD4/NF-κB signaling is aberrantly activated in the colons of human IBD biopsy samples compared to that of normal healthy controls. ZL0516, a potent, selective, and orally bioavailable BRD4 BD1 inhibitor, significantly inhibits the TNFα- and LPS-induced expression of inflammatory cytokines in human colonic epithelial cells (HCECs) and peripheral blood mononuclear cells (PBMCs) with low cytotoxicity. Intriguingly, when administered in a preventive mode, ZL0516 significantly blocks dextran sulfate sodium (DSS)-induced murine colitis. When used in a therapeutic mode, ZL0516 effectively suppresses colonic inflammation in several IBD-relevant animal models: DSS-, oxazolone (OXA)-, and flagellin (Cbir1) T cell-induced chronic murine colitis models of IBD. ZL0516 suppresses IBD inflammatory responses in vitro and in vivo by blocking the activation of the BRD4/NF-κB signaling pathway. Also, we found that RVX208, a selective BRD4 BD2 inhibitor in Phase III clinical development, only displayed marginal effects in these IBD animal models. Collectively, our results demonstrate that specific BRD4 BD1 inhibition is a novel therapeutic strategy for IBD-associated colonic inflammation, and orally effective inhibitor ZL0516 is a promising candidate for the development of a novel therapeutic regimen against IBD.

Exploring the potential mechanism of B-phycoerythrin on DSS-induced colitis and colitis-associated bone loss based on network pharmacology, molecular docking, and experimental validation

B-phycoerythrin (B-PE), a pigment protein, has found extensive applications in the food, pharmaceutical, and cosmetic industries. However, the effects and potential mechanisms of B-PE on colitis and colitis-associated bone loss remain unclear. Thus, the aim of this study was to investigate the pharmacological mechanisms of B-PE against colitis and colitis-associated bone loss using network pharmacology analysis, molecular docking, and experimental validation. Based on public databases, 99 common targets of B-PE against inflammatory bowel disease and osteoporosis were predicted. The protein-protein interaction network identified 16 core targets, including TNF, AKT1, EGFR, etc., as hub targets. Additionally, functional enrichment analyses and molecular docking results revealed that the PI3K/AKT signaling pathway may serve as a potential signaling pathway for B-PE in the treatment of colitis and colitis-associated bone loss. Furthermore, pharmacological experiments indicated that B-PE not only reversed the elevated expression of TNF-α, IL-1β, MMP9, and CXCL8a, and the reduced expression of ZO-1, E-cadherin, COL1A1, and RUNX2 in the DSS-induced colitis zebrafish model, but also enhanced the phosphorylation of PI3K and AKT, thereby mitigating inflammatory response and promoting osteogenesis. In conclusion, this study provides a theoretical basis for considering B-PE as a promising candidate for the treatment of colitis and colitis-associated bone loss.

Exploring Chemoprevention in Colorectal Cancer for Patients with Inflammatory Bowel Disease: Mechanisms of Action and Clinical Aspects

Background: Inflammatory bowel diseases (IBDs) have been associated with a higher risk of colorectal cancer (CRC) development and chronic colonic inflammation seems to have a critical role in the pathogenesis of CRC in patients suffering from IBD. In respect to that, surveillance colonoscopy at regular intervals is recommended in patients with colitis. Objective: This review aims to explore the chemopreventive potential of a range of agents, including mesalazine, thiopurines, anti-TNF agents, statins, ursodeoxycholic acid, aspirin, folic acid, and nutraceuticals. Results: These agents target inflammation, oxidative stress, and oncogenic pathways, thereby offering the potential to reduce the risk of CRC in patients with IBD. Anti-TNF agents, such as infliximab and adalimumab, not only reduce colonic inflammation, but also play a protective role against CRC by lessening the carcinogenic effects associated with prolonged inflammatory processes. Furthermore, mesalazine and thiopurines have demonstrated established efficacy, while newer biologics, including interleukin inhibitors, show promising advancements. Although nutraceuticals and dietary interventions require further clinical validation, they offer additional possibilities for non-pharmacological prevention. Conclusion: Despite progress, knowledge gaps persist regarding the long-term safety, optimal dosing, and combined use of these agents. A significant reduction in the incidence of CRC in patients with IBD could be achieved by advancing chemoprevention and personalizing strategies.

Advancing Inflammatory Bowel Disease Treatment by Targeting the Innate Immune System and Precision Drug Delivery

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, involves chronic inflammation of the gastrointestinal tract. Current immune-modulating therapies are insufficient for 30-50% of patients or cause significant side effects, emphasizing the need for new treatments. Targeting the innate immune system and enhancing drug delivery to inflamed gut regions are promising strategies. Neutrophils play a central role in IBD by releasing reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) -DNA-based structures with cytotoxic proteins-that contribute to mucosal damage and inflammation. Recent studies linking ROS production, DNA repair, and NET formation have identified NETs as potential therapeutic targets, with preclinical models showing positive outcomes from NET inhibition. Innovative oral drug delivery systems designed to target gut inflammation directly-without systemic absorption-could improve treatment precision and reduce side effects. Advanced formulations utilize properties such as particle size, surface modifications, and ROS-triggered release to selectively target the distal ileum and colon. A dual strategy that combines a deeper understanding of IBD pathophysiology to identify inflammation-related therapeutic targets with advanced drug delivery systems may offer significant promise. For instance, pairing NET inhibition with ROS-responsive nanocarriers could enhance treatment efficacy, though further research is needed. This synergistic approach has the potential to greatly improve outcomes for IBD patients.

Risk of Infection in Patients With Inflammatory Bowel Disease Treated With Interleukin-Targeting Agents: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of infection. The aim of this study was to assess the cumulative incidence and risk of infection in patients with IBD treated with interleukin (IL)-targeting agents.

METHODS

We searched PubMed, EMBASE, and Web of Science for randomized controlled trials including patients with IBD receiving IL-targeting agents compared with patients receiving placebo or treatment that only differed from the intervention arm in the absence of an IL-targeting agent. The primary outcome of interest was the relative risk (RR) of any-grade and severe infection during the induction phase.

RESULTS

There was no difference in risk of any-grade (RR, 0.98; 95% confidence interval [CI], 0.89-1.09) or severe (RR, 0.64; 95% CI, 0.38-1.10) infection in patients receiving any IL-targeting agent compared with the control group. During the maintenance period, the cumulative incidence of any-grade infection in patients receiving IL-12/23p40-targeting agents (mean follow-up 29 weeks) was 34.82% (95% CI, 26.78%-43.32%), while the cumulative incidence of severe infection was 3.07% (95% CI, 0.93%-6.21%). The cumulative incidence of any-grade infection in patients receiving IL-23p19-targeting agents (mean follow-up 40.9 weeks) was 32.16% (95% CI, 20.63%-44.88%), while the cumulative incidence of severe infection was 1.75% (95% CI, 0.60%-3.36%). During the maintenance phase of the included studies, the incidence of infection was 30.66% (95% CI, 22.12%-39.90%) for any-grade and 1.59% (95% CI, 0.76%-2.63%) for severe infection in patients in the control group.

CONCLUSIONS

There was no difference in risk of infection between patients with IBD who received IL-targeting agents compared with the control group. Case registries and randomized controlled trials reporting the safety of IL inhibitors should provide detailed information about the risk of specific infectious complications in patients with IBD receiving IL-targeting agents.

Delivery of Encapsulated Intelligent Engineered Probiotic for Inflammatory Bowel Disease Therapy

Engineered bacterial therapy holds enormous potential for treating intestinal diseases, employing synthetic biology techniques to achieve localized drug delivery within intestines. However, effective delivery of engineered bacteria to lesion sites and ensuring sustained colonization remain challenging. Here, a mucus encapsulated microsphere gel (MM) delivery system is developed to encapsulate genetically engineered bacteria capable of detecting and treating enteritis. The MM delivery system features an external mucosal coating composed of hyaluronic acid and epigallocatechin gallate, along with internal microspheres of highly biocompatible polyserine modified alginates encapsulating with the engineered probiotics. The MM delivery system effectively protects engineered bacteria harsh environment in stomach and significantly improves intestinal adhesion of the probiotics, extending colonization up to 24 h, and does not affect the entry of biomarker or release of Avcystatin. It exhibits notable diagnostic and therapeutic efficacy in inflammatory bowel disease models, thus facilitating the advancement of live biotherapeutic products toward clinical application.

Targeted surgery combined with postoperative medical therapy for residual disease for severe and multifocal Crohn disease

BACKGROUND

In patients with multifocal intestinal Crohn disease requiring surgery for complication or uncontrolled disease, resection of all the lesions may lead to diarrhea and malnutrition.

METHODS

This is a single-center retrospective review of all patients undergoing targeted surgery for multifocal Crohn disease with at least one residual Crohn disease location left behind. The primary endpoint was the rate of insufficient control of residual Crohn disease lesions requiring redo-surgery targeting these lesions. The rate of clinical remission defined by Harvey-Bradshaw index <4 was studied over time.

RESULTS

From January 2012 to August 2022, among 320 patients undergoing surgery for intestinal Crohn disease, 30 met all criteria. Before surgery, patients had received a mean of 3 medical treatment lines; 83% (n = 25) had a clinically active Crohn disease (Harvey-Bradshaw index ≥4). Surgery consisted in ileocolonic (n = 14;47%), small bowel (n = 5;17%) or colonic resection (n = 12;40%) and strictureplasty (n = 4;13%). Operative mortality was nil. Overall postoperative and severe morbidity rates were 15 of 30 (50%) and 3 of 30. Residual lesions were in the small bowel (n = 15;50%), the colon (n = 16;53%), and/or the rectum (n = 16;53%). Twenty-five patients (83%) had postoperative medical therapy. Median follow-up was 65. Six patients (20%) required reoperation for insufficient control of residual lesions at index surgery after a mean of 98 ± 8 months. The clinical remission rate increased from 17% before surgery to 59% at 6-12 months and 71% at 24 months.

CONCLUSION

In patients with multifocal Crohn disease, surgery targeted to severe and complicated lesions combined with postoperative medical treatment is a safe and effective strategy.

PepT1-targeted nanodrug based on co-assembly of anti-inflammatory peptide and immunosuppressant for combined treatment of acute and chronic DSS-induced ColitiS

INTRODUCTION

Inflammatory bowel disease (IBD), as a chronic and recurrent inflammatory bowel diseases with limited therapeutic outcomes, is characterized by immune disorders and intestinal barrier dysfunction. Currently, the most medications used to cure IBD in clinic just temporarily induce and maintain remission with poor response rates and limited outcomes. Therefore, it is urgently necessary to develop an appropriate therapeutic candidate with preferable efficacy and less adverse reaction for curing IBD.

METHODS

Five groups of mice were utilized: control that received saline, DSS group (mice received 2.5% DSS or 4% DSS), KPV group (mice received KPV), FK506 group (mice received FK506) and NPs groups (mice received NPs). The effect of NP on the inflammatory factors of macrophage was evaluated using CCK-8, quantitative polymerase chain reaction (PCR), Elisa and Western blot (WB). Immunofluorescent staining revealed the targeting relationship between NP and Petp-1. Immunohistochemistry staining showed the effect of NP on tight junction proteins. Moreover, in vivo animal experiments confirmed that NPs reduced inflammatory levels in IBD.

RESULTS AND DISCUSSION

After administering with NPs, mice with DSS-induced acute or chronic colitis exhibited significant improvement in body weight, colon length, and disease activity index, decreased the level of the factors associated with oxidative stress (MPO, NO and ROS) and the inflammatory cytokines (TNF-α, IL-1β and IL-6), which implied that NPs could ameliorate murine colitis effectively. Furthermore, treating by NPs revealed a notable reduction of the expressions of CD68 and CD3, restoring the expression levels of tight junction proteins (Claudin-5, Occludin-1, and ZO-1) were significantly restored, surpassing those observed in the KPV and FK506 groups. which indicated that NPs can reduce inflammation and enhance epithelial barrier integrity by decreasing the infiltration of macrophages and T-lymphocytes. Collectively, those results demonstrated the effectively therapeutic outcome after using NPs in both acute and chronic colitis, suggesting that the newly co-assembled of NPs can be as a potential therapeutic candidate for colitis.

pH-Sensitive Hydrogels Fabricated with Hyaluronic Acid as a Polymer for Site-Specific Delivery of Mesalamine

Hydrogels with the main objective of releasing mesalamine (5-aminosalicylic acid) in the colon in a modified manner were formulated in the present work using a free-radical polymerization approach. Different ratios of hyaluronic acid were cross-linked with methacrylic and acrylic acids using methylenebis(acrylamide). The development of a new polymeric network and the successful loading of drug were revealed by Fourier transform infrared spectroscopy. Thermogravimetric analysis demonstrated that the hydrogel was more thermally stable than the pure polymer and drug. Scanning electron microscopy (SEM) revealed a rough and hard surface which was relatively suitable for efficient loading of drug and significant penetration of dissolution medium inside the polymeric system. Studies on swelling and drug release were conducted at 37 °C in acidic and basic conditions (pH 1.2, 4.5, 6.8, and 7.4, respectively). Significant swelling and drug release occurred at pH 7.4. Swelling, drug loading, drug release, and gel fraction of the hydrogels increased with increasing hyaluronic acid, methacrylic acid, and acrylic acid concentrations, while the sol fraction decreased. Results obtained from the toxicity study proved the formulated system to be safe for biological systems. The pH-sensitive hydrogels have the potential to be beneficial for colon targeting due to their pH sensitivity and biodegradability. Inflammatory bowel disease may respond better to hydrogel treatment as compared to conventional dosage forms. Specific amount of drug is released from hydrogels at specific intervals to maintain its therapeutic concentration at the required level.

Thiopurines have no impact on outcomes of Crohn's disease patients beyond 12 months of maintenance treatment with infliximab

BACKGROUND

The emergence of new treatments the inflammatory bowel diseases (IBD) raised questions regarding the role of older agents, namely thiopurines.

AIMS

To clarify the benefits of combination treatment with thiopurines on Crohn's disease (CD) patients in the maintenance phase of infliximab.

METHODS

In this analysis of the 2-year prospective multicentric DIRECT study, patients were assessed in terms of clinical activity, faecal calprotectin (FC), C-reactive protein (CRP), and infliximab pharmacokinetics. A composite outcome based on clinical- and drug-related items was used to define treatment failure.

RESULTS

The study included 172 patients; of these, 35.5 % were treated with combination treatment. Overall, 18 % of patients achieved the composite outcome, without statistically significant differences between patients on monotherapy and on combination treatment (21.6% vs 11.5 %, p = 0.098). Median CRP, FC, and infliximab pharmacokinetic parameters were similar in both groups. However, in the sub-analysis by infliximab treatment duration, in patients treated for less than 12 months, the composite outcome was reached in fewer patients in the combination group than in the monotherapy group (7.1% vs 47.1 %, p = 0.021).

CONCLUSION

In CD patients in maintenance treatment with infliximab, combination treatment does not seem to have benefits over infliximab monotherapy beyond 12 months of treatment duration.

Selecting first-line advanced therapy for ulcerative colitis: A clinical application of personalized medicine

Ulcerative colitis (UC) is a chronic autoimmune inflammatory disease that affects the colon, leading to symptoms of bloody diarrhea, abdominal cramps, and urgency. The treatment of UC has evolved over the past few decades from locally active anti-inflammatory compounds to more selective therapies that target specific arrays of the immune system. The challenge of selecting the first advanced therapy became apparent in this rapidly expanding landscape of medications. No current investigational tools, such as genetic, immunologic, or biological markers, can guide the identification of the safest and most effective therapeutic option for each patient. Hence, physicians must carefully assess patient/disease characteristics and match them with the most suitable drug through a clinically driven assessment. In this paper, we outline patient and drug characteristics that play a role in selecting first-line advanced therapies for UC and propose an algorithm for selection.

Positioning risankizumab in the treatment algorithm of moderate-to-severe Crohn's disease

Risankizumab is a humanized monoclonal antibody that inhibits the p19 subunit of IL-23 cytokine. Recently it has been approved for the treatment of patients with moderate-to-severe Crohn's disease (CD). We conducted a scoping review to summarize the available data on risankizumab and to define its positioning in the treatment algorithm of CD. Pubmed, Embase and Scopus databases were searched up to Oct 31, 2023 to identify studies reporting efficacy and safety data of risankizumab in patients with CD. Risankizumab is an effective and safe drug for the management of patients with moderate-to-severe CD. It could be used as first-line therapy in biologic-naive patients and in patients who have previously failed other biological therapies.

Tofacitinib uptake by patient-derived intestinal organoids predicts individual clinical responsiveness

Background & Aims

Despite increasing therapeutic options in the treatment of ulcerative colitis (UC), achieving disease remission remains a major clinical challenge. Nonresponse to therapy is common and clinicians have little guidance in selecting the optimal therapy for an individual patient. This study examined whether patient-derived materials could predict individual clinical responsiveness to the Janus kinase (JAK) inhibitor, tofacitinib, prior to treatment initiation.

Method

In 48 patients with UC initiating tofacitinib, we longitudinally collected clinical covariates, stool, and colonic biopsies to analyze the microbiota, transcriptome, and exome variations associated with clinical responsiveness at week 24. We established patient-derived organoids (n = 23) to determine how their viability upon stimulation with proinflammatory cytokines in the presence of tofacitinib related to drug responsiveness in patients. We performed additional biochemical analyses of organoids and primary tissues to identify the mechanism underlying differential tofacitinib sensitivity.

Results

The composition of the gut microbiota, rectal transcriptome, inflammatory biomarkers, and exome variations were indistinguishable among UC patients prior to tofacitinib treatment. However, a subset of patient-derived organoids displayed reduced sensitivity to tofacitinib as determined by the ability of the drug to inhibit STAT1 phosphorylation and loss of viability upon cytokine stimulation. Remarkably, sensitivity of organoids to tofacitinib predicted individual clinical patient responsiveness. Reduced responsiveness to tofacitinib was associated with decreased levels of the cationic transporter MATE1, which mediates tofacitinib uptake.

Conclusions

Patient-derived intestinal organoids predict and identify mechanisms of individual tofacitinib responsiveness in UC. Specifically, MATE1 expression predicted clinical response to tofacitinib.

The role of filgotinib in ulcerative colitis and Crohn's disease

Filgotinib is an oral small molecule that selectively inhibits JAK1. It is already approved for the treatment of moderately to severely active ulcerative colitis (UC). Ongoing studies are evaluating the efficacy and safety of filgotinib in Crohn's disease (CD). The purpose of this review is to summarize the available data regarding filgotinib in the management of UC and CD. We used Pubmed, Embase and clinicaltrials.gov websites to search all available data and currently ongoing studies regarding the efficacy and safety of filgotinib in inflammatory bowel diseases. Filgotinib is an effective and safe drug for the management of biologic-naive and biologic-experienced patients with moderate-to-severe UC. The same efficacy results have not been achieved in CD.

D-Mannose promotes recovery from experimental colitis by inducing AMPK phosphorylation to stimulate epithelial repair

Delayed mucosal healing and impaired intestinal epithelial barrier function have been implicated in the pathogenesis of ulcerative colitis (UC). Accordingly, restoration of epithelial barrier function as a means to reshape mucosal homeostasis represents an important strategy for use in the treatment of UC. In this study, we examined the role and mechanisms of D-mannose in the recovery of colitis as assessed in both animal and cell models. We found that D-mannose ameliorated inflammation, promoted mucosal healing in the colon and therefore was able to induce the recovery of UC. Furthermore, D-mannose increased the expression of tight junction (TJ) proteins and reduced the intestinal permeability during the recovery of colitis. Moreover, D-mannose inhibited M1 macrophage polarization and promoted M2 macrophage polarization via inducing AMPK phosphorylation while reducing mTOR phosphorylation in both models. In addition, increased TJ protein expression and decreased paracellular permeability were observed in NCM460 cells when incubated with the supernatants of D-mannose-treated RAW264.7 cells, suggesting that M1/M2 polarization induced by D-mannose modulates the expression of TJ proteins. Further study showed that D-mannose significantly upregulated the expression of TJ proteins in DSS-treated NCM460 cells by inducing AMPK phosphorylation, indicating a direct protective effect on epithelial cells. Finally, the protective effects of D-mannose were significantly abrogated by the presence of compound C, an AMPK inhibitor. Taken together, our data indicate that D-mannose can alleviate inflammation and foster epithelial restitution in UC recovery by inducing the TJ protein expression, which are achieved by inducing AMPK phosphorylation in the epithelium and/or macrophages.

Safety of perioperative treatment with biologics in patients with inflammatory bowel disease undergoing bowel surgery: Experience from a large urban center

BACKGROUND AND AIMS

Risks of peri- and postoperative complications after bowel surgery in patients with inflammatory bowel disease (IBD) receiving biologics are still discussed controversially. We therefore addressed the safety of different biologics that were applied in our IBD center before surgery.

METHODS

Data of IBD patients who underwent bowel resections between 2012 and 2022 at our hospital were analyzed retrospectively. Exposure to biologics was defined by receiving biologics within 12 weeks before resective abdominal surgery. Safety considerations included minor complications, such as infections and wound healing disorders and major complications, e.g., anastomotic insufficiency or abscess formation.

RESULTS

A total of 447 IBD patients (334 with Crohn's disease, 113 with ulcerative colitis), 51.9% female, were included and followed for a median follow-up of 45 months [range 0-113]. A total of 73.9% (326/447) were undergoing medical treatment at date of surgery, 61.5% (275/447) were treated with biologics within 3 months and 42.3% (189/447) within 4 weeks before surgery. Most surgeries (97.1%) were planned electively and 67.8% were performed laparoscopically. Major and minor complications occurred in 20.8% (93/447) of patients. Serious complications were rare: Six patients had acute postoperative bleeding, one CD patient developed peritonitis and two CD patients died postoperatively. After adjusting for age, disease duration, disease activity, Montreal classification, and medical treatment at date of surgery, no significant differences were observed regarding complications and exposure to biologics.

CONCLUSIONS

This retrospective single center study of 447 IBD patients goes to demonstrate that perioperative use of biologics is not associated with a higher risk of complications.

Rectal delivery of 89Zr-labeled infliximab-loaded nanoparticles enables PET imaging-guided localized therapy of inflammatory bowel disease

Inflammatory bowel diseases (IBDs) like Crohn's disease and ulcerative colitis involve chronic gastrointestinal inflammation. The pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) drives IBD pathogenesis. Anti-TNF-α therapies using monoclonal antibodies (mAbs) like infliximab (INF) help treat IBD but have limitations. We developed inflammation-targeting polyphenol-poloxamer nanoparticles loaded with the anti-inflammatory mAb INF (INF@PPNP) as a novel IBD therapy. Characterization showed that INF@PPNP had favorable stability and purity. Radiolabeling INF@PPNP with 89Zr enabled tracking localization with positron emission tomography (PET) imaging. Rectal administration of 89Zr-INF@PPNP led to colon delivery with remarkably reduced systemic exposure versus intravenous INF revealed by non-invasive PET imaging. 89Zr-INF@PPNP retention at inflamed foci indicated prolonged INF@PPNP action. INF@PPNP rectally achieved similar anti-inflammatory effects as intravenously injected INF, demonstrating the high therapeutic potential. Our findings support the use of nanoparticle-based rectal administration for localized drug delivery, prolonging drug activity and minimizing systemic exposure, ultimately offering an effective approach for treating IBD.

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

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

SIRT3 Activator Honokiol Inhibits Th17 Cell Differentiation and Alleviates Colitis

BACKGROUND

Honokiol (HKL), a natural extract of the bark of the magnolia tree and an activator of the mitochondrial protein sirtuin-3 (SIRT3), has been proposed to possess anti-inflammatory effects. This study investigated the inhibitory effects of HKL on T helper (Th) 17 cell differentiation in colitis.

METHODS

Serum and biopsies from 20 participants with ulcerative colitis (UC) and 18 healthy volunteers were collected for the test of serum cytokines, flow cytometry analysis (FACS), and relative messenger RNA (mRNA) levels of T cell subsets, as well as the expression of SIRT3 and phosphorylated signal transducer and activator of transcription/retinoic acid-related orphan nuclear receptor γt (p-STAT3/RORγt) signal pathway in colon tissues. In vitro, naïve clusters of differentiation (CD) 4 + T cells isolated from the mouse spleen differentiated to subsets including Th1, Th2, Th17, and regulatory T (Treg) cells. Peripheral blood monocytes (PBMCs) from healthy volunteers were induced to the polarization of Th17 cells. After HKL treatment, changes in T cell subsets, related cytokines, and transcription factors were measured. The dextran sulfate sodium (DSS)-induced colitis and interleukin (IL)-10-deficient mice were intraperitoneally injected with HKL. These experiments were conducted to study the effect of HKL on the development, cytokines, and expression of signaling pathway proteins in colitis.

RESULTS

Patients with UC had higher serum IL-17 and a higher proportion of Th17 differentiation in blood compared with healthy participants; while IL-10 level and the proportion of Treg cells were lower. Higher relative mRNA levels of RORγt and a lower SIRT3 expression in colon tissues were observed. In vitro, HKL had little effect on the differentiation of naïve CD4+ T cells to Th1, Th2, or Treg cells, but it downregulated IL-17 levels and the Th17 cell ratio in CD4+ T cells from the mouse spleen and human PBMCs under Th17 polarization. Even with a STAT3 activator, HKL still significantly inhibited IL-17 levels. In DSS-induced colitis mice and IL-10 deficient mice treated with HKL, the length of the colon, weight loss, disease activity index, and histopathological scores were improved, IL-17 and IL-21 levels, and the proportion of Th17 cells were decreased. Sirtuin-3 expression was increased, whereas STAT3 phosphorylation and RORγt expression were inhibited in the colon tissue of mice after HKL treatment.

CONCLUSIONS

Our study demonstrated that HKL could partially protect against colitis by regulating Th17 differentiation through activating SIRT3, leading to inhibition of the STAT3/RORγt signaling pathway. These results provide new insights into the protective effects of HKL against colitis and may facilitate the research of new drugs for inflammatory bowel disease.

Efficacy and Safety of Advanced Oral Small Molecules for Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Oral small-molecule drugs [SMDs] are expanding the therapeutic landscape for inflammatory bowel disease [IBD]. This systematic review and meta-analysis summarizes the efficacy and safety of JAK inhibitor [JAKi] and sphingosine-1-phosphate [S1P] receptor modulator treatments for ulcerative colitis [UC] and Crohn's disease [CD].

METHODS

MEDLINE, Embase, and CENTRAL were searched from inception to May 30, 2022. Randomized controlled trials [RCTs] of JAKi and S1P receptor modulators in adults with UC or CD were eligible. Clinical, endoscopic, histological, and safety data were pooled and analysed using a random-effects model.

RESULTS

Thirty-five RCTs [26 UC, nine CD] were included. In UC, JAKi therapy was associated with induction of clinical (risk ratio [RR] 3.16, 95% confidence interval [CI] 2.03-4.92; I2 = 65%) and endoscopic [RR 3.99, 95% CI 2.36-6.75; I2 = 36%] remission compared to placebo. Upadacitinib was associated with histological response [RR 2.63, 95% CI 1.97-3.53]. S1P modulator therapy was associated with induction of clinical [RR 2.52, 95% CI 1.88-3.39; I2 = 1%] and endoscopic [RR 2.39, 95% CI 1.07-5.33; I2 = 0%] remission relative to placebo. Ozanimod was superior to placebo for inducing histological remission in UC [RR 2.20, 95% CI 1.43-3.37; I2 = 0%], while etrasimod was not [RR 2.36, 95% CI 0.71-7.88; I2 = 0%]. In CD, JAKi therapy was superior to placebo for induction of clinical remission [RR 1.53, 95% CI 1.19-1.98; I2 = 31%], and endoscopic remission [RR 4.78, 95% CI 1.63-14.06; I2 = 43%] compared to placebo. The risk of serious infections was similar for oral SMDs and placebo.

CONCLUSION

JAKi and S1P receptor modulator therapies are effective in IBD for inducing clinical and endoscopic remission and, in some circumstances, histological response.

Kinase Signaling in Colitis-Associated Colon Cancer and Inflammatory Bowel Disease

Colorectal cancer is a known complication of chronic inflammation of the colon ("colitis-associated colon cancer"). Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Patients with IBD are at increased risk of colon cancer compared to the general population. Kinase signaling pathways play critical roles in both the inflammation and regulating cellular processes such as proliferation and survival that contribute to cancer development. Here we review the interplay of kinase signaling pathways (mitogen-activated protein kinases, cyclin-dependent kinases, autophagy-activated kinases, JAK-STAT, and other kinases) and their effects on colitis-associated colon cancer. We also discuss the role of JAK-STAT signaling in the pathogenesis of IBD and the therapeutic landscape of JAK inhibitors for the treatment of IBD.

Paeonol alleviates ulcerative colitis in mice by increasing short-chain fatty acids derived from Clostridium butyricum

BACKGROUND

Increasing evidence suggests that repairing the damaged intestinal epithelial barrier and restoring its function is the key to solving the problem of prolonged ulcerative colitis. Previous studies have shown that paeonol (pae) can alleviate colitis by down-regulating inflammatory pathways. In addition, pae also has a certain effect on regulating intestinal flora. However, it remains unclear whether pae can play a role in repairing the intestinal barrier and whether there is a relationship between the therapeutic effect and the gut microbiota.

PURPOSES

The aim of this study is to investigate the effect of pae on intestinal barrier repair in UC mice and how the gut microbiota plays a part in it.

STUDY DESIGN AND METHODS

The therapeutic effect of pae was evaluated in a 3% DSS-induced UC mouse model. The role of pae in repairing the intestinal barrier was evaluated by detecting colonic cupped cells by Alcian blue staining, the expression of colonic epithelial tight junction protein by immunofluorescence and western blot, and the proportion of IL-22+ILC3 cells in the lamina propria lymphocytes by flow cytometry. Subsequently, 16S rRNA sequencing was used to observe the changes in intestinal flora, GC-MS was used to detect the level of SCFAs, and qPCR was used to identify the abundance of Clostridium butyricum in the intestine to evaluate the effect of pae on the gut microbiota. The antibiotic-mediated depletion of the gut flora was then used to verify that pae depends on C. butyricum to play a healing role. Finally, non-targeted metabolomics was employed to investigate the potential pathways of pae regulating C. butyricum.

RESULTS

Pae could improve intestinal microecological imbalance and promote the production of short-chain fatty acids (SCFAs). Most importantly, we identified C. butyricum as a key bacterium responsible for the intestinal barrier repair effect of pae in UC mice. Eradication of intestinal flora by antibiotics abolished the repair of the intestinal barrier and the promotion of SCFAs production by pae, while C. butyricum colonization could restore the therapeutic effects of pae in UC mice, which further confirmed that C. butyricum was indeed the "driver bacterium" of pae in UC treatment. Untargeted metabolomics showed that pae regulated some amino acid metabolism and 2-Oxocarboxylic acid metabolism in C. butyricum.

CONCLUSIONS

Our study showed that the restoration of the impaired intestinal barrier by pae to alleviate colitis is associated with increased C. butyricum and SCFAs production, which may be a promising strategy for the treatment of UC.

Role of Serum Interleukin-6, Interleukin-1β and Interleukin-10 in Assessment of Disease Activity and Nutritional Status in Patients with Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are characterised by multifactorial and chronic inflammation. Much attention has been paid to immune dysfunction in inflammatory bowel diseases. The aim of this study was to assess the usefulness of serum IL-6, IL-1β and IL-10 in determining the activity and nutritional status in IBD patients. The case-control study was carried out on 82 patients with IBD; the control group consisted of 25 clinically healthy subjects. The serum concentrations of IL-6, IL-1 β and IL-10 were determined by the quantitative sandwich enzyme-linked immunosorbent assay. There were no significant differences in IL-6 and IL-1β levels in UC and CD patients according to disease activity as assessed by the Montreal classification, Partial Mayo Score and CDAI. Significantly higher IL-6 levels were found in patients with low body fat in comparison to patients with normal body fat. Furthermore, significantly higher mean IL-6 levels were observed in patients with excess body fat in comparison to patients with normal body fat, and also in comparison to patients with deficient body fat. IL-6 and IL-1β may provide extra information regarding the nutritional status of IBD patients. IL-10 can be considered a non-invasive biomarker of IBD activity.

Understanding the efficacy of individual Janus kinase inhibitors in the treatment of ulcerative colitis for future positioning in inflammatory bowel disease treatment

Recent studies have gradually elucidated the pathogenesis of inflammatory bowel disease; thus, the Janus kinase (JAK)-signal transducers and activators of transcription pathway are strongly involved in the pathophysiology of inflammatory bowel disease. Generally, Janus kinase inhibitors are being used for the treatment of rheumatoid arthritis and other immunological diseases, with the therapeutic promising effects. Currently, in Japan, three Janus kinase inhibitors, namely tofacitinib, filgotinib, and upadacitinib, are available for the treatment of patients with active ulcerative colitis. Therefore, evaluating the efficacy and safety of each JAK inhibitor is essential for determining the role of JAK inhibitors in future therapeutic strategies for inflammatory bowel disease (IBD).

Safety Summary of Pediatric Inflammatory Bowel Disease Therapies

Therapeutic options for the treatment of pediatric inflammatory bowel disease include aminosalicylates, enteral nutrition, corticosteroids, immunomodulators, biologics, and emerging small molecule agents. Infectious risk due to systemic immunosuppression should be mitigated by appropriate screening before therapy initiation. Rare but serious malignancies have been associated with thiopurine use alone and in combination with anti-tumor necrosis factor agents, often in the setting of a primary Epstein-Barr virus infection. Potential agent-specific adverse events such as cytopenias, hepatotoxicity, and nephrotoxicity warrant regular clinical and laboratory monitoring.

Gut-licensed β7+ CD4+ T cells contribute to progressive retinal ganglion cell damage in glaucoma

Glaucoma is the leading cause of irreversible blindness. Currently, most therapeutic strategies aim to reduce elevated intraocular pressure (EIOP), but this does not always halt disease progression. Evidence suggests a role for T cells in glaucoma pathogenesis, but the underlying mechanisms remain largely unknown. Here, we found that the percentage of circulating CD4+ T cells expressing a gut-homing integrin β7 was increased in patients with glaucoma and was associated with disease stage. In an EIOP-triggered glaucoma mouse model, β7+ CD4+ T cells infiltrated the retina in the progressive phase of glaucoma via eliciting retinal endothelial cell expression of mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1). MAdCAM-1 was minimally detected in retinas of healthy mice, and neutralization with an MAdCAM-1 antibody ameliorated retinal ganglion cell (RGC) loss and glial activity in mice with glaucoma. We furthermore found that EIOP-induced β7+ CD4+ T cells homed to the gut during the acute phase of glaucoma, which was essential for progressive RGC damage in diseased mice. Gut-homing β7+ CD4+ T cells underwent transcriptional reprogramming, showing up-regulated pathways enriched in autoimmune diseases, bacteria responses, mucosal immunity, and glial activity. Gut-homing β7+ CD4+ T cells gained the competence to induce retinal MAdCAM-1 expression and to cross the blood-retina barrier. Together, our study reveals a role of gut-licensed β7+ CD4+ T cells and MAdCAM-1 in RGC degeneration and emphasizes the importance of the "gut-retina" axis in glaucoma.

Gene expression profiling in white blood cells reveals new insights into the molecular mechanisms of thalidomide in children with inflammatory bowel disease

Thalidomide has emerged as an effective immunomodulator in the treatment of pediatric patients with inflammatory bowel disease (IBD) refractory to standard therapies. Cereblon (CRBN), a component of E3 protein ligase complex that mediates ubiquitination and proteasomal degradation of target proteins, has been identified as the primary target of thalidomide. CRBN plays a crucial role in thalidomide teratogenicity, however it is unclear whether it is also involved in the therapeutic effects in IBD patients. This study aimed at identifying the molecular mechanisms underpinning thalidomide action in pediatric IBD. In this study, ten IBD pediatric patients responsive to thalidomide were prospectively enrolled. RNA-sequencing (RNA-seq) analysis and functional enrichment analysis were carried out on peripheral blood mononuclear cells (PBMC) obtained before and after twelve weeks of treatment with thalidomide. RNA-seq analysis revealed 378 differentially expressed genes before and after treatment with thalidomide. The most deregulated pathways were cytosolic calcium ion concentration, cAMP-mediated signaling, eicosanoid signaling and inhibition of matrix metalloproteinases. Neuronal signaling mechanisms such as CREB signaling in neurons and axonal guidance signaling also emerged. Connectivity Map analysis revealed that thalidomide gene expression changes were similar to those exposed to MLN4924, an inhibitor of NEDD8 activating enzyme, suggesting that thalidomide exerts its immunomodulatory effects by acting on the ubiquitin-proteasome pathway. In vitro experiments on cell lines confirmed the effect of thalidomide on candidate altered pathways observed in patients. These results represent a unique resource for enhanced understanding of thalidomide mechanism in pediatric patients with IBD, providing novel potential targets associated with drug response.

Rates, predictive factors and effectiveness of ustekinumab intensification to 4- or 6-weekly intervals in Crohn's disease

BACKGROUND

The UNITI trial reports efficacy of ustekinumab (UST) dose intensification in Crohn's disease (CD) from 12- to 8-weekly, but not 4-weekly. We aimed 1) to assess the cumulative incidence of UST dose intensification to 4- or 6-weekly, 2) to identify factors associated with dose intensification, and 3) to assess the effectiveness of this strategy.

METHODS

We performed a retrospective, observational cohort study in NHS Lothian including all UST treated CD patients (2015-2020).

RESULTS

163 CD patients were treated with UST (median follow-up: 20.3 months [13.4-38.4]), of whom 55 (33.7%) underwent dose intensification to 4-weekly (n = 50, 30.7%) or 6-weekly (n = 5, 3.1%). After 1 year 29.9% were dose intensified. Prior exposure to both anti-TNF and vedolizumab (HR 9.5; 1.3-70.9), and concomitant steroid use at UST start (HR 1.8; 1.0-3.1) were associated with dose intensification. Following dose intensification, 62.6% patients (29/55) remained on UST beyond 1 year. Corticosteroid-free clinical remission was achieved in 27% at week 16 and 29.6% at last follow-up.

CONCLUSION

One third of CD patients treated with UST underwent dose intensification to a 4- or 6-weekly interval within the first year. Patients who failed both anti-TNF and vedolizumab, or required steroids at initiation were more likely to dose intensify.

The evolving role of JAK inhibitors in the treatment of inflammatory bowel disease

INTRODUCTION

Janus Kinase inhibitors (JAKi) are a new class of oral therapies for the treatment of moderate-severe ulcerative colitis with additional potential for the treatment of moderate-severe Crohn's disease. In contrast to biologic therapies JAKi provide the opportunity for non-immunogenic once or twice daily oral therapies.

AREAS COVERED

Janus Kinase inhibitors for the treatment of ulcerative colitis and Crohn's disease based on mechanism of action, pharmacokinetics, clinical trial and real-world data regarding safety and efficacy; focusing on regulatory approvals in the U.S. and Europe.

EXPERT OPINION

Janus Kinase inhibitors are considered among the 'advanced therapies' for IBD and are approved for the treatment of moderate to severe ulcerative colitis in adults with pending approvals for Crohn's disease in the U.S. JAKi offer non-immunogenic, oral options for patient not responding to other conventional agents but, have been 'restricted' by the FDA to patients with inadequate response to TNF blockers. JAKi offer rapidly acting oral alternatives to biologic agents for moderate-severe ulcerative colitis where the risks of cardiovascular and thrombotic events noted in rheumatoid arthritis have not been observed in IBD clinical trials. Nevertheless, monitoring of infections (primarily herpes zoster) and risk factors for cardiovascular and thrombotic complications is appropriate.

Polysaccharides from Paecilomyces hepiali Prevent Acute Colitis in Association with Modulating Gut Microbiota and Treg/Th17 Immune Balance in Mice

Cordyceps exopolysaccharide (CEP) has shown emerging potential in adjustment of gut microbiota and immune cell function. In this study, a water-soluble CEP with a molecular weight of 58.14 kDa was extracted from the fermentation broth of Paecilomyces hepiali, an endophytic fungus of Cordyceps sinensis. Our results indicated that Paecilomyces hepiali polysaccharide (PHP) showed significantly preventive potential on dextran sulfate sodium (DSS)-induced colitis in mice, which can prevent colon shortening, reduce intestinal epithelial cell (IEC) destruction, suppress inflammatory cell infiltration, and regulate the balance between regulatory T (Treg) cells and T helper type 17 (Th17) cells. Meanwhile, the disturbed gut microbiota was partially restored after PHP treatment. Further Pearson correlation coefficient analyses exhibited that the alteration of the gut microbiota was significantly related to adjustment of the IEC barrier and Treg/Th17 balance. In conclusion, all findings proposed that purified PHP has the potential to develop into a promising agent for colitis prevention and adjuvant therapy via maintaining intestinal homeostasis of gut microbiota and immune system.

Advancements in Inflammatory Bowel Disease: A Narrative Review of Diagnostics, Management, Epidemiology, Prevalence, Patient Outcomes, Quality of Life, and Clinical Presentation

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is a chronic, immune-mediated disorder that impacts the gastrointestinal tract. Significant advancements in the diagnosis and treatment of IBD have been made during the past few decades, improving patient outcomes. This narrative review aims to provide an overview of recent developments in the diagnosis and treatment of IBD. Both from an evaluative and therapeutic standpoint, the management of IBD has undergone significant change. The standard of treatment for treating UC and CD patients has changed due to several medical developments. These developments include amino-salicylates, immunosuppressants, biological agents, and new therapeutics. The review also addresses the difficulties in applying these developments in clinical practice. Globally, the prevalence of IBD is rising, with Asia among the regions with the highest rates. These environments provide particular difficulties, such as poor disease knowledge, a lack of diagnostic services, and infectious IBD mimics. These issues must be resolved to diagnose and manage IBD in these populations accurately. New imaging modalities and other improvements in diagnostic methods have increased the precision and early identification of IBD. To reduce problems and improve patient outcomes, healthcare professionals treating patients with IBD must work effectively as a team. An extensive summary of current developments in the diagnosis and treatment of IBD is given in this narrative review. It draws attention to the therapeutic possibilities, difficulties, and uncertainties of integrating these developments into clinical practice. By keeping up with these changes, healthcare practitioners can better care for patients with IBD and improve their quality of life.

Inflammation-Driven Colorectal Cancer Associated with Colitis: From Pathogenesis to Changing Therapy

Patients affected by inflammatory bowel disease (IBD) have a two-fold higher risk of developing colorectal cancer (CRC) than the general population. IBD-related CRC follows a different genetic and molecular pathogenic pathway than sporadic CRC and can be considered a complication of chronic intestinal inflammation. Since inflammation is recognised as an independent risk factor for neoplastic progression, clinicians strive to modulate and control disease, often using potent therapy agents to achieve mucosal healing and decrease the risk of colorectal cancer in IBD patients. Improved therapeutic control of inflammation, combined with endoscopic advances and early detection of pre-cancerous lesions through surveillance programs, explains the lower incidence rate of IBD-related CRC. In addition, current research is increasingly focused on translating emerging and advanced knowledge in microbiome and metagenomics into personalised, early, and non-invasive CRC screening tools that guide organ-sparing therapy in IBD patients. This review aims to summarise the existing literature on IBD-associated CRC, focusing on new insights into the alteration of the intestinal barrier and the interactions with the gut microbiome as the initial promoter. In addition, the role of OMIC techniques for precision medicine and the impact of the available IBD therapeutic armamentarium on the evolution to CRC will be discussed.

Review article: Risk of cardiovascular events in patients with inflammatory bowel disease receiving small molecule drugs

BACKGROUND

In the context of an ageing inflammatory bowel disease (IBD) population, cardiovascular comorbidities become particularly relevant. Novel small molecule drugs (SMDs) for the treatment of moderate-to-severe IBD have been recently approved, including Janus kinase (JAK) inhibitors and sphingosine-1-phosphate receptor (S1P) modulators. Data from rheumatoid arthritis population have raised concerns about the risk of cardiovascular events with the use of tofacitinib, which was extrapolated to other immune-mediated diseases and other JAK inhibitors. S1P receptor modulation has been associated with potential cardiovascular events, especially bradycardia and cardiac conduction abnormalities.

AIM

To review the incidence of cardiovascular events with the use of SMDs in patients with IBD and to provide practical recommendations on mitigation strategies.

METHODS

Published literature was reviewed; recommendations were synthesised by experts in both cardiovascular diseases and IBD.

RESULTS

Evidence from the IBD population does not indicate a higher risk of cardiovascular events with tofacitinib and other JAK inhibitors. The risk is higher in patients with intermediate to high cardiovascular risk. S1P modulators may be associated with a dose-dependent, first-dose effect, transient risk of conduction abnormalities (bradycardia and AV block). Screening and monitoring of cardiovascular risk factors should be done in all patients with IBD. Risk stratification for cardiovascular disease should be performed before starting treatment with SMDs.

CONCLUSIONS

Available evidence of both JAK inhibitors and S1P modulators indicates a reassuring safety profile of SMDs from the cardiovascular perspective in the overall IBD population. Efforts should be made to identify patients with IBD at a higher risk of cardiovascular events.

Gegen Qinlian decoction activates AhR/IL-22 to repair intestinal barrier by modulating gut microbiota-related tryptophan metabolism in ulcerative colitis mice

ETHNOPHARMACOLOGICAL RELEVANCE

Gegen Qinlian decoction (GQD) is a traditional Chinese medicine derived from Treatise on febrile diseases and is clinically used for the treatment of acute ulcerative colitis (UC). However, the potential mechanism of GQD treatment for UC remains elusive.

AIM OF STUDY

In this study, we aimed to explore the involvement of gut microbiota-related tryptophan metabolism in mediating protective effects of GQD against intestinal barrier damage.

MATERIALS AND METHODS

Mice with colitis were treated with 3% dextran sulfate sodium (DSS) for 6 days. The therapeutic effects of GQD in UC mice were examined based on body weight, disease activity index (DAI), organ index, length and pathological changes in the colon. The distribution of fluorescein isothiocyanate dextran (FITC-dextran) in the intestinal tract was observed using small animal imaging, while concentration of FITC-dextran in serum was detected using a fluorescein microplate analyser. Bacterial infiltration in colon tissues was observed by fluorescence in situ hybridisation (FISH), and the bacterial load in mesenteric lymph nodes (MLNs) was further examined through bacterial culture. Subsequently, colonic goblet cells were detected using Alcian blue staining. The tight junctions of the colonic epithelium were observed using transmission electron microscopy, and the expression of tight junction proteins was detected by immunofluorescence (IF) and western blot. In addition, flow cytometry was used to analyse the proportion of interleukin-22-positive (IL-22⁺) ILC3 cells in lamina propria lymphocytes, and the content of IL-22 in colon homogenates was determined using an ELISA kit. In addition, targeted tryptophan metabolomics was used to detect the concentration of indole derivatives produced by tryptophan metabolism in faeces, and 16S rDNA was used to investigate the composition and abundance of gut microbiota-related tryptophan metabolism.

RESULTS

Administration of GQD significantly alleviated the pathological symptoms, including weight loss, increased DAI score, changes in organ index, colon shortening, and colon pathological injury in UC mice. In addition, GQD reduced the diffusion of FITC-dextran in the intestinal tract, the content of FITC-dextran in serum, and bacterial infiltration in MLNs and colon tissues. Additionally, GQD significantly increased the number of colonic goblet cells, repaired the structure of epithelial tight junctions and increased the expression of tight junction proteins. Furthermore, GQD significantly increased the proportion of IL-22⁺ ILC3 in the lamina propria, the expression of CYP1A1 protein in colon tissue, and the level of IL-22 in colon homogenates. However, the above protective effects of GQD were inhibited by co-administration of GQD and aryl hydrocarbon receptor (AhR) antagonist. Additionally, GQD restored the content of indole derivatives generated by tryptophan metabolism, regulated the diversity of the gut microbiota, and significantly increased the abundance of genes related to tryptophan metabolism.

CONCLUSION

Our results confirmed that GQD repaired the damaged intestinal barrier in UC mice by regulating gut microbiota-related tryptophan metabolism and restoring the generation of indole derivatives to activate AhR-mediated IL-22 production.

Clinical Evaluation of Risankizumab in the Treatment of Adults with Moderately to Severely Active Crohn's Disease: Patient Selection and Reported Outcomes

This article will review risankizumab, a monoclonal antibody targeting interleukin 23 (IL-23) for the treatment of moderate-to-severe Crohn's disease. The article will detail the mechanism of action and dosing strategies. Efficacy in induction and maintenances will be reviewed from available clinical trials as well as an evaluation of safety of the medication for use in Crohn's disease and other immune mediated diseases. Finally, a discussion of when to use this medication for treatment in Crohn's disease as well as how to monitor patients after medication initiation will be discussed.

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.

News in gastroenterology, hepatology and digestive endoscopy

Gastroenterology, hepatology and digestive endoscopy are rapidly evolving disciplines with significant advances in the diagnostics and treatment in the entire gastrointestinal tract. The aim of our article was to summarize new perspectives on relevant situations in gastroenterology and hepatology like acute pancreatitis, functional dyspepsia, rational indication of proton pump inhibitors, inflammatory bowel diseases (IBD), cholestatic liver diseases, alcohol induced hepatitis, non-alcoholic fatty live disease (NAFLD) and patophysiology of bilirubin and bile acids. Digestive endoscopy represents an interventional part of gastroenterology and key recent topics are mentioned like pancreatic cancer screening, arteficial intelligence, resection of low-risk neoplastic lesions, enteroscopy techniques, cholangio- and pancreatiscopy and extraluminal expansion of endoscopy techniques by means of endoscopic submucosal and transmural dissection, endoscopic myotomy and lumen apposing stents.

Current status of novel biologics and small molecule drugs in the individualized treatment of inflammatory bowel disease

Treatment strategies for inflammatory bowel disease (IBD) are rapidly evolving with the development of biologics and small molecule drugs (SMDs). However, these drugs are not guaranteed to be effective in all patients, and a "ceiling effect" of biologic monotherapy may occur. This issue highlights an unmet need for optimizing the use of biologics and predicting therapeutic responses. Thus, the development of new drugs with novel mechanisms of action is urgently needed for patients with primary nonresponse and secondary loss of response to conventional biologics and SMDs. In addition, combining different biologics or SMDs has been proposed as a novel strategy to enhance treatment efficacy in IBD, which theoretically has multidimensional anti-inflammatory potential. Based on the current evidence available for IBD, dual targeted therapy may be a promising strategy for refractory IBD patients who have failed in multiple biologic trea-tments or who have extraintestinal manifestation. Additionally, identifying the subgroup of IBD patients who are responding to biological combination therapies is also equally important in stable disease remission. In this review, we sum-marize the newly developed biologics and SMDs and the current status of bio-logics/SMDs to highlight the development of individualized treatment in IBD.

Honokiol Ameliorates DSS-Induced Mouse Colitis by Inhibiting Inflammation and Oxidative Stress and Improving the Intestinal Barrier

Ulcerative colitis (UC) is a multifactor intestinal disease with increased morbidity. Recently, pleiotropic drugs with exact biosafety have been urgently needed. Honokiol (HKL) is the major bioactive component of traditional Chinese medicine "Houpu," with almost no toxic effects and approved anti-inflammation, antioxidant, antispasmodic, etc. effects. This study examined the therapeutic effect of HKL in dextran sulfate sodium- (DSS-) induced experimental colitis. In vivo, C57BL/6 mice received 3% DSS for seven days to generate UC, and HKL was pretreated for five days and given during the whole DSS-induced period. In vitro, RAW264.7 macrophages were stimulated with lipopolysaccharide (LPS) to induce inflammation, and mouse colon epithelial cells (MCEC) were treated with HKL or pretreated with HKL and then stimulated with LPS-induced macrophage supernate to investigate the barrier enhancement roles. HKL significantly ameliorated disease activity index (DAI), colon length, and histopathological scores in DSS-induced colitis. The inflammatory mediators of interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX2) were decreased, and the tight conjunction proteins were increased in the HKL-treated group both in vivo and in vitro. Above all, HKL can relieve experimental UC through anti-inflammation, antioxidant, and epithelial barrier enhancement roles. These effects were associated with peroxisome proliferator-activated receptor γ (PPARγ)/nuclear factor-κB (NF-κB) p65, sirtuin3 (SIRT3)/adenosine 5'-monophosphate- (AMP-) activated protein kinase (AMPK), and nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase 1 (HO1) signaling pathways. In conclusion, after further clinical studies, HKL may be a promising drug for UC.

Esophageal lichen planus: Current knowledge, challenges and future perspectives

Lichen planus (LP) is a frequent, chronic inflammatory disease involving the skin, mucous membranes and/or skin appendages. Esophageal involvement in lichen planus (ELP) is a clinically important albeit underdiagnosed inflammatory condition. This narrative review aims to give an overview of the current knowledge on ELP, its prevalence, pathogenesis, clinical manifestation, diagnostic criteria, and therapeutic options in order to provide support in clinical management. Studies on ELP were collected using PubMed/Medline. Relevant clinical and therapeutical characteristics from published patient cohorts including our own cohort were extracted and summarized. ELP mainly affects middle-aged women. The principal symptom is dysphagia. However, asymptomatic cases despite progressed macroscopic esophageal lesions may occur. The pathogenesis is unknown, however an immune-mediated mechanism is probable. Endoscopically, ELP is characterized by mucosal denudation and tearing, trachealization, and hyperkeratosis. Scarring esophageal stenosis may occur in chronic courses. Histologic findings include mucosal detachment, T-lymphocytic infiltrations, epithelial apoptosis (Civatte bodies), dyskeratosis, and hyperkeratosis. Direct immuno-fluorescence shows fibrinogen deposits along the basement membrane zone. To date, there is no established therapy. However, treatment with topical steroids induces symptomatic and histologic improvement in two thirds of ELP patients in general. More severe cases may require therapy with immunosuppressors. In symptomatic esophageal stenosis, endoscopic dilation may be necessary. ELP may be regarded as a precancerous condition as transition to squamous cell carcinoma has been documented in literature. ELP is an underdiagnosed yet clinically important differential diagnosis for patients with unclear dysphagia or esophagitis. Timely diagnosis and therapy might prevent potential sequelae such as esophageal stenosis or development of invasive squamous cell carcinoma. Further studies are needed to gain more knowledge about the pathogenesis and treatment options.

Hematopoietic Stem Cell Transplantation in Refractory Crohn's Disease: Should It Be Considered?

Hematopoietic stem cell transplantation (HSCT) is widely used in benign and malignant hematological diseases. During the last decade, HSCT, mainly autologous, also gained increasing attention in the treatment of refractory autoimmune diseases. Crohn's disease (CD) is an inflammatory bowel disease leading to transmural inflammation potentially affecting all parts of the luminal gastrointestinal tract. Despite improving therapeutic options, including various biologics, some patients are refractory to all lines of available conservative therapy, leading to increased morbidity and reduced quality of life. Apart from surgery, HSCT might be a reasonable treatment alternative for refractory CD patients. This review aims to describe the current role of HSCT in CD and discusses the procedure, the correct patient selection, the clinical efficacy from initial remission to following relapse rates, and complications of this treatment.

Nanoparticles for oral delivery: targeted therapy for inflammatory bowel disease

As a group of chronic and idiopathic gastrointestinal (GI) disorders, inflammatory bowel disease (IBD) is characterized by recurrent intestinal mucosal inflammation. Oral administration is critical for the treatment of IBD. Unfortunately, it is difficult to target the bowel located in the GI tract due to multiple physical barriers. The unique physicochemical properties of nanoparticle-based drug delivery systems (DDSs) and their enhanced permeability and retention effects in the inflamed bowel, render nanomedicines to be used to implement precise drug delivery at diseased sites in IBD therapy. In this review, we described the pathophysiological features of IBD, and designed strategies to exploit these features for intestinal targeting. In addition, we introduced the types of currently developed nano-targeted carriers, including synthetic nanoparticle-based and emerging naturally derived nanoparticles (e.g., extracellular vesicles and plant-derived nanoparticles). Moreover, recent developments in targeted oral nanoparticles for IBD therapy were also highlighted. Finally, we presented challenges associated with nanotechnology and potential directions for future IBD treatment.

IBD therapeutics: what is in the pipeline?

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