Will novel oral formulations change the management of inflammatory bowel disease?

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.

Discovery of Potent and Balanced Dual RIPK2 and 3 Inhibitors as a New Strategy for the Treatment of Inflammatory Bowel Diseases

Receptor-interacting serine/threonine protein kinase 2 (RIPK2) and RIPK3 have been demonstrated to be promising targets for treating multiple inflammatory diseases, including inflammatory bowel diseases (IBDs). Due to the complexity of IBD pathogenesis, on the basis of synergy strategies, we herein describe the discovery and optimization of a series of N,7-diaryl-quinazolin-4-amine derivatives as dual RIPK2 and RIPK3 inhibitors. Based on a step-by-step process involving three rounds of structural modifications, compound 29 was identified as the most one, exhibiting balanced potency against RIPK2 (IC50 = 12 nM) and RIPK3 (IC50 = 18 nM), as well as demonstrating good selectivity over other kinase targets. Further biological evaluation confirmed that compound 29 could bind directly to RIPK2 and RIPK3, effectively suppressing NOD-induced cytokine production and cellular necroptosis. Notably, compound 29 displayed significant therapeutic effects in a DSS-induced colitis mouse model, with no detectable toxicity, indicating its promising therapeutic potential as RIPK2/RIPK3 dual inhibitors for treatment of IBD.

Synthesis of Etrasimod (APD334): Al2O3-Promoted Decarboxylative Rearrangements of Cyclopentenones with Stereochemical Inversion

This study presents an efficient synthesis pathway for etrasimod, starting from (+)-cis-4-acetoxy-2-cyclopenten-1-ol, yielding 5.6% overall with 98% enantiomeric excess. The crucial intermediate, (4R)-anilinocyclopent-2-enone, was derived from the (S)-alcohol/isocyanate adduct through a concerted, Al2O3-promoted decarboxylative rearrangement, which inverted the configuration. A tetracyclic fused lactam was formed via a one-pot acylation-Michael addition, followed by keto α-arylation. Subsequent removal of the oxo group facilitated the synthesis of cyclopenta[b]indol-3-ylacetic acid through a series of reactions, including methanolysis, indoline oxidation, and hydrolysis.

Modern drug discovery for inflammatory bowel disease: The role of computational methods

Inflammatory bowel diseases (IBDs) comprising ulcerative colitis, Crohn’s disease and microscopic colitis are characterized by chronic inflammation of the gastrointestinal tract. IBD has spread around the world and is becoming more prevalent at an alarming rate in developing countries whose societies have become more westernized. Cell therapy, intestinal microecology, apheresis therapy, exosome therapy and small molecules are emerging therapeutic options for IBD. Currently, it is thought that low-molecular-mass substances with good oral bio-availability and the ability to permeate the cell membrane to regulate the action of elements of the inflammatory signaling pathway are effective therapeutic options for the treatment of IBD. Several small molecule inhibitors are being developed as a promising alternative for IBD therapy. The use of highly efficient and time-saving techniques, such as computational methods, is still a viable option for the development of these small molecule drugs. The computer-aided (in silico) discovery approach is one drug development technique that has mostly proven efficacy. Computational approaches when combined with traditional drug development methodology dramatically boost the likelihood of drug discovery in a sustainable and cost-effective manner. This review focuses on the modern drug discovery approaches for the design of novel IBD drugs with an emphasis on the role of computational methods. Some computational approaches to IBD genomic studies, target identification, and virtual screening for the discovery of new drugs and in the repurposing of existing drugs are discussed.

Discovery of Potent and Selective Receptor-Interacting Serine/Threonine Protein Kinase 2 (RIPK2) Inhibitors for the Treatment of Inflammatory Bowel Diseases (IBDs)

Receptor-interacting serine/threonine protein kinase 2 (RIPK2) has been demonstrated to be a promising target for treating inflammatory diseases. Herein, we describe the discovery and optimization of a series of RIPK2 inhibitors derived from an FLT3 inhibitor, CHMFL-FLT3-165. Compound 10w was identified to possess an IC₅₀ value of 0.6 nM for RIPK2 and greater than 50,000-fold selectivity over its family homologous kinase RIPK1 (IC₅₀ > 30 μM). It exhibited high kinase selectivity and inhibited RIPK2 to prevent NOD-induced cytokine production following muramyl dipeptide (MDP) stimulation. In an acute colitis model, compound 10w exerted better therapeutic effects than the JAK inhibitor filgotinib and the RIPK2 inhibitor WEHI-345. These robust results of in vitro and in vivo pharmacodynamic experiments demonstrate that RIPK2 as a therapeutic target shows potential abilities for the treatment of inflammatory bowel diseases.

Clinical and Mechanistic Characteristics of Current JAK Inhibitors in IBD

Crohn's disease (CD) and ulcerative colitis (UC) are chronic, immune-mediated diseases of the gastrointestinal (GI) tract. Their etiology is complex and involves immune (eg, cytokines) and nonimmune (eg, environment) mediated contributions, causing inflammatory damage to the GI tract. Though cytokines contribute a major role in the inflammatory process of both CD and UC, there are some key differences in which cytokines are involved in the pathobiology of CD and UC. Over the past several years, new biologic-directed therapies have focused on controlling specific aspects of inflammation associated with both conditions. Although these treatments have benefited patients overall, approximately 30% of patients still do not respond to induction (initial) therapy, and up to 50% of patients lose response to treatment over a year. Many of these therapies are administered parenterally and have been associated with adverse events such as serious infections or malignancy. Therefore, there is a significant unmet medical need for these patients to minimize symptoms and promote GI healing. There are several therapeutic agents in the pipeline, including oral, small molecules, which hold much promise. One group of small molecules known as Janus kinase (JAK) inhibitors offers an additional option for treatment of chronic inflammatory conditions, based on currently available data. The article will focus on the potential benefits of JAK inhibitors as oral, small molecules, such as the potential role of selectivity, and potential risks.

Role of sphingosine-1-phosphate receptors in vascular injury of inflammatory bowel disease

Sphingosine‐1‐phosphate receptors (S1PRs) have an impact on the intestinal inflammation of inflammatory bowel disease (IBD) by regulating lymphocyte migration and differentiation. S1PR modulators as an emerging therapeutic approach are being investigated for the treatment of IBD. However, the role of S1PRs in intestinal vessels has not drawn much attention. Intestinal vascular damage is one of the major pathophysiological features of IBD, characterized by increased vascular density and impaired barrier function. S1PRs have pleiotropic effects on vascular endothelial cells, including proliferation, migration, angiogenesis and barrier homeostasis. Mounting evidence shows that S1PRs are abnormally expressed on intestinal vascular endothelial cells in IBD. Unexpectedly, S1PR modulators may damage intestinal vasculature, for example increase intestinal bleeding; therefore, S1PRs are thought to be involved in the regulation of intestinal vascular function in IBD. However, little is understood about how S1PRs regulate intestinal vascular function and participate in the initiation and progression of IBD. In this review, we summarize the pathogenic role of S1PRs in and the underlying mechanisms behind the intestinal vascular injury in IBD in order for improving IBD practice including S1PR‐targeted therapies.

M10, a Myricetin-3-O-b-D-Lactose Sodium Salt, Prevents Ulcerative Colitis Through Inhibiting Necroptosis in Mice

Background

M10 is a derivative of Myricetin by adding a hydrophilic glycosylation group. Our previous study revealed that M10 by oral administration prevented colitis-associated colonic cancer (CAC) through attenuating endoplasmic reticulum stress in mice. In current study, we evaluated the inhibitory effects of M10 on ulcerative colitis in mice model, the mechanism of M10 in preventing colitis was further investigated.

Methods

Mice model of ulcerative colitis was induced by continuous oral dextran sodium sulfate (DSS). M10 was given gavage once a day for 12 consecutive weeks. Disease activity index (DAI) was recorded by analyzing the symptoms of colitis. Intestinal barrier was analyzed by the Immunofluorescence staining assay. The structure of microvilli of intestinal epithelial cells was analyzed under Transmission electron microscopy (TEM). TEM assay was also performed to determine the formation of necroptosis in the colonic epithelium with ulcerative colitis. We performed Western blotting assay to analyze the IL-6 and NF-κB pathways, as well as the cytokine cascades related to TNF-α signaling pathway during necroptosis.

Results

M10 by oral administration demonstrated a prevention of ulcerative colitis, showing a significant decrease of DAI as compared to the model mice. Pathological analysis indicated that M10 attenuated the degree of colonic inflammation in colonic tissues. M10 restored the structures of intestinal barrier damaged by DSS. M10 prevented the activation of the IL-6 and NF-κB signaling pathways in the inflamed colonic epithelium. Further, M10 prevented necroptosis in the inflamed colonic mucosal cells through down-regulating the TNF-α pathway. Importantly, M10 demonstrated higher activities in preventing ulcerative colitis than Myricetin and control drug Mesalazine.

Conclusions

Myricetin derivative M10 prevents chronic ulcerative colitis through inhibiting necroptosis. M10 could be developed as a promising drug for the treatment of chronic ulcerative colitis.

Predictors of response and disease course in patients with inflammatory bowel disease treated with biological therapy-the Danish IBD Biobank Project: protocol for a multicentre prospective cohort study

INTRODUCTION

Inflammatory bowel diseases (IBDs) are chronic diseases of unknown cause characterised by a progressive and unpredictable disease course. In the last decade, biological treatment has become a cornerstone in the treatment of IBD. However, one-in-three-to-four patients do not respond to first-line biological agents and another third of patients see their response diminish over time. This highlights an unmet need for optimising the use of biologicals and the prediction of treatment response. Considering the multifaceted nature of IBD, we hypothesise that multiomics profiling of sequential samples from single patients could facilitate the discovery of predictive biomarkers of response to biological therapy and disease course.

METHODS

This is a multicentre prospective cohort study which will enrol 840 biological-naïve patients with IBD who initiate biological therapy in a 3-year period. Primary outcomes are the occurrence of primary non-response (evaluated at weeks 14-16) and loss of response (evaluated during entire follow-up in patients who obtain partial or full response after induction period). Each patient will be followed up for their clinical data for at least 1 year or till the end of study period (up to 4 years). Blood and stool samples will be collected sequentially during the first year of biological treatment. Intestinal tissue will be sampled after 1 year of treatment and whenever an endoscopy is performed. Samples will undergo transcriptomic, proteomic and microbial DNA analyses. Omics data will be integrated with clinical data to identify a panel of predictive biomarkers of response to biological therapy and disease behaviour in patients with IBD.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Danish Ethics Committee (H-18064178). Inclusion is ongoing at three study centres and will be initiated in two additional centres. Both positive and negative study results will be disseminated through peer-reviewed journals according to Strengthening the Reporting of Observational Studies in Epidemiology guidelines, as well as presented at international conferences.

Effect of the Sphingosine Kinase 1 Selective Inhibitor, PF543 on Dextran Sodium Sulfate-Induced Colitis in Mice

Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease, which often affects colon or rectum or both. It is now well recognized that sphingosine kinases-1/sphingosine-1-phosphate (S1P) signaling may have a very significant potential as targets for therapeutic intervention in UC. Compared with the pure dextran sodium sulfate group, administration of PF543 significantly reduced clinical symptoms with less weight loss, diarrhea, and shortening of the colon. The severity of colitis was improved with reduced disease activity index and degree of histological damage in colon. Moreover, treatment with PF543 not only decreased S1P but also inhibited mRNA expression of proinflammatory factors such as interleukin (IL)-1β and IL-6. This suggests that PF543 might exhibit an anti-inflammatory function against colitis through inhibition of expression of proinflammatory factors.

Novel polyurethane-based nanoparticles of infliximab to reduce inflammation in an in-vitro intestinal epithelial barrier model

In this study we examined the potential of novel biodegradable polymers of polyesterurethane (PU), and its PEGylated (PU-PEG) form as nanocarriers of Infliximab (INF), to treat inflammation in an in-vitro epithelial model. Nanoparticles (NPs) formulated were of average size of 200-287 nm. INF loading of NPs (INF-NPs) resulted in an increase in size and zeta potential. No cytotoxicity was observed for any of the NPs. Cellular interaction and uptake of PU NPs were similar compared with polycaprolactone (PCL) NPs and significantly higher to Poly(lactic-co-glycolic) acid (PLGA) NPs. Cellular interaction was higher for corresponding PEG-NPs. INF-PU and INF-PU-PEG NPs showed a rapid rate and extent of recovery of the epithelial barrier function in inflamed Caco-2 cell monolayers and decreased cytokine levels in inflamed monocytes. Results obtained in this study are promising and the potential of PU and PU-PEG NPs for drug delivery and targeting to treat gastrointestinal inflammation warrants further investigation.

Selective CB2 inverse agonist JTE907 drives T cell differentiation towards a Treg cell phenotype and ameliorates inflammation in a mouse model of inflammatory bowel disease

Cannabinoids are known to possess anti-inflammatory and immunomodulatory properties, but the mechanisms involved are not fully understood. CB2 is the cannabinoid receptor that is expressed primarily on hematopoietic cells and mediates the immunoregulatory functions of cannabinoids. In order to study the effect of JTE907, a selective/inverse agonist of CB2 with anti-inflammatory properties, on the differentiation of T cell subtypes, we used an in vitro system of Th lineage-specific differentiation of naïve CD4⁺ T lymphocytes isolated from the mouse spleen. The results indicate that JTE907 was able to induce the differentiation of Th0 cells into the Treg cell phenotype, which was characterized by the expression of FoxP3, TGF-β and IL-10. P38 phosphorylation and STAT5A activation were found to mediate the signaling pathway triggered by JTE907 via the CB2 receptor in Th0 lymphocytes. In mice with DNBS-induced colitis, JTE907 treatment was able to induce an increase in the number of CD4⁺CD25⁺FoxP3⁺ cells in the lamina propria after 24 h of disease onset and reduce disease severity after 48 h. Further, longer JTE907 treatment resulted in less severe colitis even when administered orally, resulting in less body weight loss, reduction of the disease score, prevention of NF-κB activation, and reduction of the expression of adhesion molecules. Collectively, the results of this study indicate that specific signals delivered through the CB2 receptor can drive the immune response towards the Treg cell phenotype. Thus, ligands such as JTE907 may have use as potential therapeutic agents in autoimmune and inflammatory diseases.

Phospholipid and Lipid Derivatives as Potential Neuroprotective Compounds

The worldwide demographical trend is changing towards a more elderly population. In particular, this phenomenon is increasing the number of neurodegenerative disease cases (e.g., Alzheimer’s disease) in advanced countries. Therefore, there is a fertile field for neuroprotective approaches to address this problem. A useful strategy to protect the membrane integrity of cells and reduce inflammatory processes. In this context, the neurons represent particularly vulnerable cells. Thus, a protection strategy should include their membrane preservation and improved anti-inflammatory processes. The contribution of phospholipid derivatives to this issue is crucial and many articles evidence their role in both health and disease. On the other hand, some lipids containing choline actively participate to increase the choline levels in the nervous system. It is acknowledged that the cholinergic system plays a pivotal role both in the central and in the peripheral nervous system. Neurons cannot synthesize choline, which is provided by the diet. The reuptake of ACh and its hydrolysis represent the principal source of choline. Therefore, to cover choline needs, choline-containing lipids may be used. There are different works which demonstrate their neuroprotective features This review article analyzes phospholipid and lipid derivatives that through different mechanisms are involved in these protective processes, although, sometimes the same molecules may behave as neurotoxic elements, therefore, their protective machinery should be detailed better.

Targeting JAK-STAT signal transduction in IBD

An unmet medical need exists for novel targeted therapies for inflammatory bowel disease (IBD) as many patients experience inadequate responses to antibody-based biologics. An oral drug formulation with reduced production costs and redundancy for healthcare staff to administer therapy ideally should result in diminished healthcare expenses and improved patient compliance. A new drug class of small molecules, the Janus kinase (JAK) inhibitors (jakinibs), fulfills these criteria and has recently shown efficacy in IBD. Here we provide an overview of the mode of action of jakinibs and provide a comprehensive overview of existing clinical studies. Convincing clinical data show that a complex cytokine-driven inflammation can efficiently be modulated by therapeutic inhibition of the JAK proteins.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

JAK-STAT Signaling as a Target for Inflammatory and Autoimmune Diseases: Current and Future Prospects

The Janus kinase/signal transduction and activator of transcription (JAK-STAT) signaling pathway is implicated in the pathogenesis of inflammatory and autoimmune diseases including rheumatoid arthritis, psoriasis, and inflammatory bowel disease. Many cytokines involved in the pathogenesis of autoimmune and inflammatory diseases use JAKs and STATs to transduce intracellular signals. Mutations in JAK and STAT genes cause a number of immunodeficiency syndromes, and polymorphisms in these genes are associated with autoimmune diseases. The success of small-molecule JAK inhibitors (Jakinibs) in the treatment of rheumatologic disease demonstrates that intracellular signaling pathways can be targeted therapeutically to treat autoimmunity. Tofacitinib, the first rheumatologic Jakinib, is US Food and Drug Administration (FDA) approved for rheumatoid arthritis and is currently under investigation for other autoimmune diseases. Many other Jakinibs are in preclinical development or in various phases of clinical trials. This review describes the JAK-STAT pathway, outlines its role in autoimmunity, and explains the rationale/pre-clinical evidence for targeting JAK-STAT signaling. The safety and clinical efficacy of the Jakinibs are reviewed, starting with the FDA-approved Jakinib tofacitinib, and continuing on to next-generation Jakinibs. Recent and ongoing studies are emphasized, with a focus on emerging indications for JAK inhibition and novel mechanisms of JAK-STAT signaling blockade.

Modulation of sphingosine-1-phosphate in inflammatory bowel disease

Inflammatory bowel diseases (IBD), including ulcerative colitis and Crohn's disease, involve an inappropriate immune reaction in the digestive tract, causing a variety of disabling symptoms. The advent of monoclonal antibodies (anti-tumor necrosis factor, anti-integrin, anti-interleukin -23) has revolutionized IBD management. Nevertheless, these agents, with potential for immunogenicity, are associated with high rates of response loss and disease relapse over time. They are also associated with high production costs. Sphingosine-1-phosphate (S1P), a membrane-derived lysophospholipid signaling molecule, is implicated in a vast array of physiological and pathophysiological processes, primarily via extracellular activation of S1P1-S1P5 receptors. S1P1, S1P4 and S1P5 are involved in regulation of the immune system, while S1P2 and S1P3 may be associated with cardiovascular, pulmonary, and theoretical cancer-related risks. Targeting S1P receptors for inflammatory conditions has been successful in clinical trials leading to approval of the non-selective S1P modulator, fingolimod, for relapsing forms of multiple sclerosis. However, the association of this non-selective S1P modulator with serious adverse events provides the rationale for developing more selective S1P receptor modulators. Until recently, three S1P modulators with differing selectivity for S1P receptors were in clinical development for IBD: ozanimod (RPC1063), etrasimod (APD334) and amiselimod (MT-1303). The development of amiselimod has been stopped as Biogen are currently focusing on other drugs in its portfolio. Following encouraging results from the Phase 2 TOUCHSTONE trial, a Phase 3 trial of the S1P modulator ozanimod in patients with moderate-to-severe ulcerative colitis is ongoing. Etrasimod is also being tested in a phase 2 trial in ulcerative colitis. These pipeline medications can be administered orally and may avoid the formation of anti-drug antibodies that can lead to treatment failure with injectable biologic therapies for IBD. Data from ongoing clinical trials will establish the relationship between the selectivity of S1P modulators and their safety and efficacy in IBD, as well as their potential place in the clinical armamentarium for IBD.