Therapeutic innovations in inflammatory bowel diseases

Anti-IL23/12 agents and JAK inhibitors for inflammatory bowel disease

IBD (inflammatory bowel disease) is a chronic inflammatory disease of the gastrointestinal tract with increasing incidence worldwide. Multiple factors, such as genetic background, environmental and luminal factors, and mucosal immune dysregulation, have been implicated in the cause of IBD, although the cause of the disease remains unknown. IL-12 and IL-23 and their downstream signaling pathways participate in the pathogenesis of inflammatory bowel disease. Early and aggressive treatment with biologic therapies or novel small molecules is needed to decrease complications and the need for hospitalization and surgery. The landscape of inflammatory bowel disease (IBD) treatment has tremendously improved with the development of biologics and small molecule drugs. Several novel biologics and small molecule drugs targeting IL-12 and IL-23 and their downstream targets have shown positive efficacy and safety data in clinical trials, and several drugs have been approved for the treatment of IBD. In the future, numerous potential emerging therapeutic options for IBD treatment are believed to come to the fore, achieving disease cure.

Screening Failure in a Large Clinical Trial Centre for Inflammatory Bowel Diseases: Rates, Causes, and Outcomes

BACKGROUND

Patients with inflammatory bowel diseases (IBD) sometimes require investigational medicinal therapy in a clinical trial. Before enrollment, patients must meet strict eligibility criteria, hampering recruitment rates. We investigated the rates, causes, and outcomes of screening failure (SF) in a tertiary IBD center.

METHODS

We reviewed all IBD patients screened for sponsored multicenter phase 1-3 induction studies with available global SF rates between January 2008 and March 2021. We compared our SF rates with the global SF rates. Causes of SF were categorized into disease activity, hematology, chemistry, microbiology, protocol violation, and withdrawal of consent. Patient outcomes were categorized into rescreening for the same trial, screening for another trial, (re)introduction of commercially available therapy, surgery, or watchful waiting.

RESULTS

During the study period, 642 local screenings were performed as part of 53 studies. We identified an overall SF rate of 17.1%, compared with 39.2% in the global study population (P < .00001). Causes of SF at our center included ineligible disease activity (36.4%), microbiology (25.5%), protocol violation (16.4%), withdrawal of consent (9.1%), chemistry (6.4%) and hematology (6.4%). Thirty SFs could have been avoided by prescreening that was more thorough. After SF, 34 patients were rescreened for the same trial, 17 screened for another trial, 38 initiated approved therapy, 9 were referred for surgery, and 12 did not receive further therapy.

CONCLUSIONS

A significant proportion of IBD patients consenting to clinical trials fail their screening. Main causes of SF are ineligible disease activity and abnormal finding on microbiology. Approximately one-fourth of SFs could have been avoided by prescreening that was more thorough.

Identification of Tubocapsanolide A as a novel NLRP3 inhibitor for potential treatment of colitis

Increasing evidence have reported that NLRP3 inflammasome has a crucial role in various kinds of immunological diseases including colitis. However, there have only a few drug candidates directly targeting inflammasomes for the therapy of colitis. Here, we first reported that Tubocapsanolide A (TA), a natural small molecule, as a novel inhibitor of NLRP3 inflammasome for the treatment of colitis. TA inhibited the activation of NLRP3 inflammasome and suppressed the secretion of IL-1β and IL-18 in macrophages. Moreover, the ASC oligomerization was inhibited by TA. The assembly of the NLRP3 inflammasome was also restrained by TA, while had little effects on potassium and chloride efflux. Biolayer interferometry analysis showed that TA could directly bind to NLRP3. Importantly, LC-MS/MS analysis further demonstrated that TA covalently bound to the cysteine 514 residue (Cys514) of NLRP3. In vivo experiments showed that TA remarkably ameliorated DSS-induced experimental colitis in mice. However, the protection of TA against DSS-induced experimental colitis was abrogated in NLRP3-deficient (Nlrp3^-/-) mice. Taken together, this study indicates TA as a novel inhibitor of NLRP3, which identifies Cys514 as a novel regulatory site of NLRP3 and suggests TA as a promising candidate compound for the treatment of colitis.

Intestinal enteroids/organoids: A novel platform for drug discovery in inflammatory bowel diseases

The introduction of biologics such as anti-tumor necrosis factor (TNF) monoclonal antibodies followed by anti-integrins has dramatically changed the therapeutic paradigm of inflammatory bowel diseases (IBD). Furthermore, a newly developed anti-p40 subunit of interleukin (IL)-12 and IL-23 (ustekinumab) has been recently approved in the United States for patients with moderate to severe Crohn’s disease who have failed treatment with anti-TNFs. However, these immunosuppressive therapeutics which focus on anti-inflammatory mechanisms or immune cells still fail to achieve long-term remission in a significant percentage of patients. This strongly underlines the need to identify novel treatment targets beyond immune suppression to treat IBD. Recent studies have revealed the critical role of intestinal epithelial cells (IECs) in the pathogenesis of IBD. Physical, biochemical and immunologic driven barrier dysfunctions of epithelial cells contribute to the development of IBD. In addition, the recent establishment of adult stem cell-derived intestinal enteroid/organoid culture technology has allowed an exciting opportunity to study human IECs comprising all normal epithelial cells. This long-term epithelial culture model can be generated from endoscopic biopsies or surgical resections and recapitulates the tissue of origin, representing a promising platform for novel drug discovery in IBD. This review describes the advantages of intestinal enteroids/organoids as a research tool for intestinal diseases, introduces studies with these models in IBD, and gives a description of the current status of therapeutic approaches in IBD. Finally, we provide an overview of the current endeavors to identify a novel drug target for IBD therapy based on studies with human enteroids/organoids and describe the challenges in using enteroids/organoids as an IBD model.

Phytotherapies in inflammatory bowel disease

Inflammatory bowel disease (IBD) has been considered as a group of heterogeneous intestinal diseases that affects multiple organs outside of the gastrointestinal tract and is due to an uncontrolled inflammatory response mediated by the immune system. The IBD etiology has not been clearly defined, and it is considered as a multifactorial disease. Due to side effects of some conventional therapies, the consumption of complementary and alternative medicines, and in particular, the herbal therapy, more than before is increasing. Herbal therapy results for management of IBD by various mechanisms including leukotriene B4 inhibition, antioxidant activity, immune system regulation of nuclear factor-kappa B, as well as antiplatelet activity are favorable, and no unfortunate events have been yet reported. In this article, we aimed to review and report the herbal therapies established for management of human IBD or evaluated by animal IBD models. Their possible mechanisms of actions are also discussed.

Positioning Tofacitinib in the Treatment Algorithm of Moderate to Severe Ulcerative Colitis

Treatment options for ulcerative colitis (UC) remain limited because conventional therapies do not succeed at controlling the disease in a considerable percentage of patients, while up to 30% of those receiving biologics are primary nonresponders and 10%-20% lose response per year, requiring an increase in the treatment dose or the use of a different drug. Recently, tofacitinib, an orally administered small molecule that inhibits the Janus kinases, was proven efficacious for inducing and maintaining remission in adult patients with moderate to severe UC. Tofacitinib may represent a therapeutic alternative for the management of UC, pending approval by the US Food and Drug Administration, the European Medicines Agency, and other international regulatory authorities. Herein, we review tofacitinib's efficacy and safety data reported from randomized controlled trials in UC populations, with the aim to define how this new molecule could be inserted into the therapeutic algorithm of patients with UC.

JAK inhibitors: Novel developments in management of ulcerative colitis

Janus kinase inhibitors are small molecules, orally administered, under development for the treatment of ulcerative colitis. These molecules reduce the immune response, blocking the signal transduction of multiple cytokines implicated in the activation of inflammation. Currently multiple JAK inhibitors are being evaluated in clinical trials. The aim of this review is to examine the efficacy and the safety of the JAK inhibitors being tested and to discuss the available data on the use of these drugs in moderate-to-severe ulcerative colitis, in order to understand how these new molecules can fit into the therapeutic algorithm of patients with ulcerative colitis.

Extracellular Vesicles From the Helminth Fasciola hepatica Prevent DSS-Induced Acute Ulcerative Colitis in a T-Lymphocyte Independent Mode

The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of these diseases based on the hygiene hypothesis, but ethical and medical problems arise. Recent reports have proved the utility of parasite materials, mainly excretory/secretory products as therapeutic agents. The identification of extracellular vesicles on those secreted products opens a new field of investigation, since they exert potent immunomodulating effects. To assess the effect of extracellular vesicles produced by helminth parasites to treat ulcerative colitis, we have analyzed whether extracellular vesicles produced by the parasitic helminth Fasciola hepatica can prevent colitis induced by chemical agents in a mouse model. Adult parasites were cultured in vitro and secreted extracellular vesicles were purified and used for immunizing both wild type C57BL/6 and RAG1^-/- mice. Control and immunized mice groups were treated with dextran sulfate sodium 7 days after last immunization to promote experimental colitis. The severity of colitis was assessed by disease activity index and histopathological scores. Mucosal cytokine expression was evaluated by ELISA. The activation of NF-kB, COX-2, and MAPK were evaluated by immunoblotting. Administration of extracellular vesicles from F. hepatica ameliorates the pathological symptoms reducing the amount of pro-inflammatory cytokines and interfering with both MAPK and NF-kB pathways. Interestingly, the observed effects do not seem to be mediated by T-cells. Our results indicate that extracellular vesicles from parasitic helminths can modulate immune responses in dextran sulfate sodium (DSS)-induced colitis, exerting a protective effect that should be mediated by other cells distinct from B- and T-lymphocytes.

Biopsy-derived Intestinal Epithelial Cell Cultures for Pathway-based Stratification of Patients With Inflammatory Bowel Disease

BACKGROUND

Endoplasmic reticulum [ER] stress was shown to be pivotal in the pathogenesis of inflammatory bowel disease. Despite progress in inflammatory bowel disease [IBD] drug development, not more than one-third of patients achieve steroid-free remission and mucosal healing with current therapies. Furthermore, patient stratification tools for therapy selection are lacking. We aimed to identify and quantify epithelial ER stress in a patient-specific manner in an attempt towards personalised therapy.

METHODS

A biopsy-derived intestinal epithelial cell culture system was developed and characterised. ER stress was induced by thapsigargin and quantified with a BiP enzyme-linked immunosorbent assay [ELISA] of cell lysates from 35 patients with known genotypes, who were grouped based on the number of IBD-associated ER stress and autophagy risk alleles.

RESULTS

The epithelial character of the cells was confirmed by E-cadherin, ZO-1, and MUC2 staining and CK-18, CK-20, and LGR5 gene expression. Patients with three risk alleles had higher median epithelial BiP-induction [vs untreated] levels compared with patients with one or two risk alleles [p = 0.026 and 0.043, respectively]. When autophagy risk alleles were included and patients were stratified in genetic risk quartiles, patients in Q2, Q3, and Q4 had significantly higher ER stress [BiP] when compared with Q1 [p = 0.034, 0.040, and 0.034, respectively].

CONCLUSIONS

We developed and validated an ex vivo intestinal epithelial cell culture system and showed that patients with more ER stress and autophagy risk alleles have augmented epithelial ER stress responses. We thus presented a personalised approach whereby patient-specific defects can be identified, which in turn could help in selecting tailored therapies.

Using Big Data to Discover Diagnostics and Therapeutics for Gastrointestinal and Liver Diseases

Technologies such as genome sequencing, gene expression profiling, proteomic and metabolomic analyses, electronic medical records, and patient-reported health information have produced large amounts of data from various populations, cell types, and disorders (big data). However, these data must be integrated and analyzed if they are to produce models or concepts about physiological function or mechanisms of pathogenesis. Many of these data are available to the public, allowing researchers anywhere to search for markers of specific biological processes or therapeutic targets for specific diseases or patient types. We review recent advances in the fields of computational and systems biology and highlight opportunities for researchers to use big data sets in the fields of gastroenterology and hepatology to complement traditional means of diagnostic and therapeutic discovery.

Acute severe ulcerative colitis: from pathophysiology to clinical management

Ulcerative colitis is a common chronic inflammatory disease of the colon and rectum, resulting from a dysregulated immune response towards intraluminal antigens in a genetically predisposed host. The disease has a varying extent and severity. Approximately 20% of patients with ulcerative colitis experience a severe flare during the course of their disease, requiring hospitalization. Acute severe ulcerative colitis (ASUC) is potentially a life-threatening condition that requires early recognition, hospitalization, correction of body fluids and electrolytes, and nutritional support if needed. Superimposed bacterial or viral infections need to be excluded and thromboprophylaxis should be started. Intravenous corticosteroids are the first-line treatment for this condition. Rescue treatment with ciclosporin or infliximab is indicated in patients who do not sufficiently respond to corticosteroids after 3-5 days, with close monitoring of the patients' symptoms, serum C-reactive protein and albumin levels. If medical therapy fails, timely colectomy should be performed to prevent critical complications. In this article, we review all relevant aspects of ASUC, from its pathophysiological background to modern management in clinical practice.

Association between psoriasis and inflammatory bowel disease: a Danish nationwide cohort study

BACKGROUND

Psoriasis, Crohn disease (CD) and ulcerative colitis (UC) are chronic inflammatory disorders with overlapping genetic architecture. However, data on the frequency and risk of CD and UC in psoriasis are scarce and poorly understood.

OBJECTIVES

To investigate the association between CD and UC in patients with psoriasis.

METHODS

All Danish individuals aged ≥ 18 years between 1 January 1997 and 31 December 2012 were linked in nationwide registers. Psoriasis severity was defined in two models: hospital visits and medication. Incidence rates per 10 000 person-years were calculated, and incidence rate ratios (IRRs) were estimated by Poisson regression.

RESULTS

In the total cohort (n = 5 554 100) there were 75 209 incident cases of psoriasis, 11 309 incident cases of CD and 30 310 incident cases of UC, during follow-up. The adjusted IRRs (95% confidence intervals) of CD were 1·28 (1·03-1·59), 2·56 (1·87-3·50), 2·85 (1·72-4·73) and 3·42 (2·36-4·95) in patients with mild psoriasis, severe psoriasis (hospital), severe psoriasis (medication) and psoriatic arthritis, respectively. Similarly, the adjusted IRRs of UC were 1·49 (1·32-1·68), 1·56 (1·22-2·00), 1·96 (1·36-2·83) and 2·43 (1·86-3·17), respectively. The 10-year incidence of CD was 2-5 per 1000 patients and of UC 7-11 per 1000 patients, depending on psoriasis severity and the presence of psoriatic arthritis. Additionally, an increased risk of incident psoriasis was found following CD or UC.

CONCLUSIONS

We observed a psoriasis-associated increased risk of CD and UC, which was higher in severe psoriasis, and an increased risk of psoriasis in patients with inflammatory bowel disease. Increased focus on gastrointestinal symptoms in patients with psoriasis may be warranted.

Bioinnovation Enterprise: An engine driving breakthrough therapies

Biological advances have radically expanded our insights into the underpinnings of health and disease. New knowledge has formed the substrate for translation-expedited in turn by the biotechnology and pharmaceutical industry into novel therapeutic solutions impacting the management of patients and populations. Indeed, this Bioinnovation Enterprise has become the dominant growth sector in drug development and the engine driving the translation of breakthrough therapies worldwide. This annual Therapeutic Innovations issue highlights recent exceptional advances by the Bioinnovation Enterprise in translating molecular insights in pathobiology into transformative therapies.