Introduction

There is an unmet medical need in the treatment of patients with moderate to severe (LA grade C or D) erosive esophagitis (EE), and those who do not achieve healing with currently available therapies. Linaprazan glurate (LG), a P-CAB and prodrug of its main metabolite linaprazan, has a favorable pharmacokinetic profile providing excellent acid control (1). This Phase 2 study was designed to support dose selection of LG for Phase 3 studies. Safety results are summarized separately.

Aims & Methods

This is a randomized, double-blind, active comparator-controlled, 5-arm parallel group, dose-finding study of LG, with lansoprazole (LAN) as the active comparator, on the 4-week healing of EE, with safety and tolerability as secondary endpoints. Adult patients with endoscopically confirmed EE with LA grade C or D or with LA grade A or B and a documented history of ≥8 weeks PPI therapy plus at least partial symptom response, were eligible for inclusion. The estimation for sample size calculations was based on the presumed responses in the LA grade C/D cohort dosing groups. Patients were randomized (1:1:1:1:1) to LG (25 mg, 50 mg, 75 mg or 100 mg: all BID doses) or LAN (30 mg QD), followed by 4-week open-label LAN treatment for all patients. All endoscopic images and videos were reassessed by a central review board, and primary endpoint was based on the central review output.

Results

A total of 248 patients were randomized to treatment. Based on the reassessed endoscopic images and videos, 182 patients had EE at screening (Full Analysis Set with EE; FAS-EE); of these, 162 patients had an endoscopy performed at 4 weeks (modified FAS-EE; LG, N=133; LAN, N=29) and were available for evaluation of healing. Modified FAS-EE C/D patients receiving LG (all 4 dosing groups) had a 4-week healing rate of 73.6% (95% CI: 59.7 -84.7), compared to 37.5% (95% CI: 8.5 -75.5) for LAN; for modified FAS-EE A/B patients receiving LG (all 4 dosing groups), the 4-week healing rate was 83.8% (95% CI: 73.8 -91.1), compared to 81.0% (95% CI: 58.1 -94.6) for LAN. The healing rates for the individual LG doses in modified FAS-EE C/D patients are presented in Table 1, showing a clear dose-response trend for LG 25 mg to 75 mg. When analyzing the FAS-EE (N=182, with the 20 patients without a 4-week endoscopy performed being imputed as “not healed”, as per the primary endpoint), data were consistent with the modified FAS-EE cohort. FAS-EE C/D patients receiving LG (all 4 dosing groups) had a 4-week healing rate of 68.4% (95% CI: 54.8 -80.1), compared to 33.3%
(95% CI: 7.5 -70.1) for LAN, and a clear dose-response trend was seen.

Conclusion

High EE healing rates were seen after 4 weeks of LG treatment in the overall LA grade C/D cohort, with the highest healing rate seen for 75 mg BID. In combination with good safety and tolerability results, these findings support further development of LG for the treatment of erosive esophagitis due to GERD.

References

References:
1. Unge P, Andersson K. Gastroenterology, 2018.

Disclosure

Prateek Sharma, Michael Vaezi, Ivan Popadiin, Andras Rosztóczy and David Armstrong: Nothing to disclose.
Peter Unge: Shareholder of and consultant to Cinclus Pharma AB
Kajsa Larsson, Maria Rosenholm and Elham Yektaei: Employees of Cinclus Pharma AB

Introduction

Gastrointestinal involvement is universal among patients with systemic sclerosis (SSc). Small intestinal dysfunction manifests with non-specific gastrointestinal symptoms (abdominal pain, distension, nausea, or vomiting), along with objective signs such as malnutrition, small intestinal bacterial overgrowth, and, in severe cases, chronic intestinal pseudo-obstruction. The pathogenesis of small intestinal dysmotility in SSc has been proposed to follow a sequential progression, beginning with neuropathy, progressing to myopathic damage, and ultimately culminating in fibrosis. Currently, there are no diagnostic techniques available to differentiate between stages of small intestinal involvement.

Aims & Methods

Aim: To assess the discriminative potential of high-resolution jejunal manometry in categorizing small intestinal dysmotility among patients with SSc.

Prospective study evaluating small intestinal motility in consecutive patients with SSc and digestive symptoms between January 2018 and July 2023 and healthy volunteers as controls. A 35-channel high-resolution manometry catheter was trans-nasally inserted into the jejunum under fluoroscopic radiological guidance. Small intestinal motility was continuously recorded for 5 h; 3 h fasting and 2 hours during continuous nutrient perfusion at 2 kcal/min. Tracings were analyzed by conventional qualitative analysis (identifying neuropathic and myopathic motility patterns) and by quantitative analysis of high-resolution parameters (measuring a motility index (MI) that integrates contractile frequency and amplitude over time, and manually counting the number of propagated contractile fronts)

Results

Twenty patients (52 ± 10 years, 95% women) with SSc and 18 healthy subjects (HS) (27 ± 6 years, 78% women) were included. By conventional visual analysis, 6 (30%) patients exhibited abnormal small intestinal motility patterns indicative of neuropathic involvement (uncoordinated bursts n=3 and postprandial minute-rhythm n=3), and 7 (35%) patients showed diminished contractile activity during fasting and after nutrient infusion (mean amplitude <20mmHg), indicative of myopathic involvement. The remaining 7 (35%) patients had apparently normal small intestinal motility.
Quantitative analysis of high-resolution parameters detected additional abnormalities in patients with SSc compared to healthy controls (table 1). A significant decrease in fasting (phase II) propagated fronts was observed in all subgroups, including those with apparently normal motility by conventional analysis. The postprandial response to nutrient infusion was reduced in 15 of 20 patients with SSc. All patients with myopathic involvement had a null response to nutrient infusion. Patients with neuropathic patterns and those with apparently normal motility by conventional analysis also exhibited a poor postprandial response, which was similarly reduced in both groups.

Table 1: Results from quantitative analysis of high-resolution jejunal manometry

Conclusion

High-resolution jejunal manometry detects abnormalities in fasting and postprandial small intestinal motility in patients with systemic sclerosis, even at early stages of intestinal involvement, when neuropathic and myopathic patterns are not evident.

References

Alcala-Gonzalez LG, Malagelada C, Galan C, Nieto A, Accarino A, Azpiroz F. Propagation patterns of jejunal motor activity measured by high-resolution water-perfused manometry. Neurogastroenterol Motil. 2021 Dec;33(12):e14240. doi: 10.1111/nmo.14240. Epub 2021 Aug 11. PMID: 34378830.

Disclosure

Nothing to declare

Introduction

Gastro-oesophageal reflux disease (GERD), caused by reflux of stomach contents into the oesophagus, results in discomfort and pain. Evidence suggests reflux- induced oxidative stress in oesophageal epithelial cells may have a role in GERD pathogenesis and symptom development. High mobility group box 1 (HMGB1), a nuclear protein found in most cell types, is actively released in response to oxidative stress. HMGB1 binds to TLR2, TLR4, and RAGE, leading to downstream inflammatory signalling.

Aims & Methods

Our aim was to investigate the potential role of epithelial-derived HMGB1 in the context of GERD.
Oesophageal biopsy tissue was obtained from consented healthy volunteers (N=10) and GERD patients categorised as functional heartburn (FH; N=7), non-erosive reflux disease (NERD; N=13), and erosive reflux disease (ERD; N=11) based on clinical assessment. Oesophageal HMGB1 mRNA was assessed by RT-qPCR. Tissue was used to assess protein expression of HMGB1, TLR2, TLR4, and RAGE using immunohistochemistry (IHC). Healthy oesophageal biopsies were used to assess HMGB1 release ex vivo following synthetic refluxate challenge (pH2, 1mM deoxycholate (DCA), 1mg/mL pepsin). Cellular translocation of HMGB1 was assessed using immunofluorescence in NE-1 cells in response to acidic bile salts (pH4, 1mM DCA).

Results

HMGB1 mRNA and epithelial protein expression were consistent between healthy control and GERD patients. TLR2 and TLR4 were expressed primarily on epithelial cells with cell quantification revealing TLR4 to be the predominantly expressed epithelial receptor. The proportion of TLR4+ cells was higher in ERD compared to healthy controls (1.4% ± 0.43 vs 7.2% ± 2.567; p<0.05). In contrast, RAGE was expressed exclusively on CD45+ leukocytes – predominantly in GERD phenotypes. Many RAGE+ immune cells in GERD tissue were in close apposition to sensory CGRP+ nerve fibres. Incubating NE-1 cells with acidic bile salts (10mins), but not acid alone, induced HMGB1 translocation to the cytosol (nuclear:cytosolic HMGB1 ratios: pH7 = 2.42 ± 0.19; pH4 = 2.66 ± 0.07; pH4 + DCA = 1.416 ± 0.06; p=0.0003). Challenging oesophageal biopsies with synthetic refluxate (5mins) led to release of HMGB1 over 18 hours compared to paired biopsies (218 ± 57 vs 586 ± 220 pg/mL/mg; p<0.05).

Conclusion

HMGB1 released by oesophageal epithelial cells following reflux may contribute to inflammatory pathways in GERD, particularly via TLR4 and RAGE on epithelial and immune cells, respectively. This is of particular interest in PPI-refractory GERD, due to the exaggerated role of bile salts in HMGB1 release. Further, the close proximity of RAGE+ leukocytes and CGRP+ nerve fibres may represent a cross-talk between epithelial cells, immune cells, and sensory nerves. HMGB1 may therefore be a potential new treatment target for GERD.

Introduction

Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease of the central nervous system (CNS) affecting young adults, with a female preponderance.¹ A large number of evidences indicate that the gut-brain axis is involved in the pathophysiology of neurodegenerative diseases, including MS. In addition to symptoms caused by CNS pathology, the majority of MS patients frequently exhibit functional gastrointestinal (GI) disorders, such as constipation, dysphagia, dyspepsia, fecal incontinence, and dysbiosis.² Novel findings in both MS patients and animal models propose the ENS as the first site of origin of MS, due to its interaction with microbial-derived factors and immune responses.^3,4

Aims & Methods

Aim: The aim of the present study, supported by a BINC-Genève grant, was to investigate the effect of cuprizone-mediated demyelination on the structural and functional integrity of the ENS.
Methods: Female C57/Bl6 (3±1 weeks old; N=18/group) mice were fed with standard diet (SHAM) or with standard diet supplemented with 0.25% (w/w) cuprizone for 4 weeks (CPZ). Animal health status was monitored by recording body weight daily. In SHAM and CPZ-treated mice changes in recognition memory and locomotor activity were evaluated using the novel object recognition, open field, beam walking tests. At the end of the behavioral tests, animals sacrificed by cervical dislocation and analyzed for changes in gut function. GI transit was assessed by measuring the distribution of nonabsorbable-FITC-labeled dextran throughout the GI tract. Changes in contractility were recorded in ileum segments following: i) 60 mM KCl; ii) cumulative addition of carbachol (CCh; 0.1-100 μM); iii) electric field stimulation (EFS, 0-40 Hz). The distribution of neuronal (HuC/D, ChAT) and glial (S100β, PLP1) markers was determined by immunohistochemistry and confocal microscopy in longitudinal-muscle-myenteric plexus whole-mount ileum preparations. Expression of myelin-related genes was analyzed by RT-qPCR in ileal tissue samples.

Results

CPZ administration led to weight loss (-20%) and caused a delayed GI transit (p<0.001), associated to deficits in recognition memory and locomotor activity. In vitro contractility studies showed reduced frequency and amplitude of contractions in CPZ mice (-10% and -35.3%, respectively; p<0.05). CPZ treatment determined changes in receptor- and not-receptor mediated excitatory responses (-28% of Emax to CCh and -33% of contraction to KCl, respectively; p<0.01) together with reduced EFS-induced contractions (-24.5% at 40 Hz; p<0.01). In the myenteric plexus of CPZ mice, we found marked alterations in glial cells distribution, accompanied by a significant reduction of the number of HuC/D⁺ neurons (-15%; p<0.01), and disrupted cholinergic network (-30% in ChAT immunoreactivity; p<0.01). Significant changes in myelin-related genes expression (MOG, MBP, PLP1) were found in ileal tissues of CPZ compared to SHAM mice.

Conclusion

Our findings show that cuprizone determines small intestine dysmotility and altered myenteric neuro-glial plasticity within the ENS of female mice. Further studies are warranted to assess the mechanisms that lead to the onset and spread of neurodegeneration within the gut, from the gut to the brain, and vice versa.

References

REFERENCES:
¹Cloake NC, et al. J Clin Med. 2018;7:342
²Levinthal DJ,et al. Mult Scler Int. 2013;2013:319201
³Wunsch M, et al. Acta Neuropathol. 2017;134:281-295
⁴Parodi B, Kerlero de Rosbo N. Front Immunol. 2021;12:718220

Introduction

Acute Severe Colitis (ASC) is a relatively common presentation to hospital which is associated with a high morbidity and mortality and requires aggressive and competent treatment. Initial assessment and management is typically performed by a non-gastroenterologist who may have had limited experience managing this subset of patients. The aim of this project was to create a care bundle for managing ASC for use on the acute medical take across Cwm Taf Morgannwg University Health Board, Wales to provide standardised care for these patients which would improve confidence and knowledge of the junior doctors treating them and in turn improve patient care.

Aims & Methods

An electronic questionnaire would be sent to a variety of junior doctors at different stages in their training who all work on the acute medical take to assess their confidence and knowledge in managing patients with ASC on the acute take and assess whether the project would be a worthwhile idea. The care bundle would then be developed and implemented and a second questionnaire would then be sent to see if it would achieve improved confidence and knowledge, ultimately providing standardised care and inevitably better patient outcomes.

Results

We received 25 responses to our initial questionnaire from junior doctors who work on the acute medical take. 20% of our respondees had never managed a patient with ASC before and 60% did not feel confident managing patients with ASC. 24% did not know exactly what drugs to administer/avoid and 28% would not feel comfortable identifying a toxic megacolon on an Abdominal X-Ray. 100% of responses thought the project would have a positive impact on the standard of care and outcomes for these patients as well as improve confidence and knowledge of the assessing doctors on the medical take.
After implementation of the care bundle, a second questionnaire was sent which received 19 responses from junior doctors who work on the acute medical take. 100% of respondees felt the care bundle gave them increased confidence and knowledge in managing patients with ASC and that it would improve patient outcomes and overall care.

Conclusion

Our project has shown an ASC care bundle can improve confidence, knowledge and training for junior doctors who encounter such patients on the acute medical take. By providing a framework for implementing best medical practice and standardised care, patient outcomes, satisfaction and overall care will inevitably be better.

References

Lamb CA, Kennedy NA, Raine T, et al. British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults. Gut 2019;68:s1-s106.

Introduction

A transmural oxidative imbalance, mainly affecting longitudinal muscle, has been reported in the different clinical phenotypes of Diverticular Disease (DD) (Pallotta L,2022; Cappelletti M,2022) but the genesis of the oxidative stress remains to be defined. Since the central role of the mitochondria for the cell metabolism and radicals production, aim of the study is to elucidate the involvement of mitochondria alterations in the different DD clinical phenotypes in order to improve the knowledge of the DD natural history and management.

Aims & Methods

Longitudinal smooth muscle tissues and cells were isolated separately from surgical specimens of complicated stenotic DD (cDD n=5), up-stream non-occlusive colon cancer with diverticula (DIV n=5) and without diverticula (controls n=5). Oxidized proteins, thioredoxin and, succinate deidrogenase (complex II) and complex IV (cytochrome c oxidase) of mitochondrial respiratory chain were evaluated on tissues by Western Blot. Mitochondrial mass, mitochondrial ROS, mitochondrial membrane potential and glutathione (GSH) were evaluated in cells by FACS. Functional cells activity was tested by image micrometry assessing maximal contraction to acetylcholine and relaxation to VIP, before and after 24h-incubation with 14mM polyphenols (Phenolea Active Complex L). Data (mean±SE) were expressed as fold variations or % decrease from controls, *p value<0.05 considered significant.

Results

In respect to control, oxidized proteins content in longitudinal muscle was increased both in DIV (5.0*±1.1) and cDD (2.6±0.6), associated to a progressive loss of the antioxidant thioredoxin molecule (DIV:70.9%±9.2;cDD:83.3%±3.4). The oxidative status resulted associated to a loss of the mitochondrial complex II succinate deidrogenase codified by nuclear DNA (DIV:43.4%±19.7;cDD:67.9%±10.3) suggestive of the electron respiratory chain impairement. Compensatory stress mechanisms likely occurred with an increase of the complex IV cytochrome c oxidase codified by mitochondrial DNA in muscle tissue (DIV:1.1±0.77;cDD:2.3±1.7) and mitochondrial mass increase (DIV:2.4±1.2;cDD:3.7*±1.3) in cells. Radicals over production was observed mainly in cDD with a cellular increase in mitochondrial ROS (cDD:1.50±0.57) and mitochondrial membrane potential (cDD:1.4±0.3). Antioxidant GSH cellular content progressively decreased from DIV (51.9%*±9.5) to cDD (72.2%*±1.5). These oxidative alterations were associated to an impairment of functional cellular activity with a reduction of contraction (DIV:51.3%*±4.5;cDD:52.5%*±8.5) and relaxation (DIV:34.9%*±14.3;cDD:37.6%*±10.6). The prominent role of oxidative stress in these functional alterations was confirmed by the ability of a 24/h polyphenols treatment to restore GSH content (DIV:1.1±0.06;cDD:1.4±0.3) and relaxation, in both DD phenotypes.

Conclusion

Oxidative stress-driven alterations are present in longitudinal muscle in DD, independently from the clinical stage. In accordance to the severity of the pathology, mitochondrial imbalance resulted more prevalent in complicated diverticular disease. The beneficial effects of the antioxidant treatment could open new tailored-therapeutic and prevention strategies still not tested in this disease.

Disclosure

No disclosure