Dupilumab demonstrated efficacy and was well tolerated regardless of prior use of swallowed topical corticosteroids in adolescent and adult patients with eosinophilic oesophagitis: a subgroup analysis of the phase 3 LIBERTY EoE TREET study.

OBJECTIVE: To assess the effect of long-term dupilumab on histological, symptomatic and endoscopic aspects of eosinophilic oesophagitis (EoE) in adolescent and adult patients with and without prior use of swallowed topical corticosteroids (STC) or prior inadequate response, intolerance or contraindication to STC. DESIGN: Pre-specified analysis of data from the phase 3 LIBERTY EoE TREET study on patients who received dupilumab 300 mg once a week or placebo for 24 weeks (W24) in parts A and B, and an additional 28 weeks (W52) in part C. Patients were categorised as with/without prior STC use and with/without inadequate/intolerance/contraindication to STC. The proportion of patients achieving ≤6 eosinophils per high-power field (eos/hpf), absolute change in Dysphagia Symptom Questionnaire (DSQ) score, mean change in Endoscopic Reference Score and Histologic Scoring System grade/stage scores were assessed for each subgroup. RESULTS: Regardless of prior STC use, dupilumab increased the proportion of patients achieving ≤6 eos/hpf and improved DSQ score versus placebo at W24, with improvements maintained or improved at W52. The DSQ score and the proportion of patients achieving ≤6 eos/hpf after switching from placebo to dupilumab at W24 were similar to those observed in the dupilumab group at W24, regardless of prior STC use or inadequate/intolerance/contraindication to STC. Improvements in other outcomes with dupilumab were similar in patients with/without prior STC use or inadequate/intolerance/contraindication to STC. CONCLUSION: Dupilumab 300 mg once a week demonstrated efficacy and was well tolerated in patients with EoE regardless of prior STC use or inadequate response, intolerance and/or contraindication to STC. TRIAL REGISTRATION NUMBER: NCT03633617.

Efficacy and safety of dupilumab up to 52 weeks in adults and adolescents with eosinophilic oesophagitis (LIBERTY EoE TREET study): a multicentre, double-blind, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Long-term management options that specifically target the underlying inflammation in eosinophilic oesophagitis are needed. Dupilumab blocks the shared receptor component for interleukin (IL)-4/IL-13; we aimed to assess its long-term efficacy and safety in adults and adolescents with eosinophilic oesophagitis enrolled in part B of the LIBERTY EoE TREET study who continued to part C (part B-C). METHODS: LIBERTY EoE TREET was a three-part, double-blind, randomised, placebo-controlled, phase 3 study conducted at 65 hospitals and private clinics across ten countries in Australia, Canada, Europe, and the USA. Adults or adolescents (aged ≥12 years) with a diagnosis of eosinophilic oesophagitis by endoscopic biopsy (peak oesophageal intraepithelial eosinophil count ≥15 eosinophils per high-power field [eos/hpf]) from at least one oesophageal region despite 8 weeks of high-dose proton-pump inhibitors (PPIs) and a Dysphagia Symptom Questionnaire (DSQ) score of at least 10 at baseline were eligible. In part B, patients were randomly (1:1:1) assigned to receive subcutaneous dupilumab 300 mg either weekly or every 2 weeks or weekly placebo until week 24. Randomisation was done centrally by interactive voice response system/web response system (IVRS/IWRS) in blocks and stratified according to age (<18 years vs ≥18 years) and use of PPI at randomisation (yes vs no). Patients, study sponsors, and investigators involved in the study were masked to the randomisation outcome. Eligible patients who received placebo in part B and continued to part C were randomly assigned again (1:1) to either weekly dupilumab (placebo/weekly dupilumab group) or dupilumab every 2 weeks (placebo/dupilumab every 2 weeks), with matching placebo alternating with dupilumab doses. Patients who were randomly assigned to one of the dupilumab dose regimens in part B remained on the same regimen in part C for an additional 28 weeks (weekly dupilumab/weekly dupilumab group or dupilumab every 2 weeks/dupilumab every 2 weeks group). Treatment assignment in part C was managed by IVRS/IWRS to maintain blinding of treatment assignment in part B. The primary endpoint of this trial has been reported; here, we report the week 52 outcomes of part B-C. Efficacy and safety analyses were done in the part C safety-analysis set, which included all patients who were randomised in part B, entered part C, and received any study drug in part C. This completed trial is registered with ClinicalTrials.gov, number NCT03633617. FINDINGS: Between Aug 12, 2019, and March 11, 2021, 240 patients were randomly assigned into part B, of whom 227 (74 in placebo group, 74 in weekly dupilumab group, and 79 in dupilumab every 2 weeks group) continued into part B-C and were included in the current analysis. 37 patients switched from placebo to weekly dupilumab, and 37 from placebo to dupilumab every 2 weeks; 74 patients continued on weekly dupilumab and 79 continued on dupilumab every 2 weeks. Of the patients who entered part B-C, 75 (33%) were adolescents, 145 (64%) male, 82 (36%) female, and 206 (91%) White. At week 52, 55 (85%) patients in the weekly dupilumab/weekly dupilumab group, 25 (68%) in the placebo/weekly dupilumab group, 54 (74%) in the every 2 weeks dupilumab/every 2 weeks dupilumab group, and 23 (72%) in the placebo/every 2 weeks dupilumab group achieved a peak oesophageal intraepithelial eosinophil count of 6 eos/hpf or less. Mean percent change from part B baseline in peak eosinophil count was -95·9% (95% CI -96·9 to -94·9) in the weekly dupilumab/weekly dupilumab group, -84·2% (-98·3 to -70·2) in the placebo/weekly dupilumab group, -84·8% (-94·3 to -75·2) in the every 2 weeks dupilumab/every 2 weeks dupilumab group, and -91·2% (-95·9 to -86·5) in the placebo/every 2 weeks dupilumab group at week 52. At week 52, mean change from part B baseline in eosinophilic oesophagitis Histology Scoring System (HSS) grade score was -1·0 point (95% CI -1·1 to -0·9) in the weekly dupilumab/weekly dupilumab group and -0·9 points (-1·0 to -0·8) in the placebo/weekly dupilumab group; mean change in eosinophilic oesophagitis HSS stage score was -0·9 points (-1·0 to -0·8) in the weekly dupilumab/weekly dupilumab group and -0·9 points (-1·0 to -0·8) in the placebo/weekly dupilumab group. Similar improvements were observed in the every 2 weeks dupilumab groups. Mean absolute change from part B baseline in DSQ score was -30·3 points (95% CI -34·5 to -26·1) in the weekly dupilumab/weekly dupilumab group, -27·3 points (-32·1 to -22·4) in the placebo/weekly dupilumab group, -20·9% (-25·4 to -16·3) in the every 2 weeks dupilumab/every 2 weeks dupilumab group, and -23·7% (-29·1 to -18·3) in the placebo/every 2 weeks dupilumab group at week 52. Mean change from part B baseline in endoscopic reference score was -5·4 points (95% CI -6·1 to -4·6) in the weekly dupilumab/weekly dupilumab group, -6·1 points (-7·3 to -4·9) in the placebo/weekly dupilumab group, -5·2% (-6·0 to -4·4) in the every 2 weeks dupilumab/every 2 weeks dupilumab group, and -4·3% (-5·4 to -3·1) in the placebo/every 2 weeks dupilumab group at week 52. During part B-C, one (3%) patient in the placebo/weekly dupilumab group, one (1%) in the weekly dupilumab/weekly dupilumab group, and one (3%) in the placebo/every 2 weeks dupilumab group received rescue medication. One (3%) patient in the placebo/every 2 weeks dupilumab group and one (1%) in the dupilumab every 2 weeks/dupilumab every 2 weeks group underwent a rescue oesophageal dilation procedure. The most common treatment-emergent adverse events were injection-site reactions (ten [14%] in the weekly dupilumab/weekly dupilumab group and four [11%] in the placebo/weekly dupilumab group). INTERPRETATION: Improvements in histological, symptomatic, endoscopic, and molecular features of eosinophilic oesophagitis observed after 24 weeks of weekly dupilumab treatment were maintained or continued to improve to week 52. These findings reinforce the importance of weekly dupilumab, rather than every 2 weeks, for the improvement of symptoms in adults and adolescents with eosinophilic oesophagitis. FUNDING: Sanofi and Regeneron Pharmaceuticals Inc.

The enteric nervous system relays psychological stress to intestinal inflammation.

Mental health profoundly impacts inflammatory responses in the body. This is particularly apparent in inflammatory bowel disease (IBD), in which psychological stress is associated with exacerbated disease flares. Here, we discover a critical role for the enteric nervous system (ENS) in mediating the aggravating effect of chronic stress on intestinal inflammation. We find that chronically elevated levels of glucocorticoids drive the generation of an inflammatory subset of enteric glia that promotes monocyte- and TNF-mediated inflammation via CSF1. Additionally, glucocorticoids cause transcriptional immaturity in enteric neurons, acetylcholine deficiency, and dysmotility via TGF-ß2. We verify the connection between the psychological state, intestinal inflammation, and dysmotility in three cohorts of IBD patients. Together, these findings offer a mechanistic explanation for the impact of the brain on peripheral inflammation, define the ENS as a relay between psychological stress and gut inflammation, and suggest that stress management could serve as a valuable component of IBD care.

Small molecules, big effects: microbial metabolites in intestinal immunity.

The mammalian intestine is host to a vast number of microbial organisms. The immune system must balance tolerance with innate and adaptive defense mechanisms to maintain homeostasis with the microbial community. Interestingly, microbial metabolites have been shown to play a role in shaping the host immune response, thus assisting with adaptations that have significant implications for human health and disease. New investigations have uncovered roles for metabolites in modulating almost every aspect of the immune system. In this minireview, we survey these recent findings, which taken together reveal nuanced interactions that we are just beginning to understand.

The Microbiome as a Circadian Coordinator of Metabolism.

The microbiome is critically involved in the regulation of systemic metabolism. An important but poorly understood facet of this regulation is the diurnal activity of the microbiome. Herein, we summarize recent developments in our understanding of the diurnal properties of the microbiome and their integration into the circadian regulation of organismal metabolism. The microbiome may be involved in the detrimental consequences of circadian disruption for host metabolism and the development of metabolic disease. At the same time, the mechanisms by which microbiome diurnal activity is integrated into host physiology reveal several translational opportunities by which the time of day can be harnessed to optimize microbiome-based therapies. The study of circadian microbiome properties may thus provide a new avenue for treating disorders associated with circadian disruption from the gut.

Enteropathogenic E. coli effectors EspG1/G2 disrupt microtubules, contribute to tight junction perturbation and inhibit restoration.

Enteropathogenic Escherichia coli (EPEC) uses a type 3 secretion system to transfer effector proteins into the host intestinal epithelial cell. Several effector molecules contribute to tight junction disruption including EspG1 and its homologue EspG2 via a mechanism thought to involve microtubule destruction. The aim of this study was to investigate the contribution of EspG-mediated microtubule disruption to TJ perturbation. We demonstrate that wild type EPEC infection disassembles microtubules and induces the progressive movement of occludin away from the membrane and into the cytosol. Deletion of espG1/G2 attenuates both of these phenotypes. In addition, EPEC infection impedes barrier recovery from calcium switch, suggesting that inhibition of TJ restoration, not merely disruption, prolongs barrier loss. TJs recover more rapidly following infection with ΔespG1/G2 than with wild type EPEC, demonstrating that EspG1/G2 perpetuate barrier loss. Although EspG regulates ADP-ribosylation factor (ARF) and p21-activated kinase (PAK), these activities are not necessary for microtubule destruction or perturbation of TJ structure and function. These data strongly support a role for EspG1/G2 and its associated effects on microtubules in delaying the recovery of damaged tight junctions caused by EPEC infection.

Microtubules are required for efficient epithelial tight junction homeostasis and restoration.

Epithelial tight junctions are critical for creating a barrier yet allowing paracellular transport. Although it is well established that the actin cytoskeleton is critical for preserving the dynamic organization of the tight junction and maintaining normal tight junction protein recycling, contributions of microtubules to tight junction organization and function remain undefined. The aim of this study is to determine the role of microtubules in tight junction homeostasis and restoration. Our data demonstrate that occludin traffics on microtubules and that microtubule disruption perturbs tight junction structure and function. Microtubules are also shown to be required for restoring barrier function following Ca(2+) chelation and repletion. These processes are mediated by proteins participating in microtubule minus-end-directed trafficking but not plus-end-directed trafficking. These studies show that microtubules participate in the preservation of epithelial tight junction structure and function and play a vital role in tight junction restoration, thus expanding our understanding of the regulation of tight junction physiology.

Enteropathogenic E. coli effectors EspG1/G2 disrupt tight junctions: new roles and mechanisms.

Enteropathogenic E. coli (EPEC) infection is a major cause of infantile diarrhea in the developing world. Using a type-three secretion system, bacterial effector proteins are transferred to the host cell cytosol where they affect multiple physiological functions, ultimately leading to diarrheal disease. Disruption of intestinal epithelial cell tight junctions is a major consequence of EPEC infection and is mediated by multiple effector proteins, among them EspG1 and its homologue EspG2. EspG1/G2 contribute to loss of barrier function via an undefined mechanism that may be linked to their disruption of microtubule networks. Recently new investigations have identified additional roles for EspG. Sequestration of active ADP-ribosylating factor (ARF) proteins and promotion of p21-activated kinase (PAK) activity as well as inhibition of Golgi-mediated protein secretion have all been linked to EspG. In this review, we examine the functions of EspG1/G2 and discuss potential mechanisms of EspG-mediated tight junction disruption.