Eosinophil Depletion with Benralizumab for Eosinophilic Esophagitis.

BACKGROUND: Benralizumab is an eosinophil-depleting anti-interleukin-5 receptor α monoclonal antibody. The efficacy and safety of benralizumab in patients with eosinophilic esophagitis are unclear. METHODS: In a phase 3, multicenter, double-blind, randomized, placebo-controlled trial, we assigned patients 12 to 65 years of age with symptomatic and histologically active eosinophilic esophagitis in a 1:1 ratio to receive subcutaneous benralizumab (30 mg) or placebo every 4 weeks. The two primary efficacy end points were histologic response (≤6 eosinophils per high-power field) and the change from baseline in the score on the Dysphagia Symptom Questionnaire (DSQ; range, 0 to 84, with higher scores indicating more frequent or severe dysphagia) at week 24. RESULTS: A total of 211 patients underwent randomization: 104 were assigned to receive benralizumab, and 107 were assigned to receive placebo. At week 24, more patients had a histologic response with benralizumab than with placebo (87.4% vs. 6.5%; difference, 80.8 percentage points; 95% confidence interval [CI], 72.9 to 88.8; P<0.001). However, the change from baseline in the DSQ score did not differ significantly between the two groups (difference in least-squares means, 3.0 points; 95% CI, -1.4 to 7.4; P = 0.18). There was no substantial between-group difference in the change from baseline in the Eosinophilic Esophagitis Endoscopic Reference Score, which reflects endoscopic abnormalities. Adverse events were reported in 64.1% of the patients in the benralizumab group and in 61.7% of those in the placebo group. No patients discontinued the trial because of adverse events. CONCLUSIONS: In this trial involving patients 12 to 65 years of age with eosinophilic esophagitis, a histologic response (≤6 eosinophils per high-power field) occurred in significantly more patients in the benralizumab group than in the placebo group. However, treatment with benralizumab did not result in fewer or less severe dysphagia symptoms than placebo. (Funded by AstraZeneca; MESSINA ClinicalTrials.gov number, NCT04543409.).

Dupilumab for Eosinophilic Esophagitis in Patients 1 to 11 Years of Age.

BACKGROUND: Dupilumab is a human monoclonal antibody that blocks interleukin-4 and interleukin-13 pathways and has shown efficacy in five different atopic diseases marked by type 2 inflammation, including eosinophilic esophagitis in adults and adolescents. METHODS: In this phase 3 trial, we randomly assigned, in a 2:2:1:1 ratio, patients 1 to 11 years of age with active eosinophilic esophagitis who had had no response to proton-pump inhibitors to 16 weeks of a higher-exposure or lower-exposure subcutaneous dupilumab regimen or to placebo (two groups) (Part A). At the end of Part A, eligible patients in each dupilumab group continued the same regimen and those in the placebo groups were assigned to higher-exposure or lower-exposure dupilumab for 36 weeks (Part B). At each level of exposure, dupilumab was administered in one of four doses tiered according to baseline body weight. The primary end point was histologic remission (peak esophageal intraepithelial eosinophil count, ≤6 per high-power field) at week 16. Key secondary end points were tested hierarchically. RESULTS: In Part A, histologic remission occurred in 25 of the 37 patients (68%) in the higher-exposure group, in 18 of the 31 patients (58%) in the lower-exposure group, and in 1 of the 34 patients (3%) in the placebo group (difference between the higher-exposure regimen and placebo, 65 percentage points [95% confidence interval {CI}, 48 to 81; P<0.001]; difference between the lower-exposure regimen and placebo, 55 percentage points [95% CI, 37 to 73; P<0.001]). The higher-exposure dupilumab regimen led to significant improvements in histologic, endoscopic, and transcriptomic measures as compared with placebo. The improvements in histologic, endoscopic, and transcriptomic measures between baseline and week 52 in all the patients were generally similar to the improvements between baseline and week 16 in the patients who received dupilumab in Part A. In Part A, the incidence of coronavirus disease 2019, nausea, injection-site pain, and headache was at least 10 percentage points higher among the patients who received dupilumab (at either dose) than among those who received placebo. Serious adverse events were reported in 3 patients who received dupilumab during Part A and in 6 patients overall during Part B. CONCLUSIONS: Dupilumab resulted in histologic remission in a significantly higher percentage of children with eosinophilic esophagitis than placebo. The higher-exposure dupilumab regimen also led to improvements in measures of key secondary end points as compared with placebo. (Funded by Sanofi and Regeneron Pharmaceuticals; EoE KIDS ClinicalTrials.gov number, NCT04394351.).

Dupilumab in Adults and Adolescents with Eosinophilic Esophagitis.

BACKGROUND: Dupilumab, a fully human monoclonal antibody, blocks interleukin-4 and interleukin-13 signaling, which have key roles in eosinophilic esophagitis. METHODS: We conducted a three-part, phase 3 trial in which patients 12 years of age or older underwent randomization in a 1:1 ratio to receive subcutaneous dupilumab at a weekly dose of 300 mg or placebo (Part A) or in a 1:1:1 ratio to receive 300 mg of dupilumab either weekly or every 2 weeks or weekly placebo (Part B) up to week 24. Eligible patients who completed Part A or Part B continued the trial in Part C, in which those who completed Part A received dupilumab at a weekly dose of 300 mg up to week 52 (the Part A-C group); Part C that included the eligible patients from Part B is ongoing. The two primary end points at week 24 were histologic remission (≤6 eosinophils per high-power field) and the change from baseline in the Dysphagia Symptom Questionnaire (DSQ) score (range, 0 to 84, with higher values indicating more frequent or more severe dysphagia). RESULTS: In Part A, histologic remission occurred in 25 of 42 patients (60%) who received weekly dupilumab and in 2 of 39 patients (5%) who received placebo (difference, 55 percentage points; 95% confidence interval [CI], 40 to 71; P<0.001). In Part B, histologic remission occurred in 47 of 80 patients (59%) with weekly dupilumab, in 49 of 81 patients (60%) with dupilumab every 2 weeks, and in 5 of 79 patients (6%) with placebo (difference between weekly dupilumab and placebo, 54 percentage points; 95% CI, 41 to 66 [P<0.001]; difference between dupilumab every 2 weeks and placebo, 56 percentage points; 95% CI, 43 to 69 [not significant per hierarchical testing]). The mean (±SD) DSQ scores at baseline were 33.6±12.41 in Part A and 36.7±11.22 in Part B; the scores improved with weekly dupilumab as compared with placebo, with differences of -12.32 (95% CI, -19.11 to -5.54) in Part A and -9.92 (95% CI, -14.81 to -5.02) in Part B (both P<0.001) but not with dupilumab every 2 weeks (difference in Part B, -0.51; 95% CI, -5.42 to 4.41). Serious adverse events occurred in 9 patients during the Part A or B treatment period (in 7 who received weekly dupilumab, 1 who received dupilumab every 2 weeks, and 1 who received placebo) and in 1 patient in the Part A-C group during the Part C treatment period who received placebo in Part A and weekly dupilumab in Part C. CONCLUSIONS: Among patients with eosinophilic esophagitis, subcutaneous dupilumab administered weekly improved histologic outcomes and alleviated symptoms of the disease. (Funded by Sanofi and Regeneron Pharmaceuticals; ClinicalTrials.gov number, NCT03633617.).

Tapinarof validates the aryl hydrocarbon receptor as a therapeutic target: A clinical review.

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that has wide-ranging roles, including regulation of inflammation and homeostasis. AhR is not a cell surface receptor; rather, it exists in a cytoplasmic complex that responds to a wide variety of structurally dissimilar endogenous, microbial, and environmental ligands. The ubiquitous expression of AhR, its ability to be activated by a wide range of ligands, and its capacity to act as a master regulator for gene expression and homeostasis make it a promising new therapeutic target. Clinical trials of tapinarof cream have now validated AhR agonism as a therapeutic approach that can deliver significant efficacy for treating inflammatory skin diseases, including psoriasis and atopic dermatitis. Tapinarof 1% cream is a first-in-class, nonsteroidal, topical, AhR agonist with a pharmacokinetic profile that results in localized exposure at sites of disease, avoiding systemic safety concerns, drug interactions, or off-target effects. Psoriasis and atopic dermatitis both involve epidermal inflammation, cellular immune responses, dysregulation of skin barrier protein expression, and oxidative stress. On the basis of the clinical effectiveness of tapinarof cream for treating inflammatory skin diseases, we review how targeting AhR may offer a significant opportunity in other conditions that share key aspects of pathogenesis, including asthma, inflammatory bowel disease, eosinophilic esophagitis, ophthalmic, and nervous system diseases.

Clinical and molecular correlates of the Index of Severity for Eosinophilic Esophagitis.

BACKGROUND: The Index of Severity for Eosinophilic Esophagitis (I-SEE) is a new expert-defined clinical tool that classifies disease severity of eosinophilic esophagitis (EoE). OBJECTIVE: We aimed to determine whether I-SEE is associated with patient characteristics, molecular features of EoE, or both. METHODS: We analyzed a prospective cohort of patients with EoE from the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR). Associations between I-SEE and clinical and molecular features (assessed by an EoE diagnostic panel [EDP]) were assessed. RESULTS: In 318 patients with chronic EoE (209 adults, 109 children), median total I-SEE score was 7.0, with a higher symptoms and complications score in children than adults (4.0 vs 1.0; P < .001) and higher inflammatory and fibrostenotic features scores in adults than children (3.0 vs 1.0 and 3.0 vs 0, respectively; both P < .001). Total I-SEE score had a bimodal distribution with the inactive to moderate categories and severe category. EDP score correlated with total I-SEE score (r = -0.352, P < .001) and both inflammatory and fibrostenotic features scores (r = -0.665, P < .001; r = -0.446, P < .001, respectively), but not with symptoms and complications scores (r = 0.047, P = .408). Molecular severity increased from inactive to mild and moderate, but not severe, categories. Longitudinal changes of modified I-SEE scores and inflammatory and fibrostenotic features scores reflected histologic and molecular activity. CONCLUSIONS: I-SEE score is associated with select clinical features across severity categories and with EoE molecular features for nonsevere categories, warranting further validation.

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.

Epidemiology and Risk Factors of Eosinophilic Esophagitis in Japan: A Population-Based Study.

BACKGROUND & AIMS: Eosinophilic esophagitis (EoE) has been increasingly diagnosed globally. However, there have been few general population-based studies in Asia. The aim of this study was to investigate EoE epidemiology in the Japanese general population. METHODS: We analyzed an employer-based health insurance claim database from January 2005 to September 2022. EoE cases were identified on the basis of the International Statistical Classification of Diseases and Health-related Problems, 10th Revision code, K20.0. We calculated the incidence and prevalence of EoE using Poisson regression and binomial distribution, respectively. Using 10 matched controls for each EoE case, a nested case-control study was performed to identify potential risk factors for EoE. RESULTS: Of 15,200,895 individuals, 1010 EoE cases were identified. The incidence and prevalence of EoE were 2.82 (95% confidence interval [CI], 2.44-3.26) per 100,000 person-years and 10.68 (95% CI, 10.01-11.37) per 100,000 people in 2022, nearly 3 and 8 times as high as those in 2017, respectively. Smoking was associated with decreased risk of EoE (odds ratio [OR], 0.45, 0.36-0.56, P < .001), whereas alcohol consumption (OR, 1.51, 1.21-1.88, P < .001) was associated with increased risk of EoE along with several allergic conditions and psychiatric disorders. EoE was not related to either body mass index or lifestyle-related diseases such as hypertension, diabetes mellitus, hyperuricemia, and dyslipidemia. CONCLUSIONS: The incidence and prevalence of EoE in Japan have steadily increased over the past 2 decades. Nevertheless, EoE remains less common in Japan compared with the United States and Western Europe. Factors contributing to the epidemiology of EoE on a global basis may improve our understanding of the contribution of genetic and environmental risk factors.

A PhysioMechanical Model of Esophageal Function in Eosinophilic Esophagitis.

BACKGROUND & AIMS: Eosinophilic esophagitis (EoE) is characterized by eosinophilic inflammation, but also heterogeneous presentations involving fibrostenotic esophageal remodeling and esophageal dysmotility. We aimed to define and evaluate phenotypes of EoE using functional lumen imaging probe (FLIP) panometry (ie, a PhysioMechanical classification of EoE). METHODS: Patients with EoE who completed FLIP during endoscopy were included in a cross-sectional study. FLIP studies were analyzed for distensibility plateau and compliance of the esophageal body, maximum esophagogastric junction diameter, and contractile response pattern. These FLIP features were then applied to define PhysioMechanical classifications. RESULTS: A total of 215 patients with EoE (mean [standard deviation] age 38 [12] years; 31% female) were included. Seven PhysioMechanical classifications were identified that differed by various clinical characteristics, including symptom duration (P < .001) and Endoscopic EoE Reference Scores (EREFS) (P < .001). In particular, patients with "nonreactive fibrostenosis" (n = 14), had greater symptom duration (median [interquartile range] 20 [10-30] years) and more frequently had EREFS grade 2 or 3 ring scores (14 of 14 patients) than patients with a "normal" PhysioMechanical classification (symptom duration: 3 [1-8] years; 4 of 50 [8%] had EREFS grade 2 or 3 rings). In addition, among patients off treatment at cross-sectional evaluation (n = 46), there was a difference between PhysioMechanical classifications in future proton pump inhibitor (PPI) response rates (ie, achieving peak mucosal eosinophil count <15 per high-powered field after PPI treatment); P = .009. PPI response ranged from 87% (13 of 15 patients) with "isolated esophagogastric junction outflow obstruction" to 11% (1 of 9 patients) with "spastic-reactive fibrostenosis." CONCLUSIONS: Classifying PhysioMechanical esophageal function in EoE based on FLIP panometry features may facilitate defining disease severity and directing management in EoE.

The Severity of Reduced Esophageal Distensibility Parallels Eosinophilic Esophagitis Disease Duration.

BACKGROUND & AIMS: Chronic inflammation of eosinophilic esophagitis (EoE) results in progressive, fibrostenotic remodeling of the esophageal wall. This study aimed to demonstrate objective changes in esophageal distensibility relative to duration of EoE disease using a functional lumen imaging probe (FLIP). METHODS: Adult patients with EoE who completed a 16-cm FLIP protocol during endoscopy were evaluated in a cross-sectional study. FLIP analysis focused on distensibility plateau (DP) of the esophageal body. The time from onset of symptoms to time of endoscopy with FLIP was assessed, as was time from symptom onset to EoE diagnosis (ie, diagnostic delay). RESULTS: A total of 171 patients (mean age 38 ± 12 years; 31% female) were included; the median symptom duration was 8 (interquartile range, 3-15) years and diagnostic delay was 4 (interquartile range, 1-12) years. At the time of endoscopy with FLIP, there were 54 patients (39%) in histologic remission (<15 eosinophils per high-power field [eos/hpf]). Symptom duration and diagnostic delay were negatively correlated with DP (rho = -0.326 and -0.309; P values < .001). Abnormal esophageal distensibility (DP ≤17 mm) was more prevalent with increased duration of symptoms (P < .004): 23% at <5 years to 64% at ≥25 years. When stratifying the cohort based on mucosal eosinophil density, patients with ≥15 eos/hpf had significantly lower DP with greater symptom duration (P = .004), while there was not a significant difference among patients with <15 eos/hpf (P = .060). CONCLUSIONS: Esophageal distensibility objectively measured with FLIP was reduced in EoE patients with greater symptom duration and diagnostic delay. This supports that EoE is a progressive, fibrostenotic disease and that FLIP may be a useful tool to monitor disease progression in EoE.

Composite score of physiomechanical esophageal function using functional lumen imaging probe panometry in eosinophilic esophagitis.

BACKGROUND AND AIMS: The evaluation provided by functional lumen imaging probe (FLIP) panometry includes esophageal distensibility/compliance (mechanics) of the esophageal body and esophagogastric junction (EGJ) and esophageal motility (secondary peristalsis). We developed a composite score using these parameters to characterize physiomechanical function in patients with eosinophilic esophagitis (EoE). METHODS: Two hundred fifteen adult patients with EoE who completed FLIP panometry during sedated endoscopy with esophageal biopsy sampling were included. FLIP metrics of esophageal body Compliance, Contractile response, Distensibility plateau, and maximum EGJ Diameter (C2D2) were scored as 0 for normal versus 1 or 2 for increasing degree of abnormality. Scores were summed to calculate the composite C2D2 score. RESULTS: The C2D2 score had a significant positive correlation with mucosal eosinophil count (ρ = .241) and total Endoscopic EoE Reference Score (ρ = .467). Among 46 patients off treatment at the baseline evaluation, future proton pump inhibitor (PPI) responders (ie, achieved mucosal eosinophil count <15 per high-powered field after PPI treatment) had lower C2D2 scores than PPI nonresponders (median, 2 [interquartile range, 1-3] vs 4 [interquartile range, 2-6], respectively; P = .003). A regression model (that controlled for age, sex, and baseline eosinophil count) showed a C2D2 score ≤3 had an odds ratio of 14.5 (95% confidence interval, 2.6-85) to predict future PPI response. However, total Endoscopic EoE Reference Scores (P = .142) and baseline eosinophil count (P = .480) did not differ between PPI responders and PPI nonresponders. CONCLUSIONS: This composite score of FLIP panometry metrics, the C2D2 score, may facilitate characterizing physiomechanical function in EoE and serve as an objective outcome measure.

Prospective study of an amino acid-based elemental diet in an eosinophilic gastritis and gastroenteritis nutrition trial.

BACKGROUND: Eosinophilic gastritis/gastroenteritis (EoG/EoGE) are rare disorders with pathologic gastric and/or small intestinal eosinophilia lacking an approved therapy. An allergic mechanism is postulated but underexplored mechanistically and therapeutically. OBJECTIVE: We evaluated the effectiveness of a food allergen-free diet (elemental formula) in controlling gastrointestinal eosinophilia in adult EoG/EoGE. METHODS: Adults aged 18 to 65 years with histologically active EoG/EoGE (≥30 eosinophils per high-power field) in the stomach and/or duodenum and gastrointestinal symptoms within the month preceding enrollment were prospectively enrolled onto a single-arm clinical trial to receive elemental formula for 6 consecutive weeks. The primary end point was percentage of participants with complete histologic remission (<30 eosinophils per high-power field in both stomach and duodenum). Exploratory outcomes were improvement in symptoms, endoscopy results, blood eosinophilia, quality of life, Physician Global Assessment score, and EoG-relevant gastric transcriptome and microbiome. RESULTS: Fifteen adults (47% male, average age 37.7 years, average symptom duration 8.8 years) completed the trial. Multi-gastrointestinal segment involvement affected 87%. All subjects had complete histologic remission in the stomach (P = .002) and duodenum (P = .001). Scores improved in overall PhGA (P = .002); EGREFS (P = .003); EGDP (P = .002); SODA pain intensity (P = .044), non-pain (P = .039), and satisfaction (P = .0024); and PROMIS depression (P = .0078) and fatigue (P = .04). Food reintroduction reversed these improvements. The intervention was well tolerated in 14 subjects, with 1 serious adverse event reported in 1 subject. CONCLUSION: An amino acid-based elemental diet improves histologic, endoscopic, symptomatic, quality-of-life, and molecular parameters of EoG/EoGE; these findings and disease recurrence with food trigger reintroduction support a dominant role for food allergens in disease pathogenesis. CLINICALTRIALS: gov Identifier: NCT03320369.

Mepolizumab for treatment of adolescents and adults with eosinophilic oesophagitis: a multicentre, randomised, double-blind, placebo-controlled clinical trial.

OBJECTIVE: We aimed to determine whether mepolizumab, an anti-IL-5 antibody, was more effective than placebo for improving dysphagia symptoms and decreasing oesophageal eosinophil counts in eosinophilic oesophagitis (EoE). METHODS: We conducted a multicentre, randomised, double-blind, placebo-controlled, trial. In the first part, patients aged 16-75 with EoE and dysphagia symptoms (per EoE Symptom Activity Index (EEsAI)) were randomised 1:1 to 3 months of mepolizumab 300 mg monthly or placebo. Primary outcome was change in EEsAI from baseline to month 3 (M3). Secondary outcomes included histological, endoscopic and safety metrics. In part 2, patients initially randomised to mepolizumab continued 300 mg monthly for 3 additional months (mepo/mepo), placebo patients started mepolizumab 100 mg monthly (pbo/mepo), and outcomes were reassessed at month 6 (M6). RESULTS: Of 66 patients randomised, 64 completed M3, and 56 completed M6. At M3, EEsAI decreased 15.4±18.1 with mepolizumab and 8.3±18.0 with placebo (p=0.14). Peak eosinophil counts decreased more with mepolizumab (113±77 to 36±43) than placebo (146±94 to 160±133) (p<0.001). With mepolizumab, 42% and 34% achieved histological responses of <15 and ≤6 eos/hpf compared with 3% and 3% with placebo (p<0.001 and 0.02). The change in EoE Endoscopic Reference Score at M3 was also larger with mepolizumab. At M6, EEsAI decreased 18.3±18.1 points for mepo/mepo and 18.6±19.2 for pbo/mepo (p=0.85). The most common adverse events were injection-site reactions. CONCLUSIONS: Mepolizumab did not achieve the primary endpoint of improving dysphagia symptoms compared with placebo. While eosinophil counts and endoscopic severity improved with mepolizumab at 3 months, longer treatment did not yield additional improvement. TRIAL REGISTRATION NUMBER: NCT03656380.

Eosinophilic Esophagitis: Etiology and Therapy.

Eosinophilic esophagitis (EoE) is a relatively recently identified but now frequently encountered antigen/immune-mediated disease which places significant burden on patients and the healthcare system. With its growing prevalence and recognition by healthcare providers in multiple disciplines, substantial progress has been made regarding the diagnostic criteria, clinical evaluation, tools for disease assessment, and immune pathways related to pathogenesis. Current treatment goals focus on the amelioration of inflammation and prevention of remodeling consequences using proton pump inhibitors, swallowed topical steroids, elimination diets, and esophageal dilation. Ongoing research holds promise for more efficacious and targeted therapies as well as a personalized approach to the care of patients with EoE.

Anti-Siglec-8 Antibody for Eosinophilic Gastritis and Duodenitis.

BACKGROUND: Eosinophilic gastritis and duodenitis are characterized by gastrointestinal mucosal eosinophilia, chronic symptoms, impaired quality of life, and a lack of adequate treatments. Mast-cell activity may contribute to the pathogenesis of the conditions. AK002 (lirentelimab) is an anti-Siglec-8 antibody that depletes eosinophils and inhibits mast cells and that has shown potential in animal models as a treatment for eosinophilic gastritis and duodenitis. METHODS: In this phase 2 trial, we randomly assigned adults who had symptomatic eosinophilic gastritis, eosinophilic duodenitis, or both conditions in a 1:1:1 ratio to receive four monthly infusions of low-dose AK002, high-dose AK002, or placebo. The primary end point was the change in gastrointestinal eosinophil count from baseline to 2 weeks after the final dose; to maximize statistical power, we evaluated this end point in the placebo group as compared with the combined AK002 group. Secondary end points were treatment response (>30% reduction in total symptom score and >75% reduction in gastrointestinal eosinophil count) and the change in total symptom score. RESULTS: Of the 65 patients who underwent randomization, 43 were assigned to receive AK002 and 22 were assigned to receive placebo. The mean percentage change in gastrointestinal eosinophil count was -86% in the combined AK002 group, as compared with 9% in the placebo group (least-squares mean difference, -98 percentage points; 95% confidence interval [CI], -121 to -76; P<0.001). Treatment response occurred in 63% of the patients who received AK002 and in 5% of the patients who received placebo (difference, 58 percentage points; 95% CI, 36 to 74; P<0.001). The mean change in total symptom score was -48% with AK002 and -22% with placebo (least-squares mean difference, -26 percentage points; 95% CI, -44 to -9; P = 0.004). Adverse events associated with AK002 were similar to those with placebo, with the exception of higher percentages of patients having mild-to-moderate infusion-related reactions with AK002 (60% in the combined AK002 group and 23% in the placebo group). CONCLUSIONS: In patients with eosinophilic gastritis or duodenitis, AK002 reduced gastrointestinal eosinophils and symptoms. Infusion-related reactions were more common with AK002 than with placebo. (Funded by Allakos; ENIGMA ClinicalTrials.gov number, NCT03496571.).

Monitoring Patients With Eosinophilic Esophagitis in Routine Clinical Practice - International Expert Recommendations.

BACKGROUND & AIMS: There are no studies or recommendations on optimal monitoring strategies for patients with eosinophilic esophagitis (EoE). Our objective was to develop guidance on how to monitor patients with EoE in routine clinical practice, on the basis of available clinical evidence and expert opinion. METHODS: A multidisciplinary, international group of EoE experts identified the following important 3 questions during several consensus meetings: why, by what means, and when to monitor patients with EoE. A steering committee was named, and 3 teams were formed to review literature and to formulate statements for each topic. In a Delphi survey, a level of agreement of ≥75% was defined as threshold value for acceptance. In a final conference, results were presented, critical points and comments on the statements were discussed, and statements were rephrased/rewritten if necessary. RESULTS: Eighteen EoE experts (14 adult and pediatric gastroenterologists, 2 pathologists and 2 allergists) with a median of 21.7 years in clinical practice, mostly academic or university-based, completed the Delphi survey, which included 11 statements and a proposed algorithm for monitoring patients with EoE. Each statement attained ≥75% agreement. Participants discussed and debated mostly about the statement concerning surveillance intervals for EoE patients with stable disease. CONCLUSIONS: It was concluded that effective maintenance treatment probably reduces the development of EoE complications, and regular, structured, and, under certain conditions, individualized clinical follow-up is recommended to assess disease activity while opening a window to monitoring side effects, adjusting therapy, and encouraging adherence to treatment. Follow-up should comprise symptom assessment and periodic or repeated endoscopy with histological assessment in specific EoE settings.

Epidemiologic Burden and Projections for Eosinophilic Esophagitis-Associated Emergency Department Visits in the United States: 2009-2030.

BACKGROUND & AIMS: Patients with poorly controlled eosinophilic esophagitis (EoE) may require unplanned emergency department (ED) visits for the management of dysphagia or food impactions. We evaluated the epidemiologic burden of EoE on ED utilization in the United States. METHODS: Data from the US Nationwide Emergency Department Sample were used to estimate weighted annual EoE-associated ED visits from 2009 to 2019. Temporal trends in population-adjusted rates of EoE visits were assessed using joinpoint regression. Autoregressive integrated moving average models were used to project EoE-associated ED visits to 2030. We also evaluated endoscopic utilization, requirement for hospitalization, and ED-related charges in patients with EoE presenting to the ED. RESULTS: A total of 11,125 unweighted (49,507 weighted) ED visits for EoE were included (69.0% male; mean age, 32.4 y). The annual volume of EoE-associated ED visits increased from 2934 (95% CI, 2437-3431) in 2009 to 8765 (95% CI, 7514-10,015) in 2019, and is projected to reach 15,445 (95% prediction interval, 14,672-16,218) by 2030. From 2009 to 2019, the number of EoE-associated ED visits increased by an average of 11.5% per year (95% CI, 10.3%-12.7%). The proportion of patients admitted to the hospital from the ED decreased from 25.6% in 2009 to 2011 to 14.0% in 2017 to 2019. Half of EoE patients presenting to the ED required an endoscopy, and nearly 40% required an esophageal foreign body removal. Total mean inflation-adjusted charges for an EoE-associated ED visit were $9025 US dollars in 2019. CONCLUSIONS: The volume of EoE-associated ED visits tripled between 2009 and 2019 and is projected to further double by 2030. This represents a substantial burden of unanticipated health care resource utilization and highlights a potential opportunity to optimize outpatient EoE care.

Esophageal Epithelium and Lamina Propria Are Unevenly Involved in Eosinophilic Esophagitis.

BACKGROUND & AIMS: The nature of the involvement of esophageal tissue in eosinophilic esophagitis (EoE) is unclear. We estimated the intrabiopsy site agreements of the EoE Histologic Scoring System (EoEHSS) scores for the grade (degree) and stage (extent) of involvement of the esophageal epithelial and lamina propria and examined if the EoE activity status influenced the intrabiopsy site agreement. METHODS: Demographic, clinical, and EoEHSS scores collected as part of the prospective Outcome Measures for Eosinophilic Gastrointestinal Diseases Across Ages study were analyzed. A weighted Cohen's kappa agreement coefficient (k) was used to calculate the pairwise agreements for proximal:distal, proximal:middle, and middle:distal esophageal biopsy sites, separately for grade and stage scores, for each of the 8 components of EoEHSS. A k > 0.75 was considered uniform involvement. Inactive EoE was defined as fewer than 15 eosinophils per high-powered field. RESULTS: EoEHSS scores from 1263 esophageal biopsy specimens were analyzed. The k for the stage of involvement of the dilated intercellular spaces across all 3 sites in inactive EoE was consistently greater than 0.75 (range, 0.87-0.99). The k for lamina propria fibrosis was greater than 0.75 across some of the biopsy sites but not across all 3. Otherwise, the k for all other features, for both grade and stage, irrespective of the disease activity status, was 0.75 or less (range, 0.00-0.74). CONCLUSIONS: Except for the extent of involvement of dilated intercellular spaces in inactive EoE, the remaining epithelial features and lamina propria are involved unevenly across biopsy sites in EoE, irrespective of the disease activity status. This study enhances our understanding of the effects of EoE on esophageal tissue pathology.

A Clinical Severity Index for Eosinophilic Esophagitis: Development, Consensus, and Future Directions.

BACKGROUND & AIMS: Disease activity and severity of eosinophilic esophagitis (EoE) dictate therapeutic options and management, but the decision-making process for determining severity varies among practitioners. To reduce variability in practice patterns and help clinicians monitor the clinical course of the disease in an office setting, we aimed to create an international consensus severity scoring index for EoE. METHODS: A multidisciplinary international group of adult and pediatric EoE researchers and clinicians, as well as non-EoE allergy immunology and gastroenterology experts, formed 3 teams to review the existing literature on histology, endoscopy, and symptoms of EoE in the context of progression and severity. A steering committee convened a 1-day virtual meeting to reach consensus on each team's opinion on salient features of severity across key clinicopathologic domains and distill features that would allow providers to categorize disease severity. RESULTS: Symptom features and complications and inflammatory and fibrostenotic features on both endoscopic and histologic examination were collated into a simplified scoring system-the Index of Severity for Eosinophilic Esophagitis (I-SEE)-that can be completed at routine clinic visits to assess disease severity using a point scale of 0-6 for mild, 7-14 for moderate, and ≥15 for severe EoE. CONCLUSIONS: A multidisciplinary team of experts iteratively created a clinically usable EoE severity scoring system denominated "I-SEE" to guide practitioners in EoE management by standardizing disease components reflecting disease severity beyond eosinophil counts. I-SEE should be validated and refined using data from future clinical trials and routine clinical practice to increase its utilization and functionality.

Loss of Endothelial TSPAN12 Promotes Fibrostenotic Eosinophilic Esophagitis via Endothelial Cell-Fibroblast Crosstalk.

BACKGROUND & AIMS: Eosinophilic esophagitis (EoE) can progress to fibrostenosis by unclear mechanisms. Herein, we investigated gene dysregulation in fibrostenotic EoE, its association with clinical parameters and specific pathways, and the functional consequences. METHODS: Esophageal biopsies from subjects with EoE were collected across 11 Consortium of Eosinophilic Gastrointestinal Disease Researchers sites (n = 311) and 2 independent replication cohorts (n = 83). Inclusion criteria for fibrostenotic EoE were endoscopic rings, stricture, and/or a history of dilation. Endoscopic, histologic, and molecular features were assessed by the EoE Endoscopic Reference Score, EoE Histology Scoring System, EoE Diagnostic Panel, and RNA sequencing. Esophageal endothelial TSPAN12 expression and functional effects on barrier integrity and gene expression were analyzed in vitro. RESULTS: TSPAN12 was the gene most correlated with fibrostenosis (r = -0.40, P < .001). TSPAN12 was lower in fibrostenotic EoE and correlated with EoE Endoscopic Reference Score, EoE Diagnostic Panel, and EoE Histology Scoring System (r = 0.34-0.47, P < .001). Lower TSPAN12 associated with smaller esophageal diameter (r = 0.44, P = .03), increased lamina propria fibrosis (r = -0.41, P < .001), and genes enriched in cell cycle-related pathways. Interleukin (IL)-13 reduced TSPAN12 expression in endothelial cells. Conversely, anti-IL-13 therapy increased TSPAN12 expression. TSPAN12 gene silencing increased endothelial cell permeability and dysregulated genes associated with extracellular matrix pathways. Endothelial cell-fibroblast crosstalk induced extracellular matrix changes relevant to esophageal remodeling. CONCLUSIONS: Patients with fibrostenotic EoE express decreased levels of endothelial TSPAN12. We propose that IL-13 decreases TSPAN12, likely contributing to the chronicity of EoE by promoting tissue remodeling through fibroblast-endothelial cell crosstalk.

Evaluating Eosinophilic Colitis as a Unique Disease Using Colonic Molecular Profiles: A Multi-Site Study.

BACKGROUND & AIMS: Colonic eosinophilia, an enigmatic finding often referred to as eosinophilic colitis (EoC), is a poorly understood condition. Whether EoC is a distinct disease or a colonic manifestation of eosinophilic gastrointestinal diseases (EGIDs) or inflammatory bowel disease (IBD) is undetermined. METHODS: Subjects with EoC (n = 27) and controls (normal [NL, n = 20], Crohn's disease [CD, n = 14]) were enrolled across sites associated with the Consortium of Eosinophilic Gastrointestinal Disease Researchers. EoC was diagnosed as colonic eosinophilia (ascending ≥100, descending ≥85, sigmoid ≥65 eosinophils/high-power field) with related symptoms. Colon biopsies were subjected to RNA sequencing. Associations between gene expression and histologic features were analyzed with Spearman correlation; operational pathways and cellular constituents were computationally derived. RESULTS: We identified 987 differentially expressed genes (EoC transcriptome) between EoC and NL (>1.5-fold change, P < .05). Colonic eosinophil count correlated with 31% of EoC transcriptome, most notably with CCL11 and CLC (r = 0.78 and 0.77, P < .0001). Among EoC and other EGIDs, there was minimal transcriptomic overlap and minimal evidence of a strong allergic type 2 immune response in EoC compared with other EGIDs. Decreased cell cycle and increased apoptosis in EoC compared with NL were identified by functional enrichment analysis and immunostaining using Ki-67 and cleaved caspase-3. Pericryptal circumferential eosinophil collars were associated with the EoC transcriptome (P < .001). EoC transcriptome-based scores were reversible with disease remission and differentiated EoC from IBD, even after controlling for colonic eosinophil levels (P < .0001). CONCLUSIONS: We established EoC transcriptomic profiles, identified mechanistic pathways, and integrated findings with parallel IBD and EGID data. These findings establish EoC as a distinct disease compared with other EGIDs and IBD, thereby providing a basis for improving diagnosis and treatment.