Scientific journey to the first FDA-approved drug for eosinophilic esophagitis

Biologics for eosinophilic oesophagitis: a systematic review and meta-analysis

OBJECTIVE

Advancing the understanding of the pathophysiology of eosinophilic oesophagitis (EoE) and other eosinophilic gastrointestinal diseases (EGIDs) has spurred research into targeted biological therapies, while the conclusive therapeutic efficacy of biologics remains uncertain. In this review, we conducted a meta-analysis of all RCTS of biologics in the treatment of EoE to evaluate their efficacy and safety and discussed their treatment of non-EoE EGIDs.

METHODS

We searched the PubMed, EMBASE, Cochrane Library, and Web of Science databases. Double-blind randomized controlled trials comparing biologics with placebo in patients with EoE and non-EoE EGIDs were collected and further screened for inclusion and exclusion. The caliber of the included literature was evaluated using the Cochrane risk assessment tool findings. Data extraction and meta-analysis were conducted using RevMan 5.4 and Stata 17.0. Clinical response and histological remission were the major endpoints.

RESULTS

Our search retrieved 3,237 articles. There were seven trials in total, comprising 792 people with EoE. Key outcomes of this meta-analysis include the following: Anti-IL-5 biologics exhibited statistically significant benefits in histological remission (RR 2.03 [CI 1.45-2.85]; p < 0.0001) compared to the placebo, but there was no significant difference in symptom relief (RR 1.06 [CI 0.88 to 1.28]; p = 0.53); anti-IL-4/13 biologics had significant effects on histologic improvement (RR 10.48 [CI 5.54-19.82]; p < 0.00001) and symptom related score reduction (RR 1.44 [CI 1.08-1.93]; p = 0.01), with a better outcome for endoscopic remission than with placebo (SMD-1.06 [CI-1.26-0.86], p < 0.00001); no statistically significant differences in adverse effects were observed between the intervention and control groups.

CONCLUSIONS

Our findings suggest that the biologics currently being investigated are considered safe and effective treatments for EoE, while their efficiency varies. However, the discussion of biologics in non-pharyngitis EGID is hampered by a lack of research, necessitating more research in high-quality trials.

Meta-Analysis: Evaluating Placebo Rates Across Outcomes in Eosinophilic Oesophagitis Randomised Controlled Trials

BACKGROUND

High placebo responses have limited drug development in eosinophilic oesophagitis. The optimal configuration of trial outcomes is uncertain.

AIMS

To inform more efficient future trial designs, to characterise clinical, endoscopic and histologic placebo responses in eosinophilic oesophagitis randomised controlled trials (RCTs).

METHODS

We updated a Cochrane systematic review and meta-analysis, searching multiple databases to January 1, 2024, to identify placebo-controlled RCTs evaluating medical therapies for patients with eosinophilic oesophagitis. The primary outcome was the pooled proportion of study-defined clinical, endoscopic and histologic responders and remitters randomised to placebo, using an intention-to-treat approach and random-effects model. Sources of heterogeneity were explored using meta-regression.

RESULTS

We included 25 RCTs. The pooled proportion of clinical response was 41.0% [95% CI: 29.7%-52.8%] with substantial heterogeneity (I2 = 74.9%). On meta-regression, older age and a higher probability of being randomised to placebo reduced the likelihood of clinical response to placebo. The pooled proportion of histologic remission defined as a peak eosinophil count [PEC] ≤ 6 eosinophils per high power field [HPF] or ≤ 1 eosinophil/HPF was 4.3% [95% CI: 2.6%-6.2%] (I2 = 23.6%) and 1.3% [95% CI: 0.5%-2.5%] (I2 = 0%), respectively. The standardised mean difference in the Eosinophilic Oesophagitis Endoscopic Reference Score to placebo was -0.25 [95% CI: -0.41, -0.10].

CONCLUSIONS

Over 40% of patients in eosinophilic oesophagitis trials respond clinically to placebo, and this is associated with trial design factors such as randomisation ratio and trial population. Objective endoscopic and histologic measures are associated with very low placebo responses.

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.).

Antibody-based therapeutics for chronic rhinosinusitis with nasal polyps

INTRODUCTION

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a prevalent inflammatory condition with heterogenous underlying endotypes, the most common being type 2 mediated inflammation. Several biologics have been developed to target specific pro-inflammatory cytokines and their receptors with proven efficacy in both quantitative and qualitative outcomes in patients with severe uncontrolled disease. However, there is an ongoing debate on the role of biologics relative to conventional therapies for CRSwNP and their efficacy in patient subgroups with non-polyp type 2 disease.

AREAS COVERED

This review examines the evidence on the efficacy and safety of biologics in CRSwNP, recommendations for their use, and discusses the broader economic factors influencing their application in clinical practice.

EXPERT OPINION

Emerging real-life data demonstrating the variable efficacy of the available biologics for patients with CRSwNP, coupled with the high cost compared to conventional therapies such as surgery, renders biologics to be considered as an add-on therapy in the majority of cases. However, ongoing research into increasing biologic dose intervals and novel therapies targeting alternative pathways may offer a more cost-effective and sustainable option in future.

Common and disparate clinical presentations and mechanisms in different eosinophilic gastrointestinal diseases

Eosinophilic gastrointestinal diseases (EGIDs) are a group of diseases characterized by selective eosinophil infiltration of the gastrointestinal (GI) tract in the absence of other causes of eosinophilia. These diseases are generally driven by type 2 inflammation, often in response to food allergen exposure. Among all EGIDs, the clinical presentation often includes a history of atopic disease with a variety of GI symptoms. EGIDs are traditionally separated into eosinophilic esophagitis (EoE) and non-EoE EGIDs. EoE is relatively better understood and now associated with clinical guidelines and 2 US Food and Drug Administration-approved treatments, whereas non-EoE EGIDs are rarer and less well-understood diseases without US Food and Drug Administration-approved treatments. Non-EoE EGIDs are further subclassified by the area of the GI tract that is involved; they comprise eosinophilic gastritis, eosinophilic enteritis (including eosinophilic duodenitis), and eosinophilic colitis. As with other GI disorders, the disease presentations and mechanisms differ depending on the involved segment of the GI tract; however, the differences between EoE and non-EoE EGIDs extend beyond which GI tract segment is involved. The aim of this article is to summarize the commonalities and differences between the clinical presentations and disease mechanisms for EoE and non-EoE EGIDs.

Sleep, Anxiety, Somatization, Quality of Life, and Resilience in Pediatric Patients With Eosinophilic Esophagitis

INTRODUCTION

Emerging evidence suggests a high burden of psychosocial comorbidities in patients with eosinophilic esophagitis (EoE), although factors associated with this burden have not been explored. We aimed to increase understanding of the psychosocial burden of EoE and assess factors that are associated with disease burden.

METHODS

We conducted a cross-sectional study of patients with EoE (n = 87) recruited from a single-center, multidisciplinary pediatric eosinophilic gastrointestinal disorders clinic (2019-2021). Participants (aged 8-18 years) completed validated assessments during routine clinic visit to assess EoE symptoms (Pediatric Eosinophilic Esophagitis Symptom Score version 2.0), quality of life (Pediatric Quality of LIfe- Eosinophilic Esophagitis), anxiety state and trait (State-Trait Anxiety Score for Children), somatization (Child Somatic Symptoms Inventory 24), sleep disordered breathing (Pediatric Sleep Questionnaire) and, in a subset (n = 35), resilience (Connor Davidson Resilience Scale). Clinical and demographic data were collected.

RESULTS

Participants were at a mean (SD) age of 12.8 (3.1) years, and 26% (n = 23) were female. Shorter disease duration (6-12 months) was associated with higher symptom burden ( P = 0.03), somatization ( P < 0.01), and anxiety (State-Trait Anxiety Score for Children Trait P < 0.01) scores. Participants with neurodevelopmental comorbidities had higher anxiety trait, somatization, sleep disordered breathing, and lower quality of life ( P < 0.01 for all). Symptom burden was significantly associated with increased somatic symptoms (adjusted β [aβ] = 0.34; 95% confidence interval 0.23-0.45) and decreased quality of life (aβ = -0.42; 95% confidence interval -0.59 to -0.25) but not state anxiety, trait anxiety, or disordered sleep breathing.

DISCUSSION

Pediatric patients with a recent diagnosis of EoE can experience higher EoE symptoms, somatization, and anxiety when compared with those with a longer-standing diagnosis. Patients earlier in their diagnosis and with neurodevelopmental disorders may experience increased somatization and anxiety that may warrant additional support services.

A unique role for IL-13 in inducing esophageal eosinophilia through MID-1 and STAT6

Introduction

Eosinophilic esophagitis (EoE) is associated with allergen-driven inflammation of the esophagus and an upregulated Th2 cytokine signature. Recombinant interleukin (IL)-13 (rIL-13) administration to mice induces some of the hallmark features of EoE, including increased eotaxin expression and eosinophil recruitment. Inflammation in EoE has previously been shown to depend on the expression of TRAIL and MID-1, which reduced protein phosphatase 2A (PP2A) activity. The relationship between IL-13 and TRAIL signalling in esophageal eosinophilia is currently unknown.

Objective

To investigate the interaction between IL-13-driven eosinophil infiltration and TRAIL or MID-1 in the esophagus.

Method

We administered rIL-13 to wild type (WT), TRAIL-deficient (Tnsf10-/-) or STAT6-deficient (STAT6-/-) mice and targeted MID-1 with small interfering RNA.

Results

rIL-13 administration to mice increased TRAIL and MID-1 expression in the esophagus while reducing PP2A activity. TRAIL deficient, but not STAT6 deficient mice demonstrated increased MID-1 expression and PP2A reduction upon IL-13 challenge which correlated with eosinophil infiltration into the esophagus. Silencing MID-1 expression with siRNA completely ablated IL-13 induced eosinophil infiltration of the esophagus, restored PP2A activity, and reduced eotaxin-1 expression.

Conclusion

IL-13-driven eosinophil infiltration of the esophagus induced eosinophilia and eotaxin-1 expression in a STAT6-dependent and MID-1-dependent manner. This study highlights a novel mechanism employed by IL-13 to perpetuate eosinophil infiltration.

Biologics in severe asthma: A pragmatic approach for choosing the right treatment for the right patient

The development of monoclonal antibody therapies targeting specific components of the pathways relevant to asthma pathophysiology has revolutionized treatment of severe asthma both in adults and children and helped to further unravel the heterogeneity of this disease. However, the availability of multiple agents, often with overlapping eligibility criteria, creates a need for pragmatic guidance for specialists undertaking care of patients with severe asthma. In this review, we provide an overview of the data supporting the clinical efficacy of biologics in distinct asthma phenotypes/endotypes. We also focus on the role of biomarkers and treatable traits, including comorbidities, in the choice of asthma biologics, highlight which treatments have been demonstrated to be steroid sparing in corticosteroid dependent asthma, and provide practical guidance that can drive shared decision making on treatment choice with patients. In addition, we summarize what is known to date regarding long-term safety of these drugs, and lastly, discuss future directions in biologics research.

The minichromosome maintenance complex drives esophageal basal zone hyperplasia

Eosinophilic esophagitis (EoE) is a chronic gastrointestinal disorder characterized by food antigen-driven eosinophilic inflammation and hyperproliferation of esophageal mucosa. By utilizing a large-scale, proteomic screen of esophageal biopsies, we aimed to uncover molecular drivers of the disease. Proteomic analysis by liquid chromatography-tandem mass spectrometry identified 402 differentially expressed proteins (DEPs) that correlated with the EoE transcriptome. Immune cell-related proteins were among the most highly upregulated DEPs in EoE compared with controls, whereas proteins linked to epithelial differentiation were primarily downregulated. Notably, in the inflamed esophageal tissue, all 6 subunits of the minichromosome maintenance (MCM) complex, a DNA helicase essential for genomic DNA replication, were significantly upregulated at the gene and protein levels. Furthermore, treating esophageal epithelial cells with a known inhibitor of the MCM complex (ciprofloxacin) blocked esophageal epithelial proliferation. In a murine model of EoE driven by overexpression of IL-13, ciprofloxacin treatment decreased basal zone thickness and reduced dilated intercellular spaces by blocking the transition of epithelial cells through the S-phase of the cell cycle. Collectively, a broad-spectrum proteomic screen has identified the involvement of the MCM complex in EoE and has highlighted MCM inhibitors as potential therapeutic agents for the disease.

Recent Advances in the Treatment of Eosinophilic Esophagitis

Eosinophilic esophagitis is an increasingly common inflammatory allergic disease of the esophagus characterized by esophageal eosinophilia and symptoms of esophageal dysfunction. The therapeutic landscape has rapidly evolved for this emerging type 2 inflammatory disorder. We review traditional therapies including updates and expert opinions in addition to promising therapies on the horizon and the history of therapies that failed to meet end points and highlight knowledge gaps for future investigations.

Local type 2 immunity in eosinophilic gastritis

BACKGROUND

Eosinophilic gastritis (EoG) associates with type 2 immunity. However, the type 2 cytokine cellular source, gastric T-cell composition, and gastric T-cell relationship (or relationships) with disease pathology remain understudied.

OBJECTIVE

We defined gastric T-cell populations and their association with histologic and endoscopic EoG pathology.

METHODS

Gastric biopsy samples (n = 6 EoG, n = 7 control) were subjected to histologic, endoscopic, and flow cytometry analyses. In a complementary cohort (n = 83 EoG), IL4, IL5, and IL13 mRNA levels were correlated with EoG pathologic parameters.

RESULTS

Gastric biopsy samples contained CD3+ T cells that were mainly CD8+; the CD8/CD4 ratio was comparable in EoG and control biopsy samples (5.7 ± 3.0 and 4.3 ± 0.6, respectively; P = .28). Gastric regulatory T (CD3+CD4+FOXP3+) and TH2 (CD3+CD4+GATA3+) cell levels were increased in EoG versus controls (2-fold, P < .05 and 10-fold, P < .001, respectively) and correlated with gastric eosinophil levels (r = 0.63, P < .05 and r = 0.85, P < .001, respectively), endoscopic pathology (r = 0.56, P < .01; r = 0.84, P < .001, respectively), and histopathology (r = 0.72, P < .01; r = 0.82, P < .01, respectively). Cytokine-positive, most notably IL-4+, TH2 cell levels strongly correlated with histologic and endoscopic scores (r = 0.82, P < .0001 and r = 0.78, P < .0001, respectively). In an independent EoG cohort (n = 83), bulk gastric IL4, IL5, and IL13 mRNA levels correlated with histologic score (r = 0.22, P < .005; r = 0.54, P < .0001; and r = 0.36, P < .0001, respectively) and endoscopic score (r = 0.27, P < .001; r = 0.40, P < .0001; and r = 0.35, P < .0001, respectively).

CONCLUSIONS

EoG is a TH2 cell-associated disease featuring increased gastric type 2 cytokine-producing CD3+CD4+GATA3+TH2 cells that strongly correlate with disease pathologies.

Understanding the Sex, Racial, and Ethnic Disparities in Eosinophilic Esophagitis

The incidence of eosinophilic esophagitis (EoE) has been rapidly increasing. EoE affects both children and adults and can present with a variety of symptoms depending on age. Multiple studies have found that EoE is more common in Caucasian men compared with other genders or racial or ethnic groups; however, the basis for that predominance is still unknown. The varied clinical illness presentation and persistence in various ethnic groups begs the question of whether genetic or environmental factors might be contributors behind EoE. This paper will review the literature regarding epidemiology, risk factors, and genetic and ethnic differences in EoE.