The Future of Food Allergy Management: Advancements in Therapies

PURPOSE OF REVIEW

To review current and future treatment options for IgE-mediated food allergy.

RECENT FINDINGS

Recent years have seen major developments in both allergen-specific and allergen-non-specific treatment options, with the first FDA-approved peanut oral immunotherapy (OIT) product becoming available in 2020. In addition to OIT, other immunotherapy modalities, biologics, adjunct therapies, and novel therapeutics are under investigation. Food allergy is a potentially life-threatening condition associated with a significant psychosocial impact. Numerous products and protocols are under investigation, with most studies focusing on OIT. A high rate of adverse events, need for frequent office visits, and cost remain challenges with OIT. Further work is needed to unify outcome measures, develop treatment protocols that minimize adverse events, establish demographic and clinical factors that influence candidate selection, and identify patient priorities.

The Role of Biologics in the Treatment of Food Allergy

The landscape of food allergy (FA) treatment is poised for a paradigm shift with the emergence of biologic therapies. The Food and Drug Administration approval of a standardized peanut powder for oral immunotherapy in 2020 marked a milestone, signaling a departure from allergen avoidance toward proactive treatment strategies. Although oral immunotherapy has been proven effective in desensitizing patients to specific allergens, there are several limitations such as lacking standardization, a long-time commitment to achieve maintenance, and adverse events. Biologics, including omalizumab, dupilumab, and antialarmins, have shown promise in treating various allergic diseases, including FA. These biologics target the underlying immunologic pathways driving allergic reactions, offering an antigen-agnostic approach. Omalizumab (anti-IgE) has been the most studied biologic in this space and can be used both as an adjunct therapy with oral immunotherapy and as monotherapy. Dupilumab targeting IL-4 and IL-13 also shows promise as an adjunct therapy. The emergence of antialarmins further broadens the spectrum of FA treatment possibilities. Biologics represent a transformative approach to FA treatment, directly addressing the underlying mechanisms. Future research should focus on patient selection criteria, personalized biomarker panels, optimal timing of intervention, and treatment durations.

Proton pump inhibitors in eosinophilic esophagitis (EoE) related to oral immunotherapy: is it as effective as in other EoE?

Oral immunotherapy (OIT) may induce eosinophilic esophagitis (EoE). Proton pump inhibitors (PPIs) are an effective treatment for EoE. However, the effect of PPI treatment is not well established in patients with EoE induced by OIT. Our primary aim was to compare the clinical, endoscopic, and histological response rates to PPIs in children with EoE induced by OIT (EoE+OIT) versus EoE patients without OIT (EoE-OIT). The secondary aims are to describe the clinical and histological features of EoE+OIT. Demographic, clinical, endoscopic, and histological findings of patients with EoE in the gastroenterology clinic at Shamir Medical Center between March 2015 and December 2022 were collected. Comparisons were performed between EoE+OIT and EoE-OIT patients. The study included 42 children (74% male, mean age 11.2), of whom 31 had EoE-OIT and 11 had EoE+OIT. There were no significant differences between groups regarding sex, comorbidities, symptoms, or endoscopic and histological characteristics at diagnosis. All 42 children were treated with PPIs after diagnosis with or without diet changes. The rates of any clinical response were 83.9% and 90.1% in the EoE-OIT group and EoE+OIT group, respectively (p = 1.0). The rate of any endoscopic response was 74.2% for EoE-OIT and 81.8% for EoE+OIT (p = 0.54). Histologically, PPIs were even more effective in the EoE+OIT group, where only 18.2% had no histological response at all compared to 51.6% in the EoE-OIT group (p = 0.1).

CONCLUSION

PPI treatment is as effective in EoE with OIT as it is in EoE due to other etiologies.

WHAT IS KNOWN

• Proton pump inhibitor (PPI) treatment is effective for achieving clinical response and histologic remission in some patients with eosinophilic esophagitis (EoE). • EoE has also been reported to be triggered by oral immunotherapy (OIT).

WHAT IS NEW

• PPI treatment in EoE with OIT is as effective as treatment for EoE due to other etiologies.

Peanut Oral Immunotherapy With or Without H1 and H2 Antihistamine Premedication for Peanut Allergy (PISCES): A Placebo-Controlled Randomized Clinical Trial

BACKGROUND

Current forms of peanut oral immunotherapy (OIT) are associated with side effects, and there is a lack of evidence addressing how to mitigate them.

OBJECTIVE

To determine whether premedication with desloratadine and ranitidine results in fewer side effects during peanut OIT/desensitization.

METHODS

A total of 43 patients with peanut allergy (mean age, 7.6 ± 2.1 years, 37% females, 63% males, baseline eliciting dose, 33 ± 26 mg) were randomized to OIT with or without concomitant H₁ and H₂ antihistamine blockade, or double-placebo. Patients, study staff/investigators, and statisticians were blinded. The primary outcomes were the frequency and severity of OIT-induced adverse events. The secondary outcomes were quality of life and eliciting doses to blinded food challenge.

RESULTS

Adverse reactions occurred more in the OIT groups compared with the double-placebo group (OIT with antihistamines vs double-placebo hazard ratio, 3.75 [95% CI, 2.79-4.72]; OIT with placebo antihistamines vs double-placebo, hazard ratio, 4.62 [95% CI, 3.61-5.62]). Patients given antihistamines cotreatment with OIT had a similar risk of adverse events compared with those who did not use antihistamines with OIT (hazard ratio, 1.23 [95% CI, 0.49-1.97]). OIT with and without antihistamines accelerated the incidence rate of adverse events compared with double-placebo (4.8 and 6.4 events per patient vs 3.5 per patient, incidence rate ratio, 2.49 [95% CI, 1.36-4.56] and 2.04 [95% CI, 1.01-4.15], respectively). Antihistamines pretreatment modestly reduced the frequency of moderate to severe adverse reactions among OIT-treated groups (1.9 per patient vs 4.2 per patient, incidence rate ratio, 0.46 [95% CI, 0.24-0.89]), primarily urticaria (0.6 vs 2.1 per patient) followed by abdominal pain (2.6 vs 4.2 per patient), but increased neuropsychiatric adverse events (primarily tiredness and sedation, 2.3 vs 0.7 per patient). Eliciting doses after treatment were similar in all groups. Quality of life improved similarly regardless of treatment with peanut OIT or placebo OIT.

CONCLUSIONS

Peanut OIT with antihistamines modestly reduce the skin and gastrointestinal components of the high incidence of adverse reactions during OIT, and there are no clear differences in improvement in quality of life whether treated with OIT, OIT with antihistamines, or placebo OIT despite OIT being effective in inducing desensitization. Safer food allergy treatment approaches that importantly improve quality of life need to be proved in future robust randomized trials.

Management of Eosinophilic Esophagitis During Oral Immunotherapy

Food allergies are antigen-driven diseases that can lead to IgE-mediated reactions of immediate hypersensitivity (eg, anaphylaxis triggered by a single food) or non-IgE reactions of delayed hypersensitivity such as eosinophilic esophagitis (eg, inability to eat multiple foods manifesting as abdominal pain, choking, dysphagia, vomiting, reflux, food impaction). Although both types of disease have their own unique set of challenges in diagnosis and management, it is a particularly vexing problem when a patient is afflicted by both conditions. This situation can happen when individuals with IgE-mediated food allergy undergo desensitization using currently available forms of oral immunotherapy. In this Grand Rounds Review, we review diagnostic approaches to oral immunotherapy-associated eosinophilic esophagitis, potential relationships between primary and secondary eosinophilic esophagitis, potential management approaches, areas of uncertainty, and upcoming research. Optimally supporting patients in their journey with food allergy requires shared decision making regarding alternative management strategies and the stimulation of robust research.

T-Cell Epitope Immunotherapy in Mouse Models of Food Allergy

Food allergy has been rising in prevalence over the last two decades, affecting more than 10% of the world population. Current management of IgE-mediated food allergy relies on avoidance and rescue medications; research into treatments that are safer and providing guaranteed and durable curative effects is, therefore, essential. T-cell epitope-based immunotherapy holds the potential for modulating food allergic responses without IgE cross-linking. In this chapter, we describe the methods in evaluating the therapeutic capacities of immunodominant T-cell epitopes in animal models of food allergy. Moreover, we explain in detail the methods to measure the allergen-specific antibody levels, prepare single-cell suspension from spleen, and prepare small intestine for immunohistochemical analysis of eosinophils and Foxp3+ cells.

Oral Immunotherapy for Food Allergy

Food allergy is a potentially life-threatening condition with no approved therapies, apart from avoidance and injectable epinephrine for acute allergic reactions. Oral immunotherapy (OIT) is an experimental treatment in which food-allergic patients consume gradually increasing quantities of the food to increase their threshold for allergic reaction. This therapy carries significant risk of allergic reactions. The ability of OIT to desensitize patients to particular foods is well-documented, although the ability to induce tolerance has not been established. This review focuses on recent studies for the treatment of food allergies such as cow's milk, hen's egg, and peanut.

Oral immunotherapy for the treatment of food allergy

Oral immunotherapy (OIT) is an emerging new therapy for food allergy. With multiple small exploratory trials and some large randomized-controlled phase 2 trials recently published and under way, there is a clear progress and interest toward making this a treatment option for patients suffering from food allergies. However, there are still many questions to be answered and parameters to fine-tune before OIT becomes an accepted option outside of the research setting. This review covers the main milestones in the development of OIT for food allergy and further discusses important specific issues that will have direct impact on its clinical application. More specifically, previous publications showing evidence for the induction of tolerance are specifically reviewed and varying safety, tolerability and efficacy parameters from previous reports are also discussed.