Omalizumab as an adjuvant in food allergen immunotherapy

Omalizumab reduces anaphylactic reactions and allows food introduction in food-allergic in children with severe asthma: An observational study

BACKGROUND

In Europe, Omalizumab (anti-IgE) is indicated for the treatment of moderate to severe asthma, but not for IgE-mediated food allergy (FA).

OBJECTIVE

We assessed the impact of Omalizumab on efficacy, safety, and quality of life (FA-QoL) in patients with moderate to severe asthma and who have a history of anaphylaxis to peanut, tree nuts, fish, egg, milk, and/or wheat.

METHODS

Food-allergic children (6-18 years) with moderate to severe asthma underwent oral food challenges (OFCs) to establish the threshold of reaction to the culprit food(s) at baseline (T0) and at 4-month intervals (T1, T2, and T3) during their first year of treatment with Omalizumab. We recorded the number and severity of food-allergic reactions, Asthma Control Test (ACT) scores, FA-QoL, and total IgE levels.

RESULTS

In 65 patients allergic to 107 foods, the No Observed Adverse Events Level (NOAEL) at T1 increased: 243- and 488-fold for fresh and baked milk, respectively; 172- and 134-fold for raw and baked egg; 245-fold for hazelnut; 55-fold for peanut; 31-fold for wheat; and 10-fold for fish. Full tolerance was achieved in 66.4% of OFCs at T1, 58.3% at T2, and 75% at T3. Ninety-five foods were liberalized in the diet of 55 patients; the remaining 12 were introduced by 10 patients at least in traces. Throughout the study, 40 out of 65 were able to get a free diet. ACT increased from 17 (Q1-Q3: 15-17) to 23.6 (Q1-Q3: 23-25). The FA-QoL score in children ≤12 years decreased from 4.63 ± 0.74 to 2.02 ± 1.13, and in adolescents from 4.68 ± 0.92 to 1.90 ± 1.50.

CONCLUSIONS

During Omalizumab therapy, a safe reintroduction of allergenic foods is feasible.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT06316414.

Targeting inhibitory Siglec-3 to suppress IgE-mediated human basophil degranulation

BACKGROUND

Sialic acid-binding immunoglobulin-like lectin-3 (Siglec-3 [CD33]) is a major Siglec expressed on human mast cells and basophils; engagement of CD33 leads to inhibition of cellular signaling via immunoreceptor tyrosine-based inhibitory motifs.

OBJECTIVE

We sought to inhibit human basophil degranulation by simultaneously recruiting inhibitory CD33 to the IgE-FcεRI complex by using monoclonal anti-IgE directly conjugated to CD33 ligand (CD33L).

METHODS

Direct and indirect basophil activation tests (BATs) were used to assess both antigen-specific (peanut) and antigen-nonspecific (polyclonal anti-IgE) stimulation. Whole blood from donors with allergy was used for direct BAT, whereas blood from donors with nonfood allergy was passively sensitized with plasma from donors with peanut allergy in the indirect BAT. Blood was incubated with anti-IgE-CD33L or controls for 1 hour or overnight and then stimulated with peanut, polyclonal anti-IgE, or N-formylmethionyl-leucyl-phenylalanine for 30 minutes. Degranulation was determined by measuring CD63 expression on the basophil surface by flow cytometry.

RESULTS

Incubation for 1 hour with anti-IgE-CD33L significantly reduced basophil degranulation after both allergen-induced (peanut) and polyclonal anti-IgE stimulation, with further suppression after overnight incubation with anti-IgE-CD33L. As expected, anti-IgE-CD33L did not block basophil degranulation due to N-formylmethionyl-leucyl-phenylalanine, providing evidence that this inhibition is IgE pathway-specific. Finally, CD33L is necessary for this suppression, as monoclonal anti-IgE without CD33L was unable to reduce basophil degranulation.

CONCLUSIONS

Pretreating human basophils with anti-IgE-CD33L significantly suppressed basophil degranulation through the IgE-FcεRI complex. The ability to abrogate IgE-mediated basophil degranulation is of particular interest, as treatment with anti-IgE-CD33L before antigen exposure could have broad implications for the treatment of food, drug, and environmental allergies.

A Comparison of Natural and Therapeutic Anti-IgE Antibodies

Immunoglobulin E (IgE) plays a critical role for the immune system, fighting against parasites, toxins, and cancer. However, when it reacts to allergens without proper regulation, it can cause allergic reactions, including anaphylaxis, through a process initiated by effector cells such as basophils and mast cells. These cells display IgE on their surface, bound to the high-affinity IgE receptor FcεRI. A cross-linking antigen then triggers degranulation and the release of inflammatory mediators from the cells. Therapeutic monoclonal anti-IgE antibodies such as omalizumab, disrupt this process and are used to manage IgE-related conditions such as severe allergic asthma and chronic spontaneous urticaria. Interestingly, naturally occurring anti-IgE autoantibodies circulate at surprisingly high levels in healthy humans and mice and may thus be instrumental in regulating IgE activity. Although many open questions remain, recent studies have shed new light on their role as IgE regulators and their mechanism of action. Here, we summarize the latest insights on natural anti-IgE autoantibodies, and we compare their functional features to therapeutic monoclonal anti-IgE autoantibodies.

A randomized, double-blind placebo-controlled study on the efficacy of Omalizumab on food allergy threshold in children with severe food allergy

BACKGROUND

Food allergy is common in childhood with some children having a low threshold and being difficult to protect from accidental ingestion of the offending food. Therapies for this potentially life-threatening condition are highly needed. The aim of this study was to evaluate the efficacy of Omalizumab in food-allergic children.

METHODS

This is a single-center, double-blind, placebo-controlled study. Food allergic children with a cumulative threshold ≤443 mg food protein at DBPCFC were randomized to Omalizumab (asthma dose) or placebo (3:1). After 3 months, a second DBPCFC was performed (steps 3, 10, 30, 100, 300, 1000, and 3000 mg food protein), followed by a separate open challenge up to 10,000 and 30,000 mg food protein if negative. Responders were defined as ≥2-step increases in threshold. Non-responders received high-dose Omalizumab. A third DBPCFC was performed after 6 months. Skin testing, blood samples, and the severity of atopic co-morbidity were registered during the study and 3 months after treatment.

RESULTS

In total, 20 children were evaluated at 3 months (14 Omalizumab, 6 placebo). All treated with Omalizumab increased their threshold at least two steps and with a significant difference between the Omalizumab and the placebo group (p = .003), although the intended number of included children was not reached. The threshold before Omalizumab treatment was 13-443 mg food protein while the threshold after 3 months of treatment increased up to 44,000 mg (1143-44,000). In the placebo group, two children improved threshold during the study.

CONCLUSION

An increase in the threshold level during Omalizumab treatment significantly improve patient safety and protected all children against small amount of allergen.

Update on In Vitro Diagnostic Tools and Treatments for Food Allergies

Food allergy (FA) is an adverse immunological reaction to a specific food that can trigger a wide range of symptoms from mild to life-threatening. This adverse reaction is caused by different immunological mechanisms, such as IgE-mediated, non-IgE-mediated and mixed IgE-mediated reactions. Its epidemiology has had a significant increase in the last decade, more so in developed countries. It is estimated that approximately 2 to 10% of the world's population has FA and this number appears to be increasing and also affecting more children. The diagnosis can be complex and requires the combination of different tests to establish an accurate diagnosis. However, the treatment of FA is based on avoiding the intake of the specific allergenic food, thus being very difficult at times and also controlling the symptoms in case of accidental exposure. Currently, there are other immunomodulatory treatments such as specific allergen immunotherapy or more innovative treatments that can induce a tolerance response. It is important to mention that research in this field is ongoing and clinical trials are underway to assess the safety and efficacy of these different immunotherapy approaches, new treatment pathways are being used to target and promote the tolerance response. In this review, we describe the new in vitro diagnostic tools and therapeutic treatments to show the latest advances in FA management. We conclude that although significant advances have been made to improve therapies and diagnostic tools for FA, there is an urgent need to standardize both so that, in their totality, they help to improve the management of FA.

The future of food allergy: Challenging existing paradigms of clinical practice

The field of food allergy has seen tremendous change over the past 5-10 years with seminal studies redefining our approach to prevention and management and novel testing modalities in the horizon. Early introduction of allergenic foods is now recommended, challenging the previous paradigm of restrictive avoidance. The management of food allergy has shifted from a passive avoidance approach to active interventions that aim to provide protection from accidental exposures, decrease allergic reaction severity and improve the quality of life of food-allergic patients and their families. Additionally, novel diagnostic tools are making their way into clinical practice with the goal to reduce the need for food challenges and assist physicians in the-often complex-diagnostic process. With all the new developments and available choices for diagnosis, prevention and therapy, shared decision-making has become a key part of medical consultation, enabling patients to make the right choice for them, based on their values and preferences. Communication with patients has also become more complex over time, as patients are seeking advice online and through social media, but the information found online may be outdated, incorrect, or lacking in context. The role of the allergist has evolved to embrace all the above exciting developments and provide patients with the optimal care that fits their needs. In this review, we discuss recent developments as well as the evolution of the field of food allergy in the next decade.

Biologicals in IgE-mediated food allergy

PURPOSE OF REVIEW

A better understanding of the most recent scientific literature in the use of biological therapy in the treatment of patients with IgE-mediated food allergy.

RECENT FINDINGS

A systematic review and meta-analysis demonstrated safety and effectiveness of omalizumab in the treatment of food allergy. The findings support the potential use of omalizumab as a monotherapy or as an adjunct to oral immunotherapy in IgE-mediated cow's milk allergy. The potential use of other biologics in the management of food allergy is subject of speculation.

SUMMARY

Different biological therapies are under evaluation for food allergic patients. The advance in literature will guide for a personalized treatment in the near future. However, additional research is needed to better understand the best candidate for each treatment, the optimal dose and timing.

Oral immunotherapy for food allergy: Translation from studies to clinical practice?

Oral immunotherapy (OIT) is now recognized as an alternative active treatment to strict food avoidance in certain patients with IgE-mediated food allergy. Studies have confirmed the efficacy of OIT to desensitize children with allergy to cow's milk, eggs, and peanuts. The benefits, risks, and constraints of OIT are becoming increasingly well understood. However, there is no consensual criteria to select patients to whom OIT could be proposed, and many issues remain to address including the definitions of desensitization and long-term efficacy, the assessment of patient's experience in real life, the optimization of buildup and maintenance protocols, and the utility of multiple food OIT. The recent authorization by medical agency concerning the first medicine for peanut OIT is a step forward towards higher standardization in the practice of OIT. This article summarizes in comprehensive narrative format data on efficacy, tolerance, impact on quality of life and adverse effects of OIT and discuss elements to consider in clinical practice before starting OIT.

Treatment for food allergy: Current status and unmet needs

The treatment of food allergy has traditionally relied on avoidance of the offending food(s) and use of emergency medications in the event of accidental exposures. However, this long-standing paradigm is beginning to shift, as a variety of treatment approaches have been and are being developed. This report provides an overview of the past, present, and future landscape of interventional clinical trials for the treatment of food allergy. It focuses on specific issues related to participant characteristics, protocol design, and study end points in the key clinical trials in the literature and examine how differences between studies may impact the clinical significance of the study results. Recommendations are provided for the optimization of future trial designs and focus on specific unmet needs in this rapidly evolving field.

Management of Anaphylaxis During Peanut Oral Immunotherapy

BACKGROUND

Peanut oral immunotherapy (POIT) has emerged as an active management option for peanut allergy, with an FDA-approved product now available for therapy. Allergic reactions, including anaphylaxis, can occur during therapy and their management is key in optimizing this treatment and patient outcomes.

PURPOSE OF REVIEW

In this manuscript, we will review the rates of allergic reactions and anaphylaxis in seminal peanut oral immunotherapy research studies. We will examine factors that can alter the risk of anaphylaxis and describe various strategies, including adjunct therapies, that have the potential to mitigate anaphylaxis risk based on published evidence.

RECENT FINDINGS

Rates of anaphylaxis and epinephrine administration vary in different research studies, but there is consensus that most POIT-related allergic reactions are mild or moderate and not severe. Certain external factors (for example, tiredness, exercise, viral illness) as well as uncontrolled allergic co-morbidities (asthma, allergic rhinitis) have been shown to increase the risk of anaphylaxis during OIT. The search of biomarkers who may predict who is at risk for severe allergic reactions is ongoing. Adjunct therapies have shown promise, but further studies are required to optimize their use alongside POIT. Our understanding of anaphylaxis during POIT has increased in recent years, resulting in better management strategies. However, future plans will need to involve all stakeholders, including physicians, patients and families, researchers, public health authorities, and the food, hospitality, and catering industries.

Food Allergy and Eosinophilic Gastrointestinal Diseases-The Next 10 Years

The first report of food allergy desensitization was in 1908, at least a few years before the first published description of a diagnostic test for food allergy. It has taken almost 100 years for food allergy to move from passive management of avoidance to a more proactive approach including prevention and treatment. In parallel, this has been matched by recognition of eosinophil gastrointestinal diseases, which were first described in the 1980s (although eosinophilic esophagitis was itself described in 1978). As we celebrate 10 years of The Journal of Allergy and Clinical Immunology: In Practice, we take the opportunity to look into the future and speculate how our practice may develop over the next decade.

Protocol design and synopsis: Omalizumab as Monotherapy and as Adjunct Therapy to Multiallergen OIT in Children and Adults with Food Allergy (OUtMATCH)

Background

Food allergy is common and causes substantial morbidity and even mortality. Safe and effective treatments for food allergy would therefore be highly desirable, especially for individuals with multiple food allergies.

Objectives

Our aim was to describe a phase 3 study on treatment of patients with multiple food allergies with omalizumab.

Methods

The study was developed as a collaboration between the Consortium for Food Allergy Research, the National Institute of Allergy and Infectious Diseases, and 2 industry sponsors (Genentech and Novartis).

Results

The study is currently under way, enrolling participants from age 1 year to age 55 years who are allergic to peanut and at least 2 other foods (including milk, egg, wheat, cashew, hazelnut, and walnut). The study is designed to address 3 major questions. First, stage 1 will study the potential value of omalizumab for the treatment of patients with peanut allergy and at least 2 other common food allergens. Second, stage 2 will directly compare treatment of patients with multifood allergies using omalizumab as monotherapy versus treatment with omalizumab-facilitated multiallergen oral immunotherapy in which omalizumab is used as an adjunctive treatment. Third, stage 3 will address the longer-term outcomes following these treatment approaches, including the introduction of dietary forms of the study foods to induce or maintain desensitization.

Conclusions

This phase 3 study will provide important information on the potential of omalizumab to treat patients with multiple food allergies.

Advances, Practical Implementation, and Unmet Needs Regarding Oral Immunotherapy for Food Allergy

Treatment of food allergy is a rapidly changing landscape, with arguably, the most significant advancement in recent years, the transition of oral immunotherapy (OIT) to clinical practice. As an innovation, OIT is a phase of rapidly increasing demand, particularly for some allergens such as peanut, egg, and milk, which have substantial evidence of efficacy. However, significant questions remain about how to best treat multiple food allergies and less common food allergies and how to optimize long-term safety and efficacy. This review summarizes the currently available resources for integrating food allergy OIT into clinical practice and focuses on the multiple remaining unmet needs such as providing an approach for OIT to food allergens for which there is no or limited evidence; practical issues related to food allergy treatment particularly when it is not going well; long-term outcomes and follow-up after OIT; and strategies to help meet the impending increase in demand.

The role of allergen-specific IgE, IgG and IgA in allergic disease

Immunoglobulin E (IgE)‐mediated allergy is the most common hypersensitivity disease affecting more than 30% of the population. Exposure to even minute quantities of allergens can lead to the production of IgE antibodies in atopic individuals. This is termed allergic sensitization, which occurs mainly in early childhood. Allergen‐specific IgE then binds to the high (FcεRI) and low‐affinity receptors (FcεRII, also called CD23) for IgE on effector cells and antigen‐presenting cells. Subsequent and repeated allergen exposure increases allergen‐specific IgE levels and, by receptor cross‐linking, triggers immediate release of inflammatory mediators from mast cells and basophils whereas IgE‐facilitated allergen presentation perpetuates T cell–mediated allergic inflammation. Due to engagement of receptors which are highly selective for IgE, even tiny amounts of allergens can induce massive inflammation. Naturally occurring allergen‐specific IgG and IgA antibodies usually recognize different epitopes on allergens compared with IgE and do not efficiently interfere with allergen‐induced inflammation. However, IgG and IgA antibodies to these important IgE epitopes can be induced by allergen‐specific immunotherapy or by passive immunization. These will lead to competition with IgE for binding with the allergen and prevent allergic responses. Similarly, anti‐IgE treatment does the same by preventing IgE from binding to its receptor on mast cells and basophils. Here, we review the complex interplay of allergen‐specific IgE, IgG and IgA and the corresponding cell receptors in allergic diseases and its relevance for diagnosis, treatment and prevention of allergy.

Update on omalizumab in allergen immunotherapy

PURPOSE OF REVIEW

To review the most relevant studies in the advancing field of omalizumab in allergen immunotherapy.

RECENT FINDINGS

Omalizumab has been used in combination with inhalant, venom, and food allergen immunotherapy. These studies suggest that omalizumab can decrease the time required to reach maintenance dosing and adverse events. However, severe adverse events do still occur. Limited long-term data suggests that there is a risk for increased reactivity after stopping omalizumab.

SUMMARY

Omalizumab in conjunction with immunotherapy has shown promising results for the treatment of allergic rhinitis, venom hypersensitivity, and food allergy, especially in the reduction of adverse events. Larger randomized, placebo-controlled trials are needed to better understand optimal dosing and duration, cost--benefit analysis, ideal patients, and long-term benefits. This combination therapy has the potential to improve treatment, particularly for high-risk patients.

Oral Immunotherapy for Children with Cow's Milk Allergy

Cow's milk allergy (CMA) is one of the most common IgE-dependent food allergies in children. Some children develop severe and persistent CMA, with near-fatal reactions after exposure to trace amounts of cow's milk (CM). Because milk and dairy products are included in various processed food products, it is difficult to completely remove milk, which negatively affects the quality of life of children with CMA. Oral immunotherapy (OIT) can alleviate food allergen-induced anaphylaxis under continuous ingestion of a little of the causative food. Children with severe CMA may benefit from OIT, but the treatment requires a long time and poses a risk of anaphylaxis. Moreover, in recent years, new therapies, including omalizumab, sublingual immunotherapy, and epicutaneous immunotherapy, have played the role of optional OIT. In this review, we present the current methods of and other attempts at OIT, and discuss OIT for safely treating CMA.

Biologics as treatment options for anaphylaxis

PURPOSE OF REVIEW

To provide the most recent insights in the use of biologicals in the treatment of patients with anaphylaxis.

RECENT FINDINGS

There is evidence that biologics such as omalizumab may be safe and effective in preventing anaphylactic reactions in patients at high risk mainly because of severe food allergy or desensitization procedures to food, airborne allergen, drugs, or hymenoptera venom.

SUMMARY

Further knowledge will guide the adoption and implementation of any new therapy including biologics for anaphylaxis according to the stratification of risk/benefits.

The use of biologics in food allergy

BACKGROUND

Food allergy continues to pose problems due to its increased frequency and its increasingly high severity. In this context, alongside the traditional avoidance strategies of allergenic foods and desensitization through the cautious progression of exposure to foods in the context of oral immunotherapy (OIT), alternative strategies have made their way in the last decades. We review the possibilities of intervention in food allergy with the use of biological drugs capable of interfering with the synthesis of IgE, with their mechanisms of action, or with complex biological mechanisms that lead to the establishment of a food allergy.

METHODS

Repeated Entrez PubMed searches using the template algorithm "Food allergy" and "biologics" or "Omalizumab" or "Dupilumab" or "milk desensitization" or "oral tolerance induction" or "oral immunotherapy" or "Etokimab" or "Tezepelumab" or "Quilizumab" or "Ligelizumab" or "Tralokinumab" or "Nemolizumab" or "Mepolizumab" or "Reslizumab" or "Benralizumab". The authors' clinical experience in paediatric allergy units of University hospitals was also drawn upon.

RESULTS

The landscape in this context has changed dramatically over the past 10 years. We have acquired knowledge mainly on the effect of different types of anti-IgE treatments in poliallergic patients with food allergy, and in patients treated with OIT. However, other mediators are being targeted by specific biologic treatments. Among them, the alarmins Il-33 and TSLP, IL-4 and IL-13, eosinophil-related molecules as IL-6, IL-8, IL-10, IL-12, and mostly IL-5, and integrins involved in the pathogenesis of eosinophilic gastrointestinal diseases (EGIDs), as SIGLEC-8.

CONCLUSIONS

The ever-better knowledge of the mechanisms of food allergy allowing these developments will improve not only the perspective of patients with the most serious immediate food allergies such as anaphylaxis, but also those of patients with related diseases such as atopic dermatitis, eosinophilic esophagitis, and EGIDs. Biologics are also intended to complement OIT strategies that have developed over the years.