Protocol for a double-blind, randomized controlled trial on the dose-related efficacy of omalizumab in multi-food oral immunotherapy

Role of biologics in severe food allergy

PURPOSE OF REVIEW

This review examine the dynamic landscape of food allergy treatment within the context of emerging biologics. Our purpose is to comprehensively evaluate the potential benefits, challenges, and transformative impact associated with the utilization of biologics in comparison to conventional therapeutic modalities.

RECENT FINDINGS

This document synthesizes recent scientific investigations to various biologics, such as omalizumab, ligelizumab, dupilumab, and tezepelumab, providing a nuanced understanding of their roles in oral immunotherapy, rapid desensitization, and overall food allergy management. Recent studies and clinical trials highlight the impact of anti-IgE treatment on food allergies, revealing critical findings such as dose-related efficacy, facilitation of rapid desensitization in peanut allergies, and the sustained positive outcomes observed in individuals with multifood allergies.

SUMMARY

The use of biologics presents a groundbreaking approach in the treatment of food allergies. The multifaceted action of these agents, along with their potential to overcome the challenges associated with traditional therapies, marks a significant advancement. Despite the persisting challenges of economic constraints and the need for further safety studies, biologics offer a promising avenue for improving the quality of life for individuals with food allergies. Ongoing research and collaborative efforts are imperative to fully realize the transformative potential inherent in these emerging therapeutic frontiers.

Utility of food allergy thresholds

Food allergy is a prevalent disease worldwide that is a significant quality-of-life burden, and accidental exposures to food allergens may elicit severe, life-threatening reactions such as anaphylaxis. The threshold level, or the dose that triggers an allergic reaction determined by oral food challenges, varies considerably among individuals suffering from food allergies. Moreover, IgE concentration, diversity, or function can only partially explain this variation in threshold; pathogenic effector TH2 cells have also been found to contribute to the eliciting dose. Though very sensitive to cofactors such as physical activity/stress, the threshold is a stable and reproducible feature of an individual's allergy over periods of many months, made clear in the past several years from treatment studies in which repeated threshold determination has been used as a treatment outcome; however, there also seem to be age-related changes at a population level. More routine determination of food allergy thresholds may help patients stratify risk to improve the management of their food allergy. Precautionary allergen labeling, such as "may contain" labels, often causes confusion since they are inconsistent and regularly contain little to trace allergen residues; thus, food products with such labeling may be unnecessarily avoided. Population-based eliciting dose levels have been determined in the literature; patients at lower risk with higher thresholds may be more confident with introducing foods with precautionary allergen labels. Understanding a patient's threshold level could aid in shared decision-making to determine the most suitable treatment options for patients, including the starting dose for oral immunotherapy and/or the use of biologics.

Flex-IT! Applying "Platform Trials" Methodology to Immunotherapy for Food Allergy in Research and Clinical Practice

There is an increasing trend in the management of food allergy toward active treatment using allergen immunotherapy (AIT). Although AIT is efficacious, treatment-related adverse events are common, particularly with oral immunotherapy in those with high levels of allergen-specific IgE sensitization. In clinical practice, these adverse events inevitably create challenges: clinicians and patients routinely face decisions whether to alter the dose itself, the frequency of dosing, and the pace of escalation, or indeed discontinue AIT altogether. Flexibility is therefore needed to adapt treatment, particularly in clinical practice, so that participants are "treated-to-target." For example, this may entail a significant change in the dosing protocol or even switching from one route of administration to another in response to frequent adverse events. We refer to this approach as flexible immunotherapy. However, there is little evidence to inform clinicians as to what changes to treatment are most likely to result in treatment success. Classical clinical trials rely, by necessity, on relatively rigid updosing protocols. To provide an evidence base to optimize AIT, the food allergy community should adopt adaptive platform trials, where a "master protocol" facilitates more efficient evaluation, including longer-term outcomes of multiple interventions. Within a single clinical trial, participants are able to switch between different treatment arms; interventions can be added or dropped without compromising the integrity of the trial. Developing platform trials for food AIT may initially be costly, but they represent a significant opportunity to grow the evidence base (with respect to both treatment outcomes and biomarker discovery) at scale. In addition, they could help understand longitudinal disease trajectories that are difficult to study in clinical trials for food allergy due to the time needed to demonstrate changes in efficacy. Finally, their adoption would achieve greater collaboration and consistency in approaches to proactive management of food allergy in routine clinical practice. As a community, we need to actively pursue this with funders and established research collaborations to deliver the very best outcomes for our patients and their families.

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.

The updated Structural Database of Allergenic Proteins (SDAP 2.0) provides 3D models for allergens and incorporated bioinformatics tools

Background

Allergenic proteins can cause IgE-mediated adverse reactions in sensitized individuals. Although the sequences of many allergenic proteins have been identified, bioinformatics data analysis with advanced computational methods and modeling is needed to identify the basis for IgE binding and cross-reactivity.

Objective

We aim to present the features and use of the updated Structural Database of Allergenic Proteins 2.0 (SDAP 2.0) webserver, a unique, publicly available resource to compare allergens using specially designed computational tools and new high-quality 3-D models for most known allergens.

Methods

Previously developed and novel software tools for identifying cross-reactive allergens using sequence and structure similarity are implemented in SDAP 2.0. A comprehensive set of high-quality 3-D models of most allergens was generated with the state-of-the-art AlphaFold 2 software. A graphics tool enables the interactive visualization of IgE epitopes on experimentally determined and modeled 3-D structures.

Results

A user can search for allergens similar to a given input sequence with the FASTA algorithm or the window-based World Health Organization/International Union of Immunological Societies (WHO/IUIS) guidelines on safety concerns of novel food products. Peptides similar to known IgE epitopes can be identified with the property distance tool and conformational epitopes by the Cross-React method. The updated database contains 1657 manually curated sequences including all allergens from the IUIS database, 334 experimentally determined X-ray or NMR structures, and 1565 3-D models. Each allergen/isoallergen is classified according to its protein family.

Conclusions

SDAP provides access to the steadily increasing information on allergenic structures and epitopes with integrated bioinformatics tools to identify and analyze their similarities. In addition to serving the research and regulatory community, it provides clinicians with tools to identify potential coallergies in a sensitive patient and can help companies to design hypoallergenic foods and immunotherapies.

Association of Reaction Symptoms and Eliciting Dose With Health-Related Quality of Life in Children With Peanut Allergy

BACKGROUND

Food allergy adversely affects the health-related quality of life (HRQoL) of patients. It is unclear whether factors such as the reaction eliciting dose (ED) and the nature of allergic reaction symptoms affect HRQoL.

OBJECTIVE

To explore associations between reaction ED or the nature of allergic symptoms and HRQoL among children with peanut allergy.

METHODS

This study was a secondary analysis of baseline data from the PPOIT-003 randomized trial in 212 children aged 1 to 10 years with challenge-confirmed peanut allergy. Children's past reaction symptoms were collected by clinicians during screening. Associations between variables of interest and parent-reported child-proxy HRQoL were examined by univariable and multivariable linear regression.

RESULTS

Mean age of study participants was 5.9 years; 63.2% were male. Children with a low reaction ED of 80 mg peanut protein had significantly poorer HRQoL (β = -0.81; 95% CI, -1.61 to -0.00; P = .049) compared with children with a high ED of 2,500 mg peanut protein. Gastrointestinal symptoms (β = 0.45; 95% CI, 0.03-0.87; P = .037), lower airway symptoms (β = 0.46; 95% CI, 0.05-0.87; P = .030), multisystem involvement (β = 0.71; 95% CI, 0.25-1.16; P = .003), or anaphylaxis (β = 0.46; 95% CI, 0.04-0.87; P = .031) during a previous reaction were associated with worse HRQoL.

CONCLUSIONS

Peanut-allergic children with a lower allergen reaction threshold experienced a greater negative HRQoL impact compared with children with higher reaction thresholds. In addition, specific past allergic reaction symptoms were associated with comparatively worse HRQoL. Children experiencing these symptoms and those with lower reaction ED require increased clinical support to manage the food allergy and are likely to benefit from interventions that can improve HRQoL.

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.

Allergen immunotherapy: progress and future outlook

INTRODUCTION

Allergy, the immunological hypersensitivity to innocuous environmental compounds, is a global health problem. The disease triggers, allergens, are mostly proteins contained in various natural sources such as plant pollen, animal dander, dust mites, foods, fungi and insect venoms. Allergies can manifest with a wide range of symptoms in various organs, and be anything from just tedious to life-threatening. A majority of all allergy patients are self-treated with symptom-relieving medicines, while allergen immunotherapy (AIT) is the only causative treatment option.

AREAS COVERED

This review will aim to give an overview of the state-of-the-art allergy management, including the use of new biologics and the application of biomarkers, and a special emphasis and discussion on current research trends in the field of AIT.

EXPERT OPINION

Conventional AIT has proven effective, but the years-long treatment compromises patient compliance. Moreover, AIT is typically not offered in food allergy. Hence, there is a need for new, effective and safe AIT methods. Novel routes of administration (e.g. oral and intralymphatic), hypoallergenic AIT products and more effective adjuvants holds great promise. Most recently, the development of allergen-specific monoclonal antibodies for passive immunotherapy may also allow treatment of patients currently not treated or treatable.

Management of IgE-mediated food allergy in the 21st century

The 21st century has seen the propulsion of research in the field of food allergy, which has driven real changes in the clinical approach. Allergen immunotherapy has been recommended for the active management of food allergy. Data have shown promising additional methods of treatment, including biologics. Efforts have been devoted to the risk stratification of food allergy and the standardization of the assessment of food-allergic severity. Alternative routes of administration of epinephrine are under investigation to minimize any mechanical issue and the fear of injections. Evidence-based guidelines have been published by the main international societies in the field of anaphylaxis and food allergy management and new updates are in preparation. In the coming years, treatment options that are currently in pre-clinical or early clinical evaluation will hopefully lead to safe and effective disease-modifying therapies for food allergy in clinical practice. The identification of reliable biomarkers and the standardization of definitions and measurement approaches, alongside a shared decision-making with patients and families, will be key for the development of personalized care and to help minimize the substantial burden of food allergy.

An overview of current clinical practice and international oral immunotherapy guidelines: A focus on Spanish, European, and Canadian guidelines

Oral immunotherapy (OIT) is a recent and evolving therapeutic option for the treatment of immunoglobulin E (IgE) mediated food allergies. Clinical practice guidelines are starting to emerge to establish the parameters of this new clinical offer. A comparative analysis reveals several areas of consensus, such as the need for an accurate diagnosis with immunoglobulin E testing and, if necessary, open food challenge before initiating therapy; a list of specific contraindications; the importance of performing OIT in an adequate setting with appropriate level of expertise; the possibility to use grocery products to perform OIT; and the need to adapt protocols to patient needs. Certain discrepancies among the guidelines also underscore various areas of uncertainty, which makes it important that decisions to pursue the treatment be reached by using a shared decision-making approach that involves patients and caregivers. Gaps of knowledge remain with regard to treatment of adolescents and adults, and optimal performance measures in practice. These guidelines are expected to evolve in the coming years as new scientific and experiential knowledge is gained.

Variations in protocol development during oral immunotherapy

Oral immunotherapy (OIT) protocols are not standardized, and a wide heterogeneity exists in the literature. OIT protocol variables include the initiation approach (fixed dose versus oral food challenge), buildup speed (slow versus fast), target maintenance dose (low versus high target dose), type of food used, and use of adjuvants among other variables. Most protocols start with an initial escalation day, which is a series of extremely low doses to safely identify the patients who are most allergic, followed by a buildup period over several months to years until the final target maintenance dose is achieved. Doses are generally increased every 1-2 weeks by a factor of 1.25 to 2 and are adapted based on the patient's symptoms. Protocols are increasingly favoring low-maintenance doses over traditional high maintenance doses, although this needs to be discussed and adapted based on the patient's preferences. Accelerated OIT schedules with using a short treatment of omalizumab can be considered in severe food allergy cases.

A review of the safety of oral immunotherapy in clinical trial and real-world studies

Safety concerns are a barrier to oral immunotherapy (OIT). This review aims to describe OIT safety events and explore potential risk factors and mitigating factors. Published clinical and real-world OIT studies were reviewed for data on safety outcomes in OIT. Gastrointestinal symptoms are one of the most common adverse reactions associated with OIT, and persistent symptoms can be associated with an eosinophilic response. Allergic reactions are increased in OIT compared with avoidance; however, these symptoms tend not to be severe and to decrease over time. Despite OIT, epinephrine usage persists in studies and life-threatening reactions (though rare) have occurred. High baseline food specific immunoglobulin E levels, aggressive dosing, uncontrolled atopic comorbidities, and poor adherence to protocols may contribute to the severity of adverse events. OIT remains a shared decision that incorporates best medical evidence and appropriate patient selection. It requires individualized care and action plans to ensure safe outcomes.

Peanut oral immunotherapy – current trends in clinical trials

Immunotherapy for allergy has been practised for over 100 years. Low-dose repeated exposure to specific allergen extracts over several months to years can successfully induce clinical tolerance in patients with allergy to insect venoms, pollen, house dust mite and domestic animals. Different regimens and routes for immunotherapy include subcutaneous, sublingual, oral and intralymphatic. Food allergies have been difficult to treat in this way due to high anaphylactic potential and only recently the first immunotherapy for peanut allergy has received regulatory approval. Several clinical trials have indicated high efficacy in desensitisation of peanut-allergic individuals using oral immunotherapy, which allows for safer administration of relatively high allergen concentrations. Still, the risk of adverse events including serious allergic reactions and high anxiety levels for patients remains, demonstrating the need for further optimisation of treatment protocols. Here we discuss the design and outcomes of recent clinical trials with traditional oral immunotherapy, and consider alternative protocols and formulations for safer and more effective oral treatment strategies for peanut allergy.

Oral Immunotherapy for Food-Allergic Children: A Pro-Con Debate

The prevalence of food allergy has increased in recent years, especially in children. Allergen avoidance, and drugs in case of an allergic reaction, remains the standard of care in food allergy. Nevertheless, increasing attention has been given to the possibility to treat food allergy, through immunotherapy, particularly oral immunotherapy (OIT). Several OIT protocols and clinical trials have been published. Most of them focus on children allergic to milk, egg, or peanut, although recent studies developed protocols for other foods, such as wheat and different nuts. OIT efficacy in randomized controlled trials is usually evaluated as the possibility for patients to achieve desensitization through the consumption of an increasing amount of a food allergen, while the issue of a possible long-term sustained unresponsiveness has not been completely addressed. Here, we evaluated current pediatric OIT knowledge, focusing on the results of clinical trials and current guidelines. Specifically, we wanted to highlight what is known in terms of OIT efficacy and effectiveness, safety, and impact on quality of life. For each aspect, we reported the pros and the cons, inferable from published literature. In conclusion, even though many protocols, reviews and meta-analysis have been published on this topic, pediatric OIT remains a controversial therapy and no definitive generalized conclusion may be drawn so far. It should be an option provided by specialized teams, when both patients and their families are prone to adhere to the proposed protocol. Efficacy, long-term effectiveness, possible role of adjuvant therapies, risk of severe reactions including anaphylaxis or eosinophilic esophagitis, and impact on the quality of life of both children and caregivers are all aspects that should be discussed before starting OIT. Future studies are needed to provide firm clinical and scientific evidence, which should also consider patient reported outcomes.

Novel Approaches in the Inhibition of IgE-Induced Mast Cell Reactivity in Food Allergy

Allergy is an IgE-dependent type-I hypersensitivity reaction that can lead to life-threatening systemic symptoms such as anaphylaxis. In the pathogenesis of the allergic response, the common upstream event is the binding of allergens to specific IgE, inducing cross-linking of the high-affinity FcεRI on mast cells, triggering cellular degranulation and the release of histamine, proteases, lipids mediators, cytokines and chemokines with inflammatory activity. A number of novel therapeutic options to curb mast cell activation are in the pipeline for the treatment of severe allergies. In addition to anti-IgE therapy and allergen-specific immunotherapy, monoclonal antibodies targeted against several key Th2/alarmin cytokines (i.e. IL-4Rα, IL-33, TSLP), active modification of allergen-specific IgE (i.e. inhibitory compounds, monoclonal antibodies, de-sialylation), engagement of inhibitory receptors on mast cells and allergen-specific adjuvant vaccines, are new promising options to inhibit the uncontrolled release of mast cell mediators upon allergen exposure. In this review, we critically discuss the novel approaches targeting mast cells limiting allergic responses and the immunological mechanisms involved, with special interest on food allergy treatment.

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.

Biologics in food allergy: up-to-date

Introduction: In recent years, the advent of immunotherapy has remarkably improved the management of IgE-mediated food allergy. However, some barriers still exist. Therefore, the effort of researchers aims to investigate new perspectives in the field of non-allergen specific therapy, also based on the current knowledge of the pathogenesis of this disease.Areas covered: This review aims to focus on the role of biologics as a treatment option in patients with IgE-mediated food allergy. These agents are characterized by their ability to inactivate the Th2 pro-inflammatory pathways. Biologics can be used both alone and in association with immunotherapy. Monoclonal antibodies targeting IgE, the IL-4/IL-13 axis, IL-5, and alarmins have been proposed and investigated for treating food allergy.Expert opinion: The clinical efficacy and safety of biologics have been demonstrated in several preclinical studies and randomized controlled trials. Future studies are still required to address current unmet needs, including the identification of the optimal dose to be used by ensuring the effectiveness of therapy.

Integrating oral immunotherapy into clinical practice

In 2020, the first food allergy treatment, an oral immunotherapy (OIT) product for peanut allergy, was approved by the Food and Drug Administration, and a peanut epicutaneous immunotherapy patch was under review. As food allergy therapies become available and widespread, allergy offices will need to adjust practices to be able to offer their patients these new treatments. OIT is an intensive therapy that requires commitment from patients and their families, and open communication with the practice is paramount. OIT may not be the right therapy for every patient, and although identifying good candidates is still an area rich for research opportunity, experience from cohorts and clinical trials provides some insight. It is important to understand the scope of practice for each member of the OIT team based on state regulations for a particular location. Staffing and space will likely dictate how many patients at an individual office could be on active OIT at one time. Emergency medications, supplies, and protocols must be in place. Screening, scheduling, visit procedures, monitoring, home dosing, dose modifications, safety precautions, adverse reactions, and maintenance will be addressed in this article. Finally, adjunct therapies under investigation will be reviewed.

Economic considerations on the usage of biologics in the allergy clinic

The advent of biologic therapies has transformed care for severe atopic disorders but their high cost poses new challenges with regard to long-term sustainability and fair allocation of resources. This article covers the basic concepts of cost-utility analyses and reviews the available literature on cost utility of biologic drugs in atopic disorders. When used within their limits as part of a multi-dimensional assessment, economic analyses can be extremely useful to guide decision-making and prioritization of care. Despite the good quality of most cost-utility analyses conducted for the use of biologics in asthma and other atopic diseases, their conclusions regarding cost-effectiveness are extremely variable. This is mainly due to the use of inconsistent estimates of health utility benefit with therapy. Development of reliable and validated instruments to measure disutility in atopic disorders and measure of indirect costs in atopic disease are identified as a priority for future research.

Strategies for Mast Cell Inhibition in Food Allergy

Mast cells are tissue resident allergic effector cells that drive IgE-mediated food allergies. There are several steps leading to mast cell activation in the context of allergic disease that can be targeted to prevent mast cell activation and degranulation. These include blocking IgE-FcεRI crosslinking and type 2 cytokine receptor activation; modulating cell-surface neural chemical receptors; stabilizing mast cell membranes to prevent co-localization of activating receptors; impeding intracellular signaling; and engaging cell surface inhibitory receptors. This review highlights several ITIM-containing inhibitory mast cell surface receptors that could serve as pharmaceutical targets to prevent mast cell activation and degranulation in the context of food allergy. When activated, these ITIM-containing inhibitory receptors recruit the phosphatases SHP-1, SHP-2, and/or SHIP to dephosphorylate the tyrosine kinases responsible for activation signals downstream of the IgE-FcεRI complex. We describe several members of the Ig and Ig-like inhibitory receptor and C-type lectin inhibitory receptor superfamilies. Fundamental studies exploring the behavior of these receptors within the context of experimental food allergy models are needed. A deeper understanding of how these receptors modulate mast cell-driven food allergic responses will shape future strategies to harness these inhibitory receptors to treat food allergy.

Cost-Effectiveness of Biologics for Allergic Diseases

The introduction of specific humanized monoclonal antibodies over the past 20 years has dramatically changed the treatment of allergic diseases. At present, 5 mAbs are licensed for treating moderate to severe allergic and eosinophilic asthma, atopic dermatitis, chronic spontaneous urticaria, chronic sinusitis with nasal polyps, and eosinophilic granulomatosis with polyangiitis. Given the high costs of biologics, understanding their cost-effectiveness is critical. As new biologics are developed and new indications are approved for existing biologics, the use of biologics for allergic diseases will increase. Conducting cost-effectiveness evaluations in parallel to efficacy and effectiveness trials will help patients, providers, payers, and policymakers in decision making.

Determinants of omalizumab dose-related efficacy in oral immunotherapy: Evidence from a cohort of 181 patients

BACKGROUND

Omalizumab has been shown to improve the safety and feasibility of oral immunotherapy (OIT), but the optimal dosage strategy is unknown.

OBJECTIVE

Our aim was to identify determinants of omalizumab dose-related efficacy in the context of OIT.

METHODS

The study sample consisted of a clinical cohort of 181 patients treated with omalizumab-enabled oral immunotherapy at 3 centers. Patients received omalizumab for at least 2 months before an initial food escalation (IFE) with a mix of up to 6 allergens. Progression through IFE steps was assessed with survival analysis. Continued food dose tolerance with omalizumab weaning was also documented.

RESULTS

Omalizumab dosage per weight alone was strongly associated with progression through the IFE (χ² = 28.18; P < .0001), whereas the standard dosage per weight and total IgE level used for asthma was not (χ² = 0.001; P = .97). When the values at time of IFE were estimated through pharmacokinetics and pharmacodynamics simulation, IFE outcome was best predicted by a model that includes levels of free allergen-specific IgE and their interaction with blocking omalizumab-IgE complexes and free omalizumab levels in serum (χ² = 65.84; degrees of freedom [df] = 2; P < .0005). The occurrence of immediate-type reactions to food dosing subsequent to weaning of omalizumab was associated with a greater ratio of specific IgE level to total IgE level at baseline (geometric mean 0.39 vs 0.16 in those without symptom; P < .0001).

CONCLUSION

In the context of OIT and IgE-mediated disease, omalizumab dosages should be adjusted for body weight alone, independently of total IgE level. The fraction of allergen-specific/total IgE may be useful to predict patients at greater risk of food dosing reactions subsequent to weaning.