Novel baseline predictors of adverse events during oral immunotherapy in children with peanut allergy

Application of PLGA-PEG-PLGA Nanoparticles to Percutaneous Immunotherapy for Food Allergy

Compared with oral or injection administration, percutaneous immunotherapy presents a promising treatment modality for food allergies, providing low invasiveness and safety. This study investigated the efficacy of percutaneous immunotherapy using hen egg lysozyme (HEL)-loaded PLGA-PEG-PLGA nanoparticles (NPs), as an antigen model protein derived from egg white, compared with that of HEL-loaded chitosan hydroxypropyltrimonium chloride (CS)-modified PLGA NPs used in previous research. The intradermal retention of HEL in excised mouse skin was measured using Franz cells, which revealed a 2.1-fold higher retention with PLGA-PEG-PLGA NPs than that with CS-modified PLGA NPs. Observation of skin penetration pathways using fluorescein-4-isothiocyanate (FITC)-labeled HEL demonstrated successful delivery of HEL deep into the hair follicles with PLGA-PEG-PLGA NPs. These findings suggest that after NPs delivery into the skin, PEG prevents protein adhesion and NPs aggregation, facilitating stable delivery deep into the skin. Subsequently, in vivo percutaneous administration experiments in mice, with concurrent iontophoresis, demonstrated a significant increase in serum IgG1 antibody production with PLGA-PEG-PLGA NPs compared with that with CS-PLGA NPs after eight weeks of administration. Furthermore, serum IgE production in each NP administration group significantly decreased compared with that by subcutaneous administration of HEL solution. These results suggest that the combination of PLGA-PEG-PLGA NPs and iontophoresis is an effective percutaneous immunotherapy for food allergies.

Two-year post-treatment outcomes following peanut oral immunotherapy in the Probiotic and Peanut Oral Immunotherapy-003 Long-Term (PPOIT-003LT) study

BACKGROUND

Few studies have examined long-term outcomes following oral immunotherapy (OIT); none have examined long-term risks and benefits associated with distinct clinical outcomes (desensitization, remission).

METHODS

Participants completing the probiotic and peanut oral immunotherapy (PPOIT) -003 randomized trial were enrolled in a follow-on study, PPOIT-003LT. Peanut ingestion, reactions, and health-related quality of life (HRQOL) were monitored prospectively. Outcomes at 1-year and 2-years post-treatment were examined by treatment group and by post-OIT clinical outcome (remission, desensitization without remission [DWR], allergic).

RESULTS

86% (151/176) of eligible children enrolled. Post-treatment peanut ingestion at 2-years post-treatment were similar for PPOIT (86.7%) and OIT (78.7%) groups, both higher than placebo (10.3%). Reactions reduced over time for all treatment and clinical outcome groups (PPOIT 31.7% to 23.3%, OIT 37.7% to 19.7%, placebo 13.8% to 6.9%; remission 27.5% to 15.9%; DWR 57.9% to 36.8%; allergic 11.6% to 7%). At 2-years post-treatment, similar proportions of remission and allergic participants reported reactions (RD 0.09 (95%CI -0.03, 0.20), p = .127), whereas more DWR participants reported reactions than remission (remission vs DWR: RD -0.21 (95%CI -0.39; -0.03), p = .02) and allergic (DWR vs allergic: RD 0.30 (95%CI 0.13, 0.47), p = .001) participants. At 2-years post-treatment, 0% remission versus 5.3% DWR versus 2.3% allergic participants reported adrenaline injector usage. Remission participants had significantly greater HRQOL improvement (adjusted for baseline) compared with both DWR (MD -0.54 (95%CI -0.99, -0.10), p = .017) and allergic (MD -0.82 (95%CI -1.25, -0.38), p < .001).

CONCLUSION

By 2-years post-treatment, remission participants reported fewer reactions, less severe reactions and greater HRQOL improvement compared with DWR and allergic participants, indicating that remission is the patient-preferred treatment outcome over desensitization or remaining allergic.

Insights into the clinical, immunologic, and genetic underpinnings of food allergy

The last few decades have seen striking changes in the field of food allergy. The prevalence of the disease has risen dramatically in many parts of the globe, and management of the condition has undergone major revision. While delayed introduction of common allergenic foods during infancy was advised for many years, the learning early about peanut allergy (LEAP) trial and other studies led to a major shift in infant feeding practices, with deliberate early introduction of these foods now recommended. Additionally, the Food and Drug Administration approved the first treatment for food allergy in 2020-a peanut oral immunotherapy (OIT) product that likely represents just the beginning of new immunotherapy-based and other treatments for food allergy. Our knowledge of the environmental and genetic factors contributing to the pathogenesis of food allergy has also undergone transformational advances. Here, we will discuss our efforts to improve the clinical care of patients with food allergy and our understanding of the immunological mechanisms contributing to this common disease.

Design of an Ara h 2 hypoallergen from conformational epitopes

INTRODUCTION

Adverse reactions are relatively common during peanut oral immunotherapy. To reduce the risk to the patient, some researchers have proposed modifying the allergen to reduce IgE reactivity, creating a putative hypoallergen. Analysis of recently cloned human IgG from patients treated with peanut immunotherapy suggested that there are three common conformational epitopes for the major peanut allergen Ara h 2. We sought to test if structural information on these epitopes could indicate mutagenesis targets for designing a hypoallergen and evaluated the reduction in IgE binding via immunochemistry and a mouse model of passive cutaneous anaphylaxis (PCA).

METHODS

X-ray crystallography characterized the conformational epitopes in detail, followed by mutational analysis of key residues to modify monoclonal antibody (mAb) and serum IgE binding, assessed by ELISA and biolayer interferometry. A designed Ara h 2 hypoallergen was tested for reduced vascularization in mouse PCA experiments using pooled peanut allergic patient serum.

RESULTS

A ternary crystal structure of Ara h 2 in complex with patient antibodies 13T1 and 13T5 was determined. Site-specific mutants were designed that reduced 13T1, 13T5, and 22S1 mAbs binding by orders of magnitude. By combining designed mutations from the three major conformational bins, a hexamutant (Ara h 2 E46R, E89R, E97R, E114R, Q146A, R147E) was created that reduced IgE binding in serum from allergic patients. Further, in the PCA model where mice were primed with peanut allergic patient serum, reactivity upon allergen challenge was significantly decreased using the hexamutant.

CONCLUSION

These studies demonstrate that prior knowledge of common conformational epitopes can be used to engineer reduced IgE reactivity, an important first step in hypoallergen design.

Eosinophil-Associated Gastrointestinal Manifestations During OIT

Gastrointestinal adverse events are common during oral immunotherapy (OIT) for food allergy and range from immediate IgE-mediated reactions to non-anaphylactic clinical presentations. This review aims to summarize recent findings on non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT. Two clinical presentations of non-anaphylactic eosinophil-associated gastrointestinal adverse events during OIT are identified, each with a different paradigm for treatment, and distinguished by their time of onset. In the first clinical entity, characterized by its onset early in the course of treatment, patients present with abdominal pain, nausea, and/or vomiting. The symptoms become evident typically within weeks to months of starting OIT. These symptoms, however, are not temporally related to the time of dose administration, as in the case of immediate IgE-mediated anaphylactic reactions. While esophageal biopsies, when performed, can demonstrate eosinophilic esophagitis (EoE), baseline esophageal eosinophilia has also been observed in food allergic patients prior to OIT. A potential non-invasive biomarker, the peripheral absolute eosinophil count (AEC), often rises during these reactions and subsides after dose reduction and subsequent resolution of symptoms. OIT can usually then be resumed, albeit at a slower pace, without a recurrence of symptoms. Risk factors for development of symptoms early during OIT include a high starting dose and a baseline AEC of greater than 600. The second, and much less frequently encountered, non-anaphylactic gastrointestinal adverse event related to OIT, presents months to years after initiating OIT. In this latter group, patients present with the classical clinical symptoms and endoscopic findings of EoE. In contrast to the acute onset group, peripheral eosinophilia is usually not observed in these cases. This OIT-associated EoE has shown good response to standard EoE treatment approaches of proton pump inhibitors or swallowed steroids. Most patients with eosinophil-associated adverse reactions are able to continue OIT and remain desensitized. Treatment approaches depend on the specific subtype of these reactions and relate to the stages of OIT treatment.

Severe Anaphylactic Reactions to Home Doses of Oral Immunotherapy for Food Allergy

BACKGROUND

Severe anaphylactic reactions to home doses may occur during food allergy oral immunotherapy (OIT).

OBJECTIVE

To study the rate and risk factors for such reactions.

METHODS

We studied all patients aged greater than 3.5 years who completed OIT in a single center between April 2010 and January 2020. All home epinephrine-treated reactions (HETRs) were identified. High-grade HETRs (HG-HETRs) were defined as HETRs involving respiratory (SpO2 of 94% or less), cardiovascular (low blood pressure), or central nervous system impairment (loss of consciousness). We investigated the rate and risk factors for HG-HETRs.

RESULTS

A total of 1,637 OIT treatments were studied: milk (880), peanut (346), tree nuts (221), sesame (115), and egg (75). Of 390 identified HETRs, 30 HG-HETRs occurred during 27 treatments (1.65% of all treatments). Nearly all (26 of 30) were during milk OIT in patients with house dust mite (HDM) sensitization and asthma (26 of 30 each). Of the 30 patients with HG-HETRs, 21 recovered with one or two epinephrine treatments, but nine (0.55% of all treatments) did not respond to a second dose of epinephrine and were deemed to have refractory anaphylaxis. Three patients required intensive care unit admission and three received epinephrine drip, but none required ventilatory support. Risk factors for HG-HETRs included milk OIT (P = .031), asthma (P = .02) and HDM sensitization (P = .02). No specific triggers for HG-HETR were identified. Of patients with HG-HETRs, 25.9% were fully desensitized, including the four non-milk treated patients; 22.2% were partially desensitized; and 51.9% failed.

CONCLUSIONS

High-grade HETRs are uncommon, particularly refractory anaphylactic reactions to home OIT doses. Although milk OIT, asthma, and HDM sensitization are the main risk factors for such reactions, identification of patients who are at risk is challenging.

Phase 3 Trial of Epicutaneous Immunotherapy in Toddlers with Peanut Allergy

BACKGROUND

No approved treatment for peanut allergy exists for children younger than 4 years of age, and the efficacy and safety of epicutaneous immunotherapy with a peanut patch in toddlers with peanut allergy are unknown.

METHODS

We conducted this phase 3, multicenter, double-blind, randomized, placebo-controlled trial involving children 1 to 3 years of age with peanut allergy confirmed by a double-blind, placebo-controlled food challenge. Patients who had an eliciting dose (the dose necessary to elicit an allergic reaction) of 300 mg or less of peanut protein were assigned in a 2:1 ratio to receive epicutaneous immunotherapy delivered by means of a peanut patch (intervention group) or to receive placebo administered daily for 12 months. The primary end point was a treatment response as measured by the eliciting dose of peanut protein at 12 months. Safety was assessed according to the occurrence of adverse events during the use of the peanut patch or placebo.

RESULTS

Of the 362 patients who underwent randomization, 84.8% completed the trial. The primary efficacy end point result was observed in 67.0% of children in the intervention group as compared with 33.5% of those in the placebo group (risk difference, 33.4 percentage points; 95% confidence interval, 22.4 to 44.5; P<0.001). Adverse events that occurred during the use of the intervention or placebo, irrespective of relatedness, were observed in 100% of the patients in the intervention group and 99.2% in the placebo group. Serious adverse events occurred in 8.6% of the patients in the intervention group and 2.5% of those in the placebo group; anaphylaxis occurred in 7.8% and 3.4%, respectively. Serious treatment-related adverse events occurred in 0.4% of patients in the intervention group and none in the placebo group. Treatment-related anaphylaxis occurred in 1.6% in the intervention group and none in the placebo group.

CONCLUSIONS

In this trial involving children 1 to 3 years of age with peanut allergy, epicutaneous immunotherapy for 12 months was superior to placebo in desensitizing children to peanuts and increasing the peanut dose that triggered allergic symptoms. (Funded by DBV Technologies; EPITOPE ClinicalTrials.gov number, NCT03211247.).

Peanut allergy: risk factors, immune mechanisms, and best practices for oral immunotherapy success

INTRODUCTION

Peanut oral immunotherapy (pOIT) is the only FDA-approved treatment for food allergy and its adoption amongst allergist immunologists and their patients is growing. pOIT is the subject of numerous clinical trials, however, the focus is often on treatment efficacy, safety, and tolerability, rather than identifying patients most likely to benefit from pOIT. Here, we review existing data on the clinical and immunological outcomes of pOIT that inform best practices for pOIT candidate selection.

AREAS COVERED

In this review, we describe the natural history of peanut allergy, summarize immunological and clinical outcomes of pOIT at different ages, discuss the optimization of pOIT in key age groups, and finally suggest an ideal age range at which to initiate pOIT for best outcomes.

EXPERT OPINION

pOIT is currently underutilized by patients and allergist-immunologists. Developing guidelines for selecting appropriate patients and optimizing treatment may help to increase access to pOIT. Many aspects of pOIT need additional study to further our understanding of the optimal timing to start pOIT, with careful consideration to clinical, immunological, and quality of life outcomes.

Targeting type 2 immunity and the future of food allergy treatment

IgE-mediated food allergy affects 6-8% of the population in the United States. Type 2 immune responses are central to the pathogenesis of food allergy, but type 2 CD4+ T cell responses have been found to be heterogeneous in food allergy suggesting a division of labor between Tfh13 and peTH2 cells in promotion of IgE class switching, modulation of intestinal barrier function, and regulation of mast cell expansion. Oral immunotherapy for the treatment of food allergy incompletely targets subsets of type 2 immunity in a transient manner, but new therapeutics targeting different levels of type 2 immunity are in current or planned trials for food allergy. These new treatments and the basis for their use are the focus of this review.

Factors associated with home epinephrine-treated reactions during peanut and tree-nut oral immunotherapy

BACKGROUND

Home reactions requiring epinephrine administration, a marker of their severity, restrict the widespread use of oral immunotherapy (OIT), but their risk factors are largely not known.

OBJECTIVE

To identify risk factors for such reactions during OIT to most allergenic foods.

METHODS

All patients who began OIT for peanut, tree nuts, sesame, or egg allergy at the Shamir Medical Center between April 2010 and January 2020 were enrolled. The patients were instructed to use their epinephrine autoinjectors during reactions consisting of severe abdominal pain, significant shortness of breath, or lethargy, or whenever in uncertainty of reaction severity. Patients with and without home epinephrine-treated reactions (HETRs) were compared.

RESULTS

A total of 757 OIT treatments for peanut (n = 346), tree nuts (n = 221; walnut n = 147, cashew n = 57, hazelnut n = 16, almond n = 1), sesame (n = 115), and egg (n = 75) allergies were administered to 644 patients. Eighty-three (10.9%) patients experienced HETRs. The highest rate of HETRs was experienced during walnut (20.4%) or hazelnut (25%) OIT, followed by peanut (9.8%), sesame (6.1%), egg (6.7%), and cashew (5.3%) OIT. Risk factors for HETRs included a reaction treated in an emergency department (ER) (P = .005) before starting OIT and a reaction treated with epinephrine during in-clinic induction (P < .001). Significantly fewer patients with (73.6%) than without (88.3%) HETRs achieved full desensitization (P = .001), but only a few patients with HETRs (8.4%) failed treatment.

CONCLUSION

Previous reaction severity is the main predictor for HETRs during OIT. These reactions are more frequent during walnut and hazelnut OIT than during OIT for other foods studied. Most patients experiencing HETRs achieved desensitization.

Inhibition of pathologic immunoglobulin E in food allergy by EBF-2 and active compound berberine associated with immunometabolism regulation

Introduction

Food allergy is a significant public health problem with limited treatment options. As Food Allergy Herbal Formula 2 (FAHF-2) showed potential as a food allergy treatment, we further developed a purified version named EBF-2 and identified active compounds. We investigated the mechanisms of EBF-2 on IgE-mediated peanut (PN) allergy and its active compound, berberine, on IgE production.

Methods

IgE plasma cell line U266 cells were cultured with EBF-2 and FAHF-2, and their effects on IgE production were compared. EBF-2 was evaluated in a murine PN allergy model for its effect on PN-specific IgE production, number of IgE⁺ plasma cells, and PN anaphylaxis. Effects of berberine on IgE production, the expression of transcription factors, and mitochondrial glucose metabolism in U266 cells were evaluated.

Results

EBF-2 dose-dependently suppressed IgE production and was over 16 times more potent than FAHF-2 in IgE suppression in U266 cells. EBF-2 significantly suppressed PN-specific IgE production (70%, p<0.001) and the number of IgE-producing plasma cells in PN allergic mice, accompanied by 100% inhibition of PN-induced anaphylaxis and plasma histamine release (p<0.001) without affecting IgG1 or IgG2a production. Berberine markedly suppressed IgE production, which was associated with suppression of XBP1, BLIMP1, and STAT6 transcription factors and a reduced rate of mitochondrial oxidation in an IgE-producing plasma cell line.

Conclusions

EBF-2 and its active compound berberine are potent IgE suppressors, associated with cellular regulation of immunometabolism on IgE plasma cells, and may be a potential therapy for IgE-mediated food allergy and other allergic disorders.

Bacillus subtilis Provides Long-Term Protection in a Murine Model of Allergic Lung Disease by Influencing Bacterial Composition

Probiotics are an attractive target for reducing the incidence of allergic disease. Bacillus subtilis is a gut-associated probiotic bacteria that can suppress allergic lung disease; however, it is not clear for how long this protection lasts. We exposed C57Bl/6 mice to B. subtilis via oral gavage and challenged them with intranasal house-dust mite for up to 8 weeks. We found that B. subtilis treatment was able to provide protection from eosinophil infiltration of the airways for 3 weeks. This loss of protection correlated with an increase in the eosinophil chemoattractant CCL24. Additionally, we demonstrate that B. subtilis treatment altered the bacterial composition by increasing the phylum Bacteroidetes and Verrucomicorbiota. The phylum Verrucomicorbiota was reduced in B. subtilis-treated mice at 8 weeks when protection was lost. These results support B. subtilis as a prophylactic for preventing the production of allergic lung disease and highlights that protection can last up to 3 weeks. This work also expands our understanding of how B. subtilis mediates protection and that in addition to modifying the immune system it is also altering the host microbiota.

Optimized Extraction of cAMP From Jujube by Ultra-High Pressure Technology and the Anti-allergic Effect for Peanut Allergy Mouse

Jujube contains abundant cyclic adenosine monophosphate (cAMP). In contrast, the extraction technology of cAMP from jujube is still to be explored. In this study, the ultra-high pressure extraction (UHPE) conditions for obtaining the maximum cAMP yield from jujube were optimized. Orthogonal array design (OAD) was applied to evaluate the effects of three variables (pressure, pressure-holding time, and liquid-to-solid ratio) by UHPE on cAMP yield. The results showed that the optimal cAMP yield (1223.2 μg/g) was derived at 300 MPa, 20 min duration, and a liquid-to-solid ratio of 2.5 ml/g. In addition, as an important functional ingredient in jujube, cAMP has potential anti-allergic effect. To develop the functional characteristics of jujube, the effect of cAMP was characterized in vivo with the Balb/c mouse model of peanut allergy, which was established by subcutaneous injection of crude peanut protein extract (PN). The results showed that treatment with cAMP in PN-sensitized mice suppressed the lesions in jejunal tissues and allergic symptoms and restored spleen index. Meanwhile, cAMP treatment reduced serum levels of specific immunoglobulin E (IgE), histamine, as well as interleukin-4 (IL-4) and stimulated the secretion of tumor necrosis factor-α (TNF-α), whereas the serum levels of interleukin-10 (IL-10) were not affected. Our results suggested that cAMP has an anti-allergic effect in PN-sensitized mice.

Could Age and Oral Challenge Outcomes Identify High-Risk Patients During Cow's Milk Oral Immunotherapy?

Objective: Severe immunglobuline E (IgE)-mediated reactions during oral immunotherapy (OIT) are major obstacles to treatment. The present study aimed to evaluate and identify clinical and laboratory biomarkers of adverse events during OIT among children with cow's milk (CM) allergy. Study Design: Eighty-six children older than 36 months who had undergone OIT with milk were enrolled. Clinical data, oral food challenge (OFC) test results, and laboratory data were recorded retrospectively. Results: The median duration of the build-up phase of OIT was 19 weeks (min 10-max 40) and the duration of the maintenance phase was 86.5 (min 1-max 132) months. A total of 11,767 CM doses were administered during the build-up phase and adverse reactions were seen in 62 (73.8%) patients with reactions registered for 157 doses among 11,767 (1/75 doses). The number of reactions during the maintenance phase was 41 (47.6%) in 24 (27.9%) patients. There was a significant reduction in the number of reactions (P = 0.000) between the build-up phase and maintenance phase. Adverse reactions and anaphylaxis were higher for patients who had cough during OFC (P = 0.003, P = 0.002, respectively) during the build-up phase and also during the maintenance phase too (P = 0.000). Evaluation for all reactions and anaphylaxis (during build-up and maintenance) with Kaplan-Meier and Cox regression analysis showed class IV-VI of CM-specific immunoglobulin E (sIgE), casein-sIgE and cough during OFC were significantly associated with increased probability of reaction and anaphylaxis. Younger age at onset of OIT was associated with risk reduction (0.017). Conclusion: Laboratory data and reactions during the OFC (especially cough) can help to identify high-risk patients during OIT.

Triggers for Home Epinephrine-Treated Reactions During Oral Immunotherapy for Food Allergy

BACKGROUND

Home reactions requiring epinephrine treatment represent a significant obstacle to oral immunotherapy (OIT) and impair treatment outcome.

OBJECTIVE

To identify potential triggers for such reactions for improvement of patient safety.

METHODS

All patients aged older than 3.7 years who began an open-label OIT treatment program to milk, peanut, egg, sesame, or tree nuts in the Institute of Allergy, Immunology, and Pediatric Pulmonology at Shamir Medical Center between April 2010 and March 2018 were enrolled. Information on home epinephrine-treated reactions (HETRs) during the up-dosing phase of OIT was collected from the documentation in patients' files and the reports were transmitted by email and via a web reporting system.

RESULTS

A total 1,270 OIT treatments were included (milk 780; peanut 256; egg 63; sesame 72; and tree nuts 99). Home epinephrine was administered in 200 treatments (15.7%) and in 70 of them a second epinephrine-treated reaction occurred. The leading identified triggers for HETRs were physical exercise temporally associated with administration of home dose (20%), and dose consumption during infectious disease (16.7%), or when fatigued (13.8%). The rate of first HETRs was highest (10.1%) to doses of 500 mg protein or less and particularly to 300 mg or less. The occurrence of first HETRs was highest (35.5%) during the first and decreased to 13.8% by the last of the 4-week home-treatment phase. Second HETRs occurred in a similar rate throughout these 4 weeks. The incidence of HETRs was highest during pollen season and vacation months.

CONCLUSIONS

The identification of factors, some protocol-dependent, that trigger HETRs should assist in improving OIT safety.

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.

The Risk Reduction of Accidental Exposure-Related Systemic Allergic Reactions Extrapolated Based on Food Challenge Data After 1 Year of Peanut Oral Immunotherapy

Introduction

The phase 3 trial PALISADE, comparing peanut (Arachis hypogaea) allergen powder-dnfp (PTAH) oral immunotherapy versus placebo in peanut-allergic children, reported that a significantly higher percentage of PTAH-treated participants tolerated higher doses of peanut protein after 1 year of treatment. This study used PALISADE data to estimate the reduction in the risk of systemic allergic reaction (SAR) after accidental exposure following 1 year of PTAH treatment.

Methods

Participants (aged 4–17 years) enrolled in PALISADE were included. Parametric interval-censoring survival analysis with the maximum likelihood estimation was used to construct a real-world distribution of peanut protein exposure using lifetime SAR history and highest tolerated dose (HTD) from a double-blind, placebo-controlled food challenge conducted at baseline. The SAR risk reduction was extrapolated using the exposure distribution and the HTD were collected at baseline and trial exit for PTAH- and placebo-treated participants.

Results

Assuming a maximum peanut protein intake of 1500 mg, participants were estimated to have < 1% probability of ingesting > 0.01 mg during daily life. The mean annual SAR risk at trial entry was 9.25–9.98%. At trial exit, the relative SAR risk reduction following accidental exposure was 94.9% for PTAH versus 6.4% for placebo. For PTAH-treated participants with exit HTD of 600 or 1000 mg without dose-limiting symptoms, the SAR risk reduction increased to 97.2%. The result was consistent in the sensitivity analysis across different parametric distributions.

Conclusion

Oral immunotherapy with PTAH is expected to result in a substantially greater reduction in risk of SAR following accidental exposure compared to placebo among children with peanut allergy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01843-2.

Latest Developments in the Management of Nut Allergies

Purpose of review

In this review, we sought to describe the most recent advances in the dietary and medical management of peanut and tree nut allergy, including selective introduction and immunotherapy.

Recent findings

Dietary updates include changes to labeling laws, improved information sources, and new apps for buying foods in shops and overseas to better protect individuals with nut allergies. There are still issues in the management of nut allergies in schools, such as parents having to resort to packed lunches instead of school meals and patients experiencing bullying. Air travel also poses concern, but additional resources are now available to travelers, and recent evidence suggest limited airborne exposure to nuts. The medical management of anaphylaxis is use of epinephrine; however, this remains underutilized. Needle length and administration devices have been recently debated considering the risk of bone penetration vs subcutaneous administration, and autoinjectors seem to deliver higher peak concentrations than syringes. Selective nut introduction has gained momentum in the last 5 years, demonstrating improved quality of life but with the need for motivated parents for continued consumption and available resources for challenges. Immunotherapy to nuts is also a rapidly developing field, with the balance of efficacy and safety being important considerations in the differing modes of administration.

Summary

The management of nut allergies is a rapidly developing field, and dietary and medical management have progressed significantly in the last 5 years. Future research directions include improving safety and efficacy of food immunotherapy and examining patients’ goals for therapy and treatment outcomes.

Addressing Common Misconceptions in Food Allergy: A Review

Background: Food allergies are common, affecting 1 in 13 school children in the United States and their prevalence is increasing. Many misconceptions exist with regards to food allergy prevention, diagnosis and management. Objective: The main objective of this review is to address misconceptions with regards to food allergies and discuss the optimal, evidence-based approach for patients who carry this diagnosis. Observations: Common misconceptions in terms of food allergy prevention include beliefs that breastfeeding and delayed introduction of allergenic foods prevent the development of food allergies. In terms of diagnosis, statements such as ‘larger skin prick tests or/and higher levels of food-specific IgE can predict the severity of food-induced allergic reactions’, or ‘Tryptase is always elevated in food-induced anaphylaxis’ are inaccurate. Additionally, egg allergy is not a contraindication for receiving the influenza vaccine, food-allergy related fatalities are rare and peanut oral immunotherapy, despite reported benefits, is not a cure for food allergies. Finally, not all infants with eczema will develop food allergies and epinephrine auto-injectors may unfortunately be both unavailable and underused in food-triggered anaphylaxis. Conclusions and relevance: Healthcare professionals must be familiar with recent evidence in the food allergy field and avoid common misunderstandings that may negatively affect prevention, diagnosis and management of this chronic disease.

Home epinephrine-treated reactions in food allergy oral immunotherapy: Lessons from the coronavirus disease 2019 lockdown

Background

Oral immunotherapy (OIT) is effective in desensitizing patients with food allergy but adverse reactions limit its use.

Objective

To study the effect of the coronavirus disease 2019 lockdown in Israel between March 15, 2020, and April 30, 2020, on the incidence of home epinephrine-treated reactions.

Methods

All patients who were in the up-dosing phase of OIT for greater than or equal to 1 month during the lockdown, or a respective period in years 2015 to 2019, were studied. The incidence of home-epinephrine treated reactions during the 2020 lockdown was compared with that in the respective period in 2015 to 2019 and to periods before and after the lockdown.

Results

A total of 1163 OIT treatments were analyzed. Two epinephrine injections occurred during 2020 (0.7%) compared with 29 injections (3.28%) during 2015 to 2019 (P = .03). Patients treated in 2020 were older (8.1 vs 7 years, P < .01) and had a significantly lower single highest tolerated dose (12 vs 20 mg protein, P < .01). The rate of milk-OIT was lower (P = .01), but the total number of milk treatments was higher (99 vs 71 to 82) in 2020 compared with 2015 to 2019. On multivariate analysis, treatments during the 2020 lockdown were performed in older patients (P = .001), primarily for nonmilk (P = .03), began with a lower single highest tolerated dose (P = .006), and were associated with significantly less home epinephrine-treated reactions (P = .05) compared with those in 2015 to 2019. Patients treated in 2020 experienced more epinephrine-treated reactions in adjacent periods before (n = 8) and after (n = 6) the lockdown.

Conclusion

The lower rate of home epinephrine-treated reactions during the coronavirus disease 2019 lockdown in Israel suggests that potentially avoidable triggers contribute significantly to the rate of adverse reactions during OIT.

Peanut oral immunotherapy in a pediatric allergy clinic: Patient factors associated with clinical outcomes

BACKGROUND

Additional information is needed to inform optimal patient selection, expected outcomes, and treatment end points for clinical peanut oral immunotherapy (OIT).

OBJECTIVE

To provide insight into the optimal patient selection, expected outcomes, and treatment end points for clinical peanut oral immunotherapy by analyzing a real-world peanut OIT cohort.

METHODS

Records were reviewed for 174 children undergoing peanut OIT at a pediatric allergy clinic. Patient age, peanut skin prick test results, and peanut-specific immunoglobulin E (sIgE) results, with inclusion of additional foods in OIT, were analyzed for correlations with OIT outcomes.

RESULTS

To date, 144 patients have achieved maintenance dosing, 50 of whom transitioned to ad lib twice-weekly peanut ingestion. A total of 30 discontinued OIT. In addition, 47 patients who underwent multifood OIT had no significant difference in reactions (FDR-adjusted P = .48) or time-to-reach maintenance (FDR-adjusted P = .48) compared with those on peanut OIT alone. Age at initiation inversely correlated with achievement of maintenance: 92% of patients 0.5 to less than 5 years, 81% of those 5 to less than 11 years, and 70% of those 11 to less than 18 years reached and continued maintenance (P = .01). Baseline peanut-sIgE level positively correlated with number of reactions during updosing (P < .001) and maintenance (P = .005), though it was not significantly different in patients achieving successful maintenance vs those who discontinued OIT (P = .09). Furthermore, 66% of patients experienced greater than or equal to 1 adverse reaction during OIT. Of those on ad lib peanut ingestion, 2 reported mild reactions after lapses in peanut consumption.

CONCLUSION

Clinical peanut OIT has similar outcomes to research protocols. OIT can be successful in older children and those with high peanut-sIgE levels, though these factors affect outcomes. Clinical and laboratory criteria can guide successful transition to intermittent ad lib peanut consumption.

Potential Efficacy of High-Dose Inhaled Salbutamol for the Treatment of Abdominal Pain During Oral Food Challenge

BACKGROUND

Abdominal pain is a frequent symptom of IgE-mediated food allergy with limited therapeutic options. Visceral smooth muscle cell relaxation can be induced through beta-adrenergic stimulation.

OBJECTIVE

To evaluate the efficacy of inhaled salbutamol empirically used to relieve abdominal pain caused by IgE-mediated allergic reactions at 1 center.

METHODS

All double-blind placebo-controlled food challenges to peanut performed at 1 center between 2016 and 2021 were reviewed to identify patients who presented abdominal pain as part of their reaction. The primary outcome measure was the delay between the initiation of therapy and improvement of abdominal pain. It was compared between patients who had received inhaled salbutamol as part of their treatment and those who did not. Cox regression was performed to control for potential confounders.

RESULTS

During the study period, 186 positive double-blind placebo-controlled food challenges were performed, including 126 for peanut allergy. Of these, 77 were treated for abdominal pain and 57 met the criteria for inclusion in the study. Patients who received salbutamol improved significantly faster (median, 12.5 minutes) than those who did not (median, 65 minutes) (χ² = 45; P < .0001). In Cox regression, the administration of salbutamol and emesis were found to increase the rate of improvement by a hazard ratio of 11.35 (95% CI, 5.40-23.9; P < .0005) and 4.00-fold (95% CI, 1.90-8.42; P < .0005), respectively.

CONCLUSIONS

This retrospective study provides hypothesis-generating evidence for the use of salbutamol in the treatment of IgE-mediated abdominal pain. Further investigation in a double-blind randomized controlled trial is warranted.

Mechanisms of oral immunotherapy

Food allergy presents a significant global health concern with up to 10% of the population affected in developed nations and a steadily increasing prevalence. In many cases, particularly with peanut, tree nut and shellfish, food allergy is a lifelong and potentially life-threatening diagnosis. While no 'cure' for IgE-mediated food allergy exists, oral immunotherapy (OIT) is a promising treatment modality with the peanut OIT drug Palforzia (Aimmune Therapeutics) the only treatment for food allergy that is currently approved by the United States Food and Drug Administration. OIT primarily induces a state of desensitization with only a minority of subjects achieving sustained unresponsiveness, a state of limited clinical remission that appears to be immunologically distinct from natural tolerance. Early humoural changes during OIT include an initial increase in allergen-specific IgE, which eventually decreases to below baseline levels as OIT progresses, and a gradual increase in allergen-specific IgA and IgG4 that continues throughout the course of OIT. Basophil hyporesponsiveness and decreased skin prick test wheal size are observed within the first year of OIT, and persistence after completion of therapy has been associated with sustained unresponsiveness. In the T-cell compartment, there is an initial expansion followed by a decline in the number and activity of T helper 2 (TH 2) cells, the latter of which may be dependent on an expansion of IL-10-producing cells, including regulatory T-cells. Our understanding of the immunomodulatory effects of OIT continues to evolve, with new technologies such as single-cell transcriptional profiling and antibody epitope analysis allowing for more detailed study of T-cell and B-cell responses to OIT. In this review, we present evidence to illustrate what is currently known about the immunologic changes induced by OIT, explore potential mechanisms and emphasize knowledge gaps where future research is needed.

A Practical, Stepwise Approach to Peanut Oral Immunotherapy in Clinical Practice: Benefits and Risks

Food allergies are common, affecting 6-8% of the children in the United States. There is a significant burden on the quality of life of allergic children and their caregivers, due to multiple dietary, social and psychological restrictions. Peanut allergy affects approximately 2-5% of the school-age children. Despite the recommended dietary avoidance, reactions tend to occur due to unintentional exposures and the fear of accidental ingestions potentially resulting in anaphylaxis and death, which creates a lot of anxiety in peanut-allergic individuals. Peanut oral immunotherapy (POIT) has emerged as a form of active treatment and has shown high efficacy in research trials with the majority of participants achieving desensitization and protection from trace exposures. An improved quality of life has also been noted following successful POIT. The risks of POIT should be balanced against the benefits resulting from successful treatment for each individual. Rates of allergic reactions and anaphylaxis are reported to be higher in individuals pursuing therapy, but most subjects will experience mild or moderate reactions during treatment. The landscape of peanut allergy management is changing and the future offers more options for patients than were previously available. Shared decision-making, which is the process of how to choose between different available options, becomes an ongoing discussion between the clinician and the patient, which will ensure achievement of the best possible outcome for the peanut-allergic child. This is a multistep process that evaluates the benefits and risks of therapy or no therapy, as well as patient and family preferences and we review it in detail in this manuscript with the aim to provide clinicians with a practical approach.

Epicutaneous immunotherapy for treatment of peanut allergy: Follow-up from the Consortium for Food Allergy Research

BACKGROUND

Consortium for Food Allergy Research investigators previously reported 52-week outcomes from a randomized controlled trial of peanut epicutaneous immunotherapy, observing modest and statistically significant induction of desensitization, highest in children ages 4 to 11 years.

OBJECTIVE

We sought to evaluate changes in efficacy, safety, and mechanistic parameters following extended open-label peanut epicutaneous immunotherapy.

METHODS

Peanut-allergic participants (4-25 years) received 52 weeks of placebo (PLB), Viaskin Peanut 100 μg (VP100) or 250 μg (VP250), and then crossed over to VP250 for PLB (PLB-VP250) and VP100 (VP100-VP250) participants and continued treatment for VP250 participants (total = 130 weeks of active epicutaneous immunotherapy). Efficacy was assessed by double-blind, placebo-controlled food challenge (5044 mg peanut protein), and adherence, safety, and mechanistic parameters were evaluated.

RESULTS

At week 130, desensitization success was achieved in 1 of 20 (5%) PLB-VP250, 5 of 24 (20.8%) VP100-VP250, and 9 of 25 (36%) VP250 participants, with median successfully consumed dose change from baseline of 11.5 mg, 141.5 mg, and 400 mg, respectively. Median age (years) for week 130 desensitization success was 6.2 years (interquartile range, 5.2-9.1) versus 9.4 years (interquartile range, 7.6-12.8) for failures (P < .001). Adherence was 96%. Adverse reactions were predominantly local patch-site reactions. Significant increases in peanut- and Ara h2-specific IgG4 observed at week 52 persisted to week 130. By a post hoc analysis, there were no statistically significant increases from week 52 to week 130 in either desensitization success or successfully consumed dose.

CONCLUSIONS

Extended treatment with VP250 was well tolerated, and desensitization observed at week 52 persisted between weeks 52 and 130. Treatment success was observed predominantly in younger participants, with younger age at initiation of active therapy an important predictor of success.

Weighing the benefits and risks of oral immunotherapy in clinical practice

Food allergies are common and affect 6-8% of children in the United States; they pose a significant burden on the quality of life of children with allergy and their caregivers due to multiple daily restrictions. Despite the recommended dietary avoidance, reactions tend to occur due to unintentional exposure to the allergenic food trigger. Fear of accidental ingestions with potentially severe reactions, including anaphylaxis and death, creates anxiety in individuals with food allergy. Oral immunotherapy has emerged as a form of active and potentially disease-modifying treatment for common food allergies encountered in childhood. The efficacy of oral immunotherapy is high, with the majority of participants achieving desensitization and, as a result, protection from trace exposures and improved quality of life. The main risk of oral immunotherapy consists of allergic reactions to treatment. In general, rates of allergic reactions and anaphylaxis are reported to be higher in individuals pursuing therapy options, but most subjects who undergo oral immunotherapy will likely experience mild or moderate reactions during treatment. Adverse events tend to reduce in both frequency and number in the maintenance period. The use of immune modulators alongside oral immunotherapy has been suggested, with the aim to improve efficacy and safety, and to facilitate the overall process. It is evident that the landscape of food allergy management is changing and that the future looks brighter, with different options emerging over time. The process of how to choose the appropriate option becomes a discussion between the clinician and the patient, which involves a joint review of the current medical evidence but also the patient's preference for balancing particular attributes of the treatment. By working together, providers and patients will ensure achievement of the best possible outcome for children with food allergies.

Slow low-dose oral immunotherapy: Threshold and immunological change

BACKGROUND

We examined the feasibility, efficacy and safety of slow low-dose oral immunotherapy (SLOIT) for egg, milk, wheat allergies, with accepted severity-stratified initial and maintenance doses.

METHODS

Children with food allergies defined by low-dose oral food challenges (LD-OFCs) to hen's egg (cumulative protein dose up to 983 mg, n = 133), cow's milk (287 mg, n = 50), and wheat (226 mg, n = 45) were recruited. Participants were divided into two groups [SLOIT and control (complete avoidance]) based on their preferences. Participants who selected SLOIT were instructed to take the safe dose daily, with monthly increases, aiming to increase the dose by 10 times in one year. The primary outcome was the proportion of participants who passed the LD-OFCs following 1 year of therapy.

RESULTS

The participants in SLOIT group ingested their antigen 92.9% of the therapy's day on average. The proportion of participants who passed LD-OFCs was 35.9% (61/170) in the SLOIT group and 8.7% (4/46) in the control group (P < .001); no large differences were observed among allergens. Among the subjects who failed LD-OFCs, the median change in the total dose in the LD-OFC was 235% (interquartile range: 100%-512%) in the SLOIT group and 100% (42%-235%) in the control group (P < .001). Provoked allergic symptoms were observed in only 0.58% (280/48,486) per programmed intake and approximately 50% of the SLOIT group did not experience any obvious allergic symptoms throughout therapy.

CONCLUSIONS

SLOIT showed significant feasibility, efficacy and safety, providing a promising option to manage patients with severe food allergies.

[Allergic immunotherapy in children and adolescents]

L’immunothérapie spécifique allergénique nécessite l’administration répétée d’allergènes dans le but de provoquer une tolérance clinique et immunologique. C’est la seule thérapeutique à visée étiologique qui permet de modifier l’évolution de la maladie en assurant une rémission après l’interruption de la procédure. La prévention de nouvelles sensibilisations par l’immunothérapie reste discutée. Nous envisagerons dans cette revue les principaux mécanismes immunologiques et les indications de l’immunothérapie chez l’enfant et l’adolescent.

Food allergy oral immunotherapy

Food allergy oral immunotherapy (OIT) has demonstrated efficacy in promoting clinically relevant immunomodulation that leads to desensitization (reduced reactivity while on OIT) in the majority of treated individuals; however, sustained unresponsiveness after OIT cessation for a specified interval has only been observed in a subset. The potential therapeutic benefits of OIT must be balanced with the risk for adverse events. These adverse events may range from self-limited or easily treated oropharyngeal, respiratory, or gastrointestinal symptoms to persistent abdominal symptoms that lead to cessation of therapy and to anaphylaxis. To date, the majority of studies have evaluated single-allergen OIT approaches; however, multi-allergen OIT has demonstrated favorable safety and efficacy outcomes, and is the subject of ongoing investigation. Recent U.S. Food and Drug Administration approval of the first licensed OIT product for peanut allergy challenges the long-standing paradigm of dietary food avoidance as the sole option for individuals with food allergy. Yet, the limitations of this "first-generation" treatment support the need for continued research and development of next-generation therapies to improve efficacy, minimize risk, and allow for broad applicability to both individuals with single-food allergy and those with multifood allergies. Optimizing future therapies will require developing novel approaches that maximize both efficacy and safety and/or tolerability outcomes, potentially through the combination with biologic therapies or adjuvants. Shared decision-making among patients, physicians, and parents and/or caregivers is critical to select optimal candidates for treatment with OIT by balancing the potential therapeutic benefit and possible risk reduction with a realistic consideration of OIT treatment burden and the risk of treatment-related adverse events.

Transcriptional changes in peanut-specific CD4+ T cells over the course of oral immunotherapy

Oral immunotherapy (OIT) can successfully desensitize allergic individuals to offending foods such as peanut. Our recent clinical trial (NCT02103270) of peanut OIT allowed us to monitor peanut-specific CD4+ T cells, using MHC-peptide Dextramers, over the course of OIT. We used a single-cell targeted RNAseq assay to analyze these cells at 0, 12, 24, 52, and 104 weeks of OIT. We found a transient increase in TGFβ-producing cells at 52 weeks in those with successful desensitization, which lasted until 117 weeks. We also performed clustering and identified 5 major clusters of Dextramer+ cells, which we tracked over time. One of these clusters appeared to be anergic, while another was consistent with recently described TFH13 cells. The other 3 clusters appeared to be Th2 cells by their coordinated production of IL-4 and IL-13, but they varied in their expression of STAT signaling proteins and other markers. A cluster with high expression of STAT family members also showed a possible transient increase at week 24 in those with successful desensitization. Single cell TCRαβ repertoire sequences were too diverse to track clones over time. Together with increased TGFβ production, these changes may be mechanistic predictors of successful OIT that should be further investigated.

Oral and sublingual immunotherapy for food allergy

PURPOSE OF REVIEW

To critically appraise the recent most relevant studies in the rapidly advancing field of food oral and sublingual immunotherapy.

RECENT FINDINGS

Food allergen-specific immunotherapy via oral (OIT) and sublingual route (SLIT) increases the threshold of reactivity to peanut, cow's milk, egg, wheat, and many other foods in the majority of the treated individuals. This desensitized state is contingent upon the continued ingestion of the maintenance doses of the food. Permanent oral tolerance is achievable in a smaller subset of the treated individuals. The optimal duration of therapy has not been firmly established but is likely dependent on the phenotype (severity and persistence). Efficacy of food-OIT is superior compared with SLIT, whereas the safety of OIT is less favorable. Standardization of treatment protocols, maintenance dosing, duration of therapy, target populations and harmonization of the outcomes are top priorities at this stage.

SUMMARY

OIT and SLIT represent two different routes of food allergen-specific immunotherapy. Although significant progress has been made in the last decade, both treatment modalities are still in the very early stages of development and further investigations are necessary to optimize the protocols and improve safety while maximizing efficacy.

Patient Characteristics and Risk Factors for Home Epinephrine-Treated Reactions During Oral Immunotherapy for Food Allergy

BACKGROUND

Oral immunotherapy (OIT) is effective in desensitizing food-allergic patients but adverse events limit its applicability.

OBJECTIVE

To identify risk factors for home epinephrine-treated reactions during the build-up phase of OIT.

METHODS

A retrospective cohort study of patients older than 3.7 years undergoing OIT for food allergy at Shamir Medical Center between April 2010 and March 2019. All patients with a final disposition of full desensitization, partial desensitization, or failure were analyzed. Risk factors and outcome of home epinephrine-treated reactions were examined.

RESULTS

A total of 1037 patients (mean age, 8.4 years) who underwent 1100 OIT treatments (milk, n = 710; peanut, n = 213; egg, n = 50; sesame, n = 57; and tree nuts, n = 70) reached a final disposition and were analyzed. Full desensitization was achieved in 763 (69.4%) treatments, partial desensitization in 219 (19.9%), and 118 (10.7%) failed. Epinephrine was administered to 121 patients (11.7%) during 10.8% of treatments. Milk OIT was a significant risk factor both for epinephrine-treated reactions (odds ratio, 2.15; 95% CI, 1.25-3.68) and for low rate of full desensitization following such reactions compared with nonmilk OIT (18.2% vs 73.9%, respectively; P < .0001). Risk factors during milk OIT included asthma, pre-OIT reaction severity, lower tolerated dose, and epinephrine-treated reactions during clinic updosing, whereas risk factors during nonmilk OIT were male sex and lower tolerated dose.

CONCLUSIONS

Milk OIT poses a significant risk for home epinephrine-treated reactions during OIT and for poor outcome following such reactions. Together with the additional risk factors described for both milk and nonmilk OIT, this information may assist in patient selection for treatment.

Sublingual immunotherapy for food allergy and its future directions

Food allergy is an important medical problem with increasing prevalence throughout the world. Different approaches of food immunotherapy are being investigated including oral, epicutaneous and sublingual routes. Sublingual immunotherapy (SLIT) for food allergy involves placement of glycerinated allergen under the tongue daily to achieve allergen-specific desensitization. SLIT has been studied in the treatment of hazelnut, peach, apple, milk and peanut allergies with substantial focus on the treatment of peanut allergy. Phase II studies have shown SLIT for treatment of peanut allergy increases the tolerated dose of peanut by a substantial margin with fewer and less severe side effects than other modalities. This review discusses the mechanisms of SLIT, early studies of its use in food allergy and larger randomized controlled trials for treatment of peanut allergy. Future directions using the mechanisms involved in SLIT include oral mucosal immunotherapy for peanut allergy.

Can food allergy be cured? What are the future prospects?

Food allergies have become a significant heath burden as prevalence continues to rise, affecting 6%-13% of the global population. In the absence of drugs approved by regulatory agencies, the current standard of care remains avoidance of allergenic foods and management of acute allergic reactions with antihistamines and epinephrine autoinjectors. Allergen immunotherapy has been shown to increase the threshold of reactivity in the majority of food-allergic individuals. However, challenges include long treatment periods, high rates of adverse reactions, and lack of permanence of desensitization and established protocols. To address these limitations, adjunctive allergen-specific immunotherapy, vaccines, and non-allergen-specific therapies (eg, monoclonal antibodies) are being explored. The future of food allergy treatment is promising with a number of clinical trials in progress. Currently, although desensitization can be achieved for the majority of individuals with food allergy through immunotherapy, continued ingestion of allergen is needed for most individuals to maintain desensitization. Further understanding of the mechanisms of food allergy and identification of biomarkers to distinguish between temporary and permanent resolution of allergies is needed before a cure, where reactivity to the allergen is permanently lost enabling the individual to consume the allergen in any amount at any time, can be envisioned.

Peanut Oral Immunotherapy: a Current Perspective

Purpose of the Review

Peanut oral immunotherapy (OIT) is one of the most studied experimental therapies for food allergy. With the recently FDA-approved peanut product, Palforzia, the goal of this article is to review the most recent data from clinical trials, discuss recent trends, and anticipate future developments.

Recent Findings

The latest research suggests that peanut OIT could be a promising option for peanut-allergic patients, with the majority of participants in research studies achieving the primary efficacy endpoint of desensitization, as well as sustained unresponsiveness in select populations. Some studies also showed improvements in food allergy-related quality of life. However, peanut OIT is not without risk or side effects, including potentially serious allergic reactions.

Summary

Future research will need to evaluate the short- and long-term effectiveness of the therapy in the real-world setting, predictors of important treatment outcomes, and the use of adjunctive therapies that may mitigate some of these allergic reactions.

CSACI guidelines for the ethical, evidence-based and patient-oriented clinical practice of oral immunotherapy in IgE-mediated food allergy

Background

Oral immunotherapy (OIT) is an emerging approach to the treatment of patients with IgE-mediated food allergy and is in the process of transitioning to clinical practice.

Objective

To develop patient-oriented clinical practice guidelines on oral immunotherapy based on evidence and ethical imperatives for the provision of safe and efficient food allergy management.

Materials and methods

Recommendations were developed using a reflective patient-centered multicriteria approach including 22 criteria organized in five dimensions (clinical, populational, economic, organizational and sociopolitical). Data was obtained from: (1) a review of scientific and ethic literature; (2) consultations of allergists, other healthcare professionals (pediatricians, family physicians, nurses, registered dieticians, psychologists, peer supporters), patients and caregivers; and patient associations through structured consultative panels, interviews and on-line questionnaire; and (3) organizational and economic data from the milieu of care. All data was synthesized by criteria in a multicriteria deliberative guide that served as a platform for structured discussion and development of recommendations for each dimension, based on evidence, ethical imperatives and other considerations.

Results

The deliberative grid included 162 articles from the literature and media reviews and data from consultations involving 85 individuals. Thirty-eight (38) recommendations were made for the practice of oral immunotherapy for the treatment of IgE mediated food allergy, based on evidence and a diversity of ethical imperatives. All recommendations were aimed at fostering a context conducive to achieving objectives identified by patients and caregivers with food allergy. Notably, specific recommendations were developed to promote a culture of shared responsibility between patients and healthcare system, equity in access, patient empowerment, shared decision making and personalization of OIT protocols to reflect patients' needs. It also provides recommendations to optimize organization of care to generate capacity to meet demand according to patient choice, e.g. OIT or avoidance. These recommendations were made acknowledging the necessity of ensuring sustainability of the clinical offer in light of various economic considerations.

Conclusions

This innovative CPG methodology was guided by patients' perspectives, clinical evidence as well as ethical and other rationales. This allowed for the creation of a broad set of recommendations that chart optimal clinical practice and define the conditions required to bring about changes to food allergy care that will be sustainable, equitable and conducive to the well-being of all patients in need.

Adverse events associated with peanut oral immunotherapy in children - a systematic review and meta-analysis

While peanut oral immunotherapy (POIT) represents a promising treatment for peanut allergies in children, safety concerns remain a common barrier to widespread adoption. We aimed to systematically assess available evidence to determine the risk and frequency of adverse events occurring during POIT, and examine study-level characteristics associated with their occurrence and severity. A systematic search of MEDLINE, EMBASE, and Web of Science was conducted through April 2019. Controlled and non-controlled studies evaluating POIT were eligible. Twenty-seven studies, involving 1488 subjects, were included. Adverse events to POIT were common and led to treatment discontinuation in 6.6% of children (95% CI 4.4–9.0; 27 studies, I² = 48.7%). Adverse events requiring treatment with epinephrine occurred among 7.6% (4.5–11.4; 26 studies, I² = 75.5%) of participants, at a rate of 2.0 per 10,000 doses (0.8–3.7; 15 studies, I² = 64.4). Use of a rush treatment phase and targeting a higher maintenance dose were associated with a higher risk and frequency of epinephrine use, while using co-treatments in addition to POIT was associated with a lower risk of treatment discontinuation due to adverse events. While adverse events to POIT are common, this study provides promising explorative evidence that certain modifications to existing treatment protocols could significantly improve treatment outcomes.

Sustained outcomes in oral immunotherapy for peanut allergy (POISED study): a large, randomised, double-blind, placebo-controlled, phase 2 study

BACKGROUND

Dietary avoidance is recommended for peanut allergies. We evaluated the sustained effects of peanut allergy oral immunotherapy (OIT) in a randomised long-term study in adults and children.

METHODS

In this randomised, double-blind, placebo-controlled, phase 2 study, we enrolled participants at the Sean N Parker Center for Allergy and Asthma Research at Stanford University (Stanford, CA, USA) with peanut allergy aged 7-55 years with a positive result from a double-blind, placebo-controlled, food challenge (DBPCFC; ≤500 mg of peanut protein), a positive skin-prick test (SPT) result (≥5 mm wheal diameter above the negative control), and peanut-specific immunoglobulin (Ig)E concentration of more than 4 kU/L. Participants were randomly assigned (2·4:1·4:1) in a two-by-two block design via a computerised system to be built up and maintained on 4000 mg peanut protein through to week 104 then discontinued on peanut (peanut-0 group), to be built up and maintained on 4000 mg peanut protein through to week 104 then to ingest 300 mg peanut protein daily (peanut-300 group) for 52 weeks, or to receive oat flour (placebo group). DBPCFCs to 4000 mg peanut protein were done at baseline and weeks 104, 117, 130, 143, and 156. The pharmacist assigned treatment on the basis of a randomised computer list. Peanut or placebo (oat) flour was administered orally and participants and the study team were masked throughout by use of oat flour that was similar in look and feel to the peanut flour and nose clips, as tolerated, to mask taste. The statistician was also masked. The primary endpoint was the proportion of participants who passed DBPCFCs to a cumulative dose of 4000 mg at both 104 and 117 weeks. The primary efficacy analysis was done in the intention-to-treat population. Safety was assessed in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT02103270.

FINDINGS

Between April 15, 2014, and March 2, 2016, of 152 individuals assessed, we enrolled 120 participants, who were randomly assigned to the peanut-0 (n=60), peanut-300 (n=35), and placebo groups (n=25). 21 (35%) of peanut-0 group participants and one (4%) placebo group participant passed the 4000 mg challenge at both 104 and 117 weeks (odds ratio [OR] 12·7, 95% CI 1·8-554·8; p=0·0024). Over the entire study, the most common adverse events were mild gastrointestinal symptoms, which were seen in 90 of 120 patients (50/60 in the peanut-0 group, 29/35 in the peanut-300 group, and 11/25 in the placebo group) and skin disorders, which were seen in 50/120 patients (26/60 in the peanut-0 group, 15/35 in the peanut-300 group, and 9/25 in the placebo group). Adverse events decreased over time in all groups. Two participants in the peanut groups had serious adverse events during the 3-year study. In the peanut-0 group, in which eight (13%) of 60 participants passed DBPCFCs at week 156, higher baseline peanut-specific IgG4 to IgE ratio and lower Ara h 2 IgE and basophil activation responses were associated with sustained unresponsiveness. No treatment-related deaths occurred.

INTERPRETATION

Our study suggests that peanut OIT could desensitise individuals with peanut allergy to 4000 mg peanut protein but discontinuation, or even reduction to 300 mg daily, could increase the likelihood of regaining clinical reactivity to peanut. Since baseline blood tests correlated with week 117 treatment outcomes, this study might aid in optimal patient selection for this therapy.

FUNDING

National Institute of Allergy and Infectious Diseases.

Oral immunotherapy for multiple foods in a pediatric allergy clinic setting

BACKGROUND

The increasing incidence of pediatric food allergy results in significant health care burden and family stress. Oral immunotherapy (OIT) can induce tolerance to peanut, milk, and egg. OIT for other foods, particularly multiple foods simultaneously, has not been thoroughly studied.

OBJECTIVE

To summarize our experience with OIT for multiple foods in a pediatric allergy clinic setting.

METHODS

Medical records were reviewed for patients undergoing OIT for multiple foods. Methods and outcomes of OIT were summarized. Outcomes were analyzed for correlation with baseline food allergen skin prick tests (SPTs) and specific IgE (sIgE) test results.

RESULTS

Forty-five patients aged 1.5 to 18 years undertook OIT for up to 12 foods, including peanut, tree nuts, seeds, legumes, and egg. At the time of review, 35 patients were receiving daily maintenance dosing, 4 had completed OIT and were continuing to eat their foods 3 times weekly, and 6 had stopped OIT because of anxiety, inconvenience, or allergy symptoms. A total of 49% of patients had reactions during the up-dosing process, mostly oral itching (33%), perioral hives (40%), and abdominal pain (35%). There was no correlation of baseline skin prick test (SPT) and sIgE test results with reaction threshold for baseline food challenge, lowest dose causing reactions during up-dosing, or time to reach maintenance. Higher baseline sIgE level but not baseline SPT result was associated with an increased number of allergic reactions during OIT. Baseline SPT correlated with stopping OIT.

CONCLUSION

A similar approach to that used for peanut OIT can be taken for nonpeanut foods and for multiple foods simultaneously. High baseline allergy test results are not a contraindication to OIT.

Parent and child perception of quality of life in a randomized controlled peanut oral immunotherapy trial

BACKGROUND

Improved quality of life (QoL) after oral immunotherapy (OIT) in peanut allergic children is often reported by their parents, while the child's perspective is less clear.

OBJECTIVE

We aimed to explore whether 2 years of OIT improved QoL in children with peanut allergy and to identify factors influencing change in QoL.

METHODS

In the open-labeled TAKE-AWAY peanut OIT trial including children with anaphylaxis to peanuts, 57 were randomized to OIT and 20 to observation. The Pediatric Quality of Life Inventory Version 4.0 was completed by parents and children at enrollment (Y₀ ), after 1 year (end of updosing; Y₁ ) and after 2 years (Y₂ ) of OIT. Minimally clinically important difference (MCID) is ≥5.3. Perceived treatment burden was recorded by visual analogue scales, including adverse events (AEs). An open food challenge (OFC) was performed at Y₂ .

RESULTS

At Y₂ , 18 children had discontinued OIT and 2 of 39 OIT children refused OFC, while 35 of 37 were desensitized to 7500 mg peanut protein. From Y₀ to Y_2, the mean change (95% confidence intervals) in QoL was 4.4 (0.5, 8.3) among child self-reports and twice as large among parental proxy reports (9.3 [4.3, 14.3]; both P < 0.0001), without significant improvement among the controls. The change in QoL was significantly different from the controls for the parental proxy reports only (P = 0.002). Neither treatment burden nor AEs significantly predicted changes in QoL.

CONCLUSION

Two years of OIT improved child-QoL as reported by parents, but not by the children, suggesting that parents may overestimate improvement in child-QoL by OIT.

Risk Factors and Treatment Outcomes for Oral Immunotherapy-Induced Gastrointestinal Symptoms and Eosinophilic Responses (OITIGER)

BACKGROUND

We recently described that oral immunotherapy (OIT)-induced gastrointestinal symptoms were associated with peripheral eosinophilic responses (termed OITIGER).

OBJECTIVE

To identify treatment outcomes after dose modification and risk factors for developing OITIGER.

METHODS

Treatment modifications in patients with OITIGER (n = 65) including cumulative dose reductions or treatment suspension were individualized and based on the severity of symptoms and an associated absolute eosinophil count (AEC, eosinophils/μL) of more than 900. Multivariate analysis for risk factors associated with OITIGER was performed in milk-OIT subjects.

RESULTS

Treatment modifications reduced the cumulative daily dosage load by a median of 50% (interquartile range, 50%-67%) in 43 of 65 (66.1%) patients, deferred dose increases in 2 of 65 (3.1%) patients, or temporarily suspended treatment in 18 of 65 (27.7%) patients. Two patients (3.1%) had no treatment intervention. Symptoms and eosinophilia abated on dosage modification, allowing for resumption of dose increases (n = 34) or reinitiation of treatment (n = 9) after a median of 29 (interquartile range, 20-56) and 19 (interquartile range, 17-44) days, respectively. OITIGER reoccurred during treatment in 10 of 54 (18.5%) patients, which resolved after further dose modification. In long-term follow-up (>3-26 months), 31 of 32 patients were asymptomatic with stable AECs. Patients with OITIGER had a higher OIT failure rate (P = .004) and were less likely to reach full desensitization (P < .001), as compared with asymptomatic patients (n = 684). Multivariate analysis identified several risk factors for OITIGER: starting dose more than 120 mg (P < .001; odds ratio, 7.14), second-month dose more than 4-fold over the starting dose (P = .037; odds ratio, 2.18), and baseline AEC more than 600/μL (P = .002; odds ratio, 3.2).

CONCLUSIONS

OITIGER is transient or reversible in most subjects, and its occurrence is related to OIT starting dose, its rate of increase, and baseline AECs.

Treatment for food allergy

The prevalence of IgE-mediated food allergy is an increasing public health concern effecting millions of persons worldwide. The current standard of treatment is strict avoidance of the offending food or foods, and to date, there are no regulatory approved treatments for food allergy. A significant amount of research has been directed at various forms of food immunotherapy, including oral, sublingual, and epicutaneous delivery routes. Although oral immunotherapy has shown the greatest promise for efficacy in terms of the amount of protein that can be ingested, it has also demonstrated less tolerability and a less favorable safety profile compared with sublingual immunotherapy and epicutaneous immunotherapy, which offers the least protection but has the best safety and tolerability profile. Studies have been conducted with adding adjuvants and anti-IgE to enhance either the efficacy or safety of food immunotherapy. Multiple concepts of food immunotherapy beyond these first-generation treatments are in either animal or early phase 1 studies.