Oral Immunotherapy for Food Allergies

Abstract

Oral immunotherapy (OIT) is a promising investigational therapy for food allergy. Clinical trials in peanut, milk, egg, and wheat allergy provide evidence that OIT can effectively desensitize a majority of individuals to a food allergen. While a portion of subjects demonstrate sustained unresponsiveness, the majority regain sensitivity with allergen avoidance. The safety and tolerability of OIT continue to limit its use in some patients. Virtually all studies report adverse reactions that are more frequent during dose escalation but may also occur during maintenance therapy. Recent studies have identified adjunctive therapies (such as omalizumab) which may mitigate adverse effects. There is a paucity of data on the long-term safety and efficacy of OIT. Further study is required before OIT is ready for routine clinical practice. This review is intended to provide the reader with an up-to-date understanding of OIT, including its mechanisms, efficacy, safety profile, and potential utility in clinical practice.

Mechanistic correlates of clinical responses to omalizumab in the setting of oral immunotherapy for milk allergy

“…Recent studies suggest that oral immunotherapy (OIT), in which allergenic food is mixed into a vehicle and then ingested in gradually increasing quantities, may hold promise as a treatment for food allergy. 2, 3 However, enthusiasm for this therapy has been tempered by the frequent occurrence of adverse reactions and the lack of sustained protection in most subjects once treatment is discontinued. 2, 3 These limitations have sparked investigations into adjunctive therapies, including omalizumab, that could improve both safety and long-term efficacy.…”

“…2, 3 However, enthusiasm for this therapy has been tempered by the frequent occurrence of adverse reactions and the lack of sustained protection in most subjects once treatment is discontinued. 2, 3 These limitations have sparked investigations into adjunctive therapies, including omalizumab, that could improve both safety and long-term efficacy. Omalizumab is a humanized monoclonal antibody that sequesters free IgE and prevents its binding to the high affinity IgE receptor, FcεRI.…”

Chinese Guideline on allergen immunotherapy for allergic rhinitis

“…As far as EPIT is concerned, more research is needed to define optimal doses (79). In the case of OIT, its limited efficacy, safety and tolerability are major drawbacks and severely curtailed the use of this technique (80). Similarly, local adverse reactions, requirement of a particular administration technique and effectiveness in rhinitis only has limit the application of LNIT in clinical practice (81,82), whereas LBIT has been abandoned already because controlled trials have failed to demonstrate clinical efficacy and adequate safety of allergen administered via this route (82).…”

Mechanisms of Tolerance Induction

“…All of them rely on regular exposure to the food allergen via the oral (oral immunotherapy, OIT), sublingual (sublingual immunotherapy), or epicutaneous (epicutaneous immunotherapy) route; subcutaneous vaccines based on modified hypoallergenic major peanut allergens are currently undergoing phase I clinical trials in adults [5,6] . While OIT induces a temporary state of increased threshold of clinical reactivity to the food allergen, dependent on daily OIT dosing (referred to as desensitization), no food immunotherapy is proven to induce/restore permanent oral tolerance ( Table 5 ).…”

“…Currently, there are no proven strategies to induce permanent tolerance; the management relies on recognition of adverse reactions and treatment of symptoms [1,4] . Considering the risk of fatal anaphylaxis, the negative impact on the nutritional status and quality of life, as well as the cost to the individual and the society, finding effective preventive and therapeutic strategies for food allergy has become a focus of many international research efforts [5,6] .…”