Wesley Burks, MD | UNC Chapel Hill | Chapel Hill, NC

University of Arkansas for Medical Sciences │ Little Rock, AR

Stanford University │ Stanford, CA

Johns Hopkins Children’s Hospital │ Baltimore, MD

Mount Sinai Hospital │ New York, NY

UNC Chapel Hill │ Chapel Hill, NC

The prevalence of peanut allergy in the US has increased in the last decade and is estimated to be about 1%. Symptoms of food allergy can be mild to severe, with peanut being the leading cause of life threatening or fatal reactions. Unlike cow’s milk and hen’s egg allergy, peanut allergy tends to persist, and only 20% of children outgrow their disease. The current standard of care in management of peanut allergy is dietary avoidance of peanut and education of the patient/family in the acute management of an allergic reaction. The burden of avoidance and constant fear of accidental exposure negatively impact the health-related quality of life for both patients and their families.

There is clearly an unmet need in the treatment of peanut allergy. Allergen immunotherapy is a technique whereby a problematic allergen is administered under tight medical supervision to train a patient’s immune system so that the patient will no longer have allergic reactions to the particular allergen. While, traditionally, allergen injection immunotherapy has proven unsafe in food allergy, some investigators have reported apparent success in using the oral route for administration of immunotherapy in food allergy. Previous peanut oral immunotherapy (OIT) studies suggested that subjects treated with OIT were able to safely consume greatly increased doses of peanuts following their course of treatment compared to placebo patients.

There are two possible outcomes to allergen immunotherapy, both of which are beneficial compared to allergen avoidance. The first outcome is called “desensitization:” as long as the patient is taking daily oral doses of the food allergen, he or she will not have allergic reactions to the food. Most of the earlier studies of successful oral food allergy have demonstrated desensitization. The second possible outcome, which is more difficult to achieve but the long-term benefits make it a more desirable outcome, is called “tolerance.” Tolerance is based on the idea that a patient can stop eating that particular food for a long time and afterwards still be able to eat the food without having an allergic reaction. Thus, after eating the food allergen for several years, enough time to cause profound changes in the immune system, the food allergen is stopped for a long period of time (6 months in the IMPACT study). The IMPACT study will investigate whether peanut OIT can induce long term tolerance, and not just desensitization, in children with peanut allergy.

In this multi-center interventional study, young children (ages 1-4) who have peanut allergy will be selected for a double blind, placebo-controlled trial of peanut OIT. After a dose escalation phase, subjects receive maintenance oral immunotherapy for an extended period. At the end of that period an assessment for peanut allergy is carried out. Then OIT or placebo is stopped, and subjects are observed during an avoidance phase. Participation will conclude with a final assessment for peanut allergy after the avoidance phase to evaluate whether they have become tolerant to peanut.

This approach provides a unique opportunity to monitor the natural course of peanut allergy and to perform comparative investigations concerning biological and immunological outcomes. A variety of assays will be employed to evaluate known immunologic markers of peanut allergy, as well as novel biomarkers that may be indicative of desensitization or tolerance that could serve as a surrogate end-point for clinical outcomes in patients undertaking immunotherapy.