Enhanced Efficacy and Confirmed Safety of a Two-Year Epicutaneous Immunotherapy (EPIT) Treatment of Peanut Allergy with Viaskin® Peanut: The Continuation of the Vipes Phase IIb Randomized Controlled Trial (RCT)

Quantitative Assessment of the Safety Benefits Associated with Increasing Clinical Peanut Thresholds Through Immunotherapy

BACKGROUND

Peanut immunotherapy studies are conducted with the aim to decrease the sensitivity of patients to peanut exposure with the outcome evaluated by testing the threshold for allergic response in a double-blind placebo-controlled food challenge. The clinical relevance of increasing this threshold is not well characterized.

OBJECTIVE

We aimed to quantify the clinical benefit of an increased threshold for peanut-allergic patients.

METHODS

Quantitative risk assessment was performed by matching modeled exposure to peanut protein with individual threshold levels. Exposure was modeled by pairing US consumption data for various food product categories with potential contamination levels of peanut that have been demonstrated to be present on occasion in such food products. Cookies, ice cream, doughnuts/snack cakes, and snack chip mixes were considered in the risk assessment.

RESULTS

Increasing the baseline threshold before immunotherapy from 100 mg or less peanut protein to 300 mg peanut protein postimmunotherapy reduces the risk of experiencing an allergic reaction by more than 95% for all 4 food product categories that may contain trace levels of peanut residue. Further increase in the threshold to 1000 mg of peanut protein had an additional quantitative benefit in risk reduction for all patients reacting to 300 mg or less at baseline.

CONCLUSIONS

We conclude that achieving thresholds of 300 mg and 1000 mg of peanut protein by peanut immunotherapy is clinically relevant, and that the risk for peanut-allergic patients who have achieved this increased threshold to experience an allergic reaction is reduced in a clinically meaningful way.

Desensitization for Peanut Allergies in Children

Immunotherapy for peanut allergy has been an exploding topic of study within the last few years. Sublingual, epicutaneous, and oral immunotherapy are being investigated and show promise in the treatment of peanut allergy. Oral immunotherapy has shown the most clinical benefit; however, sublingual and epicutaneous immunotherapy appear to have the most favorable safety profiles. Most studies to date suggest that only a minority of subjects achieve sustained unresponsiveness to peanut after discontinuation of immunotherapy. Recent efforts have been focused on identifying adjunct therapies, such as omalizumab, that may assist patients in achieving peanut desensitization more quickly and with greater success. Several underlying immunologic mechanisms, including a switch from IgE to IgG4 production and induction of T regulatory cells, have been studied although more research is needed to identify reliable biomarkers. This article will describe the immunotherapy approaches that are being investigated to induce peanut desensitization, and highlight the benefits and risks of these therapies that need to be considered before they are ready for routine clinical practice.

Current and Emerging Therapies for IgE-Mediated Food Allergy

Food allergies are a growing clinical problem leading to increased health care utilization and decreases in patient quality of life. Current treatment recommendations include strict dietary avoidance of the offending food as well as use of self-injectable epinephrine in case of accidental exposure with allergic reaction. Although many individuals will eventually outgrow their food allergies, a substantial number will not. Significant effort has been made to find novel treatments that protect patients from food-triggered reactions as well as to develop immune-modulating therapies that could lead to tolerance. In this review, three therapies that have shown the most promise for the treatment of food allergies are highlighted: oral immunotherapy, sublingual immunotherapy, and epicutaneous immunotherapy.