Epicutaneous immunotherapy protects cashew sensitized mice from anaphylaxis

Background: The prevalence of tree nut allergy has increased worldwide, and cashew has become one of the most common food allergens. More critically, cashew allergy is frequently associated with severe anaphylaxis. Despite the high medical need, no approved treatment is available and strict avoidance and preparedness for prompt treatment of allergic reactions are considered dual standard of care. In the meantime, Phase III study results suggest investigational epicutaneous immunotherapy (EPIT) may be a relevant and safe treatment for peanut allergy and may improve the quality of life for many peanut allergic children.

Objective: We aimed to evaluate the capacity of EPIT to provide protection against cashew-induced anaphylaxis in a relevant mouse model.

Methods: The efficacy of EPIT was evaluated by applying patches containing cashew allergens to cashew-sensitized mice. As negative control, sham mice received patches containing excipient. Following treatment, mice were challenged orally to cashew and anaphylactic symptoms, as well as plasmatic levels of mast-cell proteases (mMCP)-1/7, were quantified.

Results: 16 weeks of EPIT significantly protects against anaphylaxis by promoting a faster recovery of challenged mice. This protection was characterized by a significant reduction of temperature drop and clinical symptoms, 60 minutes after challenge. This was associated to a decrease in mast-cell reactivity as attested by the reduction of mMCP-1/7 in plasma, suggesting that EPIT specifically decrease IgE-mediated anaphylaxis.

Conclusion: We demonstrate that EPIT markedly reduced IgE-mediated allergic reactions in a mouse model of cashew allergy, which suggests that EPIT may be a relevant approach to treating cashew allergy.

Keywords: Cashew allergy; EPIT; Viaskin; anaphylaxis mouse model.