Epicutaneous immunotherapy: A review of safety and efficacy

Abstract Epcutaneous immunotherapy (EPIT) is a novel, non‐oral route of allergen immunotherapy, utilizing the skin and its robust density of epidermal Langerhans cells (LC) for antigen presentation. This space is non‐vascularized and impermeable, which limits allergen exposure into the bloodstream but preserves antigen presentation to regional lymph nodes to generate gut‐homing regulatory T cells. The EPIT patch utilizes natural water loss from the skin to absorb electrosprayed allergen through condensation. EPIT represents an alternative, non‐oral route of immunotherapy for food allergy, with good efficacy and strong safety profiles across multiple phase 2 and 3 studies for milk and peanut. Efficacy appears the best in very young children (1–3 years old), which has been shown to continue to enhance with extended treatment duration up to 36 months. Efficacy in slightly older children ages 4–11 years of age is less clear, but appears to be better in children ages 4–7 years of age. In clinical trials of milk and peanut EPIT, most subjects experienced adverse effects, mainly mild‐to‐moderate skin reactions localized around the patch placement site, which improve with continued duration of wear. Rates of treatment‐related anaphylaxis have been very low across all studies and ages, ranging from 1.6% to 4%, and were lowest in the infant and toddler population. While further studies of safety (1‐ to 3‐year‐olds) and efficacy (4‐ to 7‐year‐olds) are ongoing, EPIT is a potentially valuable addition to the current landscape of food allergy therapies, in particular for infants and toddlers where families may be seeking a non‐oral route of treatment. image