Immunotherapy for Peanut Allergy: 2 Pediatric Trials

By Jaclyn Bjelac, MD

Food allergies are on a steep incline. As immunologists, we are studying better ways to diagnose and treat patients with food allergies, which affect an estimated 8% of children in the United States. Avoidance remains the gold standard; however, this comes with significant psychosocial risks for children and their families, including fear, stress and bullying.

As a potential means of peanut allergy prevention, the National Institute of Allergy and Infectious Diseases (NIAID) updated practice parameters for the introduction of peanut in 2017. The new clinical guidelines recommend peanut introduction as early as 4-6 months of age in children at high risk of developing a peanut allergy, as recommended by their healthcare provider.

If tolerated, desensitization is a lifelong treatment.

Immunotherapy for food allergies

Immunologists currently offer immunotherapy for food allergies, beginning with a dose so infinitesimal that the child does not react. From there, we slowly increase the dose over time, creating a desensitized state in which a child can be exposed to the allergen and not develop the symptoms of an allergic response. Desensitization therapy does not eliminate the allergy; rather, it trains the immune system to adapt to exposure.

The data supporting peanut oral immunotherapy is quite robust, pointing to high rates of successful desensitization in patients who can tolerate the treatment. A landmark study, published in 2017, showed that low dose immunotherapy in preschool children was not only safe, but worked quite well.

There are some limitations, however. At some point during treatment, nearly all patients should expect to experience some side effects, such as mouth itching or stomach upset. As one might imagine, mild symptoms develop when a patient consumes an allergen every day — even at very low doses. Patients with uncontrolled allergic conditions, including asthma or eczema, would not be good candidates for oral immunotherapy.

A new trial, which is currently enrolling patients from Cleveland Clinic Children’s Center for Pediatric Allergy, seeks to evaluate the desensitization and side effects of oral immunotherapy using boiled peanut powder rather than a roasted product.

Boiled peanut oral immunotherapy is a promising investigational therapy that involves feeding a small, increasing dose of peanut to allergenic patients to induce desensitization. Previous studies of peanut oral immunotherapy have been limited by high rates of side effects, often leading to high subject drop-out rates. These previous studies all used peanut products that were produced by roasting.

Boiled peanut oral immunotherapy trial

Heat can affect the allergenicity of certain foods. For example, some children with milk or egg allergy may tolerate baked forms of those foods without symptoms but develop anaphylaxis if they drink a glass of milk. With peanut, roasting has been shown to increase the allergenicity of its protein. Boiling the peanut has been shown to change the shape and profile of the peanut to make it less allergenic.

In our pilot study, children with confirmed peanut allergy will be enrolled in an oral immunotherapy trial of boiled peanut powder to evaluate its effectiveness with desensitization and the frequency of side effects. The peanut powder was created for palatability and ease of dosing.

Although the boiled peanut product may be more readily tolerated than a roasted product, families are counseled that potentially serious allergic reactions, including anaphylaxis, may result. Additionally, families are given very strict dosing instructions to help minimize confounding factors, such as illness or exercise, which are known to make allergic reactions worse.

Epicutaneous immunotherapy trial

Concurrently, Cleveland Clinic Children’s Center for Pediatric Allergy is enrolling patients aged 1-3 with confirmed peanut allergy in a phase 3 study to assess the safety and efficacy of Viaskin® Peanut. This novel epicutaneous immunotherapy is another potential route to desensitization. Although oral immunotherapy appears more effective, this skin patch tends to have fewer side effects. There is some overlap in these age groups, offering some families choice in regards to which immunotherapy they might try first.