Peanut is one of the most common causes of food allergies. Peanut allergy usually starts in early childhood and lasts a lifetime. Allergic reactions can range from mild to severe and life threatening. The only way to prevent an allergic reaction is to avoid exposure to peanut. But steering clear of peanut is difficult, since it can be in foods you might not suspect.
Recent studies have shown that an experimental treatment called oral immunotherapy can reduce allergies to some foods, including peanut. This medically supervised therapy involves eating small amounts of the allergy-causing substance (allergen) to decrease the body's sensitivity to the allergen. However, oral immunotherapy often causes adverse reactions.
Researchers have begun testing another approach called epicutaneous (on the skin) immunotherapy, or EPIT. A phase 1 study previously demonstrated the safety and tolerability of a wearable patch developed by DBV Technologies. The patch, named Viaskin, delivers small amounts of peanut protein through the skin.
An ongoing trial to further evaluate peanut EPIT is sponsored by NIH's National Institute of Allergy and Infectious Diseases (NIAID) and conducted by the NIAID-funded Consortium of Food Allergy Research (CoFAR). Researchers randomly assigned 74 peanut-allergic volunteers, ages 4 to 25 years, to either a high-dose (250 micrograms peanut protein), low-dose (100 micrograms peanut protein), or placebo patch. Each day, the participants applied a new patch to an arm or between their shoulder blades.
After one year, the researchers assessed the treatments' success. Success was defined as being able to eat at least 10 times more peanut protein than they could eat before starting EPIT. Results were published online on October 26, 2016, in the Journal of Allergy and Clinical Immunology.
The low-dose and high-dose regimens offered similar benefits (46% and 48% success, respectively, compared with 12% in the placebo group). Treatment success was higher among the younger children, ages 4 to 11 years, than the older ones, where there was minimal benefit.
Nearly all study participants followed the EPIT regimen as directed. None reported serious systemic reactions to the patch, although most experienced mild skin reactions, such as itching or rash, where the patch was applied.
“The clinical benefit seen in younger children highlights the promise of this innovative approach to treating peanut allergy,” says Dr. Daniel Rotrosen, director of NIAID's Division of Allergy, Immunology and Transplantation. “Epicutaneous immunotherapy aims to engage the immune system in the skin to train the body to tolerate small amounts of allergen, whereas other recent advances have relied on an oral route that appears difficult for approximately 10 to 15% of children and adults to tolerate.”
Because EPIT appears to cause few, if any, systemic reactions and appears to be well tolerated, it may be possible to administer it for longer periods of time. The CoFAR study will continue to assess the long-term safety and effectiveness of peanut EPIT in this group. Additional studies in larger groups of children will be needed before the patch could be approved for wider use.
November 8, 2016