Researchers Hopeful Egg OIT Study Will Usher Development of Biomarkers

Some children treated with egg oral immunotherapy (OIT) are likely to continue eating and tolerating egg 5 years after treatment, according to research that may someday lead to the development of biomarkers to predict who will respond to OIT. The research was presented at the 2019 Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI).

OIT treatments are a big focus of the meeting in San Francisco, California, this year, since the theme is “Food Allergy: Advances in Prevention and Treatment.” OIT involves mixing an allergenic food into something that the patient will tolerate, like applesauce or a liquid, and increasing the dose in gradually increasing amounts.

“Long-term results and implications of egg oral immunotherapy, and food immunotherapy in general, have been lacking,” Robert A. Wood, MD, FAAAAI, and the president of AAAAI, said in a statement. “By completing this follow-up, we’re paving the way to develop biomarkers predictive of patient treatment responses, which will allow us to better mitigate treatment risks and assess oral immunotherapy clinical outcomes.”

In the study, patients aged 5 to 11 years allergic to egg were randomized to receive egg OIT for up to 4 years (n = 40) or a placebo (n = 15; year 1 only).

Patients who passed oral food challenges (OFC) while still on egg OIT therapy were considered desensitized and underwent additional OFC, as well as open feeding of egg 4 to 6 weeks after stopping therapy to assess sustained unresponsiveness (SU). The amount of egg needed to reach SU was 10 grams, or about 2 teaspoons, of egg.

Desensitization occurs when there is temporary increase in the threshold for reactivity; the person with allergies must keep eating their allergen to keep reactions at bay.

SU—or whether or not the treatment lasts—is determined by having the patient avoid the food again and then undergo another OFC to test for a reaction. For 5 years following treatment, patients were given long-term follow-up questionnaires to determine continued egg tolerance.

At study completion, 50% of patients were classified with SU, 28% as desensitized and 22% as not desensitized. Of those classified with SU, 93% were ingesting some form of egg compared with 64% of the placebo group.

Of patients reaching SU, 100% were able to ingest baked and concentrated egg compared with desensitized, not desensitized, and placebo groups (43%, 17%, and 36%, respectively).

Children who did not reach SU had more variable egg consumption and increased symptoms when they did eat egg. Epinephrine was required after concentrated egg ingestion in 3 patients who did not reach SU.

“Egg allergy is one of the most common food allergies and usually appears in early childhood. It has significant risk for severe allergic reactions and negatively affects quality of life for children with the allergy,” the study's first author, Edwin Kim, MD, assistant professor of medicine and pediatrics at the UNC School of Medicine and director of the UNC Food Allergy Initiative, said in statement.

“While the allergy does seem to go away with age, it can last into the second decade of life for most people. Any treatment that can allow the introduction of egg into the diet of someone with egg allergy provides nutritional benefits and peace of mind for the patient and their family.”

Additional study is needed to develop biomarkers to predict who will respond to OIT treatment, which will help reduce the risk of reactions and assess clinical outcomes, Wood said.

“Patients classified with sustained unresponsiveness were less likely to report adverse reactions, and more likely to report greater dietary egg intake,” said Wood. “This study conveys that egg oral immunotherapy can be a very effective treatment for egg allergies. Future studies will help us determine who will most benefit from egg oral immunotherapy, especially recognizing that even some patients on placebo were doing well five years later given that some children will naturally outgrow their egg allergy. We will use this information to design future studies and monitor the long-term implications of egg oral immunotherapy.”

Reference

Kim E, Jones SM, Burks AW, et al. A 5-year summary of real-life dietary egg consumption after completion of a 4-year egg OIT protocol. Presented at: American Academy of Allergy, Asthma & Immunology 2019 Annual Meeting; February 22-25, 2019; San Francisco, CA. Abstract 251.