LOS ANGELES – Food doses as low as 300 mg every other day are enough to retain tolerance in the maintenance phase of pediatric oral immunotherapy for food allergies, according to an investigation involving 62 children over 4 years of age.
The flexibility “to take smaller doses and still maintain desensitization” is why “a lot of our patients continued to do regular dosing of their oral immunotherapy” for up to 6 years, said Dr. Sharon Chinthrajah, a pediatric allergist and immunologist at Stanford (Calif.) University.
Dr. Sharon Chinthrajah
The children were originally involved in phase I testing of desensitization for multiple food allergies with omalizumab (Xolair). By reducing the risk of anaphylaxis, the biologic facilitated rapid escalation: 30 children on omalizumab tolerated 2-g food challenges by 9 months. It took about 2 years for 43 children to reach that level without omalizumab.
Subjects had up to five allergies from a list of 15, including egg, milk, and peanut. When tolerance was achieved, they stayed on daily 2-g dosing of each of their food allergens for 4-6 months. They and their parents were then given the option of 2-g daily maintenance dosing or dropping down to as low as 300 mg – about the equivalent of one tree nut – every other day.
The investigators reported follow-up data for 62 subjects at the annual meeting of the American Academy of Allergy, Asthma, and Immunology. Nine children on omalizumab and 22 who did not get omalizumab stuck with 2 g–daily dosing, while 18 omalizumab and 13 no-omalizumab children opted for lower maintenance dosing.
They all remained largely tolerant to 2-g challenges every 6 months for up to 46 months in the omalizumab group and 73 months in the no-omalizumab group, the end of follow-up in each group. There were no differences in immunologic parameters and no differences in tolerance testing between the two groups, and tolerance was maintained regardless of the food allergen. Only about 0.5% of reactions in either group were severe.
Dr. Kari Nadeau
“We were excited to find that going down to 300 mg was just as protective” and that long-term maintenance dosing is safe, said Dr. Kari Nadeau, professor of pediatric immunology and allergy at the university. “These are important messages. There’s not a lot of follow-up data on food [oral immunotherapy]. Patient flexibility is key to long-term outcomes,” she added.
“I think people who had milk, egg, and wheat allergies probably didn’t reduce their intake during maintenance, since these are the ones they tend to enjoy,” Dr. Chinthrajah said, but the risk of severe reactions remains, “so we still require patients to carry reaction medication, and review autoinjector use when they come back to our center for testing and food challenges.”
There was no industry funding for the work, and the investigators said they have no relevant disclosures.