A new allergy medication is prompting clinicians to adjust their approach to oral food challenges — medically supervised tests in which clinicians give increasing doses of an allergen like peanut or milk to see how a patient reacts.
The FDA in 2024 approved omalizumab (Xolair) to help reduce allergic reactions in adults and children aged 1 year or older with immunoglobulin E-mediated food allergy. Patients receiving the injections are supposed to avoid foods to which they are allergic. In the event of an accidental exposure, the medication can afford protection against a serious reaction.
The approval opened a new frontier in allergy therapy but also raised questions without clear answers, like: How can patients be sure the medication is working? And how will they know if they “outgrow” an allergy, as some people do?
After the approval, clinicians wrote to the American Academy of Allergy, Asthma & Immunology seeking advice.
Earlier this year, a committee for the academy published a report with “consensus-based guidance” on using omalizumab for food allergy and acknowledged that clinical guidance will likely evolve as groups monitor and report real-world outcomes.
In the meantime, the committee suggested that various approaches to treatment, including the use of oral food challenges to assess treatment response, could be used.
“Clinicians should consider assessing treatment success against individualized goals that the patient and prescribing clinician have set for therapy,” they wrote.
Any food challenges “to assess treatment response should be offered no earlier than 16-20 weeks after initiating omalizumab therapy,” the duration of treatment in a randomized trial that supported the drug’s approval for food allergy, they wrote. “In nonresponding patients, the clinician should strongly consider discontinuation of omalizumab given lack of benefit.”
Although its use for food allergy is relatively new, omalizumab is not a new medication. The drug first was approved for asthma in 2003. The drug also is approved to treat chronic spontaneous urticaria and chronic rhinosinusitis with nasal polyps.
‘Bite Safe’ Testing?
Scott Sicherer, MD, director of the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York City, fielded the inquiry when a clinician wrote to the American Academy of Allergy, Asthma, & Immunology’s “Ask the Expert” column last year wondering: “With recent approval of Xolair for management of food allergies, how do we approach food challenges?”
In some cases, additional food challenges make sense before starting omalizumab to confirm or rule out possible allergies, so patients are not avoiding certain foods unnecessarily while on therapy, responded Sicherer, who coauthored a 2024 paper in The New England Journal of Medicine about omalizumab for the treatment of multiple food allergies.
After starting therapy, a scaled back food challenge to determine whether treatment has rendered an allergen “bite safe” might be reasonable, added Sicherer, meaning a patient could accidentally have a bite of the food in question without a severe reaction.
“Given that the commitment to treatment includes time and expense and there are no good biomarkers yet, and a small percentage of people do not respond, I think many patients would like an [oral food challenge] to some agreed upon amount of the food, perhaps something they would view as ‘bite safe,’” Sicherer wrote in his response. “If the treatment is not protecting them to small amounts, why continue?”
The exact parameters of such a test could depend on the patient’s goals, Sicherer told Medscape Medical News.
Some patients might simply look for reassurance that they could eat half a peanut without a problem.
If that is the case, “maybe that is what we would aim for,” Sicherer said. “It’s not like there is a rule written down about this.”
Introducing Egg
Sicherer’s reply also discussed ways to handle a scenario where a patient on omalizumab had egg, cashew, and peanut allergies — with the egg allergy expected to resolve.
One approach could involve discontinuing omalizumab for at least 4-5 months before performing an oral food challenge with egg, he wrote.
Alternatively, clinicians might conduct a food challenge with egg while the patient remains on omalizumab.
If they tolerate the full amount of egg on therapy, they could be encouraged to eat that food regularly, Sicherer said.
Then if the patient eventually stops omalizumab and has symptoms after eating egg, then perhaps the allergy never resolved, he added.
Shared Decisions
Understanding a family’s goals and preferences is crucial, said Jennifer Dantzer, MD, assistant professor of pediatrics in the Division of Allergy, Immunology, and Rheumatology at Johns Hopkins University School of Medicine in Baltimore.
Decisions about food challenges for patients on omalizumab is “something that we are talking through with every family,” said Dantzer, who has studied the medication and coauthored the article in The New England Journal of Medicine with Sicherer.
The definition of treatment success can vary. In some cases, a child might be able to consume a full serving of an allergen. Or a patient might react to a relatively small amount but have a reaction that is far less severe than before.
Either instance could be deemed a success. Results from food challenges can provide reassurance that certain activities like dining out are now lower risk, Dantzer said.
For now, clinicians have no firm guidelines about when to reassess therapy or consider adjusting the dose. “I think the allergy community would like there to be a bit more guidance,” Dantzer said. “Hopefully with time that will become available.”
Sicherer’s institution received funding for participating in a trial of omalizumab for food allergy. Dantzer’s research on patient-centered outcomes is supported by grants from the National Institutes of Health and Food Allergy Research & Education.