Patients introduce allergens into their diets after using omalizumab

Key takeaways:

• All the patients in the study had an allergy to peanut and at least one other food.
• Successful dietary introduction was defined as consuming a median of 300 mg of protein or more each day.

SAN DIEGO — Patients with multiple food allergies introduced allergens into their diets after using omalizumab, researchers reported at the 2025 American Academy of Allergy, Asthma & Immunology/World Allergy Organization Joint Congress.

However, the amounts they consumed decreased over time, Jennifer Dantzer, MD, FAAAAI, MHS, assistant professor of pediatrics in pediatric allergy, immunology and rheumatology, Johns Hopkins University School of Medicine, said during her presentation.

“Let’s look at this novel approach,” Dantzer, who is also a member of the Healio Allergy/Asthma Peer Perspective Board, said.

The cohort included the first 60 patients (median age, 8.5 years; 58% male; 70% white) who completed stage 1 of the placebo-controlled Omalizumab as Monotherapy and as Adjunct Therapy to Multi-Allergen Oral Immunotherapy in Food Allergic Children and Adults, or OUtMATCH, trial.

Allergies included peanut (n = 60), cashew (n = 28), egg (n = 27), milk (n = 25), walnut (n = 23), hazelnut (n = 8) and wheat (n = 9). Also, dietary consumption was part of the initial treatment plans for 82% of these patients.

These patients then entered a 24-week open-label omalizumab (Xolair; Genentech, Novartis) extension followed by a set of oral food challenges before discontinuing treatment in stage 3.

Based on individual preferences and the results of their final food challenge, patients then began dietary consumption, practiced rescue OIT, or practiced avoidance for each of their three allergens.

To begin dietary consumption of each allergen, patients had to tolerate 600 mg or more of that protein, or 1,044 mg cumulative, during the OFC at the end of the open-label extension.

“They got an individualized plan for each of their studied foods,” Dantzer said. “The objective of this stage was to determine if allergen in foods could be safely introduced into the diet after stopping omalizumab, which is a new and unique approach.”

Individual plans for individual allergens also could change throughout this stage of the study, Dantzer continued.

“The focus of this analysis was on the introduction of allergenic foods into the diet in the form of dietary consumption,” she said. “Food introduction started with an in-clinic observed open feeding with the starting amount based on the food challenge result and, again, patient preference.”

As part of their individualized plans for each allergen, patients received guides explaining retail dietary options as well as minimum and maximum amounts, such as peanut butter or candy for peanuts or yogurt, cheese and ice cream for milk.

“The family and the participant had a choice on what foods they wanted to eat, and this could change day-to-day, so they did not have to eat the same thing every day,” Dantzer said. “The amount that they did eat could change over time based on symptoms or their preference.”

Overall, 82% of these treatment plans started with dietary consumption.

When 300 mg of the allergen’s protein was consumed each day, measured quarterly, dietary consumption was considered successful. But when patients could not tolerate at least 300 mg of daily consumption during the first 6 months, it was discontinued, and they could choose rescue OIT or avoidance.

At 12 months, 74% of those plans ended with dietary consumption. Among the 18% of treatment plans that began with rescue OIT, 31% ended with rescue OIT, 34% ended with avoidance and 34% ended with dietary consumption.

At 67%, “most treatment plans ended with eating the allergen,” Dantzer said.

Specifically, 95% of patients started with dietary consumption for at least one food, with 84% of these patients ending with dietary consumption of at least one food. Also, 68% began with dietary consumption for all three foods, and 63% of them ended with dietary consumption of all three.

“At study discontinuation or the end of their 12-month period, 80% of participants were on dietary consumption for at least one food, 58% for all three foods, 18% were avoiding all three foods and 3% were on rescue OIT,” Dantzer said.

But rates of successful consumption declined from 3 months to 12 months, Dantzer said. Success rates for peanut fell from 92% to 56%. For cashew, rates fell from 85% to 50%. Rates for walnut fell from 78% to 44% and rates for hazelnut fell from 88% to 38%. Drops also included 91% to 70% for egg, 87% to 61% for milk and 100% to 63% for wheat.

Median amounts of daily consumption fell through 12 months for all foods as well, except for wheat, with lower medians for peanut and tree nuts compared with milk, egg and wheat.

Dantzer said that the decreases in amounts consumed appear to be multifactorial.

“We looked at the association between reported symptoms and decreased consumption and found no clear relationship between the symptoms and these decreases,” she said. “These decreases were common in participants, both with and without reported symptoms.”

There was an association between reported symptoms and decreased consumption for peanut between months 0 and 3 for peanuts (P = .036) and for egg between months 3 and 6 (P = .017), Dantzer said, adding that taste and patient preference also were factors.

“For example, some did not want to continue to eat peanut every day, or did not want to eat large amounts of peanuts if they did not like the taste,” she said.

There were no predictors of success either, Dantzer continued, although there was an association between the cumulative tolerated dose during the screening challenge and success for peanuts only.

“This was a small sample size, so these findings need to be further explored in a larger dataset,” she said.

The patients assigned to dietary consumption for all foods throughout the study (n = 26) had a total of 104 adverse events, including 19 events among 12 patients (46%) related and 38 events among 13 patients (50%) possibly related to dietary consumption.

Also, five of the six adverse events treated with epinephrine were related to dietary consumption. Of five adverse events that met the criteria for anaphylaxis, three were related and one was possibly related to dietary consumption.

“It is a small number, but possible that this could have been related to the wear-off of omalizumab,” Dantzer said. “To put this into context, this was adverse events associated with eating three allergens daily for up to a year, and considering the number of doses given, this [adverse event] rate was relatively small.”

Among the patients on a mix of dietary consumption and rescue OIT or only rescue OIT, 32 patients had 216 adverse events, with 78 related or possibly related to dietary consumption and 34 related or possibly related to rescue OIT.

Additionally, 17 episodes of anaphylaxis were related or possibly related to dietary consumption, seven episodes were related or possibly related to rescue OIT, and four episodes were related or possibly related to both, with most episodes occurring before month 6.

“We also knew to monitor for eosinophilic esophagitis, and there were four participants who developed EoE,” Dantzer said, “with two felt to be related or possibly related to dietary consumption and two related or possibly related to rescue OIT.”

Limitations of the study included its small sample size and difficulties in determining the relatedness of adverse events to specific foods, as patients consumed multiple allergens, Dantzer said.

“We have no comparison to alternative approaches,” she continued. “So, we can’t say that this is the best approach. We definitely have a need for more detailed information about patient decision-making and patient-centered outcomes.”

Despite these adverse reactions and the patients who returned to avoidance of their allergens, the researchers concluded that most patients successfully introduced their allergens into their diets after 24 to 48 weeks of using omalizumab.

“We are entering an exciting time in food allergy management, continuing to work to address the individual needs and goals of each patient,” Dantzer said.

Dantzer cautioned that this is not a one-size-fits-all treatment, with omalizumab currently approved in combination with strict food avoidance to reduce reactions that may happen with accidental exposures to allergens, although she remained optimistic.

“These results indicate that omalizumab may allow patients to introduce their allergen into their diet, and this additional use may be valuable to many patients,” Dantzer said.

Reference:

• Omalizumab is superior to oral immunotherapy in multi-food allergy treatment study. https://www.aaaai.org/about/news/news/2025/omalizumab. Published Feb. 10, 2025. Accessed Feb. 10, 2025.