Drug Slashes Risk of Severe Allergic Reactions to Multiple Foods

WASHINGTON — Regular courses of omalizumab (Xolair) injections increased the amount of peanut and other foods that multi-food allergic children could consume without an allergic reaction, data from the first stage of the randomized OUtMATCH trial showed.

Of the 177 children and adolescents randomized, 67% of those who received the monoclonal anti-immunoglobulin E (IgE) antibody were able to ingest at least a 600-mg dose of peanut protein without a moderate or severe reaction compared with 7% of those who received placebo (P<0.001), reported Robert A. Wood, MD, of Johns Hopkins University School of Medicine in Baltimore, at the American Academy of Allergy, Asthma & Immunology (AAAAI) annual meeting.

Results for key secondary endpoints — the consumption of cashew, milk, and egg in single doses of at least 1,000 mg each without dose-limiting symptoms — were similar (P<0.001 for all comparisons):

• Cashew: 41% of the omalizumab group vs 3% of the placebo group
• Milk: 66% vs 10%
• Egg: 67% vs 0%

This was also the case for other secondary endpoints including the consumption of walnuts (64% vs 13%, respectively), hazelnuts (65% vs 14%), and wheat (75% vs 13%). Results were simultaneously published in the New England Journal of Medicine.

“These levels of protection are likely to exceed those that would be needed for the amounts of food that are typically encountered during accidental exposure, which highlights the possible use of omalizumab as monotherapy to reduce the daily risk of food allergic reactions while recognizing that this protection would require ongoing dosing as well as continued avoidance of allergenic foods,” Wood and colleagues wrote in their study.

Based on these findings, the FDA recently approved omalizumab for the treatment of IgE-mediated food allergy in adults and children 1 year and older, to help reduce certain allergic reactions, including the risk of anaphylaxis, following accidental exposure to one or more foods. It was originally approved for the treatment of moderate to severe persistent allergic asthma in 2003, and is also approved to treat chronic spontaneous urticaria and chronic rhinosinusitis with nasal polyps.

During his presentation, Wood noted that what he really wants is more options for patients, pointing out that multiple food allergies are much more limiting for patients and their families compared with a single allergy.

“Somebody who has peanut allergy, they may be doing great with strict avoidance or they may be so anxious about their peanut allergy that their life is paralyzed and it really would benefit from some form of therapy,” he said.

In an accompanying editorial, Gary Wong, MD, of the Chinese University of Hong Kong, explained that having multiple food allergies can make life difficult for patients in a number of ways, with little opportunities for relief.

“In the absence of a curative treatment for food allergy, allergen avoidance has been the cornerstone of the management of food allergy,” he wrote. “As a result, quality of life is compromised because of lifestyle restrictions and the constant fear of reactions associated with accidental exposure.”

“Oral immunotherapy for peanut allergy has been shown to be effective in increasing the reaction threshold, but such treatment was associated with more allergic and anaphylactic reactions when compared with the standard recommendation of avoidance,” he added. “Furthermore, immunotherapy has not been shown to improve the quality of life of patients with peanut allergy.”

In the study, the first 60 patients who completed the first stage were enrolled in a 24-week open-label extension. Wong expressed some doubts regarding the long-term efficacy of treatment, as 21% of these participants showed a decreased reaction threshold for peanut allergens.

“These findings arouse concern about the durability of treatment response,” he said. “With regard to quality-of-life assessments, no changes from baseline were seen in either caregiver or participant scores at the end of the first stage of the trial.”

“In real life, people want treatments that will decrease the risk of accidental allergic reactions, lift the burden on their daily lives, simplify their dietary restrictions, and improve their quality of life,” Wong wrote.

The findings raise a number of questions, he noted, including whether patients with mild reactions would choose regular injections instead of allergy avoidance, or whether omalizumab could be used as an adjunct to improve the safety profile of oral immunotherapy.

“Data regarding the possible benefits of omalizumab with respect to important patient-centered outcomes and quality of life are needed before we can make recommendations for patients in clinical practice,” Wong concluded. “Will the use of omalizumab, either as monotherapy or as an adjunct to immunotherapy, really ‘outmatch’ other treatment options for patients with multiple food allergies?”

Co-author R. Sharon Chinthrajah, MD, of Stanford University School of Medicine in California, told MedPage Today that the results of the study have the potential to address food allergy disparities, as indicated by the level of patient involvement, particularly during the COVID-19 pandemic, which overlapped with the study.

“I think it shows the dedication of our patients and their families that they kept showing up, in spite of being in the midst of a pandemic where people were avoiding hospitals — and patients are still coming in to make sure that they could get injections,” she said, adding that patients were not only ensuring their own care, but were “providing a legacy for all food allergy families.”

For this double-blind study, participants across 10 U.S. centers were randomized 2:1 to receive omalizumab or placebo administered subcutaneously with the dose based on weight and IgE levels every 2 to 4 weeks for 16 to 20 weeks. Overall, 180 patients underwent randomization from September 2019 through November 2022, and 177 were included in the analysis.

Of the 118 who received omalizumab, mean age was 6.5, 58% were boys, and median total IgE level was 700 IU/mL. Of the 59 who received placebo, mean age was 7, 53% were boys, and median total IgE level was 712 IU/mL. A majority of participants also had asthma, atopic dermatitis, and allergic rhinitis.

Patients with severe asthma, a history of severe anaphylaxis to the included foods, prior immunotherapy for any of the trial foods, and those who had received monoclonal antibody therapy 6 months or less prior to the trial were excluded.

Patients underwent laboratory testing and skin prick tests to confirm the presence of a food allergy. Peanut allergies were the most common, followed by cashew, walnut, egg, milk, hazelnut, and wheat.

Only three adults were included in the study, and the majority of the participants were non-Hispanic and white, which could limit generalizability of the findings, Wood and colleagues noted. In addition, modified asthma-based dosing of omalizumab was used based on doses in previous studies, which excluded patients with high baseline IgE levels, many of whom might be “excellent candidates for this therapy,” they wrote.

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