A recent clinical trial has revealed that omalizumab (marketed as Xolair) is more effective than oral immunotherapy (OIT) in treating multi-food allergies in individuals who are highly sensitive to even trace amounts of common food allergens. The study demonstrated that a significant portion of participants who received an extended course of omalizumab were able to tolerate higher amounts of food allergens, compared to those undergoing OIT, despite experiencing fewer side effects.
OIT, which is a prevalent approach to treating food allergies in the United States, involves gradually consuming increasing doses of a food allergen to reduce the body’s allergic response. However, this process often comes with allergic reactions and intolerable side effects that cause many participants to discontinue treatment. This trial’s findings, published in an online supplement to The Journal of Allergy and Clinical Immunology, and presented at the 2025 American Academy of Allergy, Asthma & Immunology/World Allergy Organization Joint Congress in San Diego, show omalizumab’s potential as a more tolerable alternative to OIT.
Study Overview and Results
The study enrolled 177 children and adolescents (ages 1-17) and three adults (ages 18-55) from 10 locations across the United States. All participants had confirmed allergies to very small amounts of common foods, including peanuts, eggs, milk, cashews, wheat, hazelnuts, or walnuts. Participants who had previously completed the first stage of the trial entered the second stage, which compared omalizumab with OIT.
During the second stage, participants received injections of omalizumab for eight weeks. Afterward, they were split into two groups. Group A received omalizumab in combination with multi-food OIT, while Group B received omalizumab alongside placebo OIT. Over the following weeks, participants in Group A continued the OIT treatment, while those in Group B maintained omalizumab injections with placebo OIT.
The study found that 36% of participants in Group B (receiving omalizumab and placebo OIT) could tolerate 2 grams or more of peanut protein and two other food allergens without an allergic reaction by the end of the treatment period. In contrast, only 19% of participants in Group A (who received omalizumab and OIT) could do the same. The difference was primarily attributed to the higher incidence of allergic reactions and other intolerable side effects among those undergoing OIT, leading to a quarter of them discontinuing the treatment.
Mechanism of Omalizumab
Omalizumab works by targeting immunoglobulin E (IgE), the antibody responsible for triggering allergic reactions. It binds to IgE, preventing it from interacting with immune cells that are responsible for allergic responses. This reduces the sensitivity of these cells to allergens, making the body less likely to have an allergic reaction when exposed to the food allergens in question.
This trial marks the second stage of a groundbreaking clinical study, which previously showed that omalizumab increased the tolerance of multi-food allergic children to allergens such as peanuts, eggs, milk, wheat, and tree nuts. The trial now compares the efficacy of omalizumab as a monotherapy versus its use as an adjunct to OIT.
Study Outcomes and Comparisons
The results highlighted that omalizumab was superior to OIT in treating multi-food allergy, especially for those with a very low tolerance to allergens. Despite receiving omalizumab before and during the early months of OIT, participants in Group A experienced numerous allergic reactions and side effects, leading to their discontinuation of therapy. In contrast, no participants in Group B, who only received omalizumab, had significant side effects that forced them to leave the study.
When evaluating only those participants who completed the treatment, the same proportion of both groups could tolerate at least 2 grams of peanut protein and their other allergens. However, the better tolerance in Group B participants who received omalizumab injections and placebo OIT points to the effectiveness of omalizumab over OIT, which often carries significant risks of adverse reactions.
Future Directions
The OUtMATCH study, led by experts like Robert Wood, M.D., and R. Sharon Chinthrajah, M.D., is still ongoing, with continued funding from the National Institute of Allergy and Infectious Diseases (NIAID), along with support from pharmaceutical companies like Genentech and Novartis. The results of this trial could have far-reaching implications for treating food allergies, especially for patients with multi-food allergies who currently face limited treatment options.
The trial’s success may lead to new, more effective, and safer treatments for food allergies, potentially changing the landscape of allergy therapy by offering a more tolerable and effective solution for individuals with multiple food allergies.
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