Review of Omalizumab (XOLAIR) for Multiple Food Allergies

In 2024, the Food and Drug Administration (FDA) extended the approval of omalizumab (XOLAIR) to include reducing allergic reactions, such as anaphylaxis, that may occur with accidental exposure to one or more foods in adults and children aged 1 and older with food allergies.[1] Omalizumab, a monoclonal antibody, is the first drug approved to reduce allergic reactions to multiple food allergens after accidental exposure.

The FDA first approved omalizumab in 2003 for moderate to severe persistent allergic asthma in adults and children aged 6 and older. Subsequently, the agency approved omalizumab for chronic rhinosinusitis with nasal polyps in adults and chronic spontaneous urticaria in adults and children aged 12 and older. Omalizumab is not an emergency treatment for allergic reactions. Importantly, people must continue to avoid food allergens during treatment.

Food allergies affect 5% of children and 7% of adults in the United States. They are a common cause of anaphylactic reactions (systemic allergic reactions of any severity) and anaphylaxis (a sudden, potentially life-threatening, severe generalized allergic reaction).[2] To date, there is no cure and the only way to prevent allergic reactions is to strictly avoid food allergens.[3] Since avoidance is not always possible and accidental exposures can occur, all people at risk for severe food allergies should carry an epinephrine injector (ADRENACLICK, AUVI-Q, EPIPEN, EPIPEN JR, SYMJEPI or generics) for immediate treatment.

In 2020, the FDA approved an oral peanut allergy powder (PALFORZIA) to reduce allergic reactions in children after accidental exposure to peanuts.[4] Public Citizen’s Health Research Group designated Palforzia as a Do Not Use drug because its overall benefit-risk profile is unfavorable. Based on the variability of the benefits discussed below and the lack of long-term safety and efficacy data, we have designated omalizumab for food allergies as Do Not Use for Seven Years.

Omalizumab binds to and thereby reduces the serum concentration of an antibody called immunoglobulin E (IgE), which can trigger allergic reactions. The drug is injected subcutaneously (under the skin) every two to four weeks. The dose and dosing frequency is determined by patients’ IgE levels and body weight.

Omalizumab costs between $9,000 and $144,000 per year (depending on the dosing regimen)[5] and is one of 15 drugs in the current round of Medicare drug price negotiations.[6] The negotiated prices should go into effect in 2028.

Safety of omalizumab

Omalizumab has a boxed warning — the FDA’s most prominent warning — for anaphylaxis, which may be life-threatening and can occur at any time during therapy.[7] Moreover, omalizumab has been associated with serious adverse events such as malignancies, acute asthma symptoms, joint pain, rashes and eosinophilic conditions (including cardiac complications and neuropathy). For the treatment of food allergies, compared with placebo in clinical trials, the most common adverse effects of omalizumab were injection-site reactions (16% vs. 11%) and fever (6 % vs. 4%). For the treatment of multiple food allergies, the incidence of adverse events and serious adverse events in the omalizumab group (63% and 3%) and placebo group (78% and 2%) was comparable.[8]

Efficacy of omalizumab

The efficacy of omalizumab was assessed in a double-blind, randomized, placebo-controlled trial that included 165 children aged 1 to 17 years and three adults aged 19 to 24 years.[9],[10] All participants were allergic to peanuts and to at least two additional foods including cashew, egg, hazelnut, milk, walnut and wheat. At the beginning of the trial, during oral food challenges, all participants reacted to 100 milligrams (mg) or less of peanut protein and 300 mg or less of the other food allergens. Importantly, however, participants at high risk of anaphylactic reactions to food allergens were excluded.

The participants were randomized to receive either omalizumab or placebo subcutaneously every two to four weeks (depending on their weight and IgE serum levels). After 16 to 20 weeks, the food challenge tests were repeated.[11] Significantly more participants who received omalizumab (68%, as compared with 5% in the placebo group) tolerated a single dose of at least 600 mg of peanut protein (equivalent to about 2.5 peanuts) without moderate to severe symptoms (such as whole-body hives, vomiting or persistent coughing).

Participants in the omalizumab group also were significantly more likely than those in the placebo group to tolerate a single dose of at least 1,000 mg of peanut, cashew, egg protein and milk.[12] Omalizumab-treated participants also were more likely to be able to consume two or three food groups without reactions than those in the placebo group. For example, 39% of those who received omalizumab were able to consume a single dose of at least 1,000 mg of three foods, compared with none in the placebo group.

Response rates to treatment were highly variable, however.[13] For about 17% of participants with peanut allergy, the treatment failed: Even small amounts (at least 100 mg) of peanut protein could not be tolerated.[14]

Moreover, although omalizumab increased the reaction threshold to food for many participants in two small trials, treatment also led to decreased food-allergen tolerance in some participants,[15] and allergic reactions requiring treatment with antihistamines or epinephrine were frequent.[16] One of the studies was an open-label extension that included the first 60 participants in the clinical trial described above.[17]

The variable results of the clinical trials raise important questions about which patients might benefit from omalizumab treatment. For example, patients with low reaction thresholds to food may benefit more than those with high thresholds. Moreover, determining how long treatment is needed or whether treatment was even successful is difficult. Repeated oral food challenges, which are costly and time consuming, are necessary to assess reaction thresholds, especially across different food groups.[18],[19] Although omalizumab is approved for children as young as 1 year, long-term safety data for young children are not available. As allergies to several food allergens (such as milk and egg) are frequently outgrown during childhood, safety data are particularly relevant.

What You Can Do

If you or a family member has food allergies that affect health, avoid exposure to the foods to reduce or eliminate the risk of allergic reactions. If you are at risk of anaphylaxis, carry an epinephrine injector. Adequate data are not yet available to assess who would benefit from omalizumab treatment and when the benefits of treatment outweigh the risk of serious adverse events, including anaphylactic reactions. Until more data become available, Public Citizen’s Health Research Group recommends that you do not use omalizumab for seven years.
 

References

[1] Food and Drug Administration. FDA approves first medication to help reduce allergic reactions to multiple foods after accidental exposure. February 16, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-medication-help-reduce-allergic-reactions-multiple-foods-after-accidental. Accessed June 4, 2026.

[2] National Center for Health Statistics. Allergies. January 9, 2026. https://www.cdc.gov/nchs/fastats/allergies.htm#print. Accessed June 4, 2026.

[3] Nowak-Węgrzyn A. Food allergy management: Allergen-nonspecific therapies. UpToDate. Updated March 10, 2026.

[4] PALFORZIA: A burdensome peanut-allergen drug with serious risks and unknown long-term benefits.Worst Pills, Best Pills News. November 2023. https://www.worstpills.org/newsletters/view/1565. Accessed June 4, 2026.

[5] Omalizumab (Xolair) for food allergy. Med Lett Drugs Ther. 2024;66(1699):54-56.

[6] Centers for Medicare & Medicaid Services. CMS announces selection of drugs for third cycle of Medicare drug price negotiation program, including first-ever Part B drugs. January 27, 2026. https://www.cms.gov/newsroom/press-releases/cms-announces-selection-drugs-third-cycle-medicare-drug-price-negotiation-program-including-first. Accessed June 4, 2026.

[7] Genentech. Label: omalizumab (XOLAIR). February 2024. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/103976s5245lbl.pdf. Accessed June 4, 2026.

[8] Wood RA, Togias A, Sicherer SH, et al. Omalizumab for the treatment of multiple food allergies. N Engl J Med. 2024;390(10):889-899.

[9] Genentech. Label: omalizumab (XOLAIR). February 2024. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/103976s5245lbl.pdf. Accessed June 4, 2026.

[10] Wood RA, Togias A, Sicherer SH, et al. Omalizumab for the treatment of multiple food allergies. N Engl J Med. 2024;390(10):889-899.

[11] Genentech. Label: omalizumab (XOLAIR). February 2024. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/103976s5245lbl.pdf. Accessed June 4, 2026.

[12] Ibid.

[13] Ibid.

[14] Genentech. Label: omalizumab (XOLAIR). February 2024. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/103976s5245lbl.pdf. Accessed June 4, 2026.

[15] Wood RA, Togias A, Sicherer SH, et al. Omalizumab for the treatment of multiple food allergies. N Engl J Med. 2024;390(10):889-899.

[16] Tseng H, Wood RA, Isola J, et al. Oral food challenges after treatment with omalizumab in the clinical setting. J Allergy Clin Immunol Pract. 2026;14(5):1142-1152.e2.

[17] Wood RA, Togias A, Sicherer SH, et al. Omalizumab for the treatment of multiple food allergies. N Engl J Med. 2024;390(10):889-899.

[18] Nowak-Węgrzyn A. Food allergy management: Allergen-nonspecific therapies. UpToDate. Updated March 10, 2026.

[19] Sampson HA, Bird JA, Fleischer D, et al. Who are the potential patients for omalizumab for food allergy? Ann Allergy Asthma Immunol. 2024;132(5):569-571.