Can omalizumab (Xolair) injections be used to treat IgE‑mediated food allergy?

Omalizumab (Xolair) for IgE-Mediated Food Allergy

Yes, omalizumab is FDA-approved for reducing allergic reactions, including anaphylaxis, from accidental food exposure in patients aged 1 year and older with IgE-mediated food allergy, and must be used alongside continued food allergen avoidance. 1

FDA-Approved Indication

• Omalizumab received FDA approval specifically for reducing Type I allergic reactions, including anaphylaxis, that may occur with accidental exposure to one or more foods in adult and pediatric patients aged ≥1 year with IgE-mediated food allergy 1
• This is NOT a treatment for emergency allergic reactions or anaphylaxis—patients must still carry epinephrine and avoid known food allergens 1
• The approval represents the only currently available drug that can mechanistically reduce IgE-mediated food allergic reactions 2

Dosing for Food Allergy

• Dosing is individualized based on baseline serum total IgE level (IU/mL) and body weight (kg), using specific dosing tables provided in the FDA label 1
• The dose is administered subcutaneously every 2 or 4 weeks depending on the calculated dose 1
• Total IgE levels remain elevated during and up to one year after treatment, so retesting IgE during therapy cannot guide dose adjustments 1

Critical Safety Requirements

Anaphylaxis Risk with Omalizumab Itself

• Anaphylaxis occurs in approximately 0.09-0.2% of patients receiving omalizumab, with reactions potentially occurring after the first dose or even beyond one year of regular treatment 3, 4, 5
• Mandatory observation periods: 2 hours after each of the first 3 injections, then 30 minutes after subsequent injections—this captures 75% of anaphylactic reactions 4, 5
• All patients must carry an epinephrine autoinjector for 24 hours following each injection, as reactions can occur up to 4 days later 4
• Omalizumab must be initiated in a healthcare setting with providers prepared to manage life-threatening anaphylaxis 1

Patient Selection Criteria

• Patients must have documented IgE-mediated food allergy with positive skin testing or specific IgE to the relevant food allergen 1
• Baseline serum total IgE levels should fall within the dosing table ranges (generally 30-1500 IU/mL depending on weight) 1

Clinical Efficacy Evidence

Monotherapy for Food Allergy

• Omalizumab monotherapy significantly increases the tolerated dose of multiple foods compared to pre-treatment baseline 6
• It increases the threshold of tolerated doses for milk, egg, wheat, and baked milk 6
• Treatment improves quality of life and reduces food-induced allergic reactions 6

As Adjunct to Oral Immunotherapy

• When combined with oral immunotherapy (OIT), omalizumab allows significantly higher rates of desensitization and enables patients to tolerate higher allergen doses in shorter timeframes compared to OIT alone 7, 6
• Omalizumab reduces adverse reactions during OIT, including anaphylaxis, and improves treatment adherence 7, 8
• The combination supports high-dose desensitization and higher maintenance doses compared to placebo plus OIT 6

Important Clinical Caveats

• Long-term sustainability of tolerance after omalizumab discontinuation remains uncertain—this is not a cure 7
• Omalizumab is used in conjunction with continued food allergen avoidance, not as a replacement for avoidance strategies 1
• The drug does not eliminate the need for emergency epinephrine for accidental exposures 1
• Cost is substantially higher than conventional allergy medications, though reduction in severe reactions may offset expenses 5

Mechanism of Action

• Omalizumab is a recombinant humanized monoclonal antibody that selectively binds free circulating IgE 3
• This binding decreases IgE receptor expression on mast cells, basophils, and dendritic cells, preventing the allergic cascade 3
• The drug reduces mediator release from effector cells, thereby dampening allergic responses 9