Omalizumab: First Approved Anti-IgE Therapy for Multiple Food Allergies

Approximately 10% of adults and 7.6% of children in the United States have food allergies. Allergic reactions to foods can be life threatening, which requires patients and caregivers to be constantly diligent in avoiding foods that may trigger an immune-mediated event. Until recently, the only FDA-approved treatment for food allergy was oral immunotherapy (OIT), which involves daily ingestion of small doses of antigen to gradually build up a patient's tolerance. This therapy can be burdensome, requiring multiple office visits, and it is not without serious risk, including anaphylaxis. Anti-IgE therapy with omalizumab has recently been approved as an alternative to OIT to reduce the risk of allergic reaction associated with IgE-mediated food allergy.

Omalizumab is an anti-IgE monoclonal antibody that has recently shown promising results for treating multiple food allergies in the first phase of the OUtMATCH clinical trial. This drug is administered by subcutaneous injection every 2-4 weeks based on a patient's weight and serum IgE levels. By binding and neutralizing serum IgE antibodies, omalizumab reduces the body's sensitivity to allergen exposure, allowing for an increased threshold dose of antigen exposure before an allergic reaction ensues.

Small clinical trials of anti-IgE therapy for the management of food allergies have been reported since 2003. Monotherapy with omalizumab has been reported to increase the tolerance threshold to various foods, including peanut, cow's milk, egg, and wheat. When combined with OIT, small trials have demonstrated that omalizumab facilitated the speed of desensitization and reduced the risk of adverse allergic reactions compared with OIT alone. The OUtMATCH trial is the largest trial to date, and it has demonstrated that omalizumab significantly increases the threshold dose for experiencing an adverse allergic reaction among subjects with allergies to multiple foods, including peanuts, cashew, milk, egg, walnut, wheat, or hazelnut.

Omalizumab is a novel treatment strategy for multiple food allergies. By increasing the tolerance to foods that induce allergies, patients may experience a reduced risk of immune-mediated reactions on accidental allergen exposure. Uncertainty remains about the ideal candidates for omalizumab, its comparative effectiveness, practical implementation, and long-term outcomes. Ongoing trials and future real-world data are expected to clarify these issues, including its impact on reducing anaphylaxis, ED visits, and hospitalizations. Patient-specific factors and available options should be discussed with the patient in the shared decision process as an essential component in choosing the therapeutic strategy.