The US Food and Drug Administration (FDA) has approved omalizumab injection (Xolair, Genentech) for children aged 1 year or older and adults to reduce immunoglobulin E─mediated severe allergy to multiple food items.
Omalizumab is intended for repetitive use to lower the risk for allergic reactions. However, it is important to note that it has not been approved for the immediate emergency treatment of individuals with allergic reactions, including anaphylaxis. Individuals on omalizumab must continue avoiding foods to which they are allergic.
Initially approved in 2003 for the treatment of moderate to severe persistent allergic asthma in specific patients, omalizumab's applications have expanded over the years. It has now also been approved for treating chronic spontaneous urticaria and chronic rhinosinusitis with nasal polyps in certain patients.
Omalizumab, a monoclonal antibody, acts by preventing immunoglobulin E from binding to its receptors.
Almost 6% of people in the United States were diagnosed with food allergies in 2021. There is currently no cure for food allergy. The standard treatment involves strict avoidance of allergenic foods and prompt administration of epinephrine in the event of accidental exposures.
"This newly approved use for Xolair will provide a treatment option to reduce the risk of harmful allergic reactions among certain patients with Ig E-mediated food allergies," said Kelly Stone, MD, PhD, associate director of the Division of Pulmonology, Allergy, and Critical Care in the FDA's Center for Drug Evaluation and Research, in a news release. "While it will not eliminate food allergies or allow patients to consume food allergens freely, its repeated use will help reduce the health impact if accidental exposure occurs."
The recent approval was based on a multicenter, double-blind, placebo-controlled study of 168 pediatric (at least 1 year of age or older) and adult patients who were allergic to peanuts and at least two other foods, including milk, eggs, wheat, cashews, hazelnuts, or walnuts. The researchers randomly assigned patients to receive either omalizumab or placebo treatment for 16-20 weeks. The primary outcome was the percentage of patients who were able to eat at least 600 mg of peanut protein (equivalent to 2.5 peanuts) without moderate to severe allergic symptoms at the end of the 16-20-week treatment course.
Overall, 68% (75 of 110 patients) in the omalizumab group could eat at least 600 mg of peanut protein without moderate to severe allergic symptoms compared with only 6% (3 of 55 patients) in the placebo group. It is noteworthy that 17% of the individuals who were administered omalizumab experienced no substantial alteration in their tolerance to peanut protein, being unable to tolerate ≥ 100 mg of peanut protein. Therefore, it is still necessary to continue strict allergen avoidance despite treatment with omalizumab.
A higher proportion of patients taking omalizumab vs placebo were able to consume at least 1000 mg of cashews (42% vs 3%), milk (66% vs 11%), or eggs (67% vs 0%) without experiencing moderate to severe allergic symptoms.
The most common side effects were injection site reactions and fever. Omalizumab comes with certain warnings and precautions such as anaphylaxis, malignancy, fever, joint pain, rash, parasitic (worm) infection, and abnormal laboratory tests.
A boxed warning highlights the potentially life-threatening nature of anaphylaxis, which has been reported after the first dose, as well as beyond 1 year post-initiation of treatment. Treatment initiation is recommended in a healthcare setting equipped to manage anaphylaxis. Selected patients who can tolerate the initial omalizumab treatments without experiencing anaphylaxis may be suitable for self-administration, subject to discussion with a healthcare provider.