New Drug
Lauren Howell, PharmD
On February 16, 2024, FDA approved the first medication indicated to help reduce allergic reactions to more than one type of food after accidental exposure. Xolair (omalizumab—Genentech) injection is approved for the reduction of type I allergic reactions, including reducing the risk of anaphylaxis that may occur with accidental exposure to one or more foods in adults and children 1 year or older.
While this breakthrough for individuals with food allergies does not mean that they can consume allergens freely, it does mean that repeated use of the medication can help to reduce allergic reactions if accidental exposure occurs. Xolair was previously approved to treat allergic asthma, chronic spontaneous urticaria, and chronic rhinosinusitis in certain patients, but this new indication provides a treatment option for those with food allergies, for which there is currently no cure.
Recommended dosage and administration
The recommended dosage of Xolair is 75 mg to 600 mg administered subcutaneously every 2 or 4 weeks. The exact dose and dosing frequency should be determined based on a serum total immunoglobulin E (IgE) level measured before the start of treatment and body weight. If significant changes to body weight occur during treatment, the dose should be adjusted.
During treatment, total IgE levels are elevated and can remain elevated for up to 1 year after Xolair is discontinued. Because of this, retesting of serum IgE levels during treatment should not be used to adjust the dose that the patient receives.
If there is an interruption in treatment that lasts less than 1 year, the dose given should be based on the serum IgE levels that were obtained at the initial dose determination. If treatment is interrupted for 1 year or longer, total serum IgE levels should be retested and a new dosing determination should be made.
Xolair is indicated to be used in conjunction with food allergen avoidance and is not intended to replace it. It is also not indicated for the emergency treatment of allergic reactions, including anaphylaxis.
Adverse effects, warnings, and precautions
Xolair carries a boxed warning for anaphylaxis presenting as bronchospasm, hypotension, syncope, urticaria, or angioedema of the throat or tongue. This anaphylaxis can occur after the first dose of Xolair but may also occur 1 year after beginning regularly administered treatment.
Due to this risk, Xolair should be administered in a health care setting and patients should be closely observed after administration. Once therapy has been safely established, the health care provider may determine whether self-administration by the patient or caregiver is appropriate based on assessment of risk for anaphylaxis and mitigation strategies.
The most common adverse reactions in patients receiving Xolair for treatment of IgE-mediated food allergy are pyrexia and injection site reactions. Malignancies have been observed in clinical studies. Corticosteroids should not be abruptly discontinued upon initiation of Xolair therapy.
Be alert to eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and neuropathy, especially when oral corticosteroid dose reduction occurs. Stop Xolair if patients develop signs and symptoms such as serum sickness, including fever, arthralgia, and rash.
Clinical studies
The safety and efficacy of Xolair were evaluated in a multicenter, randomized, double-blind, placebo-controlled food allergy trial that included 168 patients ranging between 1 year and 56 years old. These patients were allergic to peanuts and at least two other foods, including milk, egg, wheat, cashew, hazelnut, or walnut, and experienced dose-limiting symptoms (e.g., moderate to severe skin, respiratory, or GI symptoms) to a single dose of up to 100 mg of peanut protein and up to 300 mg protein of each of the other two foods. Patients with a history of severe anaphylaxis were not included in the study.
Patients were randomized to either receive Xolair or placebo for 16 to 20 weeks. The primary efficacy endpoint was the percentage of patients who were able to consume a single dose of at least 600 mg of peanut protein without dose-limiting symptoms (68% in the Xolair treatment group and 5% in the placebo group).
Similar results were seen when patients were exposed to a single dose of at least 100 mg of cashew, milk, or egg protein. Xolair treatment led to statistically higher response rates than placebo for all three foods. ■