A drug designed to reduce allergic reactions to more than one type of food has been approved by the US Food and Drug Administration (FDA) for the first time, the organization announced on February 16.

Plenty of treatments targeting individual food allergens have been trialed in the past – but this is the first drug to tackle multiple at once to gain FDA approval, reducing the severity of allergies to foods including peanuts, milk, and eggs in just one shot.

Xolair, or omalizumab, is an injectable monoclonal antibody treatment, which contains immune proteins that bind to the molecule immunoglobulin E (IgE), known to trigger allergic reactions. By prohibiting IgE from binding to its receptors, the drug can curtail Type I reactions, reducing the risk of anaphylaxis upon exposure to multiple foods.

However, Xolair – approved for use in certain adults and children 1 year or older – is not intended for the immediate, emergency treatment of allergic reactions. Instead, it is recommended for repeat use to reduce the likelihood of severe reactions occurring and minimize the risks if they do. 

Injections every two to four weeks serve as a preventative measure to enable patients to build tolerance to food allergens. Importantly, people on the drug should continue to avoid foods they’re allergic to.

Xolair was initially approved for the treatment of allergic asthma in 2003, and is also approved for use in people with chronic spontaneous urticaria and chronic rhinosinusitis with nasal polyps.

“This newly approved use for Xolair will provide a treatment option to reduce the risk of harmful allergic reactions among certain patients with IgE-mediated food allergies,” Dr Kelly Stone, associate director of the Division of Pulmonology, Allergy, and Critical Care in the FDA’s Center for Drug Evaluation and Research, said in a statement. 

“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 approval comes off the back of a successful clinical trial, which saw 67 percent of subjects with a peanut allergy and at least two other food allergies able to eat a single dose of peanut protein without moderate to severe allergic symptoms. This is compared to just 7 percent in the control group. Similar rates of improvement were observed when assessing people's reactions to cashews, milk, and eggs.

However, 17 percent of people had no significant change in their peanut protein tolerance. “As a result, continuation of strict allergen avoidance is still necessary, despite treatment with Xolair,” the FDA added.

Side effects included injection site reactions and fever, and the drug’s label cautions against anaphylaxis, malignancy, fever, joint pain, rash, and parasitic (worm) infection.

As a result, the FDA states Xolair should only be started in a healthcare setting and only for those without a history of known severe hypersensitivity to Xolair or any of its components.

Still, for those with food allergies – around 6 percent of people in the US, according to the Centers for Disease Control and Prevention – Xolair could offer a much-needed new treatment option.