What’s the Data on Xolair for Food Allergies?

I have a toddler with severe food allergies. Is the new drug Xolair as life-changing as it seems?
—Skeptical and hopeful

I have written before— both in ParentData and Cribsheet — about preventing allergies in kids by early introduction of allergens. But even with early introduction, some kids will develop allergies, and some will be severe. In principle, people can be allergic to almost anything, but most food allergies in kids are caused by just a few things: peanuts, tree nuts, eggs, milk, soy.

For children or adults with severe food allergies, they can be incredibly scary and restrictive. We may imagine that it’s easy to deal with a peanut allergy by, say, not eating peanut butter sandwiches. But for someone with a severe version of this allergy, they may never be able to go to a restaurant, for fear of a severe reaction to something in the air. For this reason, there has been a lot of effort to develop treatments that would desensitize people to allergens. Not so they can eat a peanut butter sandwich but so they can go on an airplane or to a birthday party.

The one approved treatment for severe allergies is a medication called Palforzia, which is approved for treatment of peanut allergies. This medication is part of an approach called oral immunotherapy. It works by exposing children to small, but increasing, amounts of the allergen to develop a tolerance. I’ve written more about that treatment here.

The new medication Xolair is exciting because it promises a second possible treatment avenue and one that isn’t limited to peanuts. This medication — generic name omalizumab — is already approved and in use to treat some types of asthma and other conditions. It’s a monoclonal antibody that works by decreasing the reaction to allergens.

The big news is a new trial, published this week in the New England Journal of Medicine. This trial analyzed data from 177 children with severe food allergies. Inclusion in the trial required an allergy to peanuts plus to at least two other foods from a list (eggs, milk, cashews, wheat, hazelnuts, or walnuts). Put differently, this was a very allergic population. Two-thirds of the group received the treatment and one-third got a placebo. At the end of the study, the researchers evaluated whether the treatment group was less reactive to an allergen challenge. As is common in this type of study, it specified a particular amount of the allergen — someone “passed” if they were able to tolerate that amount, and not otherwise. The primary endpoint was based on tolerance of peanuts.

The medication was very effective. Two-thirds of the treatment group were able to tolerate the specified endpoint, versus just 7% of the placebo group. This is a large treatment effect, and the authors found similarly large impacts on other allergens.

This is — broadly — great news. Not only does it provide a possible treatment for kids over 1 with severe food allergies, but it also offers hope for further development of this type of treatment. These options are only likely to get better over time. This option may be more palatable to some parents than the existing oral immunotherapy, since severe reactions to the treatment were much less common.

A few caveats, though. First, although two-thirds of the treatment group responded, one-third did not. This treatment, at least at these doses, didn’t work for everyone. Second, even successful treatment doesn’t mean people can go out and eat a lot of the allergen. This is really a way to make accidental exposures less dangerous. Finally, this treatment is an injection given every two to four weeks, indefinitely. This may make it less palatable to children.

Overall, even with caveats, this is life-changing news for many families. Yay for a win for science!