Drug Could Stop Life-Threatening Food Allergies in Millions

A drug used for asthma has been found to treat food allergies “shockingly well”, in a breakthrough that could offer new protection for millions affected.

This is the discovery of Northwestern Medicine scientists, who have revealed the already FDA-approved drug nearly eliminated life-threatening allergic reactions to food allergens in mice.

Around 33 million people in the U.S. have at least one food allergy—that is nearly one in 10 adults and one in 13 children.

While just over half of all adults and 42 percent of children with food allergies have experienced a severe reaction, predicting an individual’s risk of this happening and preventing it remains challenging.

Currently, the only two FDA-approved treatments for certain food allergies are an oral immunotherapy for peanut allergy (which doesn’t work for everyone and can itself trigger anaphylaxis, according to the researchers) and an expensive injection called omalizumab (which also isn’t effective for everyone.)

While anaphylaxis is currently primarily treated with epinephrine (adrenaline), it’s hoped the asthma drug called Zileuton could offer a simple pill that temporarily shields allergic individuals by blocking the body’s anaphylactic pathway before it activates.

“It was actually shocking how well Zileuton worked,” said Dr. Stephanie Eisenbarth, study author and Allergy and Immunology chief at Northwestern’s Feinberg School of Medicine, in a statement.

“After treatment with Zileuton, 95 percent of the mice showed almost no symptoms of anaphylaxis. The treatment reversed their risk from 95 percent susceptible to 95 percent protected,” added Adam Williams, study author and allergy and immunology professor at Feinberg, in a statement.

The revelation came after the researchers identified, in mice, a previously unknown role for a gene called DPEP1, which they found was essential in regulating anaphylaxis, a potentially fatal and rapid allergic reaction.

By using Zileuton to block the pathway involving this gene, the scientists nearly eliminated allergic responses in mice that were previously highly susceptible to food-induced anaphylaxis.

The mice were given peanut extract orally—peanuts being the most common cause of anaphylaxis due to food in people—shortly after receiving Zileuton.

“For the past decade we have been working to understand why some people with a positive blood test for a food allergy have no symptoms when they eat that allergen, whereas others have severe allergic reactions (anaphylaxis),” Eisenbarth and Williams told Newsweek.

“The goal is to find ways to make people with symptomatic food allergy tolerate exposure to allergens. We had many theories about what could provide this form of protection but none could explain it.

“So, we turned to an unbiased approach to potentially discover unexpected pathways. Through a genetic screen we found DPEP1 and the leukotriene pathway.”

The newly identified pathway followed a ‘forward genetic screen’ lasting a year, a research method where scientists breed generations of mice to determine the specific genes responsible for biological differences like susceptibility to food allergy.

Once they found the DPEP1 gene controlled inflammatory molecules called leukotrienes in the gut (inflammatory molecules already targeted by asthma drugs), they tested Zileuton, which blocks their production. “The idea that absorption of intact allergens is constantly regulated in the gut by this leukotriene pathway is completely unexpected,” said Eisenbarth and Williams.

They hope their findings pave the way for better preventative methods, rather than treating the symptom.

“The idea is to take a single dose right before a potential exposure to prevent anaphylaxis, rather than a drug (e.g., epi-pen) to treat a reaction after it has started. We see this especially valuable in ‘high risk’ situations in which accidental allergen exposures are more likely, such as getting on a flight, going to a restaurant, or a child attending a birthday party,” the study authors explained.

“It is important to emphasize that so far, we only have data from mouse models. Our current clinical trial [which started last month] will test whether this could also work in humans. Because we do not know how continuous treatment would affect the gut or the immune system, we are not considering this a daily treatment.”

The researchers said that they didn’t observe any side effects in the mouse study. They added: “Rarely in people, this drug has induced changes in liver function tests when taken continuously, but we only give one single dose, and therefore such reactions would be unlikely.”

“This is a totally different, out-of-the-box approach to treat food allergy, unlike anything we’ve tried before,” Williams noted.

Current diagnostic tests only estimate allergy risk, not tolerance. While the researchers believe some people are naturally protected, this is also an area for further research.

“The clinical trial is the first step in testing whether we can block food allergen absorption in people through the same pathways. If the answer is yes, the next step would be to test whether people with food allergy are protected from anaphylaxis,” the researchers concluded.

“But there are a lot of other exciting questions, like whether this pathway is regulated by things in our environment such as changes in the microbiome induced by diet.”

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Reference

Hoyt, L. R., Liu, E., Olson, E. C., Jacobsen, D. R., Siniscalco, E. R., Krier-Burris, R. A., Greenfield, K. G., McBride, C. D., Alfajaro, M. M., Amat, J. A. R., Zhao, Z., Xu, L., Philip, V., Verma, A., Fourati, S., Senger, D. L., Zhang, L., Bunyavanich, S., Glass, S. E., Coffey, R. J., Wilen, C. B., Williams, A., & Eisenbarth, S. C. (2025). Cysteinyl leukotrienes stimulate gut absorption of food allergens to promote anaphylaxis in mice. Science, 389(6656).