While cancer and airborne allergies would seemingly go together like oil and water, a recent study led by investigators at Northwestern University Feinberg School of Medicine has uncovered that a drug typically used to treat certain types of leukemia and lymphoma can also prevent reactions to some of the most common allergic reactions. Findings from the new study—published recently in the Journal of Allergy and Clinical Immunology in an article entitled “Ibrutinib, a Bruton’s Tyrosine Kinase Inhibitor Used for Treatment of Lymphoproliferative Disorders, Eliminates Both Aeroallergen Skin Test and Basophil Activation Test Reactivity”—could also have even greater implications for adults with food allergies.
Researchers found that cancer patients who were allergic to allergens such as cat dander and ragweed saw their allergic skin test reactivity reduced by 80% to 90% in 1 week, and this persisted with continued use of the drug for at least 1 to 2 months.
“It almost completely knocked out the patients' skin test and blood cell allergic reactivity,” remarked senior study investigator Bruce Bochner, M.D., professor of medicine at Northwestern University Feinberg School of Medicine.
In the current study, Dr. Bochner and his colleagues performed traditional allergy skin tests and the basophil activation test, a related allergy test using blood cells, on cancer patients before they had taken the drug ibrutinib, 1 week after use, and again after 1 to 2 months of continued use. Ibrutinib is an FDA-approved drug currently on the market as a successful and less toxic alternative to chemotherapy for patients with chronic lymphocytic leukemia and mantle cell lymphoma.
Previous research on ibrutinib told the researchers that the compound was a generally well-tolerated cancer drug successful in blocking a protein within cells called Bruton's tyrosine kinase (BTK). BTK plays a crucial role in B-cell activation, growth, and maturation and mast cell and basophil activation, the latter two cells being responsible for immediate allergic reactions. The investigators focused on whether this BTK inhibitor could also shut down an enzyme inside cells that is involved when you have an allergic reaction.
“Ibrutinib is considered a game changer in these two types of cancers,” explained co-author Leo Gordon, M.D., professor of cancer research at Feinberg. “We understood that it might have some biologic effects in what Bruce is interested in, so we were happy to participate in his study. It's an interesting repurposing of that drug.”
While the study was small—only two patients qualified out of about 35 that were screened for allergies—the implications are much larger for later phases of this study. The Northwestern team is now testing how successful the drug is at targeting allergies to food, such as tree nuts and peanuts.
“Preventing or lessening the severity of an allergic reaction to the food you've ingested that you're allergic to is kind of the holy grail of food allergy treatment,” Dr. Bochner noted. “I don't know if this or similar drugs will ever make it possible for a peanut-allergic person to eat peanut butter and jelly sandwiches, but we're excited to use this approach to teach us how to lessen the risks of food allergy reactions.”
The expanded study is testing adults with food allergies to see if their skin test and basophil activation test responses show a similar reduction with just a few doses of ibrutinib and how long such benefits might last. If the results are favorable, the next step would be to get funding to actually test whether taking a BTK inhibitor will improve the ability of food-allergic adults to eat foods they're allergic to.
“The hope is that drugs like BTK inhibitors will protect people with food allergies from having anaphylaxis, or at least increase how much of that food they can eat without reacting,” Dr. Bochner concluded. “Maybe they'll increase from being able to eat just one peanut to 10 before they react. Or maybe they'll be able to eat a full meal's worth of peanuts. We want to know if this would safely change their actual ability to eat foods that they currently need to avoid.”