Alpha-Gal Patients Allergy Drug Cut Reactions in 95% in Study
Researchers told an allergy conference that 95% of 64 alpha-gal patients taking omalizumab had fewer or milder reactions to red meat. The findings are unpublished, and one allergist warned the costly drug is meant to keep patients safe, not to let them eat meat again.
An allergy drug may reduce severe reactions in alpha-gal patients, according to a study presented Thursday at the annual meeting of the American College of Allergy, Asthma and Immunology. Researchers found that 95% of participants taking omalizumab saw meaningful reductions in the frequency or severity of their allergic reactions.
Alpha-gal syndrome is a red meat allergy triggered by a tick bite. The findings have not yet been published in a peer-reviewed journal.
The study included 64 people with confirmed alpha-gal diagnoses. They took omalizumab for an average of 23 months.
How the allergy develops
The condition is mainly linked to the lone star tick. The tick can pick up a sugar molecule called alpha gal from the blood of mammals such as cows, deer, pigs and goats. If it then bites a human, it can pass the sugar on.
In some people, that triggers an allergic reaction to red meat and, in some cases, gelatin and dairy products. Reactions range from hives to severe stomach pain to life-threatening anaphylaxis. Doctors typically advise patients to avoid red meat, meat-based soups and gravies, and to consider avoiding gelatin or dairy.
What the drug does
Omalizumab, sold as Xolair, is already approved for people with severe food allergies, including peanut, egg and dairy. It targets immunoglobulin E (IgE), the antibody that drives allergic reactions, and removes it from the bloodstream.
"If you have less IgE, it's going to take a much higher dose of an allergen to trigger a reaction," said Dr. Erin McGintee, an allergy and immunology specialist at ENT & Allergy Associates and a tick-borne disease adviser at Stony Brook Medicine.
The drug is not a cure, and patients still need to avoid the foods they are allergic to. It acts as a safety layer, turning a potentially severe reaction after accidental exposure into a more manageable one.
Dr. Collette Tilly, an allergy and immunology fellow at the University of North Carolina at Chapel Hill who led the study, said the findings suggest omalizumab "may offer an important additional option for patients who continue to experience reactions."
A patient's experience
Candice Matthis, 46, of Charlottesville, Virginia, was diagnosed in 2019 after 12 years of symptoms. She later co-founded the nonprofit Alpha-Gal Foundation. She was not part of the study.
Doctors prescribed her omalizumab for other food allergies, and she has taken it for a year. "It's definitely helped with my reactivity," she said. She recalled accidentally drinking whole milk in a coffee: "My stomach hurt a little bit, but I didn't have anaphylaxis."
Caution on use
McGintee, who was not involved in the study, called the data "really exciting and encouraging." She cautioned against using the drug to let alpha-gal patients eat red meat again.
"This is a pharmaceutical product that's not inexpensive," she said. "The purpose of it is to keep people safe and prevent life-threatening allergic reactions."
Eight people in the study were able to fully incorporate red meat into their diets again. Tilly cautioned against reading that as evidence that omalizumab can lead to remission of alpha-gal syndrome.
