A new study finds that the asthma medication Xolair may substantially reduce severe allergic reactions in people who have multiple food allergies and are accidentally exposed to those foods.
Data published Sunday in the New England Journal of Medicine shows that repeated injections of the medication over the course of several weeks reduced the severity of allergic reactions in certain adults and children as young as 1 who are allergic to peanuts and other foods such as milk, egg and wheat.
The US Food and Drug Administration expanded its approval of omalizumab, which is marketed under the brand name Xolair, last week to include people with food allergies based on an interim analysis of the study.
By including several foods in the new study, the researchers were able to determine that Xolair could, in theory, reduce an allergic reaction if a person were to consume multiple foods that they're allergic to at one time, experts say.
"This is an amazing step forward in our field," said Dr Sharon Chinthrajah, a senior author of the study and an associate professor at Stanford University. "There's so much fear and anxiety that goes into everyday activities for food allergy patients or parents of a food allergy patient."
Xolair gives people with food allergies some protection against accidental exposure that could result in anaphylaxis, a serious and sometimes life-threatening allergic reaction that requires immediate medical treatment, including an epinephrine injection, she said.
"I have patients who are in their teens with just a peanut allergy who have never been allowed to eat in the restaurant because there's that much fear of the unknown," said Dr Robert Wood, lead author of the study and director of the Eudowood Division of Allergy, Immunology and Rheumatology at Johns Hopkins Children's Center.
There is no cure for food allergies, and the only other FDA-approved treatment is Palforzia, an oral immunotherapy for peanut allergies in children between 4 and 17 years old.
"But the reality is that most of our patients don't just have peanut allergy," Wood added. "Having something that's really agnostic to the specific food is going to cover far more food allergy patients."
Successful treatment in children
Xolair is developed and promoted by Genentech and Novartis in the US and was approved in 2003 to treat moderate to severe persistent allergic asthma.
For its approval for people with food allergy, the FDA required a phase 3 placebo-controlled trial including a "full dataset of peanut-allergic people," Wood says, because peanut allergies are among the most common food allergy, especially in children.
The foods used in the study were peanut, cashew, egg, milk, walnut, hazelnut and wheat, which are some of the most common allergens, Wood said.
For the study, which was funded by the National Institutes of Health, the researchers enrolled 180 people with a history of peanut allergy and at least two other food allergies. Each was randomly assigned to a group that got an omalizumab injection or a placebo every two to four weeks for 16 to 20 weeks.
All but three of the participants were 17 or younger, the researchers noted. The adults in the study were between 19 and 28, according to Wood.
When analyzing the results, the researchers looked at the 177 participants who were between the ages of 1 and 17.
"Out of our 177, 68 were ages 5 or below," Wood said, noting that before this trial, Xolair had never been studied below the age of 6.
This is especially important, the researchers say, because the prevalence of food allergy peaks at 1 to 2 years old.
"To have a large group of study participants in the very youngest age group was very meaningful," Wood said. "We know a lot about this drug from all its years of use in asthma, but the safety of young children has not been studied, so that was an important reassuring aspect of the study."
A total of 118 participants were given omalizumab while 59 were given a placebo.
After 16 weeks of treatment, the study showed 79 of the 118 - about 67% - who were given omalizumab met the primary endpoint criteria, meaning they were able to tolerate at least 600 milligrams or more of peanut protein, which is equal to about 2.5 peanuts.
By comparison, about 7% of participants - four of 59 - who received placebo injections met that criteria.
Of the omalizumab group, 44% were able to successfully consume a cumulative dose of 6044 milligrams of peanut protein, equivalent to about 25 peanuts, the researchers found.
Participants who received omalizumab were also more likely to tolerate other allergens such as cashew, egg and milk than the placebo group, the study said.
"The trial also has limitations," the researchers note. "Only three adults were included, and the cohort was mostly non-Hispanic and White, which could reduce the generalizability of the results."
How safe is Xolair?
For some people with food allergies, Xolair is safer than oral immunotherapy treatments, according to Dr Thomas Casale, a professor of medicine and pediatrics at the University of South Florida Tampa and a past president of the American Academy of Allergy Asthma and Immunology, who was not involved with the new study.
Xolair "provides as much protection or more protection" than the FDA-approved peanut drug, Palforzia, Casale says, which essentially works by exposing children to controlled dosages of peanut protein until they've reached a maintenance level.
Xolair does not expose users to a specific allergen and has been given to patients ahead of oral immunotherapy treatments to prevent adverse events, Casale says.
Unlike oral immunotherapy, Xolair is an anti-IgE injection, according to Wood. "IgE is an antibody that our immune system makes, and it is specifically related to developing allergy."
Once our bodies makes IgE antibodies that respond to a specific allergen, such as milk or peanut, a full-blown allergic reaction is triggered when those antibodies are exposed to that food, Wood said. "The purpose of Xolair is to bind and block those IgE antibodies, preventing an allergic reaction."
Wood adds that Xolair's safety is underlined by the fact that many people with asthma who receive the drug also have food allergies, and it treats both conditions.
Xolair's side effects include reactions at the injection site and fever, the FDA notes.
A 'lifelong' commitment?
For people who have multiple severe food allergies and even moderate to severe allergic asthma, Casale says, Xolair might be the best treatment option. But for those with milder allergic reactions, the medication may not be worth the cost.
For food allergy treatment, the estimated list price for Xolair ranges from about US$2900 for children to US$5000 for adults each month, according to Genentech.
"The actual cost paid by most patients is typically lower based on their insurance coverage and other financial assistance programs available," Lindsey Mathias, a spokesperson for Genentech, previously told CNN.
The monthly cost will also vary from person to person depending on several factors including body weight and dose.
Omalizumab injections are given in 75- to 600-milligram (mg) doses once every two or four weeks by a health care provider or at home through self-injection, according to Novartis. Dose and dosing frequency are determined by a patient's weight.
Chinthrajah says more research is needed on who would be the best candidate for Xolair and how long they would need to use it.
"We're not there in the field yet, to be able to identify who is the most severe phenotype and how do we protect them right now," she said.
People who aren't sure whether they should seek out Xolair for themselves or their children should weigh the pros and cons with their doctor, Casale says.
"The other thing to keep in mind with these biologics: They only work when you get them," he said.
Xolair does not eliminate food allergies, and unlike with some environmental allergies such as pollen, many people never outgrow them, Casale added.
"If you're on this drug and it only works when you get it, then you're talking about a potentially lifelong therapy."
CNN
