Sandra Hong, MD, chair of allergy and immunology and director of the Food Allergy Center of Excellence at Cleveland Clinic, in Ohio, sees firsthand how situations that feel ordinary to most people strike fear in the hearts of her patients with food allergies.
Not only do some experience reactions to milk when they eat a cheese pizza — they can’t be in the same room with someone enjoying a slice nearby. “That would be terrifying,” Dr. Hong said.
Omalizumab (Xolair), recently approved by the US Food and Drug Administration as monotherapy for the treatment of food allergies, may now bring peace of mind to these patients and their families by reducing their risk of dangerous allergic reactions to accidental exposure.
While the drug does not cure food allergies, a phase 3, placebo-controlled trial found that after 16 weeks of treatment, two thirds of participants were able to tolerate at least 600 mg of peanut protein — equal to about 2.5 peanuts — without experiencing moderate to severe reactions.
An open-label extension trial also found the monoclonal antibody reduced the likelihood of serious reactions to eggs by 67%, milk by 66%, and cashews by 42%. The results of the study were published in The New England Journal of Medicine.
The treatment is approved for children as young as the age of 1 year and is the only treatment approved for multiple food allergies. It does not treat anaphylaxis or other emergency situations.
Patient Selection Key
While 8% of children and 10% of adults in the United States have a true food allergy, Brian Vickery, MD, chief of allergy and immunology and director of the Food Allergy Center at Children’s Healthcare of Atlanta, noted that a significantly higher proportion of the population restricts their diet based on perceived food intolerances.
“Most important for family doctors prior to prescribing the medication will be to be sure that the diagnosis is correct,” Kim said. “We know that allergy blood and skin testing is good but not perfect, and false positive results can occur,” said Edwin Kim, MD, chief of the Division of Pediatric Allergy and Immunology and director of the University of North Carolina Food Allergy Initiative at the University of North Carolina School of Medicine, Chapel Hill, who was a coauthor on the study in the New England Journal of Medicine. “ An allergist can conduct food challenges to confirm the diagnosis if results are unclear.”
Even for patients with confirmed IgE-mediated allergies, Dr. Hong said selecting patients who are good candidates for the therapy has “nuances.”
Patients must be willing and able to commit to injections every 2-4 weeks. Dosing depends on body weight and the total IgE levels of each patient. Patients with IgE levels > 1850 UI/mL likely will be disqualified from treatment since the clinical trial did not enroll patients with total IgE above this level and the appropriate dose in those patients is unknown.
“My recommendation for family physicians who are counseling food-allergic patients interested in omalizumab treatment is to partner with an allergist-immunologist, if at all possible,” Dr. Vickery said. He added that patients should have a comprehensive workup before beginning treatment because starting omalizumab would reduce reactivity and alter the outcome a diagnostic oral food challenge.
Two populations Dr. Hong thinks might particularly benefit from the therapy are college students and preschoolers, who may be unable to completely avoid allergens because of poor impulse control and food sharing in group settings.
“The concerns we have about this age group are whether or not there might be other factors involved that may impede their ability to make good decisions.”
Less control of the environment in dorms or other group living situations also could increase the risk of accidental exposure to a food allergen.
For the right patients, the treatment regimen has significant advantages over oral immunotherapy treatment (OIT), including the fact that it’s not a daily medication and it has the potential to treat allergic asthma at the same time.
“The biggest pro for omalizumab is that it can treat all of your food allergies, whether you have one or many, and do it all in one medication,” Dr. Kim said.