A study led by Johns Hopkins Children’s Center shows omalizumab — an injectable, Food and Drug Administration (FDA)-approved medication for treating asthma and other allergic conditions — substantially reduced potentially life-threatening reactions in patients with an allergy to peanut and other common food allergies.
A report on the first stage of a three-stage study, which was funded by the National Institutes of Health (NIH), was published February 25 in The New England Journal of Medicine and was presented February 25 at 1:45 p.m. EST during a late breaking symposium at the American Academy of Allergy, Asthma & Immunology annual meeting in Washington, D.C. The FDA recently approved omalizumab for treatment of multiple food allergies following an interim analysis based on this study.
In the study, investigators compared the effects of 16–20 weeks of omalizumab injections with placebo injections in 180 participants ranging from age 1 to 55 with a history of peanut allergy and at least two other food allergies. The subjects were randomly assigned to receive omalizumab or placebo. All but three of the participants were age 17 or younger.
Researchers found after 16 weeks, 66.9% of patients treated with omalizumab were able to tolerate 600 milligrams (mg) or more of peanut protein — equal to about 2.5 peanuts, compared with 6.8% of participants who received placebo injections. The researchers also found that omalizumab injections increased participants’ threshold reactivity not just to peanuts but to other common food allergens — milk, eggs, wheat, cashews, walnuts and hazelnuts — to levels that would protect most patients from reactions after accidental exposure.
“A majority of people not only reached the primary endpoint of 600 mg or more of peanut, an amount that exceeds most accidental exposures, but also the majority of participants tolerated 4,000 mg of peanut protein, which is equivalent to about 15 peanuts,” says Robert Wood, M.D., director of the Eudowood Division of Allergy, Immunology and Rheumatology at Johns Hopkins Children’s Center, and the study’s principal investigator. . In addition, almost 50% of participants who received omalizumab were able to successfully eat a cumulative dose of 6,044 mg of peanut protein — which is equal to about 25 peanuts.
During the study, omalizumab also significantly increased the reaction threshold for tree nuts, milk, eggs and wheat. About 69% of participants could tolerate a cumulative dose of 1,044 mg of two foods, and 47% were able to tolerate a cumulative dose of 1,044 mg of three foods.
The research team also assessed the effects of longer periods of omalizumab treatment. The first 60 participants entered a 24-week extension phase of the study. Researchers found most participants’ reaction threshold remained the same or increased when they continued receiving omalizumab during this period. Researchers also studied the safety of omalizumab with, they say, reassuring results that are similar to what is known for the medication’s use for other conditions. They say this is important since the medication had never been studied in children as young as 1 year of age.
The investigators caution that while the overall study indicates the benefits and safety of omalizumab to treat food allergies, there was substantial variability in response among individual participants. For example, 14% of subjects did not tolerate even 30 mg of peanut. Therefore, patients will still need to avoid the foods to which they are allergic even when treated, and continue to carry self-injectable epinephrine. The researchers also note that the study was limited in that participants were mostly non-Hispanic and Caucasian, and that future studies would be needed to assess the drug’s effectiveness in more diverse populations.
