Previous studies provided proof of concept that peanut oral immunotherapy could be given safely to young children and have a therapeutic effect.
A recent clinical trial conducted by the National Institutes of Health (NIH) has found that giving oral immunotherapy to highly peanut-allergic children between 1 and 3 years of age safely desensitized them to peanut exposure and induced remission of peanut allergy in one-fifth of the patients, according to an NIH press release.
The immunotherapy consisted of a daily oral dose of peanut flour of 2.5 years. In this trial, remission was defined as being able to eat 5 grams of peanut protein, equivalent to 1.5 tablespoons of peanut butter, without having an allergic reaction 6 months after completing immunotherapy. The youngest children and those who started the trial with lower levels of peanut-specific antibodies were most likely to achieve remission, according to the study.
“The landmark results of the IMPACT trial suggest a window of opportunity in early childhood to induce remission of peanut allergy through oral immunotherapy,” said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, part of NIH, in the press release. “It is our hope that these study findings will inform the development of treatment modalities that reduce the burden of peanut allergy in children.”
The IMPACT trial sought to evaluate the potential of oral immunotherapy to change the immune system, as well as whether providing peanut oral immunotherapy early in life when the immune system is still maturing could modify a child’s immune response to peanut. Previous studies provided proof of concept that peanut oral immunotherapy could be given safely to young children and have a therapeutic effect, according to the press release.
Approximately 150 children between 1 and 3 years of age participated in the IMPACT trial at 5 academic medical centers in the United States. Only children who had an allergic reaction after eating a half-gram of peanut protein or less were eligible to join the study. Each child was assigned at random to receive either flour containing peanut protein or a placebo flour of similar appearance.
The flours were then mixed with foods such as applesauce or pudding to help mask their taste, and no one except a site pharmacist and a site dietician knew who received peanut flour or placebo flour until all data were gathered and the study visits ended.
The children in the treatment group ate gradually escalating daily doses of up to 2 grams of peanut protein, equivalent to approximately 8 peanuts, during a 30-week period. Consumption of the daily dose of peanut or placebo flour for an additional 2 years then continued.
Next, the children endured an oral food challenge in which they received gradually increasing doses of peanut protein up to a cumulative maximum of 5 grams, following a stop of treatment and avoiding peanuts for 6 months.
Finally, the children underwent a repeat oral food challenge with 5 grams of peanut protein. The children who did not have an allergic reaction during the challenge were later fed 8 grams of peanut butter, equivalent to 2 tablespoons, on a different day to confirm that they could eat peanut without having an allergic reaction.
The end of the treatment period showed that 71% of children who had received peanut flour were desensitized to peanuts compared to only 2% of those who had received the placebo flour. Desensitization in this trial was defined as being able to eat 5 grams of peanut protein during the first oral food challenge without having an allergic reaction.
After 6 months of peanut avoidance following treatment, 21% of children who had received peanut flour could eat 5 grams of peanut protein during the second oral food challenge without having an allergic reaction and were in remission. Conversely, only 2% of children who had received placebo flour were in remission at that time.
The researchers found that lower levels of peanut-specific immunoglobulin E antibodies at the start of the trial and being younger predicted whether a child would achieve remission. An analysis also found an inverse relationship between the age at the start of the trial and remission, with 71% of 1-year-olds, 35% of 2-year-olds, and 19% of 3-year-olds experienced remission.
Most reactions in the trial were mild to moderate in severity, although approximately all the children who received peanut flour had at least 1 dose-related reaction during treatment. Further, 21 children received the rescue drug epinephrine for 35 moderate reactions to peanut flour during the 2.5-year treatment period.
Oral immunotherapy induces remission of peanut allergy in some young children. NIH. January 20, 2022. Accessed January 24, 2022. https://www.nih.gov/news-events/news-releases/oral-immunotherapy-induces-remission-peanut-allergy-some-young-children