Scientists develop new way to treat potentially deadly peanut allergies

By Stephen Beech

A successful new way of treating children with a potentially deadly allergy to peanuts has been developed.

The method helps youngsters with the allergy to tolerate "tablespoons" of peanut butter within 18 months, say scientists.

The "very exciting" results have been hailed as "a huge step forward" in personalizing food allergy treatment.

Eating gradually increasing doses of shop-bought peanut butter enabled children with the allergy to safely consume peanuts, says an American research team.

Youngsters in a trial achieved "significantly higher and long-lasting" rates of desensitization compared to children who avoided peanuts, according to the study published in the journal NEJM Evidence.

Study lead author Professor Scott Sicherer said: “Our study results suggest a safe, inexpensive and effective pathway for allergists to treat children with peanut allergy who can already tolerate the equivalent of at least half a peanut, considered a high-threshold peanut allergy.

“Our findings open the gateway to personalized threshold-based treatments of food allergy and will encourage additional studies that delve deeper into peanut and other foods for this approach that might be a game-changer for the majority of people with food allergies.”

The most common approach to a food allergy is to avoid the food, but in recent years peanut oral immunotherapy—medically supervised, very gradual daily feeding of increasing amounts of pharmaceutical-grade peanut protein—has become an option for individuals with peanut allergies.

Study co-senior author Professor Julie Wang, of the Icahn School of Medicine, New York, said: “Years ago when people with milk and egg allergies were advised to undertake strict avoidance, our team initiated studies that found most people with milk and egg allergies could tolerate these foods in baked goods, which changed the global approach to these allergies.

“The research team recognized that more than half of people with peanut allergy can tolerate half a peanut or more, and thought that this group of people might be treatable if we took a different approach to peanut oral immunotherapy.

"We were thrilled to find that this treatment strategy was even more successful than we had anticipated.”

To test the hypothesis, the research team recruited 73 children, aged four- to 14 years old, who were assigned, at random, to either test the new treatment method or continue avoiding peanuts.

The children in the peanut ingestion group began with a minimum daily dose of one-eighth of a teaspoon of peanut butter and gradually increased their dose every eight weeks over the course of 18 months, ending at one tablespoon of peanut butter or an equivalent amount of a different peanut product.

All dose increases took place under medical supervision.

None of the study participants in the peanut-ingestion group had severe reactions or needed epinephrine during home dosing, and only one received epinephrine during a supervised dosing visit.

Following the treatment regimen, children from the peanut-consuming group participated in a feeding test, supervised by the study team, to evaluate how much peanut they could eat without an allergic reaction.

All 32 children from the peanut-consuming group who participated in the feeding test could tolerate the maximum amount of nine grams of peanut protein, or three tablespoons of peanut butter.

By contrast, only three of the 30 children from the avoidance group who underwent the feeding test after avoiding peanuts for the duration of the study could tolerate that amount.

Because the trial took place during the COVID-19 pandemic and some families preferred avoiding close encounters indoors, some did not return to the study site for the feeding test.

Using a common statistical technique to account for the children who missed the feeding test, the research team reported that 100% of the ingestion group and 21% of the avoidance group tolerated an oral food challenge that was at least two doses more than they could tolerate at the beginning of the study.

To test if the response to treatment was durable, children in the peanut-ingestion group who could tolerate nine grams of protein during the feeding test went on to consume at least two tablespoons of peanut butter weekly for 16 weeks and then avoided peanuts entirely for eight weeks.

A total of 26 of the 30 treated children who participated in a final feeding test after the eight-week abstinence period continued to tolerate nine grams of peanut protein, which the research team says indicated that they had achieved "sustained unresponsiveness" to peanuts.

The three participants from the avoidance group who could eat nine grams of peanut protein without reaction at the earlier food test were considered to have developed a natural tolerance to peanuts. A

Analysis of data collected from all 73 study participants revealed that 68.4% of the peanut-ingestion group achieved sustained unresponsiveness, while only 8.6% of the avoidance group developed a natural tolerance.

Sicherer, Director of the Elliot and Roslyn Jaffe Food Allergy Institute at Mount Sinai Kravis Children’s Hospital, New York, added: “These study results are very exciting and a huge step forward in personalizing food allergy treatment.

“My hope is that this study will eventually change practice to help these children and encourage additional research that includes this approach for more foods.”