Food allergies affect 250 million people worldwide, and have risen by 350 per cent in the last 20 years. Peanut allergy has increased at the greatest rate.
While allergies to egg, milk, wheat and soy generally resolve during childhood, nut and seafood allergies often persist throughout life. But now a trial for the treatment of peanut allergy at the Murdoch Children's Research Institute has shown the strongest evidence yet that a cure may be possible.
At the end of the original trial in 2013, 82 per cent of children who received the oral immunotherapy were deemed tolerant to peanuts and went home eating peanut. Four years later, the majority of children are still eating peanut (80 per cent) and have passed a further challenge test confirming long-term tolerance to peanut (70 per cent).
This provides the strongest evidence yet that a cure may be possible for peanut allergy and holds important implications for attacking the modern food allergy epidemic.
Peanut allergy is the commonest cause of anaphylaxis, a life-threatening allergic reaction, and one of the commonest causes of death from food allergy.
Research led by Professor Mimi Tang, who pioneered the probiotic and peanut immunotherapy (PPOIT) treatment, followed up children four years after they completed the initial trial. Children in the original PPOIT randomised trial were given either a combination of the probiotic, Lactobacillus rhamnosus, together with peanut protein in increasing amounts, or a placebo, once daily for 18 months, then tested to see if they had developed tolerance to peanut.
Amazingly, more than 80 per cent of children who received the combination probiotic peanut oral immunotherapy treatment were able to tolerate peanut at the end of the trial, compared to less than four percent in the placebo group. Children who developed tolerance to peanut in the first trial were instructed to introduce peanut as part of their normal diet after the study ended; whereas children who remained peanut allergic were advised to continue peanut avoidance according to current care.
The latest study investigated whether the benefits of the oral treatment were maintained four years later.
Prof Tang said the new study showed that the majority of PPOIT-treated children who tolerated peanut at the end of the original trial were still eating peanut without reactions four years later.
"The importance of this finding is that these children were able to eat peanut like children who don't have peanut allergy and still maintain their tolerant state, protected against reactions to peanut. We are now examining whether these beneficial effects of our novel treatment have also resulted in improved quality of life," she said.
Prof Tang says it also suggests the exciting possibility that tolerance is a realistic target for treating food allergy - a major step forward in identifying an effective treatment to address the food allergy problem in Western societies.
This follow up study was funded by MCRI and the Australian Food Allergy Foundation. The PPOIT technology received a $15 million funding commitment in 2016 from capital investment firm, OneVentures. The biotech company Prota Therapeutics, was jointly set up by the MCRI and OneVentures to develop PPOIT towards an FDA approved product with a plan to make the vital treatment globally available to people with peanut allergy.
Dr Suzanne Lipe, CEO of Prota Therapeutics, said the results of the investigation, demonstrating such a high proportion of subjects still continuing to be tolerant four years later, was extremely promising and if confirmed in a larger Phase III study, would represent a paradigm shift in the way peanut allergy is managed.
"Rather than using therapy that protects against accidental ingestion, Prota's products aim to provide sustained long term effects and the ability to include peanut in the diet," Dr Lipe said.
"For the first time, we could have products on the market that provide meaningful and long lasting treatment benefits, which allow sufferers to eat peanut products without thinking about it, as part of a regular diet just like unaffected people."
Ten year old Olivia first became involved in the peanut allergy trial when she was two and a half. At around that age she reacted to just a small bite of a peanut butter sandwich. Her lips began to swell. Olivia's mother, Tanya May, said that having a child with peanut allergy was extremely stressful.
"Going to parties and play dates required extra planning – making sure we took Olivia's Epipen and taking food for her. She could not even easily go into play centres at shopping centres - nothing could be done spontaneously."
May says being part of the trial changed Olivia's life.
"Previously, I had to explain to parents about the Epipen if I had to leave her somewhere," May said.
"By the time she went on camp in grade 3 (last year) she was given the all clear and the Epipen was not required."