Immunotherapy for peanut allergy proves effective four years on

A treatment for deadly peanut allergy undergoing clinical trials at the Murdoch Childrens Research Institute (MCRI) has been found to show long-lasting effects, providing what is claimed to be the strongest evidence yet that a cure may be possible for peanut allergy.

The news comes more than four years after Professor Mimi Tang pioneered the probiotic and peanut immunotherapy (PPOIT) treatment, which saw participants introduced to the probiotic Lactobacillus rhamnosus in conjunction with peanut protein. The method was intended to modify the allergic response to peanut so the immune system produces protective responses, rather than a harmful response, to the peanut protein.

Children in the original PPOIT randomised trial were given either a combination of Lactobacillus rhamnosus and peanut protein in increasing amounts, or a placebo, once daily for 18 months, then tested to see if they had developed tolerance to peanut. At the conclusion of the trial, 82% of children who received PPOIT were deemed tolerant to peanut, compared to less than 4% in the placebo group.

Four years later, the majority of children who gained initial tolerance are still eating peanut as part of their normal diet (80%) and have passed a further challenge test confirming long-term tolerance to peanut (70%). The results have been published in The Lancet Child & Adolescent Health.

“These children had been eating peanut freely in their diet without having to follow any particular program of peanut intake in the years after treatment was completed,” said Professor Tang. “Over half were consuming moderate to large amounts of peanut on a regular basis, others were only eating peanut infrequently.

“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.”

The follow-up study was initially funded by MCRI and the Australian Food Allergy Foundation, before receiving a $15 million funding commitment in 2016 from capital investment firm OneVentures. Biotech company Prota Therapeutics has since been set up by the MCRI and OneVentures to develop PPOIT towards an FDA-approved product, with a plan to make the vital treatment available globally to people with peanut allergy.

Dr Suzanne Lipe, CEO of Prota Therapeutics, said the results of the investigation are extremely promising and, if confirmed in a larger Phase III study, could 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.