New food allergy therapies show promise

They're no cure, but the new treatments are tipped to be safer and better than oral immune therapy.

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A raft of exciting new therapies for food allergies will offer safer and more effective alternatives to oral immunotherapy, experts have revealed.

Speaking at the ASCIA conference in Melbourne this month, they said epicutaneous immunotherapy (delivering the allergen dose through a patch on the skin) was showing particular promise, while other treatments included biologics and involved using precision medicine.

Stanford University paediatric allergy and immunology specialist Associate Professor Sharon Chinthrajah said, US trials of epicutaneous immunotherapy were already showing high rates of compliance, safety and success in desensitisation.  

“Biomarkers showed persistent effects from week 52 to week 130, with increases in peanut specific IgG4,” said Professor Chinthrajah, pointing to the EPIT study, which trialled peanut skin patch (Viaskin Peanut) on patients between the ages of four and 25 for up to 130 weeks. 

Some had placebo for a year and switched to 250mcg patches for the remaining period. Of these, 5% achieved desensitisation. Another group switched from 100mcg patches for a year to 250mcg and 21% of those achieved desensitisation, as did 36% of those who used the 250mcg patches for the entire time.  

As with other types of food allergy immunotherapy, successful patients were mostly young, in this case with a median age of around six. 

Another study underway in toddlers (EPITOPE) suggests that patches work for them too. Top line results show that after one year of treatment, 67% of children who wore a patch on their back daily achieved desensitisation. 

“The lovely thing about [epicutaneous immunotherapy] is it is much, much, much safer than taking something orally,” said Murdoch Children’s Institute paediatric allergist Associate Professor Kirsten Perrett.

“Adverse events are very infrequent. Most of them are related to skin, a little bit of eczema.”

Treatment-related anaphylactic reactions occurred in 1.6% of children, she noted, “basically because of accidental ingestion for the little kids, which is much lower in adults and teenagers”.  

However, long term efficacy and safety was “the big unknown”, she added. 

Biologics with oral immunotherapy, and on their own, are also showing encouraging results, said Professor Chinthrajah. Biologics are currently used for asthma and urticaria, but not as a treatment for food allergy.

At Stanford University they have been trialling omalizumab, a humanised anti-IgE monoclonal antibody, as an “umbrella” at the start of multiallergen desensitisation, Professor Chinthrajah said.

She said they had found that adding the biologic improved the safety, speed, efficacy and long-term outcome of multi-food desensitisation.

Questions remain about the optimal dose and duration of omalizumab in treating food allergy, but many studies have been done to date, and more are underway, she said. For instance, the MIMIX study found no difference in safety between high and low doses of the drug.

“Both of these groups after 18 weeks of treatment showed changes in their immune parameters. And all patients were able to incorporate multi food into their diet following the clinical trial,” Professor Chinthrajah said.  

It’s also possible that omalizumab alone, without oral immunotherapy, could be used to increase threshold doses for children who have reactions to very small amounts of allergen.

“There is some data to suggest how high people can go, but I think more data will come from the OUTMATCH study,” she said.

Biologics are also being trialled in Australia.

“We’ve got some kids on a trial with Novartis [ligelizumab] and it’s wonderful,” Professor Perrett told ASCIA delegates.

“These kids have reacted at very low doses to their own food challenges. They have one injection per month, then three months later, another food challenge and they sail through. And the families and kids are just ecstatic because it’s keeping them safe and they’re not taking any allergen daily.” 

Researchers were “looking at a whole package of biomarkers,” she said. These include the participant’s phenotype – multifood or single food allergy, pre-existing eczema or asthma or other conditions – and using this information with blood biomarkers and potentially their skin prick tests “to see if there’s some sort of algorithm,” she explained. 

“We will have biomarkers where we can actually say, this kid would do best with this product and that will give them this outcome. And the family and the child and the treating clinicians can make that decision together about what’s right for that child,” Professor Perrett said.