The Hunt for a Food Allergy Cure: Where Is It Heading?
Originally published in Allergic Living‘s Summer 2013 edition.
FOR four years in a row, there were upbeat reports at the annual meeting of the American Academy of Allergy Asthma & Immunology about the progress with oral immunotherapy – the most basic type of desensitizing treatment imaginable for food allergy.
Called OIT for short, it involves feeding a food like milk or peanut to allergic children. The children start by swallowing microscopic specks of their allergen on a daily basis. If they can manage that, they progress to a tiny bit larger daily dose, then a bit bigger again, and on it goes until they reach their maintenance dose – an amount of the food that they’ll need to eat every day at home for months or even years.
Some lucky kids even finished their clinical trials able to eat full servings as their daily “dose” – perhaps a glass of milk, an ice cream cone or a handful of peanuts. When you consider that scant years before, there were precisely zero food allergy treatments in the pipeline, the news of these studies was phenomenal.
Yes, there was a high rate of reaction – mostly stomach aches and itchy mouths – accompanying the treatment, and some children had stronger reactions and could not proceed. But something remarkable was also happening: a majority of the allergic kids were able finish their trial eating some amount of their allergen every day – a food that had long been viewed as their personal poison, one that could be life-threatening. The presenting researchers were optimistic; the mainstream media began using the “cure” word.
Then came the March 2013 meeting of the AAAAI. Dr. Wesley Burks, the organization’s outgoing president and a pioneer of OIT research, quickly signaled times had changed. He told the assembled allergists that it was not at all clear that long-term tolerance – in which a person on oral immunotherapy could stop taking daily doses of their allergen and still be protected – was achievable.
Burks spoke of encouraging OIT results, like the significant gains in patients’ peanut consumption in one of his studies, but also of instances of patients quite abruptly losing the ability to eat the food without reacting. His message was: “The treatment is promising, but it’s not ready yet.”
Burks raised eyebrows, but a later presentation from Johns Hopkins University became the talk of the conference. The preliminary findings of a long-term follow-up on two milk OIT studies were both surprising – and disappointing.
The Hopkins researchers surveyed 32 children and teens who had completed the two OIT studies, and had been given clear instructions on what milk products to consume daily. Three to five years after graduating from their trials, only 25 percent were consuming milk without ever getting symptoms, while 16 percent had stopped their daily doses because of symptoms. The rest were reacting (to varying degrees), either frequently or occasionally. Among those reacting, almost a third reported a “systemic” or more serious reaction.
Pulling no punches, Dr. Robert Wood, director of pediatric allergy and immunology at Johns Hopkins said: “Some of the more dramatic failures had looked like absolute successes in the study. They were about as close to ‘cured’ as we could imagine.”
Although it wasn’t completely clear, Wood says the loss of protection in these kids is likely tied to reducing the daily milk dose. “A lot of them just ratcheted down their milk exposure because they were having reactions,” he said. “And as they ratcheted down exposure, they lost some, most or all protection that the study had given them.”
Was this small investigation the beginning of the end for OIT? Definitely not, say several leading allergists, including Wood and Burks, who is the chair of pediatrics at the University of North Carolina’s school of medicine.
It’s more that the long-term results are a flag on the play, an indicator that scientists can’t presume the level of protection reached in a one- or two-year OIT trial will not change over time. The same goes for its cousin the sublingual immunotherapy trial (which involves giving the allergen doses in tiny amounts in under-the-tongue drops or tablets).
“We need long-term followup,” stresses Wood. “Letting kids go at the end of the study is not the end of the story.”
He and Burks both view the bigger picture as far more positive. “To go from where we were 10 years ago, which was to say that ‘we probably can’t give food to a highly allergic patient safely at all,’ to say now that some patients are having extremely good outcomes, is big progress,” said Wood. “The long-term potential is very real.”
But he does see a need to temper expectations of just how quickly an OIT-style of treatment will be available at the allergist’s office.
What several allergists tell this magazine is that OIT in and of itself may not be the solution, nor the only treatment option. The therapy may simply be a first stage, which needs to evolve. In fact, it appears that’s already happening.
Next: Great hopes for combination therapies