Development for peanut allergy sufferers

A Stanford-led pilot study revealed that one injection of an antibody treatment let people with severe peanut allergies eat a nut’s worth of peanut protein two weeks later. The research provides evidence that the antibody is a safe, effective and rapid food allergy treatment. A paper describing the findings from the study is published in JCI Insights.

Food allergies can develop at any point in life, with the only existing treatment, oral immunotherapy, requiring patients to eat tiny, gradually escalating doses of their food-allergy triggers under medical supervision. This treatment can take six months to a year and can cause allergic reactions along the way. In contrast, 73% of people with severe peanut allergies who received the antibody could consume a modest amount of peanut protein 15 days after a single injection.

“What’s great about this treatment as an option for food allergies is that people did not have to eat the food to get desensitised. Although this is still in the experimental stages, we’re delivering on the hope of testing a drug that won’t be for one food allergy but for many, and for other allergic diseases, too,” said Kari Nadeau, MD, PhD, professor of medicine and paediatrics at Stanford, and the paper’s senior author.

The antibody treatment, called etokimab, interferes with the action of interleukin-33, an immune-signalling molecule. IL-33 triggers a range of immune-system responses that culminate in allergic reactions. For those with peanut allergies, consuming peanuts causes IL-33 to activate a second immune actor, immunoglobulin E. IgE is plentiful in those with allergies and triggers various aspects of the allergic response, such as mouth and throat itchiness, hives, breathing difficulties and anaphylactic shock.

“By inhibiting IL-33, we potentially inhibit features of all allergies, which is promising,” Nadeau said.

The treatment has already been tested in people with other immune diseases, including asthma and eczema. In this study, 15 adults with severe peanut allergies received an injection of etokimab, while five others, who also have severe peanut allergies, received a placebo. Fifteen days later, participants tried eating a small amount of peanut protein under medical supervision, with results revealing that 11 out of 15 participants in the etokimab group could consume 275 mg of peanut protein without an allergic reaction, while no placebo recipients could do so. At day 45, 4 out of 7 people in the etokimab group could consume peanut protein, a feat not achieved by those in the placebo group.

“We were surprised how long the effects of the treatment lasted,” Nadeau said.

Participants receiving etokimab had less peanut-specific IgE in their blood at day 15 than placebo recipients, and also experienced changes in other immune markets, suggesting the treatment temporarily provided a less-allergic immune profile. No participants in the trial reported severe side effects.

Researchers will repeat the study with more participants, seeking biomarkers that identify which individuals could benefit from the antibody treatment. The appropriate timing and dosing amount of the antibody also needs to be determined.

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