Vaccine brings hope for peanut allergy sufferers
An experimental vaccine has offered hope for thousands of people with a life-threatening peanut allergy after showing promising results in trials.
One injection of the antibody treatment allowed them to eat a nut’s worth of peanut protein two weeks later.
It is early evidence that the vaccine is ‘‘a safe, effective and rapid food allergy treatment’’, scientists at Stanford University in California said.
Experts believe that peanut allergy rates have doubled and possibly tripled over the past few decades. About one in 50 primary school-age children in Britain is estimated to be affected.
In those with severe allergies, the immune system misidentifies peanut protein as a malevolent invader. The body gears up to expel it but attacks itself. Symptoms include breathing difficulties and a fall in blood pressure. The injection works by snuffing out the immune response at an early stage.
The ability to digest a small amount of peanut could transform lives, protecting allergy sufferers from, for example, a stray nut in a sandwich. It could ease the daily fear of eating food they have not prepared themselves.
The only existing treatment is known as oral immunotherapy. It requires patients to eat tiny, gradually escalating doses of the food that triggers their allergy. This can take up to a year and cause allergic reactions along the way. By contrast, 73 per cent of the allergy patients who received the antibody treatment could eat a modest amount of peanut protein 15 days later.
‘‘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,’’ Kari Nadeau, a professor of medicine and of paediatrics at Stanford, said.
‘‘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.’’
The antibody, etokimab, interferes with a molecule known as IL33, which plays a critical role in the chain reactions of immune-system responses. In someone with a peanut
‘‘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.’’
allergy, IL-33 helps to trigger a cascade of effects that can include mouth and throat itchiness, hives, breathing difficulties and anaphylactic shock.
‘‘By inhibiting IL-33, we potentially inhibit features of all allergies, which is promising,’’ Dr Nadeau said. It has also been tested for other immune diseases, including asthma and eczema.
Fifteen adults with severe peanut allergies received an injection of etokimab, while five others received a placebo. Fifteen days later, they tried eating a small amount of peanut protein. In the etokimab group, 73 per cent could eat 275mg of peanut protein – one nut’s worth – without an allergic reaction. No placebo recipients were able to. After 45 days, 57 per cent of the etokimab group passed the food challenge and there were no side-effects.
The results were published in the journal JCI Insight and there are plans for larger trials.