Oral immunotherapy shows positive results in adults with peanut allergy

A new study, led by King’s College London and Guy’s and St Thomas’ NHS Foundation Trust, has shown promising results, demonstrating that peanut oral immunotherapy (OIT) may be an effective treatment for adults with peanut allergies. The trial, known as the Grown-Up Peanut Immunotherapy (GUPI) study, is the first to focus specifically on adults with clinically diagnosed peanut allergies. While OIT has shown effectiveness in achieving desensitisation in children, there has been limited evidence showing its safety and effectiveness in adults—until now.

What is peanut oral immunotherapy (OIT)?

Peanut OIT is a treatment approach designed to help people with peanut allergies become less sensitive to peanuts. The idea is to build tolerance by gradually introducing small, controlled amounts of peanut protein over time. This helps the immune system learn to tolerate peanuts better, so that if a person accidentally eats some, they may not have a severe reaction. OIT is not a cure for peanut allergy, but it can increase the amount a person can safely tolerate.

Please note any treatment involving OIT should only be carried out under the supervision of a qualified allergy specialist.

How did the GUPI trial work?

The trial involved 21 adults aged 18 to 40, all clinically diagnosed with peanut allergy, confirmed through skin prick tests, blood tests, and oral food challenges.

Participants started by consuming small doses of peanut flour mixed with food, gradually increasing the amount over several weeks, with supervised doses administered in a clinical setting. At home, participants continued daily doses for two weeks before returning for supervised increases in dosage.

The final phase involved a controlled food challenge to test participants’ ability to tolerate peanuts, with increasing doses of either peanut protein or a placebo. Participants then continued daily dosing for at least three months before exiting the trial as well as the option of continuing post-study.

What did the study find?

• 67% of participants were able to exit the trial consuming the equivalent of four peanuts without experiencing an allergic reaction.
• While most allergic reactions during treatment were mild (over 95% were low-grade), a few more serious reactions did occur, including one requiring adrenaline in hospital and one severe reaction during exercise.
• Participants who completed treatment reported feeling significantly less anxious about food, more comfortable in food-related situations, and generally experienced a better quality of life.

What’s next?

Currently, peanut oral immunotherapy (OIT) for adults remains an investigational treatment and is not yet available through the NHS. However, these findings offer hope for adults with peanut allergies and represent a promising step toward expanding treatment options beyond childhood.

More research is needed to confirm the long-term safety and effectiveness of OIT in adults, as the study’s small sample size limits the strength of its conclusions. Larger trials are required to better understand OIT’s safety, identify which adults are most likely to benefit, and assess whether long-term tolerance can be achieved and maintained without ongoing daily peanut consumption.

In the future, this approach may also be adapted to treat other common food allergies in adults, such as those to cow’s milk, eggs, and wheat.

The study was funded by the National Institute for Health and Care Research (NIHR). You can read more here: https://onlinelibrary.wiley.com/doi/full/10.1111/all.16493