Immunotherapy for food allergies was first attempted more than 100 years ago, but it is only in the last 5-10 years that this has become a potential treatment option. There are three main methods which are being assessed to deliver immunotherapy for food allergy:
- Oral immunotherapy, where the doses are swallowed
- Epicutaneous immunotherapy, where the food allergen is applied to the skin in a special patch or plaster
- Sublingual immunotherapy
Oral immunotherapy (OIT)
In oral immunotherapy, small but increasing doses of the food allergen are given to affected individuals over a period of months, until the body is ‘trained’ not to react. A number of studies are underway or have been completed, both in the UK and abroad, demonstrating the effectiveness of this technique. However, up to 20% of patients do not tolerate the treatment, and others can experience frequent allergic reactions due to the doses, including anaphylaxis. Moreover, the effects are not generally long-lasting: if the doses are stopped, the allergy returns.
Several studies – both commercial and non-commercial – are currently taking place in the UK:
The Grown Up Peanut Immunotherapy Study (GUPI) is being run at Guy’s and St Thomas’ NHS Foundation Trust, London, and is assessing the effectiveness and safety of Oral Immunotherapy in adults with peanut allergy. The study began in May 2018 and the estimated completion date is September 2021.
Boiled Oral Peanut Immunotherapy (BOPI) is a research programme based at Imperial College, London, which uses boiled peanut instead of roasted peanut to reduce clinical reactivity. Researchers propose showing that using boiled peanuts for OIT is better tolerated than conventional peanut-OIT, which uses roasted peanut flour. The study team are now studying this in a further clinical trial which began in mid 2019.
Aimmune Therapeutics manufactures Palforzia, which is an oral treatment that aims to provide children with serious peanut allergy with some tolerance to peanut protein. The idea is to reach a level of tolerance where accidental exposure to small amounts of peanut would not result in a serious reaction. Palforzia was approved for NHS use by the National Institute for Clinical Excellence (NICE) in December 2021 but access to NHS treatment is currently very limited. In October 2022, the Scottish Medicines Consortium (SMC) decided not to approve Palforzia for NHS use in Scotland.
Camallergy (Cambridge Allergy Ltd) is a spin-off company founded by researchers at Cambridge University Hospitals NHS Foundation Trust which is planning to launch a peanut-based oral immunotherapy treatment. In 2014, the team revealed results of their trials involving children with peanut allergy aged 7-16. The majority of participants were able to tolerate peanuts after the immunotherapy treatment, with further increasing levels of tolerance over time. There was no improvement in the control group. A control group comprises participants who do not receive the treatment and are then used as a benchmark to measure the success of the treatment in those participants that did receive it. Camallergy is now preparing for the next phase of the studies to confirm the results in children and possibly adults. A private service for patients is now up and running. This typically includes seven visits to the allergy clinic and annual follow-up visits. Further information is available at camallergy.com
- Epicutaneous immunotherapy (EPIT)
EPIT is a novel way of desensitising children with food allergy and is being developed by DBV Technologies, a global biopharmaceutical company with offices in the USA, France and Australia. Their product, Viaskin, is an electrostatic patch that activates the immune system through intact skin. The intention is that it will be self-administered, non-invasive and easy to use.
Studies are ongoing to assess Viaskin for milk and peanut allergy. The company says: “Viaskin safely provides allergenic information to the immune system without entering the bloodstream. Once applied to skin, Viaskin creates a condensation chamber that hydrates the skin and solubilizes the allergen allowing it to penetrate the epidermis.” At the time of publishing this article, a study assessing EPIT in peanut-allergic children was currently recruiting in the UK. More information at www.dbv-technologies.com
- Sublingual immunotherapy (SLIT) for food allergies
Sublingual immunotherapy is similar to oral immunotherapy, except the treatment (containing the food allergen) is held under the tongue rather than swallowed. A number of studies have been published investigating SLIT for food allergy including to milk and peanut. While SLIT appears to be much safer than oral immunotherapy, it is also less effective, although a recent study found some benefit after three years of treatment.
Researchers at Imperial College London are currently investigating whether using SLIT as a pre-treatment before OIT can improve the safety of conventional immunotherapy in cow’s milk allergy. The study, known as SOCMA, began in July 2018 and is expected to finish at the end of 2020.
Other treatments under study
Many groups are investigating ways to improve outcomes in oral immunotherapy, predominantly for peanut allergy. Researchers in Melbourne are looking at whether combining peanut-OIT with probiotics improves treatment results, while a study led out of Sydney is assessing whether a dietary fibre supplement can have a similar effect. Finally, a group in Boston commenced a study in June 2019 to look at whether a medicine called VE416 (which contains inactive bacteria) in combination with vancomycin (an antibiotic) can improve outcomes in oral immunotherapy for peanut.
Final message
Immunotherapy treatment for food allergies must be conducted by medical experts in a clinical setting as the treatment is associated with a risk of reaction. It’s a case of “don’t try this at home”.
***DISCLAIMER***
This is an overview of treatments under development. Given the pace of research and development into new therapies it should not be treated as wholly complete or comprehensive.
