• Dr Emma Derbyshire

A Novel Treatment for Peanut Allergy: An Oral Immunotherapy in Phase III Clinical Development

What is Peanut Allergy?

Peanut allergy is one of the most common food allergies, and peanuts are included as an ingredient in many food stuffs. Peanuts are not actually a true nut as they grow underground, and are classified as a legume, which is the same family as peas, beans and lentils. However, the proteins in peanuts are similar in structure to nuts that grow on trees, termed tree nuts, which include cashews, almonds, walnuts, Brazil nuts, hazelnuts, pistachios, pecans and macadamia nuts. For this reason, people who are allergic to peanuts can also be allergic to tree nuts.

Unlike some food allergies an allergy to peanuts and tree nuts is lifelong in many people and can cause a severe, potentially life-threatening allergic reaction, termed anaphylaxis. Allergic reactions can be unpredictable, and only a very small amount of peanut can cause a reaction.

The number of children diagnosed with peanut allergy in the UK has more than doubled during the past two decades.

Oral Immunotherapy for Peanut Allergy

Peanut oral immunotherapy has previously been shown to induce desensitisation in peanut-allergic subjects, although no treatment has reached clinical development until now.

A group of clinical research scientists has teamed together to form the PALISADE Group in order to develop a novel peanut-derived oral immunotherapy drug for peanut allergy called AR101, which is currently in Phase III clinical development.

During a randomised, double-blind, placebo-controlled Phase II clinical trial, to assess safety and efficacy, AR101 demonstrated an acceptable safety profile and sufficient clinical activity as a potential immunomodulatory treatment for peanut-allergic children and young adults.

A Phase III clinical trial has recently been completed where AR101 was administered as an oral immunotherapy in children and adolescents who were highly allergic to peanut. Participants began on a 100mg dose, which was slowly built over 24 weeks to a 300mg dose. This higher dose of peanut protein was well tolerated and was ingested without dose-limiting symptoms. Furthermore, at the end of the trial, 67.2% of participants were able to ingest a 600mg challenge dose without dose-limiting symptoms. However, efficacy was not shown in participants over the age of 18.

The Future

AR101 is the lead investigational drug of Aimmune, a clinical-stage biopharmaceutical company developing proprietary product candidates and advancing a therapeutic approach for the treatment of peanut and other food allergies. Aimmune currently has more than 1,000 participants in clinical trials for AR101 and are continuing to advance toward providing a regulatory-approved treatment for patients with peanut allergy. AR101 could be a game changer in the protection of our children, with peanut allergy, from having a severe reaction after accidental exposure.


PALISADE Group of Clinical Investigators (2018). AR101 Oral Immunotherapy for Peanut Allergy. N Engl J Med 379(21):1991-2001

Bird JA et al (2018) Efficacy and Safety of AR101 in Oral Immunotherapy for Peanut Allergy: Results of ARC001, a Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Trial. J Allergy Clin Immunol Pract 6(2):476-485