Several studies into the use of oral immunotherapy for the treatment of food allergies have shown promising short-term results. However, most have not provided meaningful protocols for maintenance doses, nor have they been followed up over long periods of time to determine whether the effects are long lasting.
A series of Phase 1 and Phase 2 clinical trials at the Sean N. Parker Center for Allergy and Asthma Research at Stanford has shown treatment via oral immunotherapy combined with an allergy-reducing drug, Omalizumab can bring sustained resistance to multiple food allergens to those who were previously sensitised.
Following initial trials that were published in 2014, participants were eating two grams per day of their food allergens (in the case of peanut allergy, this equates to eating about eight peanuts each day). Previous work had shown that if participants completely stopped eating the foods they had become desensitized to after finishing their course of oral immunotherapy, they were likely to return to an allergic state. Therefore, participants were encouraged to keep to a maintenance dose which could be two grams per day or a lower dose of 300 mg per day of each of their allergens. Some also switched to eating the food every other day instead of daily.
Participants were tested every six to 12 months for up to six years and all were able to maintain their tolerance to their allergens, regardless of whether they were ingesting the lower or higher allergen doses. None of the patients experienced severe allergic reactions, although some mild and moderate reactions were reported, and patients were advised to always carry an Epipen as a precaution.
Further work is now being undertaken to elucidate how the treatment induces and maintains tolerance and this knowledge is likely to bring refinements to the treatment.
Andorf et al. 2017 Allergy, Asthma & Clinical Immunology. Vol 13(52) doi: 10.1186/s13223-017-0224-7 Open Access paper available.
Andorf et al. 2017 Allergy, Asthma & Clinical Immunology. Vol 13(51) doi: 10.1186/s13223-017-0223-8 Open Access paper available.