An advisory panel to the US Food and Drug Administration (FDA) considered the evidence on the efficacy and safety of a new peanut allergy treatment.
Peanut allergy has increased in recent years
Peanut allergy is one of the most common food allergies amongst children in the US. Reporting of the condition is on the rise, with a study in 2017 finding that peanut allergy in children had increased 21 percent since 2010, and almost 2.5 percent of children in the US may be affected. Symptoms of peanut allergy vary but can include indigestion, vomiting, diarrhea, skin rash, cough, throat tightness, wheezing, and shortness of breath. The most severe allergic reaction, “anaphylaxis”, is life-threating and causes impaired breathing, swelling of the throat, and a sudden drop in blood pressure. Anaphylaxis is a medical emergency and must be treated immediately with epinephrine (adrenaline), usually given by an auto-injector pen, which is carried by known allergy sufferers.
Oral immunotherapy may help to modify allergic reaction to peanuts
Apart from advice on avoiding peanut-containing foods and prescribing an epinephrine auto-injector in case of accidental exposure, allergy specialists may administer peanut allergy treatment to modify a person’s allergic response. In oral immunotherapy, allergy sufferers are given gradually increasing doses of peanut protein, to help the immune system to learn to tolerate it. A similar approach has been used for several decades for other allergies such as pollen and pet hair but had not been tried for food allergies. In a new peanut allergy treatment called AR101, capsules containing carefully controlled doses of peanut products are used to gradually expose an individual to peanuts and reduce their allergic reaction. Children taking AR101 still need to avoid peanut-containing foods, but the treatment aims to offer protection from accidental exposure to peanuts – a source of anxiety for affected children and their parents.
In clinical trials of AR101, participants gradually increased their dose from one-500th of a peanut to a maintenance dose of about one peanut. Among 294 highly allergic young people who completed a year-long study, 84% could tolerate two peanuts with no more than mild allergic symptoms, and 63% could tolerate three peanuts following treatment. Approval for the treatment is currently sought for 4 to 17-year-olds, but allergy sufferers may need to take the therapy long-term in order to maintain protection, although this requires further investigation.
Oral immunotherapy has possible side effects
There are side effects associated with the oral peanut immunotherapy treatment, mostly related to allergic reactions. Combined analysis of several trials found that the chance of needing epinephrine was around three-times higher in those on treatment compared to those who were not. Twenty percent of participants in the AR101 phase III clinical trial dropped out of the study because of side effects. Exercise, hot showers, illness, or tiredness were found to increase the chance of an allergic reaction. Long-term data on AR101 is not yet available, so it is not clear if the protection response is consistent and maintained, or for how long treatment should be continued. However, despite the possible side effects, many children with peanut allergies and their parents are prepared to accept the risks of new treatments, as the anxiety of accidental exposure is very stressful.
FDA to consider expert panel’s advice before deciding on treatment approval
On considering the evidence, the expert advisory panel concluded that AR101 can reduce allergic reactions from accidental exposure to peanuts. It endorsed a proposed safety plan for use of the product in children and teenagers, which involves administering the first dose and every increased dose of AR101 under supervision in a “certified facility”. The panel’s advice will be reviewed by the FDA before a final decision is made on whether to approve the product.
Written by Julie McShane, MA MB BS
Reference: Couzin-Frankel J. Science, September 13, 2019. “First peanut allergy treatment gains backing from FDA advisory panel” (Posted in: Science and Policy Section, doi:10.1126/science.aaz5008) https://www.sciencemag.org/news/2019/09/first-peanut-allergy-treatment-gains-backing-fda-advisory-panel?utm_campaign=news_daily_2019-09-13&et_rid=605481053&et_cid=2987101
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