Weighing the Risks and Rewards of Peanut Oral Immunotherapy.

Abstract

For the millions of people with peanut allergies, oral immunotherapy offers the possibility of fewer allergic reactions and a life lived with far less anxiety. That life could be on the horizon: the US Food and Drug Administration (FDA) is expected to rule on the first peanut desensitization product, Aimmune Therapeutics’ biologic, AR101, later this year. But a recent meta-analysis highlights an underappreciated issue. For many, the treatments actually increase allergic reactions. The study, published in The Lancet, analyzed 12 randomized clinical trials involving 1041 participants followed up for a median of 1 year. The trials compared oral immunotherapy with placebo, peanut avoidance, or, in 1 case, sublingual immunotherapy. In all the studies, both the treatment and control groups were told to continue avoiding peanuts, the current approach to managing peanut allergies. Oral immunotherapy outperformed no oral immunotherapy on the standard primary end point: an estimated 40% of the treatment group passed a supervised, inclinic oral food challenge, or “provocation,” at the end of the studies compared with about 3% of the control group. But the oral immunotherapy group had an increased risk of serious adverse events. No deaths occurred, but based on the 9 trials that measured anaphylaxis—both treatment-related and accidental—the researchers estimated the risk to be 22% with oral immunotherapy compared with just 7% without it. They reported that oral immunotherapy would lead to an additional 15 anaphylaxis events per 100 treated individuals. The treatment group also had more frequent anaphylaxis, used epinephrine more often, and had more reactions like asthma attacks, hives, swelling, and vomiting.