Peanut allergy affects nearly 1.5 million children in the United States, most of whom remain allergic to peanuts for life. These children and their families must remain ever vigilant. The threat of accidental exposure, which can only be treated with injectable epinephrine, persists, underscoring the need for effective therapies.
In a clinical trial (IMPACT trial, #NCT01867671) report published in The Lancet, scientists have found initiating peanut oral immunotherapy in children aged four or under who are highly allergic to peanuts, may be effective in inducing desensitization or remission.
The trial was led by A. Wesley Burks, MD, CEO of UNC Health, dean of the UNC School of Medicine, and vice chancellor for medical affairs in the University of North Carolina at Chapel Hill, and Stacie Jones, MD, professor of pediatrics at the University of Arkansas for Medical Sciences and Arkansas Children’s Hospital in Little Rock.
Burks said, “The serious and unpredictable nature of food allergic reactions can be worrisome for affected children and their parents. Other than avoidance and medication to treat allergic reactions or anaphylaxis, there are no treatment options, resulting in a considerable burden on allergic children and their caregivers to avoid accidental exposure. In severe cases, this can restrict peanut-allergic children’s freedoms, particularly when it comes to navigating daycare or schools and public spaces where access to a safe diet is in jeopardy for young children. Exploring safe and effective therapy options for children with peanut allergy is crucial to improving quality of life for this group of patients, particularly as most children remain allergic for their lifetime.”
Immunotherapy involves repeated exposure over time to gradually increasing doses of the allergen, to reduce anaphylactic responses of the immune system. During the 30-week trial period, the children were offered small quantities of peanut protein powder, which was increased gradually to two grams daily, under close supervision.
The scientists measured desensitization and remission of peanut allergy in 146 allergic children where desensitization was scored through the safe consumption of 5 g peanut protein powder in a supervised food challenge, after two and a half weeks of daily oral peanut immunotherapy, and remission was scored by the participants’ ability to repeat the food challenge 26 weeks after the treatment was stopped.
The researchers report 68 of 96 allergic children (71%) who received the immunotherapy were desensitized to peanuts versus one in 50 in the placebo group (2%), and 20 of 96 allergic children achieved remission (21%).
Jones said, “As the first large study in a preschool age group to test earlier interventions, we found that the treatment induced desensitization in a majority of peanut-allergic children and around one in five achieved remissions. We also saw an additional one in five children whose peanut tolerability did not reach our threshold for remission but still increased significantly after treatment.”
In a post-hoc analysis, the investigators found 71% of the one-year-olds, 35% of the two-year-olds, and 19% of the three-year-olds achieved remission. This led the researchers to infer that starting the immunotherapy at a younger age resulted in a greater likelihood of remission. They suggest further investigations into this finding as it may help determine an early developmental time window when peanut oral immunotherapy is most effective. In addition, the investigators also found, lower levels of peanut-specific immunoglobulin E antibodies at the start of the trial improved the likelihood of a child’s achieving remission.
The randomized controlled trial reports most children treated with the oral immunotherapy achieved desensitization after two and a half years of treatment, and one in five remained in remission 26 weeks after treatment ended.
The results were published in an article titled, “Efficacy and safety of oral immunotherapy in a randomized, placebo-controlled study of 1-3-year-old children with peanut allergy: Findings from the Immune Tolerance Network IMPACT trial.” The IMPACT trial was funded by NIAID through its Immune Tolerance Network.
“The landmark results of the IMPACT trial suggest a window of opportunity in early childhood to induce remission of peanut allergy through oral immunotherapy,” said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH. “It is our hope that these study findings will inform the development of treatment modalities that reduce the burden of peanut allergy in children.”
Based on earlier proof-of-concept studies that suggested peanut oral immunotherapy could be safe and therapeutic in very young children, the IMPACT investigators reasoned receiving this immunotherapy early in life when the immune system is still maturing, may modify an allergic child’s immune response to peanuts.
Adverse reactions to the oral immunotherapy were mild to moderate in severity, with nearly all treated children experiencing at least one dose-related reaction during experimental treatment. Twenty-one children experienced 35 moderate reactions to the immunotherapy during the 2.5 year trial and were treated with the rescue drug epinephrine.
Matthew Greenhawt, MD, Children’s Hospital Colorado, University of Colorado School of Medicine (who was not involved in the study) said, “IMPACT data advance our understanding of peanut oral immunotherapy, showing that peanut oral immunotherapy can produce desensitization in very young children with good safety. Although peanut oral immunotherapy at any age is not without some risk of an allergic reaction, this is a reasonable treatment consideration for very young children with peanut allergy, guided by an allergy specialist, in the context of shared decision making. Oral immunotherapy has the potential to help manage disease through treatment, not fear and avoidance.”
