Learning Early About Peanut allergy (LEAP)

Studies: Learning Early About Peanut allergy (LEAP); Persistence of Oral Tolerance to Peanut (LEAP-On)

Sponsor: NIH-National Institute of Allergy and Infectious Diseases (NIAID)

Collaborator: Immune Tolerance Network (ITN)

Prime: Rho

Project Status: Completed

Start and End Dates: LEAP: December 2006–May 2014; LEAP-On: May 2011–May 2015

Disease: Peanut allergy is a food allergy that produces mild to severe reactions, including hives, coughing, choking, trouble breathing, and anaphylaxis, which can be fatal if not treated immediately. Peanut allergy prevalence has doubled over the past 10 years in countries that encourage avoiding peanuts during pregnancy, lactation, and infancy. Currently, no cure exists for peanut allergy, which affects about 1.5% of young children.

Objective: The LEAP study tested the hypothesis that early introduction of peanut in the diets of children at high risk for developing peanut allergy could lead to a reduction in peanut allergy at age 5. The LEAP-On follow-up study sought to determine whether the reduction in peanut allergy among those in the peanut-consuming group would be maintained if they avoided eating peanut for 12 months.

Study Information: The LEAP study enrolled 640 infants, 4 to 11 months of age, who were considered to be at high risk for developing peanut allergy due to the presence of severe eczema and/or egg allergy at screening. They were randomized to either avoid peanut completely, as per the pediatric guidelines in place at the time, or to consume approximately 6 grams of peanut protein each week given over the course of 3 meals until the age of 5. The LEAP-On follow-up study followed 556 of the original 640 children in LEAP (both peanut eaters and avoiders) for a 12-month period of peanut avoidance.

Rho served as the statistical and data coordinating center for the ITN, providing support for statistical analysis, safety monitoring, and data management, as well as supporting study protocol and manuscript development. Rho also supported the next phase of the study, LEAP-On, which sought to determine whether the reduction in peanut allergy among those in the peanut-consuming group would be maintained if they avoided eating peanut.

Results: For the LEAP study, at 5 years of age, the group randomized to consume peanut had a rate of peanut allergy 81% lower than that of the group that avoided peanut. In the LEAP-On follow-up study, after 12 months of avoiding peanuts, only 4.8% of the original peanut consumers were discovered to be allergic, compared with 18.6% of the original peanut avoiders.

Full details of the studies and results were published in The New England Journal of Medicine and can be found in the following articles:

Public Health Impact: LEAP study results indicate that high-risk infants who consumed a snack containing peanut prevents them from developing the allergy. The LEAP study was the first randomized trial that prevented food allergy in a large cohort of high-risk infants. The LEAP-On follow-up study demonstrated that peanut consumption could be stopped for at least one year without impacting a child’s ability to tolerate peanut.

Five years prior to the publication of the LEAP results, an expert panel convened by NIAID of the NIH issued a report entitled Guidelines for the Diagnosis and Management of Food Allergy in the United States. Because of a lack of definitive studies at the time, the report did not offer strategies for the prevention of peanut allergy. However, in light of the results of the LEAP trial, another expert panel was convened in 2015 to review new evidence. After reviewing the evidence, the expert panel concluded that the “early introduction of peanut will result in the prevention of peanut allergy in a large number of infants.” The expert panel developed 3 addendum guidelines to the earlier report that provide guidance to healthcare providers on the early introduction of peanuts into the diets of infants. The final document entitled Addendum Guidelines for the Prevention of Peanut Allergy in the United States: Report of the NIAID–Sponsored Expert Panel was published in January 2017. The entire report may be found at https://www.niaid.nih.gov/sites/default/files/addendum-peanut-allergy-prevention-guidelines.pdf.


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  • Clinical Data Management
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  • Protocol Design/Development
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