Persistence of Oral Tolerance to Peanut (LEAP-On)

The Persistence of Oral Tolerance Induction to Peanut and Its Immunological Basis (ITN049AD)

ITN049AD (LEAP-On) Study is a continuation of the ITN032AD LEAP Study (NCT00329784).

Peanut Allergy, a recognized public health concern, is a common and potentially life-threatening food allergy for which there is no treatment. ITN032AD (LEAP) Study evaluated whether early exposure to peanut promotes tolerance and provides protection from developing peanut allergy in children who are allergic to eggs or who have severe eczema. ITN049AD (LEAP-On) Study will evaluate persistent tolerance to peanut by assessing the effect of twelve months of cessation of peanut consumption in LEAP Study participants who consumed peanut and those who avoided peanut over the previous five years.

Study Overview

• Status: Completed
• Conditions: Egg Allergy; Hypersensitivity; Eczema; Food Allergy
• Intervention / Treatment: Other: Avoidance of peanut

Detailed Description

This is a two-sample comparison employing all available study participants in both arms of the LEAP (NCT00329784) study at visit 72. After obtaining informed consent, LEAP participants who are evaluable for peanut allergy at age 60 months (V60) will be enrolled into this study, the LEAP-On (NCT01366846) Study. All LEAP-On participants will avoid peanut for an additional 12 months regardless of their previous allocation to the LEAP Study consumption arm (Group A) or the LEAP Study avoidance arm (Group B).

At V72, after 12 months of this new intervention, all participants will have skin prick testing (SPT), specific IgE and a repeat oral challenge to peanut to determine the frequency of peanut allergy in both groups. The LEAP Study decision table will be used to determine the presence of peanut allergy. Briefly, peanut allergy will be based on the presence of a positive oral peanut challenge with objective signs of allergy. Tolerance will be established on the basis of a negative oral peanut challenge (tolerating 5 g of peanut protein in the absence of symptoms). For participants who do not have an oral challenge or an oral challenge at V72 with a determinate outcome, the following criteria will be used to determine their outcome at V72:

• If the participant is tolerant and has an IgE > 0.1 and/or SPT > 0 mm at V60, the participant will be considered non-evaluable and will not be included in the analysis.
• For all other participants, the V60 outcome will be applied to the V72 outcome (last observation carried forward).

Predictive values of peanut-specific IgE and/or SPT will not be used in the LEAP-On study because participants in the peanut consumption arm in the LEAP study are tolerating peanuts despite having high IgE and/or SPT.

• Study Type: Interventional
• Enrollment (Actual): 556
• Phase: Phase 2

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE1 7EH
    • Evelina Children's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 years to 5 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• All LEAP Study participants who are evaluable for peanut allergy at year 5 by LEAP (ClinicalTrials.gov ID NCT00329784) Study criteria.
• Parent or guardian willing to provide informed consent.

Exclusion Criteria:

• Unable or unwilling to comply with study intervention and procedures.
• Participation in other food allergy intervention trials.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Peanut avoidance after continuous peanut consumption; These participants were the peanut consumption group of the ITN032AD (LEAP) study	Other: Avoidance of peanut; All participants will be assigned to peanut avoidance as per United Kingdom (UK) public health recommendations and will avoid exposure to peanut protein during the study until the last study visit when they will receive the Oral Food Challenge.
Experimental: Continued peanut avoidance; These participants were the peanut avoidance group of the ITN032AD (LEAP) study	Other: Avoidance of peanut; All participants will be assigned to peanut avoidance as per United Kingdom (UK) public health recommendations and will avoid exposure to peanut protein during the study until the last study visit when they will receive the Oral Food Challenge.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Skin Prick Test Stratum	At 72 months of age, eligible participants were given an oral food challenge (oral intake of 5g of peanut protein in a single dose). Participants were considered to not have peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 13.7g of peanut protein administered in increments. These participants were considered to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have PA.	72 months
Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Treatment Group	At 72 months of age, eligible participants were given an oral food challenge (oral intake of 5g of peanut protein in a single dose). Participants were considered to have no peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 13.7g of peanut protein administered in increments. These participants were considered to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have PA.	72 months
Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Skin Prick Test Stratum in the Per Protocol Population	At 72 months of age, eligible participants were given an oral food challenge (oral intake of 5g of peanut protein in a single dose Participants were considered to have no peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 13.7g of peanut protein administered in increments. These participants were considered to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have peanut allergy.	72 months
Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Treatment Group in the Per Protocol Population	At 72 months of age, eligible participants were given an oral food challenge (oral intake of 5g of peanut protein in a single dose Participants were considered to have no peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 13.7g of peanut protein administered in increments. These participants were to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have PA.	72 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Peanut Allergy (PA) at 60- and 72-month Visits Within the Peanut Avoidance After Peanut Consumption Group	At 60 and 72 months of age, eligible participants were given an oral food challenge (intake of 5g of peanut protein in a single dose). Participants were considered to have no peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 9.4g/13.7g (month 60/month 72) of peanut protein administered in increments. These participants were considered to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have PA.	60 months and 72 months
Number of Peanut Avoidance After Peanut Consumption Group Participants With Peanut Allergy (PA) at 60- and 72-month Visits Within in the Per Protocol Population	At 60 and 72 months of age, eligible participants were given an oral food challenge (intake of 5g of peanut protein in a single dose). Participants were considered to have no peanut allergy (PA) if they experienced no reaction following the food challenge. Those who did react were offered a double-blind, placebo-controlled food challenge with a total of 9.4g/13.7g (month 60/month 72) of peanut protein administered in increments. These participants were considered to have PA if they experienced a reaction at any point during the dose escalation. For participants for whom data from the oral food challenge were either inconclusive or not available, a diagnostic algorithm based on the results of a SPT and the values for peanut-specific IgE were used to determine whether or not a participant should be considered to have PA.	60 months and 72 months

Collaborators and Investigators

• Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
• Collaborators: Immune Tolerance Network (ITN)
• Investigators: Study Chair: Gideon Lack, MD, Evelina Children's Hospital

Publications and helpful links

General Publications

• Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, Brough HA, Phippard D, Basting M, Feeney M, Turcanu V, Sever ML, Gomez Lorenzo M, Plaut M, Lack G; LEAP Study Team. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015 Feb 26;372(9):803-13. doi: 10.1056/NEJMoa1414850. Epub 2015 Feb 23. Erratum In: N Engl J Med. 2016 Jul 28;375(4):398.
• Santos AF, Du Toit G, Lack G. Is the use of epinephrine a good marker of severity of allergic reactions during oral food challenges? J Allergy Clin Immunol Pract. 2015 May-Jun;3(3):429-30. doi: 10.1016/j.jaip.2014.12.009. No abstract available.
• Gruchalla RS, Sampson HA. Preventing peanut allergy through early consumption--ready for prime time? N Engl J Med. 2015 Feb 26;372(9):875-7. doi: 10.1056/NEJMe1500186. Epub 2015 Feb 23. No abstract available.
• Du Toit G, Sayre PH, Roberts G, Sever ML, Lawson K, Bahnson HT, Brough HA, Santos AF, Harris KM, Radulovic S, Basting M, Turcanu V, Plaut M, Lack G; Immune Tolerance Network LEAP-On Study Team. Effect of Avoidance on Peanut Allergy after Early Peanut Consumption. N Engl J Med. 2016 Apr 14;374(15):1435-43. doi: 10.1056/NEJMoa1514209. Epub 2016 Mar 4.

Helpful Links

• National Institute of Allergy and Infectious Diseases (NIAID) website
• LEAP Study informational website
• Immune Tolerance Network website

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): May 1, 2015
• Study Completion (Actual): May 1, 2015

Study Registration Dates

• First Submitted: June 2, 2011
• First Submitted That Met QC Criteria: June 2, 2011
• First Posted (Estimate): June 6, 2011

Study Record Updates

• Last Update Posted (Actual): March 10, 2017
• Last Update Submitted That Met QC Criteria: January 30, 2017
• Last Verified: January 1, 2017

More Information

Terms related to this study

• Keywords: Peanut
• Additional Relevant MeSH Terms: Immune System Diseases; Hypersensitivity, Immediate; Hypersensitivity; Egg Hypersensitivity; Food Hypersensitivity
• Other Study ID Numbers: DAIT ITN049AD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: ITN049AD (LEAP-On) is a continuation of the ITN032AD LEAP Study. The plan is to share data in: 1.) ImmPort, a long-term archive of clinical and mechanistic data from DAIT-funded grants and contracts; and 2.)TrialShare, a clinical trials research portal developed by the Immune Tolerance Network.

Study Data/Documents

1. Individual Participant Data Set
   Information identifier: LEAP-On (ITN049AD)
2. Study protocol synopsis; datasets and figures from published NEJM 2016 article
   Information identifier: LEAP-On (ITN049AD)