Clinical Trial: Persistence of Oral Tolerance to Peanut

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

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

Brief Summary:

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.


Detailed Summary:

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

Current Primary Outcome:

  • Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Skin Prick Test Stratum [ Time Frame: 72 months ]
    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.
  • Number of Participants With Peanut Allergy (PA) at 72 Months of Age - by Treatment Group [ Time Frame: 72 months ]
    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

    Original Primary Outcome: Proportion of participants with peanut allergy at year 6 in the group who consumed peanut and the group who avoided peanut in the LEAP Study [ Time Frame: Year 6 ]

    Current Secondary Outcome:

    • Number of Participants With Peanut Allergy (PA) at 60- and 72-month Visits Within the Peanut Avoidance After Peanut Consumption Group [ Time Frame: 60 months and 72 months ]
      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.
    • 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 [ Time Frame: 60 months and 72 months ]
      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.


    Original Secondary Outcome:

    • Proportion of participants with peanut allergy at year 6 in the group who consumed peanut in the LEAP Study [ Time Frame: Year 6 ]
    • Proportion of subjects with allergic sensitization to selected ingested and inhaled allergens, and with seasonal rhino-conjunctivitis, perennial rhinoconjunctivitis, and asthma. [ Time Frame: Year 6 ]
    • Incidence of adverse events, and nutritional evaluations. [ Time Frame: Year 6 ]
    • Results of cellular and humoral assessments of immune response related to the development of allergy or tolerance to specific allergens. [ Time Frame: Year 6 ]


    Information By: National Institute of Allergy and Infectious Diseases (NIAID)

    Dates:
    Date Received: June 2, 2011
    Date Started: May 2011
    Date Completion:
    Last Updated: January 30, 2017
    Last Verified: January 2017