Persistence of Oral Tolerance to Peanut
Condition: Eczema; Egg Allergy; Food Allergy; Hypersensitivity
MeSH terms: Hypersensitivity; Food Hypersensitivity; Egg Hypersensitivity
Study type: Interventional
Phase: Phase 2

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 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.
    

Intervention name(s): Avoidance of peanut
Intervention type(s): Other
Intervention description(s): 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.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Peanut