Peanut Oral Immunotherapy in Children: IMPACT Follow Up Study

This application is being submitted as a follow-up to Protocol "Oral Immunotherapy for Induction of Tolerance in Peanut Allergic Children-The IMPACT Study." The IMPACT study was a double-blind, placebo-controlled study of peanut oral immunotherapy in children 12-48 months of age. As part this protocol, all participants who received placebo treatment were promised the opportunity to receive open label treatment at the conclusion of the double-blind phase and initial follow-up. At the time of submitting that protocol, the investigator did not specify any detailed protocol for the open label crossover treatment, as this is an evolving field, but the investigator is now ready to offer this open label treatment as promised.

This study will enroll up to 20 subjects aged 4-9 years old who were enrolled in the placebo arm of the IMPACT study.

Once subjects have completed participation in the IMPACT study, subjects will be offered the option of participating in this open label, peanut oral immunotherapy study.

After the informed consent has been signed, subjects will undergo an initial dose escalation to peanut protein to establish the starting dose for the build-up phase. The starting dose of peanut protein for the build-up phase will be the highest tolerated dose during the initial dose escalation. The subject will return to the study site and the first starting dose of peanut protein will be given under observation. Subjects will be sent home with doses of peanut protein to administer at home.

Subject will return every 2 weeks for dose adjustments. Once subjects have tolerated a dose under observation, subjects will then continue dosing at home with OIT and return to the research unit every 2 weeks for a 1-step dose escalation to a maximum daily dose of 1000 mg. Participants who do not reach the 1000mg dose by 40-weeks of build-up phase may enter the maintenance phase at their highest tolerated dose.

When subjects reach their maximum tolerated dose of either 1000 mg per day, or the maximum tolerated dose during the 40 weeks of the build-up phase, subjects will enter the maintenance phase. Subjects will continue daily dosing of peanut protein at the maximum tolerated dose during the 12-week maintenance phase.

At the end of the maintenance phase, subjects will undergo an open peanut oral food challenge to a maximum of 4000 mg of peanut protein to determine individualized guidelines for the introduction of peanut into the subject's diet based on the outcome of the open peanut challenge The primary objective of this protocol is to provide open label peanut oral immunotherapy (OIT) for those subjects who received placebo treatment in the IMPACT Study .

Secondary objectives will include:

1. Efficacy of the treatment, as defined by an end of treatment oral peanut challenge.

Safety, as measured by the incidence of adverse events and the proportion of subjects who discontinue treatment due to adverse events

Eligibility Criteria:
Inclusion Criteria:

Patients who meet all of the following criteria are eligible for enrollment as study participants, including participants who:

* Subjects who were randomized to the placebo arm of protocol NA_00077852 "Oral Immunotherapy for Induction of Tolerance in Peanut Allergic Children."
* Parent guardian must be able to understand and provide informed consent
* Peanut allergy, as defined by a reaction to a cumulative dose of ≤1000 mg of peanut protein during the End-of-Treatment food challenge from Protocol NA_00077852 "Oral Immunotherapy for Induction of Tolerance in Peanut Allergic Children"

Exclusion Criteria:

Patients who meet any of these criteria are not eligible for enrollment as study participants, including participants who:

* Inability or unwillingness of a parent guardian to give written informed consent or comply with study protocol
* History of severe anaphylaxis to peanut, defined by severe hypoxia, hypotension, neurological compromise, confusion, cardiovascular collapse, or loss of consciousness
* Significant chronic disease (other than asthma, rhinitis, or atopic dermatitis) requiring therapy; e.g., heart disease or cystic fibrosis which is judged by the investigator to have potential impact on study outcomes or safety.
* Severe or poorly controlled atopic dermatitis per investigator's discretion
* Past or current history of eosinophilic gastrointestinal disease
* Diagnosis of asthma that meets any of the following criteria:

  * Uncontrolled asthma (as per Global Initiative for Asthma \[GINA\] latest guidelines)
  * History of 2 or more systemic corticosteroid courses or 1 systemic course within the 3 previous months prior to visit 1 for treating wheezing
  * Prior intubation/mechanical ventilation for asthma
* Currently receiving β-blocking agents, angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, calcium channel blockers or tricyclic antidepressant therapy.
* Current participation in another clinical trial or participation in another clinical trial in the last 90 days