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High Threshold Peanut Challenge Study

Study Purpose

This protocol is designed to better characterize a sub-population of peanut sensitized individuals who may be non-allergic, despite significant sensitization, or who may be allergic, but at high threshold doses. By specifically targeting participants who met the initial screening criteria of the active adult PN OIT study, Protocol 2012p002153 / AADCRC MGH-004 (MGH-004), but failed to react during the pre-treatment 443 mg challenge to peanut, the investigators anticipate that the investigators will identify individuals who have become spontaneously tolerant, despite persistent sensitization. The investigators might also find that clinical sensitivity persists but only with higher thresholds, or that sensitivity has increased (or is variable) since the previous allergen exposure. By repeating DBPCFCs through to a full serving dose (7.4 gram), the investigators will distinguish participants who react only at higher doses from those who were not truly peanut allergic, address whether their sensitivity has changed, and have the opportunity to further investigate their immune response to peanut allergen.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

No
Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.


An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.


Searching Both is inclusive of interventional and observational studies.

Interventional
Eligible Ages 7 Years - 55 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - Failure to react to 443 mg of peanut protein during the DBPCFC1 visit of protocol 2012p002153 / AADCRC MGH-004.
  • - Males and females of all ethnic/racial groups aged 7-55 years old who are otherwise healthy.
  • - Willingness to sign consent (or for parent/guardian to sign consent).
  • - Willingness to sign the assent form, if consent provided by parent/guardian.

Exclusion Criteria:

- History of severe anaphylaxis - Severe or Moderate asthma - Poorly controlled asthma - Diagnosis of other severe or complicating medical problems, including autoimmune or chronic immune inflammatory conditions or gastrointestinal inflammatory conditions - Inability to cooperate with and/or perform oral food challenge procedures - Primary Immune Deficiency - Current use of beta blockers, angiotensin converting enzyme inhibitors, or monoamine oxidase inhibitors - Women of childbearing potential who are pregnant, planning to become pregnant, or breastfeeding - Use within the past 6 months of other systemic immunomodulatory treatments - Clinical signs or symptoms of anemia - Hematocrit <0.36 for adult females or <0.38 for adult males - Hematocrit <0.34 for children 7-18 years of age - Weight <23 kg

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.

NCT02698033
Phase

Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

N/A
Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Massachusetts General Hospital
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Wayne G Shreffler, MD, PhD
Principal Investigator Affiliation Massachusetts General Hospital
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Other, NIH
Overall Status Active, not recruiting
Countries
Conditions

The disease, disorder, syndrome, illness, or injury that is being studied.

Peanut Allergy
Additional Details

The primary objective of the study is to identify and characterize a sub-population of peanut sensitized individuals who are not allergic to peanut and characterize their immunological phenotype in comparison with the low-threshold peanut allergic individuals enrolled in the adult PN OIT study (2012P002153/AADCRC MGH-004). The investigators also wish to identify and characterize the sub-population of high-threshold peanut-allergic individuals who have clinical reactivity to peanut allergen but only at higher doses and characterize their immunological phenotype in comparison with the low-threshold peanut allergic individuals enrolled in the adult PN OIT study (2012P002153/AADCRC MGH-004). Some of the The investigators will identify these high-threshold peanut allergic and sensitized, but non-allergic individuals by recruiting subjects who enrolled in 2012POO2153 but failed to meet all of the inclusion criteria

  • - specifically, they failed to have objective symptoms during a food challenge with a cumulative total dose of 443 mg.
The investigators will then clarify their status by conducting a double-blind placebo-controlled food challenge to peanut, using higher doses of peanut. The investigators will draw blood before and after this food challenge, and collect urine and stool at the time of the challenge for studies of immune mechanisms. The specific clinical, mechanistic, and exploratory objectives are as follows: Clinical Objective: To evaluate the clinical status of peanut-sensitized individuals previously passing a DBPCFC to 443 mg as being either: non-allergic, stably high-threshold allergic or more clinically reactive on repeat exposure. Mechanistic Objectives: To determine whether clinical sensitivity to peanut allergen (as defined by the eliciting dose during food challenge) is directly associated with the relative frequency within a peanut-specific regulatory CD4+ CD45RA- T cell subset (based on expression of CTLA-4, FOXP3, SGMS-1, FANK-1 and other validated iTreg signature genes) before the DBPCFC or 6-8 weeks after the DBPCFC. To determine whether clinical sensitivity to peanut allergen (as defined by the eliciting dose during food challenge) is inversely associated with the the relative frequency within a peanut-specific Th2 effector CD4+ CD45RA- T cell subset (based on expression of GATA-3, RASGRP1, IL4R and other validated Th2 signature genes) before the DBPCFC or 6-8 weeks after the DBPCFC. To determine whether there has been a detectable expansion and/or diversification of Arah2-specific B cells since the previous (PNOIT2 screen fail) peanut allergen exposure and again 6-8 weeks after the DBPCFC by affinity selection of circulating cells and NGS of BCRs and how any such change correlates with clinical tolerance on DBPCFC. To determine whether the extent of either mast cell or basophil reactivity is significantly greater among high-threshold peanut allergic participants that the investigators anticipate identifying in this protocol versus the low-threshold peanut allergic participants already identified. Exploratory Objectives: To describe the gene expression profiles and clonal diversity of regulatory and effector T cell subsets among high-threshold peanut allergic participants versus the low-threshold peanut allergic patients to better understand the phenotype and ontogeny of these subsets and potentially discover new therapeutic pathways. To determine if increases in mast cell activation can be detected through measurement of serum and urinary LTE4 over the course of a large dose exposure to peanut allergen during DBPCFC, and if decreases in LTE4 can be measured as a marker of tolerance. To determine whether microbial dysbiosis is associated with the development of desensitization, oral tolerance, or persistent gastrointestinal adverse events while on oral immunotherapy.

Arms & Interventions

Arms

Experimental: Peanut Flour

Double-blind food challenge with peanut flour

Placebo Comparator: Oat Flour

Double-blind food challenge with oat flour

Interventions

Drug: - Peanut flour

A Double-blind, placebo-controlled food challenge will consist of two challenges performed on separate days. One challenge will consist of 7 doses of peanut given every 20 minutes in increasing amounts up to a total of 7 grams of whole peanut (4 grams of peanut protein) masked by inclusion in vehicle food. The other challenge will consist of placebo material given similarly.

Other: - Toasted oat flour

A Double-blind, placebo-controlled food challenge will consist of two challenges performed on separate days. One challenge will consist of 7 doses of peanut given every 20 minutes in increasing amounts up to a total of 7 grams of whole peanut (4 grams of peanut protein) masked by inclusion in vehicle food. The other challenge will consist of placebo material given similarly.

Contact Information

This trial has no sites locations listed at this time. If you are interested in learning more, you can contact the trial's primary contact:

For additional contact information, you can also visit the trial on clinicaltrials.gov.

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