Original Article
Preparation and Analysis of Peanut Flour Used in Oral Immunotherapy Clinical Trials

https://doi.org/10.1016/j.jaip.2016.11.034Get rights and content

Background

Oral immunotherapy (OIT) is an investigational therapeutic approach for the treatment of food allergies. Characterization of the drug product used in oral immunotherapy trials for peanut allergy has not been reported.

Objective

To quantify relative amounts of the major peanut allergens and microbial load present in peanut flour used in OIT trials and assess whether these parameters change over a 12-month period. We also anticipate that this report will serve as a guide for investigators seeking to conduct OIT trials under Food and Drug Administration–approved Investigational New Drug applications.

Methods

Densitometric scanning of Ara h 1 and Ara h 2 resolved on SDS-PAGE gels was used to assess allergen content in peanut flour extracts. Microbial testing was conducted on peanut flour under US Pharmacopeia guidelines for the presence of Escherichia coli, salmonella, yeast, mold, and total aerobic bacteria. In addition, aflatoxin was quantified in peanut flour. Reported results were obtained from 4 unique lots of peanut flour.

Results

Relative amounts of the major peanut allergens were similar between different lots of peanut flour and remained stable over a 12-month period. E coli and salmonella were absent from all lots of flour. Yeast, mold, total aerobic bacteria, and aflatoxin were within established US Pharmacopeia guidelines on all lots tested and remained within the criteria over a 12-month period.

Conclusions

Peanut flour used as a drug product contains the major peanut allergens and has low levels of potentially harmful microbes. Both these parameters remain stable over a 12-month period.

Section snippets

Drug manufacturing process

The overall process of drug manufacturing occurs in several stages: (1) bulk peanut flour is received; (2) the bulk flour is tested for compliance with established US Pharmacopeia guidelines for the presence of microbes (see Table I); (3) the bulk flour is examined for the presence of Ara h 1 and 2 and their consistency in relative quantity to a reference standard and the previous lot of peanut flour; (4) finally, the peanut flour is used to manufacture drug product doses. For the initial

Ara h 1 and Ara h 2 are present in lightly roasted peanut flour

As part of the process for the acceptance of the raw material (drug substance, ie, bulk peanut flour) our group performed analysis of every peanut flour lot before being used for the manufacturing of the drug product. Part of the assessment is confirming the identity of the product. Our group and others have demonstrated the presence of Ara h 1 and Ara h 2 in peanut flour.22, 23 The native proteins have been isolated and their genes cloned.24 Figure 1 shows an SDS-PAGE gel with purified Ara h 1

Discussion

OIT holds great promise as a treatment modality for food allergies, including peanut allergy.28 OIT is administered in exact quantities using an investigational drug product manufactured from peanut flour. Peanut flour is a fairly crude drug product in that it contains the active ingredients (ie, peanut allergens) along with presumably inert ingredients including nonallergenic proteins, carbohydrates, lipids, micronutrients, and so forth. Therefore, the source material needs to be consistent

References (34)

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This work was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health (Award Number AI068074) and by the National Center For Advancing Translational Sciences of the National Institutes of Health (Award Number UL1TR001117).

Conflicts of interest: J. P. Berglund has received consultancy fees from the University of North Carolina and Etubics Corporation. B. Burnett is employed by Duke University. A. W. Burks has received research support from the Food Allergy & Anaphylaxis Network, National Institutes of Health (NIH), and Wallace Research Foundation; has received personal fees from Food Allergy Research and Education for being Chairman (2013-2015) and a member of the research advisory board; was a board member for the NIH Allergy, Immunology, and Transplantation Research Committee Review Panel, NIH Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section, and World Allergy Organization; has received consultancy fees from Aimmune Therapeutics, Epiva Biosciences, Genentech, Merck, Regeneron Pharmaceuticals, Stallergenes, Sanofi US Services, and Valeant Pharmaceuticals North America; received personal fees as an independent contractor for pharmaceutical product development; and is a minority stockholder of Allertein. M. Kulis has received research support from NIH-National Institute of Allergy and Infectious Diseases and the Department of Defense and is employed by the University of North Carolina at Chapel Hill. The rest of the authors declare that they have no relevant conflicts of interest.

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