EPL provides routine peer reviews, a specialized type of third-party review assuring accuracy and data quality in a toxicology study.

EPL pathologists, Drs. Peter C. Mann and Jerry F. Hardisty, authored a book chapter that serves as an informative and resourceful reference on the purpose of and how peer reviews are conducted (Mann and Hardisty, 2013).  The chapter covers everything from qualifications of a peer review pathologist to how the different types of peer reviews are conducted and the peer review statement.  The chapter also provides numerous suggested references that are useful in understanding peer reviews as a component of your development program.

While the main purpose of a peer review is to improve the quality of the pathology data and narrative, it is important to note what a peer review is not.  A peer review is not a re-read of a study, but rather a review of a defined subset of organs/tissues from the study. This review is where the peer review pathologist brings a level of expertise either in the study type, mechanism of the findings, current diagnostic criteria and nomenclature or class-effect that the study pathologist may not have rather than generating a second set of data but.  The pathology data in a study are generally improved because of the experience or expertise of the peer review pathologist, increasing confidence in the pathology data in the decision process during the development program.

Another potential benefit to your development program is that many EPL pathologists routinely perform peer reviews for sponsors who do not have inhouse pathology expertise.  In these instances, the EPL pathologist is a scientific partner and provides continuity across studies with regards to how the pathology findings are recorded and helps to prevent discrepancies in data interpretation, improving your pathology data.

Types of peer reviews:

Prospective formal peer review.  Unlike the prospective informal peer/consultation review, the formal peer review is fully documented in a peer review memorandum or peer review statement.  The conduct of the formal peer review and the peer review pathologist is included in the study protocol either when the protocol is being generated or by protocol amendment.  See the chapter referenced below to understand better the generally applied criteria used in developing a formal peer review of a subset of high dose and control animals and potential target tissues.

Retrospective peer review.  In some instances, a formal peer review may be conducted after a study has been completed and the pathology report has been signed and dated.  This type of peer review is requested when there is a specific issue regarding a target tissue or diagnostic criteria used.  The methodology is identical to the prospective formal peer review with an important difference: all changes in the study data must be fully documented, and an audit trail must be produced.  Because the study is finalized, it is required that an Amended Study Report be issued to incorporate and changes to the pathology data set and study conclusions.

Using specialized software and other established systems, EPL has unparalleled experience conducting pathology peer reviews and Pathology Working Groups for government and industry clients in the United States and abroad. We have the staff and experience to perform all types of peer reviews.  Please contact us to discuss your peer review needs.


Mann, P.C., Hardisty, J.F., 2013. Peer Review and Pathology Working Groups. In: Haschek, W.M., Rousseaux, C.G., Wallig, M.A. (Eds.), Haschek and Rousseaux’s Handbook of Toxicologic Pathology. Elsevier Inc., Academic Press, pp. 551–564.

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Please contact EPL if you want to discuss peer reviews.