According to the study, which was published recently in the open access journal PLOS Biology​, less than one-fifth of investigator brochures referenced animal studies were peer-reviewed.

https://www.outsourcing-pharma.com/Article/2018/04/17/Why-is-pharma-grounding-costly-trials-on-low-quality-preclinical-studies-Researchers-ask?utm_source=newsletter_daily&utm_medium=email&utm_campaign=17-Apr-2018&c=B5LaTvdHM6Ch3RvtmfK8HdNifCkCOvzJ&p2=