Alternative Models of Developmental and Reproductive Toxicity in Pharmaceutical Risk Assessment and the 3Rs

In the pharmaceutical industry, preclinical developmental and reproductive toxicity studies are conducted in laboratory animals in order to predict and prevent adverse effects of drugs on human reproductive health and development. However, these studies require a relatively large number of animals and are usually conducted late in the drug development process. Early, simple, and inexpensive screening assays could facilitate smarter decisions, reductions in animal use, and development of safe drugs. The current state and future needs for alternative models of developmental and reproductive toxicity are reviewed here. The most popular predictive developmental toxicity assays are embryonic stem cells, rodent whole embryo culture, and zebrafish, each of which involves fairly well-developed techniques with demonstrated utility in drug discovery and development. In vitro or ex vivo methods for male and female reproductive toxicity are less established, but there are promising assays available or being developed that may be useful in drug development, especially for elucidating mechanisms or screening backup compounds. While a number of challenges remain, much progress has been made in alternative developmental and reproductive toxicity models to date, and there is a strong collective enthusiasm in the industry to continue moving them forward. Therefore, it appears that these approaches may be widely used in the near future.