The embryonic stem cell test for the early selection of pharmaceutical compounds.

Potential teratogenicity is a major consideration in the development of pharmaceutical substances. Currently its assessment involves large numbers of animal tests at high cost. This study assessed the feasibility of using the embryonic stem cell test (EST), validated by ECVAM in 1999, as a tool for the prediction of embryonic toxicity of pharmaceutical substances early in their development programmes. ESTs were carried out on 6 chemicals with well established toxicity characteristics established from literature and from the ECVAM study, and then on 10 Roche internal pharmaceutical substances already tested in vivo. The model correctly classified 81% of the substances. Further experiments are necessary to increase the database of the assay.