EPA continues to validate ToxCast screening tool by testing more than 100 drugs

The U.S. Environmental Protection Agency will continue validating its ToxCast screening tool by screening more than 100 drugs provided by Pfizer, GlaxoSmithKline, Sanofi-Aventis, and Merck. These drugs never entered the marketplace because they demonstrated different types and levels of toxicity when the pharmaceutical companies conducted the early stage clinical trials required by the Food and Drug Administration as part of the drug development process. EPA researchers will quickly screen the drugs and then compare those results with the clinical trial results. Assessment of the similarities and differences in the results will improve EPA's ability to screen chemicals for toxicity.

"For the first time, we'll have both ToxCast screening data and results from toxicology studies and human clinical trials," said Dr. Paul Anastas, EPA's assistant administrator of the Office of Research and Development. "This is an important step in accessing the treasure trove of data that the pharmaceutical industry has in ways that helps protect human health and the environment."

Because of the high cost and the long process of conducting chemical testing, only a small fraction of the thousands of available chemicals have been assessed for potential human health risk. EPA is using its ToxCast screening tool to help efficiently understand how chemicals may impact processes in the human body that could lead to adverse health effects. Currently, ToxCast includes 500 automated chemical screening tests that have assessed more than 300 environmental chemicals.

The clinical trial data will help EPA select the ToxCast screening tests and biological profiles that are the most predictive. The tests and profiles will be used as indicators of potential toxicity for future chemical screening. The ToxCast screening results will be available online for scientists and the interested public to use.

This collaboration was fostered by the International Life Sciences Health and Environmental Science Institute, a non-profit organization of international scientists representing academia, industry, regulatory agencies, and government institutions that come together to reach consensus on complex scientific questions. The organization adopted the inclusion of failed drug candidates into ToxCast as their emerging issue of 2009.

Source: U.S. Environmental Protection Agency