10 October 2007
Stem cell project to replace animal toxicity tests
A new government-backed initiative to use embryonic stem cells for toxicity testing in drug development was launched on 2 October.
The project, called Stem Cells for Safer Medicine, could replace some animal use in liver toxicity screening of drugs. £1 million is being invested in the first year, in a five-year £10 million programme. The initial projects will aim to develop human embryonic stem cells into liver tissue in vitro.
Large pharmaceutical companies involved in the project, such as AstraZeneca and GlaxoSmithKline, acknowledge that animal models for toxicity testing of drugs fall far short of being reliable predictors of the clinical situation. This is a significant problem, because liver toxicity is the single biggest cause of failure of new drugs.
Professor Ian Cotgreave of AstraZeneca stated that pre-clinical regulatory testing for liver toxicity gives no better predictability than random chance. There is a problem with false positives; often drugs pass tests in two animal species but fail for safety reasons in phase I clinical trials. In these situations, tests on human liver cells in vitro might have revealed what animal tests did not, and at a much earlier stage of drug development, saving huge amounts of money and time as well as animals’ lives.
Stem Cells for Safer Medicine, which is backed by the Medical Research Council and the Department for Universities, Innovation and Skills, aims eventually to produce stem cells specific to different genetic profiles, to predict the effects of drugs on different patient populations.