Less than 10% of drugs which reach clinical development stageactually make it to the marketing stage. This is due to the fact that, duringtests on animals, the effectiveness of the drugs as well adverse side effectson humans can never be fully ascertained. Such high rates of rejection can beavoided by using stem cell technology for pre-clinical tests, thereby savingmillions for drug developers.

According to one estimate, it takes a new drug at least 14years and more than US$ 1 billion from its discovery to being soldcommercially. One big reason is non availability of reliable models to checktoxicity of drugs in humans. Some unsafe drugs like Bextra and Vioxx even getpast the testing stage and are approved for sale, only to be recalled later ata huge loss to the drug companies.

 The excitement about stem cell technology for therapy isunderstandable, but its impact on healthcare through drug development may be themost significant news in the near future. For example, stem cell technology mayprovide an endless supply of heart or liver cells. This alone can result inmillions of dollars of saving in direct testing costs.

 The drug majors like AstraZeneca, GlaxoSmithKline and Rocherecognized the potential of stem cell technology and in 2007, they started anew venture called Stem Cells for Safer Medicines Ltd. This facility will allowthem to develop ways for using human embryonic stem cells to screen potentialnew drugs for any side effects on humans before starting clinical tests.