Human embryonic stem cells could "revolutionise" drug discovery and testing, according to an article in the latest issue of the journal Nature Reviews Drug Discovery. There are significant problems to be overcome before the cells can be commercially useful, but their potential is enormous, contend Colin Pouton and John Haynes, of the Department of Pharmaceutical Biology, at Monash University in Melbourne. ESCs can be used for primary screens, secondary pharmacology, safety pharmacology, metabolic profiling and toxicity evaluation. Drug discovery will be more efficient and fewer experiments on animals and people will be needed.

Admittedly, it is still proving difficult to make embryonic stem cells differentiate into other cell types properly, an essential requirement for reliable testing. However, when this hurdle is overcome, they will "certainly provide commercial opportunities for innovative small and medium-sized enterprises."

Indeed, this may already be happening, the article hints. "Advances in stem-cell technology have considerable commercial potential, which means that it is possible that the published [academic] literature lags behind commercial activity and the patent literature," it says. Since 2001, 246 patent applications with the words "embryonic stem cells" in their abstract have been published in the US.