In the US, big pharma worries about public reaction, given that the use of human embryos is controversial, and so they've left the field to universities and biotechnology businesses. More companies, however, are expected to join, according to Philip Wright, science director at the Association of the British Pharmaceutical Industry, who will also serve as chief executive of SC4SM.
SC4SM is the international pharmaceutical industryâ€™s first public-private partnership on human embryonic stem cells, following a recommendation by a 2005 report on the future of stem cell research in Britain. "It has taken a long time to set up because of the sensitivities. We have an ethical framework that says we should only use existing embryonic stem cell lines [in the UK stem cell bank] and next year we will have an independent ethics advisory board to provide further advice," says Wright.
The first phase of a five-year, $20 million program will focus on producing liver cells. Ian Cotgreave, head of molecular toxicity for AstraZeneca, says "the liver is a key organ for toxicity. It is the dustbin of the body, which neutralizes and destroys drugs and toxins.â€
Unexpected liver toxicity is the biggest single reason why medicines fail during trials. AstraZenecaâ€™s Exanta, a blood-thinning drug, was a recent casualty. Animal tests had given no clue to this problem, Cotgreave confides. â€œThe predictability for liver toxicity from pre-clinical regulatory testing is almost as good as tossing a coin.â€
SC4SM plans to fund five projects over the next year, aimed at converting human embryonic stem cells into liver cells, which should be a more reliable guide to a new drugâ€™s effect on the human liver. Two biotech companies with research labs in Dundee â€“ CXR Biosciences and Cellartis â€“ are working on liver cells for toxicity and are likely to be involved.
The consortiumâ€™s long term strategy will include the conversion of stem cells into other cell types. The second target will be cardiomyocytes (heart cells). SC4SM will not investigate the therapeutic use of stem cells directly to treat disease, though it will collaborate with researchers who are doing so.