Stem cell setback?

A week is a long time in stem cell research. On Wednesday 11 September, UK science minister Lord Sainsbury was proudly trumpeting to a conference in London that the UK was fast becoming the natural home of stem cell research, with scientists there making progress at an "astonishing" rate.Just four days later, PPL Therapeutics — the Edinburgh-based company that helped create Dolly the sheep — announced it was closing its stem cell research programme after failing to find any buyers.The timing has understandably raised doubts about whether the hype over the potential for stem cell research in the development of new therapies for devastating diseases is matched by progress in the lab.The company's decision has also highlighted the fact that it's likely to be some considerable time before patients begin to see any large-scale therapeutic benefits from the new technology.PPL, by virtue of its involvement in the Dolly project, is one of the better-known British biotech ventures. But its main focus has been on the use of animals as 'production lines' for new protein treatments for lung disease and cystic fibrosis.Earlier this year, it announced plans to sell off the two elements of its regenerative medicine business: the xenotransplantation programme and the stem cell research project.Despite months of "actively pursuing buyers," the company says, it has failed to secure the sale of either. In a statement detailing its interim accounts, it said it still hoped to find a buyer for the xenotransplantation programme but was pulling the plug on stem cell research. "After a thorough review of the UK stem cell programme, it has become clear that no value can be extracted from this programme at this time and, accordingly, it has been agreed that it should now be closed. A number of patents have been filed and these will be maintained and out-licensed where possible."It's a far cry from two years ago, when PPL announced it was forming a subsidiary company to explore the potential of stem cell-based therapies, initially for diabetes treatment. At the time, confidence shone through. It even predicted the subsidiary could eventually grow into a separate listed company.Its plan — launched under former research director Alan Colman — was to exploit its animal expertise to short-circuit the search for a way of using stem cells to mass produce human insulin-producing islet cells.Scientists elsewhere had already proved that it was possible to use donor islet cells taken from the pancreas to produce insulin in diabetic patients. The problem was, it needed at least three donated pancreases to make enough islet cells to treat just one patient.PPL's plan was to provide an alternative approach by producing animal islet cells from pigs bred to lack both copies of a gene involved in organ rejection. The gene, α-1,3 galactosyl transferase, encodes an enzyme that adds a sugar to the surface of pig cells that is recognised by the human immune system as foreign.But the decision to scrap the project is a business one, insists PPL spokeswoman April D'Arcy, and in no way indicates failure. "This work was at a very early stage and we had not got very far with it. We had only been doing the diabetes work for a very short time, so when we came to selling it, people just were not interested because it had no real value. "But that's not to say the programme was not moving forward, it's just there was no value to people from outside. We had no intellectual property. If a company comes along and wants to take over a business they need to feel they are buying something other than the people doing the work."PPL is adamant the potential for its diabetes treatment strategy remains sound and the closure says nothing about stem cell science failing to come up with the goods. "This is not a setback because lots of other people are doing stem cell research and will continue to do it," says D'Arcy. "There's nothing fundamentally wrong with the research. It's just, at the moment, there's no commercial value to it. "We were in a situation where we had money in the bank but knew if we kept diverting it to research that was not along our core technology lines then we would run out of money faster."Tim Allsop, principal scientist at Stem Cell Sciences Ltd, also based in Edinburgh, believes the message for all fledgling biotech firms is that they have to be in it for the long-term. Stem cell research, he adds, is not about making a fast buck.His company, which has a tie-up with Aventis, is concentrating on the use of embryonic stem cells as a tool for speeding up drug discovery programmes. Its expertise is in mouse embryonic stem cell technology, which it expects will translate well into the human equivalent. But he admits there are some formidable scientific obstacles. "One relates to whether we can get the human cell equivalent to do what we want it to do, in other words control the biology of it. Part of that relates to a much deeper understanding of how cells differentiate. Mouse cells have been worked on for decades and yet there's still a lot more needs to be understood about them. "We would want to show that an embryonic stem cell product would have scored some success within the next five years. And in terms of clinical trials with transplanted embryonic stem cells, we would be hoping for some feedback within five to seven years."

Stem cell setback?

Doubts emerge after the company that created Dolly the sheep shuts stem cell programme.

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