April 25, 2024

Have embryonic stem cells crashed and burned?

This is the way the joyride ends: Not with a bang but a whimper. An elevated epigraph seems appropriate for the final act of a dream which has sustained public support for human embryonic stem cell (hES cell) research for a decade. Only a year after launching a human trial for spinal cord injuries Geron Corp has pulled the plug on all stem cell research to focus on cancer drugs.

This is the way the dream ends: Not with a bang but a whimper. An elevated epigraph seems appropriate for the final act of a drama which has sustained public support for human embryonic stem cell (hES cell) research for a decade. Only a year after launching a human trial for spinal cord injuries Geron Corp has pulled the plug on all stem cell research to focus on cancer drugs.

For some it was a tragedy. Daniel Heumann, a board member of the Christopher and Dana Reeve Foundation, said: “I’m disgusted. It makes me sick. To get people’s hopes up and then do this for financial reasons is despicable. They are treating us like lab rats.”

His exasperation is understandable. A cure for spinal cord injury was the Ultima Thule of hES cell research. Quadriplegic Christopher Reeve became an icon for the campaign to use hES cells. In the light of his courage and strength of personality, ethical reservations became petty quibbles and the sour scowls of naysayers. He was convinced that he and other would one day walk again thanks to the mysterious powers of hES cells. This hope created the US$3 billion California Institute for Regenerative Medicine (CIRM). It persuaded legislators in other states and countries to authorise embryo research.

But it these hopes have crashed and burned. Only one other company now specialises in hES cells. What killed Geron’s hopes was cash, not ethics. Its share price had plummeted from US$6.34 to $1.60 over the past year and its hyper-optimistic CEO, Thomas Okarma, departed in February. Investors have been burnt. The Street, a financial news service, said caustically:

“Geron’s ignominious reputation as a serial money-raiser that only succeeded in leaving investors holding the bag may forever tarnish the entire embryonic stem cell field in Wall Street’s eyes. The risk it too great, the payoff (if it ever comes) is too far off.”

In interviews scientists put on a brave face, but the news is a huge blow to supporters of the therapeutic potential of hES cells. In particular, the CIRM, founded and funded by taxpayers precisely to exploit that potential, is looking more and more like a gigantic white elephant.

As critics of the ethically contentious treatment have argued for years, it now seems clear that embryonic stem cells will not lead to miracle cures. “Advances in the stem cell field are disruptive innovations that have the potential to supersede earlier innovations, hES cells being one of those. I don’t know if Geron looks at it that way, but I do,” Roger Pedersen, a leading stem cell scientist at Cambridge, told ScienceInsider.

Embryonic stem cells may have been the most hyped scientific innovation of a generation. Is there any hope left after the hype? Yes, says New Scientist, in its response to the startling news of Geron’s failure.

Treatments based on adult stem cells are undoubtedly in the lead, with some very encouraging results this year… So at the moment, adult cells are leading the way clinically? Absolutely. For instance, there are almost 200 trials under way globally using mesenchymal stem cells extracted from bone marrow. In terms of sheer numbers and commercial potential, they are way in front.”

Michael Cook
embryonic stem cells