Geron, the company that helped pioneer human embryonic stem (hES) cell research, said yesterday that it is stopping its first-in-the-world clinical trial and pulling out of further stem cell work. The company, based in Menlo Park, California, will instead concentrate on its anticancer therapies, CEO John Scarlett said in a statement. "Deciding to move out of the stem cell business was a very difficult decision to make," he told investors and journalists this morning.
Geron helped to fund the work of James Thomson at the University of Wisconsin, Madison, who in 1998 was the first to isolate hES cells. That agreement gave the company exclusive licenses for a number of hES cell patents. Last year, it launched the world's first clinical trial, which was designed to treat eight patients with spinal cord injury, using neuronal cells derived from hES cells. Four have been treated so far, and Geron says it will continue following them. It will not enroll any new patients, however. The company returned a $6.5 million loan from the California Institute for Regenerative Medicine (CIRM), a taxpayer-funded body set up to support research on stem cells, especially hES cells. CIRM agreed earlier this year to loan Geron up to $25 million to fund the trial.
Scarlett, who joined the company in late September, said the decision allows Geron to continue operating without raising new money for the next year and a half, when it expects results from a half-dozen phase II trials of two cancer drugs. As part of the stem cell downsizing, the company will cut 66 full-time positions, 38% of its workforce.
Stephen Kelsey, Geron's chief medical officer, said in the conference call that so far patients showed neither significant side effects nor any improvement in their condition. Given the small scale of the study, he said, stopping early may not be such a loss. "We applied for and received permission to run a very small safety study with a low dose of cells," he said. "We're halfway through, and the data have been remarkably consistent. We will be reporting the results, and it will be a fair reflection of what would have happened if we had completed the study."
Some observers had reservations about the trial from the start, worrying that the animal results were not strong enough to justify a human trial. But many had been pulling for the company nonetheless. "It's with a sense of loss that I see this news," says Roger Pedersen of the University of Cambridge in the United Kingdom, who was one of the researchers to receive funding from Geron in the mid-1990s to attempt to derive hES cells. He says the company may be reacting not only to the long timeline to bring cell therapies to the clinic, but also to a possible weakening of its intellectual property portfolio. The development of induced pluripotent stem (iPS) cells, which are adult cells genetically reprogrammed to resemble embryonic ones, means that Geron's exclusive licenses may be worth less. "Advances in the stem cell field are disruptive innovations that have the potential to supercede earlier innovations, hES cells being one of those. I don't know if Geron looks at it that way, but I do," Pedersen says.