By David Prentice

Editor's note. This first appeared on Dr. Prentice's blog at http://www.frcblog.com/2010/10/geron-begins-questionable-human-experiments

David Prentice

In its usual style, Geron has put out a press release that it has injected the first patient for its trial of embryonic stem cells for spinal cord injury. Of course their main goal is to increase their stock price and cash flow from investment. Not about science, not about helping patients. After all, this is just an announcement that the patient has been injected with millions of cells. No results, no peer-reviewed publication, nada.

Contrary to what most of the news stories report, Geron is not injecting growing embryonic stem cells into a patient. They inject cells made from embryonic stem cells, in this case cells called "oligodendrocyte progenitors." Oligodendrocytes form a sheath around nerve fibers, like insulation. The injected ESC-derived cells are progenitors or precursors, only partly specialized; theoretically the cells will grow, migrate and specialize around the spinal cord, creating a sheath around nerves and also perhaps secreting nerve growth factors to enhance nerve survival.

From the total of two published rat studies on which the human experiment is based, Geron already knows that their ESC-derived cells will not work on chronic spinal cord injury; patients must be recruited and injected within the first 14 days after their injuries. They also know that the patient must be juiced with immunosuppressive drugs, so that the injected cells are not rejected by the immune system, since they are foreign to the body.

And because of the significant possibility that ESC-derived cells can run amuck, growing out of control or forming improper tissues throughout the body, Geron has already said they will have to monitor the patients for 15 years to assess the danger.

The danger has made even some proponents of embryonic stem cell research concerned about the risky nature of Geron's human experiment, instead of making a political point.

The Geron experiment in patients is not blinded, randomized, or controlled, and spinal cord injury patients can show spontaneous improvement within the three months after injury, even up to 18 months. It will be difficult to determine whether Geron's injected cells had any real effect. We wish the patient well, but think Geron is irresponsible for this premature hype.

Of note is that now, a year and a half after approval, Geron has finally listed their experiment, the only approved embryonic stem cell trial, at ClinicalTrials.gov. As of this writing, there were 2,002 adult stem cell trials in patients listed.

Despite the overwhelming success of adult stem cells for patients, few have heard the good news. Adult Stem Cells have already shown published scientific evidence documenting effective treatment for spinal cord injury.

That peer-reviewed evidence includes not only safety but also improvement of chronic spinal cord injuries, including in patients up to 15 years after their injury. Dr. Jean Peduzzi Nelson of Wayne State University discussed this research in her recent Senate testimony [http://www.frcblog.com/2010/09/adult-stem-cells-best-kept-secret-treating-spinal-cord-injury]; Laura Dominguez is one of the spinal cord injury patients who has benefitted from adult stem cells [http://www.stemcellresearchfacts.org/i-will-walk-again].