FDA Approves First Clinical Trial With Human Embryonic Stem Cells: The Audacity of Hype

Date: 01/26/2009

Decision shows, once again, that embryonic stem cells still lag far behind adult stem cells in treating patients.
The FDA on 1/23/09 gave a green light for a clinical trial using human embryonic stem cells to treat spinal cord injured patients. Despite all the hype this decision has generated in the media, the fact remains that embryonic stem cells lag far behind adult stem cells in treating patients for spinal cord injury – as well as dozens of other diseases and conditions. 

The FDA approved trial is not designed to test the efficacy of hESCs in treating spinal cord injuries, but only as a test of the safety of transplanting such cells into the patients. This is because in numerous studies with animals, embryonic stem cells have been shown to form –often lethal — tumors. Thus, even if the patients show no improvement from the treatment, they will still have to be monitored for the rest of their lives for the possibility of tumor formation.

In stark contrast, as documented in the peer-reviewed literature, adult stem cells have been shown to be both safe and efficacious in providing improvements to spinal cord injured patients:

  • A study from September 2008 by Australian researchers documented modest improvement in a spinal cord injured patient using the patient’s own adult nasal cells (“Autologous olfactory ensheathing cell transplantation in human paraplegia: a 3-year clinical trial,” Mackay-Sim A et al. Brain 131: 2376 – 2386, Sept 2008).
  • A June 2006 clinical trial in Portugal involved 7 patients, all of whom enjoyed improvements to their condition after being treated with their own adult stem cells, including increased movement and sensation, with some patients regaining some voluntary muscle movement and some bladder function.

(“Olfactory mucosa autografts in human spinal cord injury: a pilot clinical study,” Lima C et al. Journal of Spinal Cord Medicine 29, 191-203, 2006).


Appearing on Good Morning America, Sean Morrison, director of the University of Michigan Center for Stem Cell Biology, was asked by host Diane Sawyer: “What about it doctor? Do you think it could have been done with adult stem cells?” Morrison’s response:

“I don’t think there’s an adult stem cell that’s ready for use in clinical trials that could be used to do what Geron is doing with these [embryonic stem] cells. The adult stem cells don’t have same capacity to give rise to the large number of cells that Geron needs for this trial. And the reprogrammed cells that people have heard so much about still require the use of viruses that would prevent them from being used in clinical trials.”

Given that clinical trials using adult stem cells for spinal cord injury have already occurred, Morrison’s remarks make little sense. Obviously, enough adult cells were generated to conduct the two clinical trials cited above. Moreover, the Portuguese trial involved seven patients; Geron plans to test 8 to 10 patients, not a significantly greater number that would require a significantly greater amount of cells. In addition, the lead researcher for the Portuguese trials, Dr. Carlos Lima, has succeed in generating large enough numbers of adult stem cells to have treated dozens of patients worldwide for spinal cord injury, with all of them showing some therapeutic benefit (one such patient, Jacki Rabon, can be seen describing her treatment and the benefits she received from it).

As to the reprogrammed cells, Morrison is again woefully behind on his literature reading of the actual science. Several groups have now shown that they can reduce or eliminate the viruses and some of the genes needed for reprogramming, and have shown in mice that the reprogrammed cells work as well as or better than embryonic stem cells made by destroying embryos.


So why all the fuss over a safety trial using embryonic stem cells to treat spinal cord injury when adult stem cells have already been shown to be safe and efficacious in treating spinal cord injured patients? Perhaps the answer is to be found more in money than in medicine. That’s because embryonic stem cells can be patented while a patient’s own adult stem cells cannot.
London’s National Institute for Medicine’s Dr. Geoffrey Raisman, one of the world’s leading researchers on the use of adult stem cells to treat spinal cord injured patients, notes that “this is not the most popular way of attempting to heal spinal injuries. That would be to produce patented chemicals, which drug companies can make and sell. What we’re proposing could be carried out by any very modestly equipped hospital with neurosurgery. There are no patents. It makes it a very unpopular form of research…We’re producing a procedure where the patient is their own cure. You can’t patent a patient’s own cells, thank God.” (The Guardian (London) 11/30/05).
Just as drugs are patented, so can embryonic stem cells – at potentially great profit for the biotech industry. So if the long term goal is to increase profitability by obtaining patents for the complex procedures that reduce the safety risks and produce usable embryonic stem cell-derived treatments that are also patentable, then the development of such treatments may present a more desirable goal for the biotech industry.
But if the goal is to put patients, not patents, first, and provide near term benefits but at lesser long term profits, then adult stem cells are, from a therapeutic perspective, clearly preferable.