July 2014 – We have written several articles in the past few years about stem cells and their potential as therapeutics for spinal cord injury (SCI). There is still confusion about stem cells and recently there has been some good, bad, and downright ugly information coming to light.
The Good. One of the good things about stem cells is that they are not all the same. Different stem cells have different capabilities. For example, embryonic stem cells have the potential to become any type of cell in the body, including nervous system cells. Mesenchymal stem cells, however, are much more restricted in the types of cells they can become, and they may be much better suited for secreting chemicals that reduce inflammation. There are two US companies that are working very hard to safely and appropriately test stem cells in FDA-regulated clinical trials for SCI. Asterius Biotherapeutics recently acquired the embryonic stem cells products, intellectual property, and clinical data from Geron Corporation, which was conducting a phase I clinical trial in acute SCI and stopped a couple years ago for economic reasons. Asterius is now interacting with the FDA to begin a different clinical trial in SCI. StemCells Inc. is testing the safety and efficacy of a fetal central nervous system stem cell product. They are targeting early chronic SCI and The Miami Project will become a site in their upcoming phase II trial. One really important component about these 2 products is that the cells are very strictly purified and characterized before they are injected into people; we do a very similar process with our Schwann cell products and we cannot stress enough how important it is to do such a rigorous process.
The Bad. One of the bad things about stem cells is that they have been over-hyped by the media in regard to their readiness for treating multiple diseases. As a result, stem cell tourism has become a lucrative yet unethical business worldwide. No stem cells have been proven to be effective therapies for SCI, therefore everything is still experimental and carries with it significant risk – hence it is extremely unethical to charge people money for unproven, risk-filled therapies. Very commonly, mesenchymal stem cells are sold as treatments for multiple diseases, including SCI. The term mesenchymal stem cells can be confusing because there are actually many different sub-types of cells that are collectively referred to as “mesenchymal stem cells” and they are not all good for therapeutics. There is an increasing push for developing definitions and standards for mesenchymal stem cells (see Nature 25 July 2013 volume 499 page 389). The Miami Project supports the position statement published in 2009 by the International Campaign for Cures for Paralysis. “We do not rule out the possibility that cellular therapies may improve function and quality of life for recipients and justify the risks, but insist that the onus is on the providers to deliver such proof from a valid clinical-trial program.” We believe that it is unethical to sell unproven therapies and we do not advise people with spinal cord injuries to participate in such treatment procedures.
The Ugly. The ugly thing about unethical people selling unproven, unregulated stem cell products is that innocent people get hurt. Many negative effects go unreported, but we know they happen. In 2011, the German government shut down the XCell-Center because a young boy died as a result of treatments they sold. In 2012, 60 Minutes presented a huge expose on stem cell fraud. And just recently, a case report was published in the Journal of Neurosurgery: Spine revealing a large tumor-like mass that developed inside the spinal cord of a person who had olfactory mucosa tissue transplanted into the injury site by the highly controversial Carlos Lima in Portugal. Olfactory mucosa tissue contains a large variety of cells, not just the olfactory ensheathing cells that are much better studied as a potential therapeutic. The mass was discovered 8 years after the transplantation.
The bottom line is that stem cells as potential therapeutics for SCI is indeed a very exciting field. However, it is extremely important that the cells be characterized very carefully, that cell processing standards be refined and followed, that the cells are tested in proper clinical trial settings with extensive follow-up and long-term monitoring, and that we truly identify the benefit associated with different types of stem cells.