Geron (GERN) reported recently that they developed a stem cell therapy that enabled paralyzed rats to walk. There have been no dangerous side effects in 2,000 animal trials. The therapy uses human embryonic stem cells, and it is not complicated in theory. Myelin is a fatty substance that provides insulation for nerve fibers, which is important for motor function. When a spine is damaged, myelin is usually stripped off. Just as an electric cord shorts out when its insulation is peeled away, the missing myelin disrupts the body's ability to transmit sensory signals, resulting in paralysis. So as embryonic stem cells can turn into any type of tissue in the body, for Geron's rat studies, the stem cells were developed into oligodendrocytes. These cells help nerve fibers replace myelin.
Geron spent $150 million over 13 years perfecting this treatment for spinal injuries. More than 250,000 people in the U.S. have paralyzing spinal injuries, with about 11,000 new cases reported each year. It's too bad Christopher Reeve couldn't live long enough to see it approved. That will be a great day, if GERN can complete the long and winding road through the FDA.
The company has assembled a 25,000-page filing just to ask permission to begin Phase I trials. They will file in the first half of this year, with no decision expected before the anti-embryonic stem cell Bush Administration leaves office. McCain, Clinton, and Obama all oppose Bush's limits on funding for human embryonic stem cells.
Under the current regime, Geron had to use stem cell colonies that were not exposed to mouse skin cells, commonly used to provide nutrients to the stem cell culture, but capable of transmitting viruses. The FDA also made Geron show that injected rats stayed free of tumors or other side effects for up to a year. Because the rats were so severely injured, they had no control over their bodily functions, so lab technicians had to empty each rat's bladder three times a day by hand for the whole year to keep the rats' kidneys from failing. (The next time you hear someone complaining about their job, ask them if they'd rather be a lab tech at Geron.)
