Does a surge in StemCells Inc stock price mean a stem cell cure for spinal cord injury is closer to reality?
No.
At least not in my opinion. Investors may see it a little differently but I hope that people with a connection to spinal cord injury take a bit of a pause when reacting to the latest update from StemCells Inc. (Nasdaq:STEM).
On February 12, StemCells Inc released their twelve-month results from the first patient cohort in the company’s Phase I/II clinical trial of its proprietary HuCNS-SC® product candidate (purified human neural stem cells) for chronic spinal cord injury.
As a phase I/II clinical trial, the company is looking to determine the treatment’s safety and preliminary efficacy (including changes in sensation, motor function and bowel/bladder function). The study, conducted at Balgrist University Hospital in Switzerland, plans to enroll 12 individuals who have sustained a thoracic (T2-11) level injury between 3 and 12 months before the start of the treatment. The first cohort comprised 3 individuals with complete thoracic injuries (ASIA A). The 2nd and 3rd cohorts will comprise individuals with incomplete injuries (ASIA B and ASIA C).
Clearly, this is not a big trial. Although a decent indication of the treatment’s safety can likely be determined, its ability to lead to improvements will be a little harder to interpret.
So, why did StemCells Inc stock prices surge after they released their results on the 12-month outcomes for the first cohort (the 3 with complete thoracic injuries) from the trial? I guess it is because investors were buoyed by what could be very encouraging results on 2 of the 3 subjects. But, is this encouragement warranted? If I was investor, I’d be a little more cautious.
The results of this first cohort indicate that two of the three subjects showed improvements in sensory function that persisted through the end of the 12-month observation period. One of these two converted from a complete injury (ASIA A) to an incomplete (ASIA B). This conversion from complete to incomplete sounds rather remarkable and one can understand why people might be getting excited about the results.
“The multi-segment gains observed in sensory function in two patients at six months have endured at the 12-month assessment. In addition, between the six- and 12-month evaluations, one patient converted from a complete to an incomplete injury,” said Armin Curt, M.D., Professor and Chairman of the Spinal Cord Injury Center at Balgrist University Hospital, University of Zurich and principal investigator of the clinical trial.
“Importantly, the persistence of these sensory gains at the 12-month evaluation was seen across more than one clinical measure. While much more clinical research needs to be done to demonstrate efficacy, the types of changes we are observing are unexpected and very encouraging given that these are patients in the chronic stage of complete spinal injury.”
But wait a second. It should be noted that many people undergo spontaneous conversion from complete to incomplete (click here to see a review in the Journal, Spinal Cord). Granted, when it happens, most experience this conversion within the first three months after injury, but it can happen over the first year after injury.
Thus, it could have happened without the treatment at all. In addition, because the trial is not a controlled one (in which a group undergoes the same treatment, except that they have a “placebo” injected into the spinal cord instead of the stem cells), we can’t really know if it was the stem cells or some other aspect of the treatment (such as physiotherapy) that lead to the improvements observed. Until more subjects go through the trial, we shouldn’t get too excited about one example of success.
StemCells Inc’s President and CEO, Martin McGlynn does start to provide similar advice, noting “While we need to be cautious when interpreting data from a small, uncontrolled trial, to our knowledge, this is the first time a patient with a complete spinal cord injury has been converted to a patient with an incomplete injury following transplantation of neural stem cells.”
I guess he is right – it’s probably the first time someone receiving stem cell treatment has converted from complete to incomplete spinal cord injury. But, just remember, this is not the first time someone has experience this kind of conversion. For many individuals with spinal cord injury, it happens spontaneously, without stem cell treatment. The StemCells Inc trial does not yet provide convincing evidence that their stem cells treatment is directly responsible for either the improvements in sensation or conversion from complete to incomplete spinal cord injury as reported on Feb 12.
Some may read this and complain that I’m overly cynical or pessimistic. Maybe, but as a former spinal cord injury researcher, I’ve learned to become an optimistic cynic (or maybe a cynical optimist). There is great value in the research that companies like StemCells Inc and Neuralstem are doing (and what Geron started doing). At the very least, they are figuring out how to do these trials – how to conduct them safely and determine if a treatment-based effect occurred. These are huge, costly and risky undertakings and they will ultimately help move the field closer to a cure. Someday.
However, with the stakes so high, there is a tendency toward prematurely interpreting results and sometimes over-interpreting them to boot. That’s why we all need to employ a bit of cynical optimism when we hear results like those from StemCells Inc’s first 3 spinal cord injury subjects.
So what does all of this mean for those with chronic spinal cord injury? I’m not sure we really know yet. Are we closer to a cure? StemCells Inc investors seem to think so, but I’m not so sure. I’ll wait for more convincing data to be released before I risk my money on it.
Note: in the next issue of The Spin magazine (out in March), we will be featuring an article on Neuralstem and their SCI-specific stem cell research in the United States. You might also be interested in our article, Risky Business, featured in the Spring 2012 issue of The Spin magazine.
