While the findings described in this news release are enticing and hopeful, they were derived from animal studies, not human clinical trials. While the release eventually explains that, it went on to make crystal ball projections of being “close to a time when we can offer adult stem cells as a promising source for personalized therapies for this and other human diseases.”
Research efforts to manipulate pluripotent stem cells for use in various disorders, including retinal degeneration, are widespread and some forms of stem cell therapy using cells derived from embryonic stem cells, for instance, are already in human trials. The novel source of cells for this rat study is important, but this research does not stand alone. Even a little bit of context would have helped.
Macular degeneration is a serious condition affecting millions of Americans each year. It is largely a disease of the elderly who slowly lose their central vision as cells in the back of eye die. Smoking, race and genetic predisposition can also affect the onset of this condition. The damage is irreparable but if a treatment could be possible through new research, it would provide an improvement in the quality of life for many people burdened by this condition.
However, raising hopes among patients for an imminent solution based on work on lab rats is troublesome; this work could be years away from human application.
At no time during the release is the potential cost of a possible treatment ever mentioned. That’s understandable since the work is only being done in animal models and far-removed from eventual clinical use. But the release suggests that human use is close at hand. If the procedure were ready for clinical use in humans, it would involve costly eye surgery as well as the very costly and complicated manipulation of human skin cells so that they become stem cells. While the cost of these processes will inevitably fall, it’s likely to remain substantive.
Now that we’ve established that the work was done in lab rats, did the news release quantify how successful the experimental approach was? Did it give numbers about how many animals were “treated” and how many benefited?
The release only stated: “The stem cell injection resulted in 130 days of preserved vision in laboratory rats, which roughly equates to 16 years in humans.” But that doesn’t give any idea of the rate of effectiveness – even in rats. And equating this – at this early stage – to what could happen in humans is, well, imaginative.
The release fails to mention any potential harms from the procedure, although it appears to involve piercing of the eyeball and injecting cells inside. It would also appear that the procedure requires a small slice through the cornea to release pressure within the eye from adding the stem cells. And while the eye is well-known to be one of the fastest healing of our organs, any surgery involves potential risks. While the release does point out that the cells, as they multiply, form a kind of protective layer in the back of the eye, it does not mention — as the actual research paper does — that that layer may interfere with the supply of nutrients to cells in the eye, leading to their death. Nor does the release mention the potential problem of rejection of the foreign cells, which the research paper explains.
The release gave no true sense of the huge leap there may be between findings in lab rats and experiments in people. Instead, it pushed heavily the implication that humans will soon benefit. The headline literally says, “Stem cell injection may soon reverse vision loss . . .” A co-author is quoted saying they’re “close to a time” when this approach can be used on humans.
How does one compare rat vision with human vision? In the published journal article about this work, the researchers explain that they used several tests to gauge whether the animals could detect movement and other measure of “seeing.” But humans require vision to include clarity and detail and the tests used in this research can only provide a gross measure of those factors.
Finally, in some of the early Phase I human trials with other stem cell therapies, response was neither universal nor beyond the “promising” stage of improved light recognition.
There was no disease-mongering of the serious problem of macular degeneration in the news release.
The release includes at the end a listing of funding sources for this research and there is no information to suggest any conflict of interest. The original research paper specifically states there are no conflicts.
The news release included no discussion of alternative approaches or other research being done on age-related macular degeneration.
There are ongoing early clinical trials of stem cells in the treatment of AMD using cells differently derived than the ones reported here. So there are “alternatives” to this particular type of stem cell therapy that also may show promise. There are a few reports from Japan and elsewhere suggesting that there are alternatives to “bolus injections” of stem cells that may pose risks.
In addition, some current federal clinical trials have found that some vitamin and mineral supplements appear to reduce the risk of late-onset of the disease by as much as 25 percent.
So this is not the only work being done in this field, as the news release might suggest to some journalists or to the general public. Even a brief mention of other research would have been important context to improve public comprehension.
The release suggests, through researcher quotes and other descriptions that this treatment may be just around the corner. That is clearly an exaggeration. The researchers still need more work in animal models. Then they will require FDA approval for an investigational drug. If that comes about, then substantial clinical trials in humans will be needed. All told, that could mean years of additional wor, before the procedure might be available for people.
Is that how you would define “soon” or “close to a time”?
We will give the news release the benefit of the doubt on this criterion. But here’s why it’s a coin toss.
The release states: “This is the first study to show preservation of vision after a single injection of adult-derived human cells into a rat model with age-related macular degeneration.”
That may be. There are some ways in which these particular stem cells are novel. But other stem cell approaches have been developed and in some cases are in in early phase human trials or animal tests.
However, since we have already dinged this release in the “Alternatives” criterion above for failing to give that context, we’ll give it the benefit of the doubt here.
The headline’s use of “may soon reverse vision loss,” Svendsen’s quote saying they’re “close to a time” of treating humans, and the cavalier referral to the “next steps” without explaining that means many more years of study, all support a rating of unsatisfactory in this category. Anytime a news release raises hopes for treatment of a now-untreatable disease, it has to live up to those expectations. This one didn’t.