Whenever I see a stem cell headline like this one from a recent Baltimore Sun piece, it raises many questions: Stem cells apparently reverse woman’s blindness.
First of all, is the reporter, Meredith Cohn in this case, being cautious enough with that “apparently” in the headline? Part of the reason for this question is that the “treatment” in question is unproven, so far there’s no public data beyond 1 patient, and I wasn’t able to find evidence of an IND for this so it’s unclear if the FDA is OK with it.
Second, I immediately wonder what kind of stem cells are being used. In this case, the physician who is doing the study, Dr. Jeffrey Weiss in Margate, Fla, is injecting bone marrow stem cells into the patients’ eyes.
Third, does it make any sense to inject bone marrow cells into a person’s eyeball to treat a vision condition? I’m not a vision or bone marrow scientist, but there’s no obvious rationale to me. Even the doctor doesn’t claim to know for sure how it might work. Anti-inflammatory? Mobilization of or enhanced survival of endogenous cells? Other?
Fourth, is it safe? Who knows. There would definitely be some risks associated with transplanting these stem cells into the eye. Update: a mouse study from right here at UC Davis a few years ago suggests more broadly that this kind of approach might be safe for one particular type of retinal injury ( HT to @SurgeonRetina on Twitter), but that’s a long way away from being sure that what the human study that we are focusing on here is doing is safe.
Fifth, is there a charge? In this case, yes, it costs patients $20,000. This makes me even more concerned. Does 100% of this money go to running the trial? Or is there some profit (i.e. total funds generated exceed total costs of the trial)?
Sixth, will this newspaper article encourage other patients to take the same risk? I think it probably will. The article includes some caveats, but enough?
Digging more into the article, there’s some confusing text about FDA regulations and how they apply to this trial:
“The U.S Food and Drug Administration must permit the use of “investigational” drugs, and the NIH requires that researchers attest they have such permission to register a trial. While the FDA continues to tweak regulations, there are exceptions when stem cells aren’t considered drugs, such as when they are minimally processed and taken from and used in the same person.”
I’m not clear what this means.
The FDA “must permit” investigational drugs she writes, but the way it is written is confusing and again I’m not aware that this study has that permission. Does it? If so, I hope to hear about that. Cohn leaves this issue up in the air.
She also doesn’t touch on the crucial homologous use issue. Cells must be used in a clinically homologous manner or they are automatically drugs requiring pre-approval. Does bone marrow seem similar to the eye?
The clinicaltrials.gov listing is here and the business doing the study is Retinal Associates of South Florida in collaboration with MD Stem Cells. So far I haven’t been able to find evidence that this is a traditional phased FDA-approved clinical trial.
Unfortunately we are seeing more and more of these kinds of unusual listings at clinicaltrials.gov. The listings are called “clinical trials” by those doing them and the media, and patients have to pay.
This kind of human stem cell clinical experiment is exactly the type of thing that we need more clarity about from the FDA.
Sumber aciknadzirah.blogspot.com