You may have seen one of the many news reports this week about an “adult” stem cell treatment gone bad. In it, doctors, not working in regulated industry or in the bounds of a clinical trial, injected stem cells derived from a person’s fatty tissue into the eyeballs of three people in an attempt to treat a vision-destroying condition called macular degeneration—and all three lost what remaining vision they had. T
In a separate experience, two people received “reprogrammed” stem cells, also called “induced pleuripotent stem cells” or “iPSCs,” for the same condition, and they did not appear harmed, and may have been showing early signs of improvement, one year later. In this second case, the cells are described as having undergone rigorous quality testing before being injected into the patients’ eyeballs.
The two cases are described in this week’s New England Journal of Medicine. The links above are to those reports; subscription may be required to read them. NEJM makes some of its editorials and perspective pieces generally available, other articles not. Two such articles, one from FDA and one from a physician at Boston Childrens’ Hospital, address these cases. In both opinion articles, the authors argue that careful regulation and quality control of stem cell studies is critical to their ethical testing.
To say this position is hard to argue with is a gross understatement. I will confess that on this blog, in the past, I have wondered whether some use of “adult” or “somatic” stem cells is over-regulated, as, for example, when such cells are obtained from a woman’s fatty tissue, and reinjected into her in an attempt at breast reconstruction after surgery. I’ve seen proposals in the past for work like that, and it seemed pretty straightforward—recovering a cell layer from a centrifuge, and reinjecting, all under sterile conditions. The doctors in question in the case I saw were not in any way trying to cut any corners. But existing regulation would have prevented their proposed breast-surgery work without a couple million dollars’ worth of the kind of work needed, and usually funded by industry, before commencing human trials of a new treatment.
The macular degeneration cases do indeed push one back in the direction of regulation. Injecting into the eye is rather riskier than some other uses. There are established clinical uses of adult stem cells—notably in bone marrow transplantation, potentially in other cases. But it can be too easy to miss risks. We should have our “hype detectors” well calibrated when it comes to stem cell therapies, even with those that use ethically-derived cells (i.e., not from the creation or destruction of human embryos).