The Flourishing, Unregulated Industry In Expensive, Experimental Therapy
THE patient testimonials sound incredible: a mother with a severely autistic child, a young man struggling to live with cystic fibrosis and a disabled patient with multiple sclerosis. All claim healing through the power of stem-cell therapies, which are sometimes described in adverts as “miraculous”. A paper published on June 30th by Paul Knoepfler of UC Davis and Leigh Turner of the University of Minnesota in Cell Stem Cellfound about 350 businesses in America selling stem-cell therapies for a wide range of ailments, many more than previously thought. This has reignited a long-simmering debate about the oversight of stem-cell clinics or, rather, the lack of it.
In one corner are patients, injured American football players and proponents of rugged individualism. These include Rick Perry, a former governor of Texas, who received them for a back injury. In the other corner is the drug regulator, the Food and Drug Administration (FDA), which put so much heat on the Texas clinic that treated Mr Perry, Celltex, that it moved to Mexico. Also in the FDA’s corner are a large number of scientists and doctors, who argue that clinical trials are the only standard that allows putative medicines to be distinguished from outright quackery.
Stem-cell clinics mostly use adult stem cells from the patients themselves (for example, from fat tissue), grown in a dish and then reinjected. These are different from embryonic stem cells and they do not require the destruction of an embryo. However, some companies do advertise placental and amniotic stem cells. The sources of such cells are unknown.
The promise is real enough. For example, earlier this year a study showed that patients with end-stage heart failure fared far better when given stem cells extracted from their own bone marrow. Stem cells seem to home in on damaged or inflamed tissues and play a variety of roles in repairing them. However, some of the treatments being sold promise to help neurodegenerative diseases for which no cell therapy has yet proved effective.
Patients have been lining up to receive them, and in some instances paying tens of thousands of dollars. The clinics maintain that what they are doing is safe, though without proper oversight it is hard to know if this is true. Problems have been known to crop up. One clinical trial which injected olfactory stem cells into a woman with paralysis found that, eight years after her unsuccessful treatment, she had developed growths of nasal tissue on her spine. There have been reports of complications, and even a few lawsuits. Another concern is that desperate patients are simply throwing away their money.
The discovery of a flourishing industry in America will put pressure on the FDA to resolve the impasse over oversight. At the heart of the debate is whether stem cells are biological drugs, and thus regulated by the FDA, or whether they are tissue transplants which are not (and do not require clinical trials). Although they would seem to be tissue transplants, to qualify as such stem cells need to be “minimally” manipulated and also carry out the same functions in the treated tissue as they do in the tissue from which they were extracted.
The FDA is preparing to pounce. In October it issued draft guidelines. It says most of the stem cells involved will require rigorous approval before they can be used in patients. There will be a hearing on the guidelines in September. This is likely to become a media circus, with patient advocates likely to attend and extol the benefits of the treatments they received.
It is this sort of feeling that is driving the REGROW Act, an attempt by lawmakers to force the FDA to do away with the need for proper clinical trials for stem cells. This would create a fast-track system, similar to the one already in place in Japan, which grants conditional approval to proposed treatments with few data on safety or efficacy. The Alliance for Regenerative Medicine, a lobby group, opposes the act, saying that scientific trials are needed to ensure safety. The FDA needs to tread carefully, though: too much pressure on these clinics will not cure the problem, but merely drive it back over the border.
Article by Gary Green: The Economist