Three Women Blinded In Stem Cell Clinical Trial
Some doctors worry about rush to approve stem cell therapies. These cases show why
Three women suffering from a degenerative eye condition were blinded—likely permanently—in a clinical trial for stem cell therapy, according to a report published Wednesday in the New England Journal of Medicine.
The women, who were all between the ages of 72 and 88, had a common medical condition called age-related macular degeneration, in which cells in the retina begin to die off, resulting in spotty or blurred vision. Researchers suspected stem cells derived from the patient’s own body could regenerate some of the cells lost to the disease. So in the clinical trial, which was conducted in 2015, researchers removed some blood and fat from participants’ anesthetized abdomens, treated the cells in a standardized way to make them revert to stem cells, then injected into their eyes. They were instructed to use an eyedrops antibiotic for a few days. The three patients had found the trial listed on the government web site clinicaltrials.gov, and had each paid $5,000 for the procedure. The informed consent form listed that blindness was possible as a result of the procedure.
A few days after the patients received the injected stem cells, the participants ended up in the hospital with vision loss, detached retinas, and hemorrhage. The patients lost vision; subsequent checkups led doctors to conclude that they would likely never regain their sight.
Despite the fact that the participants found the procedure on clinicaltrials.gov, the informed consent forms do not mention that it is in fact a clinical trial. “The patients paid for a procedure that had never been studied in a clinical trial, lacked sufficient safety data, and was performed in both eyes on the same day,” the study authors write. Injecting something experimental into both eyes is both not safe and not typical, they continue.
Recently researchers have been testing lots of different medical uses for stem cells, from treating multiple sclerosis to spinal cord injuries. With the passage of the 21st Century Cures Act in December, Congress cleared the way for faster regulatory approval for promising treatments based on stem cells. At least 13 clinical trials were registered to treat AMD alone as of November 2016, the article authors write.
But anecdotes like these bolster those who counsel restraint when it comes to stem cells. “Although numerous stem-cell therapies for medical disorders are being investigated at research institutions with appropriate regulatory oversight, many stem-cell clinics are treating patients with little oversight and with no proof of efficacy,” the article authors write.
Jeffrey Goldberg, a professor of ophthalmology at Stanford University and one of the authors of the article, calls this a “call to awareness for patients, physicians and regulatory agencies of the risks of this kind of minimally regulated, patient-funded research,” according to a press release.