First patient treated in stem cell study
Monday, October 11, 2010; 7:05 PM
Doctors have injected millions of human embryonic stem cells into a patient partially paralyzed by a spinal cord injury, marking the beginning of the first carefully designed attempt to test the promising but controversial therapy, officials announced Monday.
The patient was treated Friday at the Shepherd Center, a 132-bed hospital in Atlanta that specializes in spinal cord and brain injuries, according to announcement by the hospital and Geron Corp. of Menlo Park, Calif., which is sponsoring the research.
The hospital is one of seven sites participating in the study, which is primarily aimed at testing whether the therapy is safe. Doctors will also conduct tests to see whether the treatment restores sensation or enables the patient to regain movement. No additional information about the first patient was released.
The milestone was welcomed by scientists eager to finally move the research from the laboratory to the clinic, as well as by advocates for patients and by patients hoping for cures. Although the cells have been tested in animals, and some clinics around the world claim to offer therapies using human embryonic stem cells, the trial is the first to have been vetted by a government entity and aimed at carefully evaluating the strategy. After repeated delays, the Food and Drug Administration gave the go-ahead in July.
But the move was criticized by those with moral objections to any research using cells from human embryos, and it is raising concern even among many proponents. Some argue that the experiments are premature, others question whether they are ethical, and many fear that the trials risk disaster for the field if anything goes awry.
"Without knowing more clinical detail, there's little I can say," said Steve Goldman, chairman of the department of neurology at the University of Rochester in New York. "In more general terms . . . I remain concerned about the long-term safety of unpurified grafts of embryonic stem cell derivatives. Time will tell."
David Prentice, senior fellow for life sciences at the Family Research Council, said: "Geron is helping their stock price, not science and especially not patients. It will be years before there is hard evidence about safety or effectiveness. Adult stem cells have published evidence documenting effective treatment of spinal cord injury."
Supporters of the privately funded research are confident that it has been exhaustively vetted. The FDA has demanded extensive experiments in the laboratory and on animals to provide evidence that the cells hold promise and are safe enough to test in people.
"Initiating the . . . clinical trial is a milestone for the field of human embryonic stem cell-based therapies," said Thomas B. Okarma, Geron's president and chief executive, in a statement. "This accomplishment results from extensive research and development and a succession of inventive steps."
Donald Peck Leslie, Shepherd's medical director, said: "We are pleased to have our patients participating in this exciting research. Our medical staff will evaluate the patients' progress as part of this study. We look forward to participating in clinical trials that may help people with spinal cord injury."
But some scientists worry that if patients are hurt by the cells - or even if there's no hint that the cells help - it could be a devastating blow to the field. They cite the case of Jesse Gelsinger, whose 1999 death from a gene therapy experiment set that once-highly touted field back years.
Safety worries - most prominently fears that the cells could cause tumors - prompted the FDA to repeatedly demand additional data from Geron, including, most recently, assurance that cysts that developed in mice injected with the cells posed no threat.
Although Geron eventually hopes to test the cells for many different medical problems, the first trial will involve 10 patients who were partially paralyzed by a spinal cord injury in the previous one to two weeks. Surgeons injected the first patient with about 2 million "oligodendrocyte progenitor cells," created from embryonic stem cells, in the hopes that the cells will form a restorative coating around the damaged spinal cord. In tests in hundreds of rats, partially paralyzed animals walked.
Spinal cord injuries, however, are highly unpredictable. Patients often improve on their own, for example, making it difficult to evaluate whether the cells had any effect. Some wonder whether trauma victims who have so recently suffered a life-altering injury will agree to the experiments out of desperation without fully grasping the risks. There is also concern that the therapy risks worsening the patients' conditions, perhaps making them fully paralyzed.
But company officials said they are confident. Even if problems occur, research shows that the cells do not leave the site of the injury, indicating that patients would not suffer any ill effects, Okarma said. Extra precautions, including assigning each subject an independent advocate, will guarantee that volunteers fully understand their decisions, he said.
In the meantime, officials at Advanced Cell Technology of Santa Monica, Calif., are hoping for the FDA's go-ahead to start injecting 50,000 to 200,000 cells into the eyes of 12 patients with Stargardt's macular dystrophy. "Retinal pigmented epithelial cells," also made from human embryonic stem cells, should replace those ravaged by the progressive loss of eyesight, which usually begins in childhood. Studies in rats found that the cells helped prevent further vision loss and even restored some sight. The company hopes that the approach will work for many conditions, including macular degeneration, the leading cause of blindness among the elderly.
The announcement comes as the future of federal funding for embryonic stem cell research remains in doubt. A federal judge ruled in August that the Obama administration's more permissive policy for funding the research violated a federal law prohibiting taxpayer money being used for research that involves the destruction of human embryos. The Justice Department is appealing the decision.