Experts say they are optimistic about the future of stem cell research in the U.S., even though the first government-approved trial designed to test an embryonic stem cell therapy in people has been canceled, it was announced yesterday.
The trial, which began about a year ago, was examining the use of stem cells derived from human embryos to treat patients left paralyzed by spinal cord injuries. The main goal of the trial was to test the therapy's safety.
Geron, the company conducting the trial, said it did not have the funds to pursue both its stem cell and cancer research programs, and opted to focus on cancer.
Many have expressed disappointment about the cancellation, but experts said today the field is ripe to move forward.
Researchers worldwide are testing stem cell therapies in human trials, said Mark Noble, director of the Stem Cell and Regenerative Medicine Institute at the University of Rochester School of Medicine in New York, and the overall impact of the canceled trial on the field, in terms of scientific advancement, is relatively minor.
For spinal cord injuries in particular, several other groups are pursuing what Noble said are more promising approaches to reversing paralysis. "That's why I don’t think it's a scientific loss," Noble said.
Human embryonic stem cells can give rise to virtually any cell in the human body.
Geron used human embryonic stem cells to produce specialized cells called oligodendrocytes, which could then be turned into myelin, a material that surrounds and protects axons (long projections of nerve cells) in the spinal cord.
But other researchers are working on therapies that use different types of cells derived from adult tissues to repair the damage from spinal cord injury. For instance, a therapy being tested by researchers at The Miami Project to Cure Paralysis, part of the University of Miami Miller School of Medicine, involves the use of so-called Schwann cells, derived from the nerves of patients. These cells protect the axons of nerves other than those of the brain and spinal cord. The researchers are awaiting approval from the Food and Drug Administration to pursue a clinical trial testing the therapy.
Dr. Joshua Hare, director of the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine, said the cancellation of the Geron trial may generate "more enthusiasm for the other approaches," to treat spinal cord injury, including the use of stem cells derived from bone marrow, and other types of regenerative medicine, which "help the body heal itself," Hare said.
Another trial that will use stem cells derived from human embryos to attempt to treat eye diseases will begin in July, according to the Washington Post.
Geron will continue to follow the four patients who were treated with their stem cell therapy , and will continue to update the scientific community about their progress, but will not enroll more patients in the study. So far, there have been no adverse events from the treatment, the company said in a statement.
Noble said Geron's cancellation may indicate the perilous nature of medical research funded by corporations.
"One interpretation of the Geron decision is that it's critical to increase the involvement of the academic centers," Noble said. "For me, I don’t care if what we do makes a profit; I care whether we get somebody out of a wheelchair."
Pass it on: A trial that was testing the use of stem cells derived from human embryos as treatment for spinal cord injuries has been canceled, but the field will continue to move forward, experts say.