WASHINGTON – Reports touting recent approval of human clinical trials of a treatment for spinal-cord injuries using embryonic stem cells ignore the "great strides" already being made using adult stem cells, according to leaders of the National Catholic Bioethics Center.
"News stories are playing up the potential of the use of embryonic stem cells, as they have been for nearly a decade, despite the lack of significant progress," said an unsigned Jan 26 commentary posted on the website of the Philadelphia-based bioethics centre.
But adult stem cells "are already in extensive clinical use", the commentary added.
Geron Corp. in Menlo Park, California, announced on Jan 23 that the Food and Drug Administration (FDA) had approved human clinical tests in paralysed patients with acute spinal cord injury, using a stem-cell treatment developed from destroyed human embryos.
The stem-cell line used to develop the treatment came from embryos that had already been destroyed before former President George W. Bush’s 2001 announcement barring federal funding of any stem-cell research involving embryos destroyed after the date of Bush’s decision.
Dr Thomas Okarma, president and CEO of Geron, said the FDA approval "marks the beginning of what is potentially a new chapter in medical therapeutics – one that reaches beyond pills to a new level of healing: the restoration of organ and tissue function achieved by the injection of healthy replacement cells".
The clinical trials, expected to begin this summer, would involve eight to 10 patients with "documented evidence of functionally complete spinal cord injury" who would receive injections between seven and 14 days after the injury. Up to seven U.S. medical centres were expected to participate in the trials.
After the injections, patients would be measured for any improvement in bowel or bladder function, return of sensation or leg movement.
The National Catholic Bioethics Center commentary said embryonic stem cells "are not genetic matches for the patients in whom they are injected", thus requiring the use of dangerous anti-rejection drugs.
"Few are reporting that cells with the same properties and potential as the embryonic are now available through the process of ‘differentiation’," the commentary added, referring to the creation of induced pluripotent stem cells from cells taken directly from the patient.
The so-called IPS cells could be used to regenerate heart tissue or brain cells and even to treat spinal injuries.
Despite the problems with rejection and the progress shown with IPS cells, "scientists continue to claim that embryonic stem cells are the ‘gold standard’ in the field of regenerative medicine", the bioethics centre commentary said.
"Stem-cell research is the only scientific discipline where the paradigm for success is a procedure that does not work and where other avenues that have proven successful are found wanting because they fail to live up to that defective standard," it added.
Some observers said it was significant that FDA approval for Geron’s trials came three days into the administration of President Barack Obama, who has said he would overturn Bush’s ban on federal funding of stem-cell research involving the destruction of new embryos.
But the approval was coincidental, according to officials at the FDA and Geron. - By Nancy Frazier O’Brien, cns