Stem Cell Science Takes an Ambitious Step Forward

SOURCE: Gabriela Cezar lab, University of Wiscsonsin-Madison

Microscopic view of neural precursor cells derived from human embryonic stem cells.

By Michael Rugnetta | January 23, 2009

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Report: A Life Sciences Crucible: Stem Cell Research and Innovation Done Responsibly and Ethically

Interactive timeline: A Brief History of Stem Cell Research

The Geron Corporation of Menlo Park, California announced today that the FDA has granted clearance for a Phase I clinical trial of their human embryonic stem cell-based therapy in patients with spinal cord injury. The therapy is known as GRNOPC1 and will be administered in small doses for safety testing, which is the purpose of a Phase I clinical trial.

This is a milestone for regenerative medicine research and demonstrates that there is a vast scientific landscape that has been obscured by the stale debate over the permissibility of using human embryos as sources of stem cells in basic research. Yet as we argue in or report, “A Life Sciences Crucible: Stem Cell Research and Innovation Done Responsibly and Ethically,” it is crucial for the federal government to allow the National Institutes of Health to fund basic human embryonic stem cell research. Only when federal funding is permitted will scientists have the knowledge to proceed more strategically with regard to an overall biomedical research and innovation agenda for regenerative medicine.

“A Life Sciences Crucible” calls for the new administration to form a working group under the Recombinant DNA Advisory Committee in the Department of Health and Human Services. This group would allow an array of experts—including scientists conducting basic, translational, and clinical research—to come together and decide which clinical trials are the most urgent and the most promising. RAC meetings are held in public and allow policymakers, public health professionals, and patient advocates to advise the FDA and companies pursuing clinical trials. It would remain the FDA’s duty to decide on the scientific merit, trial design, and safety of a particular drug or therapy. But the working group could help consolidate HHS’s fragmented research and regulation duties into a robust innovation agenda for regenerative medicine.

Geron’s preliminary data indicate that the spinal cord therapy holds promise both in terms of safety and efficacy. Geron submitted more than 21,000 pages of data on 24 animal studies that utilized over 5 billion cells in order to gain clearance for Phase I clinical trials. Cells in the animal studies did not migrate away from the spinal cord or form tumors over a 12-month period after their injection into rats and mice. In vitro studies showed that there was minimal recognition of the cells by the human immune system, which means that a low-dose of anti-rejection drugs are likely to be needed in the clinical trials. The actual cells that will be administered to the clinical trial subjects are known as oligodendrocytes, which are derived from embryonic stem cells by the introduction of proteins known as growth factors. Once injected into the spinal cord, they can then develop into support cells for nerves.

Geron built many precautions into the study, but this is still a relatively high-risk form of therapy, in part because it deals with the spinal cord. Some scientists such as Geoff Raisman of University College London and Stephen Minger of King’s College London have reservations about the first studies of human embryonic stem cell-based therapies taking place in patients with spinal cord injuries since it is not a life-threatening condition and might not be targeting the main cause of paralysis. A better first step might be research on embryonic stem cell therapies for macular degeneration, since the eye is a confined space. The uncertainty surrounding these and other issues is exactly why a working group is needed to offer guidance on the overall strategy for innovation in regenerative medicine.

As Evan Snyder, a stem-cell researcher at the Burnham Institute for Medical Research in California told the UK’s Guardian, “The one hope that everybody has is that nothing bad happens.” Indeed, as the first clinical trial of its kind, the Geron trial has a lot riding on it, and any setback will affect the entire field of embryonic stem cell research. Let’s hope that this ambitious first step pays off.

Report: A Life Sciences Crucible: Stem Cell Research and Innovation Done Responsibly and Ethically

Interactive timeline: A Brief History of Stem Cell Research