Geron Corp. CEO Thomas Okarma at the company's headquarters in Menlo Park, Calif., in 2001. Thomas said Friday the company gained U.S. federal permission to inject eight to 10 patients with cells derived from embryonic stem cells. (Julie Jacobson/Associated Press)

The U.S. Food and Drug Administration has given the green light to human clinical trials of an embryonic stem-cell-based therapy for spinal cord injuries, a biotechnology firm said Friday.

The regulator has given permission to Geron Corp. of Menlo Park, Calif., to inject embryonic stem cells into eight to 10 people recently paralyzed due to spinal cord injuries. The research aims to regrow nerve tissue.

President Barack Obama, who took office on Tuesday, was expected to reverse former president George W. Bush's executive order that restricted federal funding on research involving human embryonic stem cells.

'All sorts of opportunities'

Advocates of embryonic stem cell research say it could lead to potential treatments for diseases such as Alzheimer's, Parkinson's and cancer by restoring organ and tissue function.

Scientists say embryonic stem cells are the most useful because they have the potential to become any type of cell within the body.

"This now will hopefully set the stage for improved ways of differentiating these cells, make these embryonic stem cells turn into other cell types that we can use for other diseases," said Mick Bhatia, scientific director with the Cancer and Stem Cell Biology Research Institute at McMaster University in Hamilton.

If the study reveals a transplant function for the cells, it will "open up all sorts of opportunities and enthusiasm to continue this research," Bhatia said.

Though other countries have claimed to have done similar research, it will be the first time that the results from the study will be clearly disseminated to scientists and physicians around the world, he said.

Though the focus is currently on spinal cord injuries, diseases where there is no medication or surgery available, such as Parkinson's and Alzheimer's, will see the most promise from the research, he said.

"I think that that's where we see the promise of these cells replacing those cells that have been damaged by unknown processes of the disease and see if we can't recover function," he said.

But the research is controversial since embryos are destroyed to obtain the stem cells.

Safety focus of trial

Dr. Thomas Okarma, president and CEO of Geron, said the injections will be made in the spine. Several medical centres around the U.S. will participate in the research, which he said has not received U.S. government funding.

The aim is "not to make somebody … get up and dance the next day," he said, but to achieve some level of ability that can be improved by physical therapy.

Determining safety is the main purpose of the trial, but researchers will also check for improvements such as return of sensation in the legs or movement, Okarma said.

Safety is the focus, agreed Evan Snyder, a stem cell researcher at the Burnham Institute for Medical Research in La Jolla, Calif.

"The one hope that everybody has is that nothing bad happens," Snyder said.

Peter Wilderotter, the president and chief executive of the Reeve Foundation, welcomed the announcement.

"There has been so much speculative and unsubstantiated information about the use of stem cells in spinal cord injury; it is important to study these cells in a rigorously designed clinical trial that is monitored by the FDA," Wilderotter said in a statement.

Actor Christopher Reeve, who died in 2004, became an advocate for embryonic stem cell research after he was paralyzed from the neck down in 1995 in a horseback riding accident.

Also on Friday, Obama signed an executive order reversing Bush's ban on funding for international groups that aid in abortions, White House spokesman, Bill Burton said.

With files from the Associated Press