Federal regulators have green-lighted the first trial of an embryonic stem-cell treatment in humans.

The U.S. Food and Drug Administration (FDA) gave the go-ahead for Geron Corporation to start a phase I safety trial of its therapy GRNOPC1 for spinal cord injuries, the Menlo Park, Calif.–based company announced today. It first sought permission for the trial four years ago and spent much of the last year trying to satisfy the FDA’s concerns about it.

"This 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,” Thomas Okarma, Geron's president and CEO, said in a statement today.

The trial will involve up to 10 patients and will test whether it is safe to inject nerve cells from embryos into the site of their injuries, according to Geron. A study published in 2005 in the Journal of Neuroscience found that giving rats the injections seven days after a spinal cord injury improved their motor function.

Wise Young, director of The W. M. Keck Center for Collaborative Neuroscience at Rutgers University, hailed the FDA’s decision, but says his expectations are tempered. “It’s a big deal—it’s a long time in coming. There’s a lot of hope riding on this,” Young tells ScientificAmerican.com. But he cautions that people should not expect "a miraculous result" from this initial trial. "I do believe cellular therapy will have a beneficial effect," he says, "but it’s very important to understand that we’re just starting. We have a long road to go.”

Geron and FDA officials told The Wall Street Journal that it was a coincidence that the announcement came just three days after George Bush left the White House. Bush restricted federal funding of embryonic stem cell research. "The FDA looks to the science on these types of issues, and we approve [such applications] based on a showing of safety," FDA spokesperson Karen Riley told the Journal. “Political considerations have no role in this process."

Pres. Obama said during his campaign that he would lift the ban on federal funding of research on embryonic stem-cell lines produced after August 9, 2001. But he told CNN on January 18 that he may ask Congress to undo it. Lawmakers passed legislation three times during the Bush administration that would have erased the limit and allowed research on stem cells from embryos at fertility clinics (with donors' consent) that would otherwise be discarded; Bush vetoed them all. "I like the idea of the American people's representatives expressing their views on an issue like this," Obama told CNN. 

That may not be a bad thing, Young says. “If he were to reverse this on his own, it takes Congress off the hook. It’s much more important that Congress makes sure this doesn’t happen again,” he says. “What is worrisome is that if Obama did just reverse the rule, stem cells would be a political football in Congress to trade for something else. It’s really important from the viewpoint of the advocacy community that legislation is passed so other presidents don’t come in and say, ‘I will forbid this.’”

Image © iStockphoto/Mads Abildgaard