The Food and Drug Administration (FDA) has just approved the first clinical trial using human embryonic stem cells, which now appears safe enough to use on humans. On Friday, the agency cleared the way for the world’s first clinical trial of a therapy derived from human embryonic stem cells.

This will probably be used in early June, as a handful of patients with severe spinal cord injuries will be eligible for injections of specialized nerve cells designed to enable electrical signals to travel between the brain and the rest of the body. The treatment was successful on rats, which regained the ability to walk and run, an ability they once lost.

The innovative treatment has been under development by Calif.-based Geron Corp. for nearly 10 years. If it works, it would help validate years of hope and investment in the nascent field of regenerative medicine. Stem cell therapies could even benefit people with such intractable diseases such as Alzheimer’s, Parkinson’s and multiple sclerosis.

The first stem cells were created using molecules from mice and cows, and scientists feared they might be rejected by the human body. However, the newer stem cells that are animal-free have not been eligible for federal research funding under the policy set by President Bush in 2001. Therefore, many people had expected FDA approval for any therapy to be years away.

With the new approval, it’s sure that more clinical trials are sure to follow. Geron’s chief executive even said the FDA’s decision has nothing to do with the change of administrations in Washington, even if, unlike former president Bush, Barack Obama has voiced strong support for human embryonic stem cell research.

Another use for the stem cells could help patients with Type 1 diabetes, as they can turn into insulin-secreting islet cells. In addition, they can also turn into cardiac tissue that could repair damage made by heart attacks. As for the spinal cord therapy, it looks like the stem cells won’t help paralyzed patients walk again, but it could substantially improve their quality of life.

The first patients to receive such treatments will be injected with 2 million of the cells seven to 14 days after a spinal cord injury. Afterwards, patients will be given a low-dose anti-rejection drug for 60 days in order to ensure their bodies don’t reject the GRNOPC1 cells, even though research indicates the cells won’t be recognized by the human immune system.

However, researchers still say that a cure could still be years away, but everyone fears that, if an improvement isn’t immediate and dramatic, people might turn their backs on human embryonic cells altogether. It remains to be seen if there will be any success with this kind of treatment.