First human clinical trial of embryonic stem cell therapy begins

Patients with severe spinal cord injuries hope the first human clinical trial of embryonic stem cell therapy is proven safe and effective. Image: a.drian's/Flickr

Embryonic stem cell research took a major step forward last week with the first human clinical trial. The patient, who has a severe spinal cord injury, was injected with embryonic stem cells at the site of the trauma. The clinical trial, which will test 10 patients for a period of two years, will be used to determine if the treatment is safe for humans.

Privately funded stem cell research

The human clinical trial using embryonic stem cells to treat spinal cord injuries is being directed by Geron Corp., a biopharmaceutical company based in Menlo Park, Calif. The Washington Post reports that the patient, who is partially paralyzed by a spinal cord injury, had millions of embryonic stem cells injected into the site of the damage at an Atlanta hospital. The privately funded clinical trial is a milestone in stem cell research, but promises to be controversial in the wake of a renewed ban on federal funds for the research, imposed by a district court in August. The Justice Department is appealing.

Hope for patients with spinal cord injuries

The human test of embryonic stem cell therapy is called a Phase I trial. The Los Angeles Times reports that Phase I intends to determine the safety of the treatment, which was tested extensively on animal subjects. Up to 10 patients with spinal cord injuries between the third and 10th thoracic vertebrae will be tested. The stem cells must be injected no later than 14 days after the injury occurred. Before injection, the stem cells, which can develop into any type of cell in the body, are transformed into “glial” cells that insulate nerve fibers. Scientists are betting that by growing the coating that protects nerve cells, signals may be allowed to travel through the spinal cord once again.

A possible cure for paralysis

The embryonic stem cells should behave like they are in the womb building the spine in a fetus, according to Geron CEO Dr. Thomas Okarma. Okarma told CNN that the process resembles fixing an electrical cable. If the outer fibers are damaged and wire is exposed, the cable shorts out. With a spinal cord injury, the glial cells penetrate the fibers and reinsulate the nerve, much like patching a cable. The result could be permanent repair of the damage causing the paralysis. The goal is to bring a patient from complete paralysis to a point where they can respond to physical therapy.