It expects to enroll about a dozen patients whose injuries are between three and 12 months old.
“To date, the focus has been on the acute spinal cord injury phase,” StemCells CEO Martin McGlynn said in a telephone interview. “That’s an important area to address, but the largest unmet need is those who have passed that immediate acute phase of injury.”
About 1.3 million Americans have chronic spinal cord injuries, but most studies have shown that any treatment attempt must take place within days after the injury to do any good.
StemCells Inc, based in Palo Alto, California, said the relevant ethics committees have approved the trial, which it plans to conduct in Switzerland due to the expertise of the investigator and the institution it selected as well as the strong network in Europe for spinal cord patients and referrals.
A study published earlier this year showed that mice treated with StemCells’ nerve stem cells — which are extracted from aborted fetuses — were able to walk better than those treated with ordinary human skin cells or a placebo, even when the treatment came weeks after their injury.
The cells are a form of stem cell, the master cells of the body. These are technically adult stem cells, taken from the partly developed brains of fetuses and tested for qualities showing they are destined to form particular types of nerve cells.
Animal trials have shown that the cells migrate along the spinal cord to the point of injury, and then differentiate into neurons and specialized cells that create the insulation necessary for proper transmission of nerve impulses from the brain to below the level of the injury.
Patients in the StemCells trial will receive a single infusion of cells into the spinal cord. Results are expected within months of the treatment.
Geron Corp last month launched the first trial of human embryonic stem cells, but that study is in patients with new spinal cord injuries.
Geron’s stem cells come from human embryos left over from fertility treatments. They have been manipulated so that they have become precursors to certain types of nerve cells.
U.S. regulators took several years before granting final clearance to the Geron trial. StemCells does not expect to have to wait anywhere that long.
“There are a whole host of issues associated with the embryonic stem cell platform,” McGlynn said. “Thankfully our neural stem cells don’t have those safety concerns.”
By Deena Beasley
(Editing by Dhara Ranasinghe)