Fetal stem cells: a clinical trial update

by Joe Rojas-Burke, The Oregonian Monday June 08, 2009, 1:10 PM

A potential stem cell treatment for the deadly childhood illness known as Batten disease cleared safety testing at Oregon Health & Science University.

Children with Batten disease lack a crucial enzyme, which causes toxins to accumulate and destroy brain cells. Affected children aren't likely to survive past their teens. Researchers are attempting to restore production of the missing enzyme using stem cells isolated from fetal brain tissue.

StemCells Inc., a California biotechnology firm developing the treatment, said it is the first application of human neural stem cells to be tested in a clinical trial overseen by the U.S. Food and Drug Administration. (OHSU has received cash and stock from StemCells Inc. in a number of licensing and sponsored research agreements with the publicly traded company since 1997.)

Doctors at OHSU's Doernbecher Children's Hospital implanted the company's proprietary stem cells in the brains of six children in advanced stages of Batten disease. All of the children appeared to tolerate the implanted cells without serious side effects, and the cells remained viable during the 12 month study, researchers reported at a scientific meeting on Monday. One patient died about a year following transplantation, but company scientists and independent safety monitors concluded that the natural progression of the disease caused the death.

Researchers still don't know if the treatment will work as intended to prevent brain damage or disabling symptoms. But the preliminary results have convinced the company to invest in further clinical trials, said Dr. Stephen Huhn, a vice president at StemCells Inc.

Patients in the first trial "already had a severe amount of neuronal degeneration and brain atrophy due to the advanced stage of their disease and only a limited number of brain cells remaining to protect, making it difficult to measure any degree of efficacy," Huhn said.

"Our objective is to initiate a second trial designed to test the potential for efficacy in patients in a much earlier stage of the disease."