November 22, 2010

Clinical Trial To Use Stem Cells To Battle Blindness

A Massachusetts-based company has been given Food and Drug Administration (FDA) approval to conduct a trial in which embryonic stem cells will be used to treat individuals suffering from an eye condition that can lead to blindness.

Advanced Cell Technology (ACT), a biotechnology firm that specializes in regenerative medicine, will use the stem cells to treat individuals suffering from Stargardt's Macular Dystrophy, a degenerative condition that affects the part of the retina where incoming light rays are focused. According to the company, the disease usually begins in children between the ages of 10 and 20, and ultimately leads to blindness due to degeneration of the retinal pigment epithelium, or RPE.

"There is currently no treatment for Stargardt's disease," Dr. Robert Lanza, ACT's Chief Scientific Officer, said in a statement Monday. "Using stem cells, we can generate a virtually unlimited supply of healthy RPE cells, which are the first cells to die off in SMD and other forms of macular degeneration."

"We've tested these cells in animal models of eye disease. In rats, we've seen 100% improvement in visual performance over untreated animals without any adverse effects," he added. "Our studies showed that the cells were capable of extensive rescue of photoreceptors in animals that otherwise would have gone blind. Near-normal function was also achieved in a mouse model of Stargardt's disease. We hope to see a similar benefit in patients with various forms of macular degeneration."

The ACT researchers, who plan to conduct a trial on 12 Stargardt's patients, are just the second team of medical experts to receive FDA approval for experiments using human embryonic stem cells. In October, Geron Corp began using the cells on patients who suffering from spinal cord injuries.

According to a press release, the company plans to conduct a "prospective, open-label study that is designed to determine the safety and tolerability of the RPE cells following sub-retinal transplantation to patients with advanced SMD." Multiple clinical sites will be used for the trial, and among those being considered by ACT are the Jules Stein Eye Institute at UCLA; the Casey Eye Institute in Portland, Oregon; the University of Massachusetts Memorial Medical Center; and New Jersey Medical School.

In an interview with AP Science Writer Malcolm Ritter, Lanza said that the primary focus would be gauging the safety of various stem cell doses. Each of the 12 patients will be treated with healthy scavenger cells, according to Ritter, and only one eye of each patient will be injected. Lanza added that he hopes the researchers will "see some improvement in visual acuity," but added that such a development would be "a bonus" and not the primary focus of the experiments.


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