Science and Health

US starts human blindness trial using stem cells

(Xinhua)
Updated: 2010-11-23 08:59

WASHINGTON - The US Food and Drug Administration (FDA) has approved Massachusetts-based Advanced Cell Technology's application for using retinal cells derived from human embryonic stem cells to treat patients with Stargardt's Macular Dystrophy (SMD), the company said Monday.

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The case is the second human trial of human embryonic stem cells approved in the United States.

Stargardt's Macular Dystrophy causes progressive vision loss, usually starting in children between 10 and 20 years of age. Eventually, blindness results from photoreceptor loss associated with degeneration in the pigmented layer of the retina, called the retinal pigment epithelium (RPE).

"There is currently no treatment for Stargardt's disease," said Dr Robert Lanza, ACT's Chief Scientific Officer, in a statement. "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 percent improvement in visual performance over untreated animals without any adverse effects."

According to Lanza, the company's 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. The company hope to see a similar benefit in patients with various forms of macular degeneration.

The ACT's Phase I/II trial will be 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. A total of 12 patients will be enrolled in the study at multiple clinical sites.

Embryonic stem cells have been at the center of funding controversies in the United States because the research involves destroying the embryos, which some have argued is akin to abortion. But, many researchers consider embryonic stem cells the most versatile types of stem cells, as they can morph into any type of cell.

Last month, California-based Geron Corporation began using human embryonic stem cells to treat a patient with acute spinal cord injuries in the first authorized test of the technology in the United States.