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Pfizer Eyes New Use For Stem Cells

Big drug companies have largely stayed away from testing exotic stem-cell treatments. But now Pfizer is betting that a radical new adult stem-cell treatment may be able to stave off diabetes-induced retina damage, a leading cause of blindness. In an unusual deal, the big drug maker is funding the creation of a biotech company in San Diego called EyeCyte, which will develop stem-cell treatments for eye diseases. The company is based on work by Scripps Research Institute ophthalmologist Martin Friedlander, who has pinpointed bone- and blood-marrow stems cells that, in animal experiments, have a remarkable ability to target and repair damaged blood vessels in the eye. Abnormal blood vessels are a key problem in both diabetic eye disease and macular degeneration.

In the future, patients with early signs of blood-vessel damage in the eye might go to the doctor in the morning and leave a blood sample. Adult stem cells would be isolated in the lab over the next few hours, and then the patient would come back in the afternoon and get an injection of his own purified stem cells into the eye. That single injection could stave off further blood-vessel damage for years, preserving eyesight that would otherwise be lost.
"It is unbelievable. These cells know where to go and they target the site of injury," said Friedlander. In his lab, he has cured mice "10 times over" in work funded by the National Eye Institute. The big question, he said, is whether the treatment will help people.

Developing a complicated procedure to purify stem cells for human trials was difficult at Scripps, because academic settings and government grants support basic research, not the applied-process development required for such targeted research, and Friedlander didn't want to go the typical venture-capital route. So instead, he approached Pfizer (nyse: PFE - news - people ) about funding a company to commercialize the therapy. His timing was good, as Pfizer this April started a new regenerative-medicine unit devoted to therapies involving stem cells. "Pfizer has put its flag in the ground that there is future in regenerative medicine," said Corey Goodman, president of the company's biotech unit. "The eye is a very good place to be starting--it is an isolated organ, and there is a huge need."

The drug maker is putting in a modest $3 million to get the new company of the ground. But if the therapy looks promising in a couple of years, Pfizer has the right of first refusal to buy it outright. The concept is to combine "the entrepreneurial spirit of the start-up, but with the muscle and clout and access to resources of a pharmaceutical company," said Goodman. It's far from being a passive investment; Goodman says Pfizer's top scientists will work with Friedlander and his team. Goodman also says Pfizer would consider more deals like this in the future. The company has little to lose by trying new things. Its stock is in the dumps, and its main drug, Lipitor, will face patent expiration in 2011.

Few good treatments exist for diabetic retinopathy, in which blood vessels that bring oxygen to the retina grow abnormally, leading to leakage of fluid or blood cells. To solve the problem, doctors sometimes resort to the radical step of using lasers to kill retina cells responsible for peripheral vision in order to preserve enough oxygen for those engaged in central vision. Far better would be a treatment that repaired the vessel damage and restored proper blood flow. The first focus for EyeCyte will devise an efficient procedure for isolating and purifying the stem cells, called "CD44 high." Purified stem cells would be injected into a patient's eyes, where they would mature into support cells that could jump-start healing.

The object is to have a stem-cell treatment ready for human trials within three years, said Mohammad A. El-Kalay, EyeCyte chief executive and a veteran of several cell-therapy companies. When he heard about the technology four years ago, he "got very excited" because it looked like there might be enough cells in one patient's blood to treat the eyes without having to laboriously grow more cells in the lab. "The goal is to intervene with these progenitor cells, stabilize the eye and prevent things from getting worse," said Friedlander. If it works as well as he hopes, one stem-cell injection might prevent further damage for as long as a decade. Friedlander's stem-cell therapy could one day compete with drugs like Lucentis from Genentech (nyse: DNA - news - people ). This drug is approved for macular degeneration and is in testing for diabetic eye disease. Novartis (nyse: NVS - news - people ) also sells treatments for various eye diseases. Besides Pfizer, one of the few big drug companies involved in cell therapy is Johnson & Johnson (nyse: JNJ - news - people ). It is an investor in the San Diego biotech company Novocell, which is developing stem-cell therapy to cure diabetes.