Results from two new clinical trials have added support for the use of human embryonic stem cells as treatment for the dry form of macular degeneration. Stem cells injected into the eye appear to have replaced the missing cells damaged by the disease, with no serious side effects. One study suggests it may have even improved patients’ vision.
Researchers from Hadassah-Hebrew University Medical Center in Jerusalem, Israel, conducted studies designed to test the safety of the procedure in human subjects. They injected a suspension of either 50,000 or 200,000 retinal pigment epithelial (RPE) cells derived from human embryonic stem cells underneath the patients’ retina. The surgical procedure was well-tolerated. Within a few weeks, they could see signs that the retina was healing at the injection site, and images of the back of the eye suggest the possibility that the transplanted RPE cells survived. Patients’ vision remained largely stable throughout the study, and they suffered no unexpected side effects.
“We’re encouraged by the results thus far,” said Eyal Banin, M.D., Ph.D., lead investigator and one of the developers of the technology. “But this is just a first step in the long road towards making regenerative cell therapy a reality in macular and retinal degeneration.”
An additional trial site for this stem cell treatment is expected to open soon in the United States.
A second research group from Bascom Palmer Eye Institute in Miami has conducted two studies using RPE cells derived from human embryonic stem cells to treat patients with dry AMD, as well as patients with a different form of retinal degeneration called Stargardt disease. It’s the most common form of inherited juvenile AMD. Like dry AMD, there is no treatment available for this blinding disease.
Stem cells implanted in these patients survived for up to three years, and there were no side effects. Some of these patients even gained vision.
“RPE cells appear to be well tolerated in the human eyes,” said lead researcher Ninel Z. Gregori M.D., of Bascom Palmer Eye Institute. “There were no serious adverse events attributable to the transplanted RPE cells, including no tumor formation. “This study supports further development of human embryonic stem cell-derived RPE for degenerative diseases of the macula.”
SOURCE: Press Release