Stem cells for the treatment of eye diseases? The American Medicines Agency (FDA) has approved the use of retinal epithelial cells, which were obtained from human embryonic stem cells, for the first time in a study to treat juvenile macular degeneration.
The US researchers want to treat the eye disease, also known as Stargardt's disease, with the help of embryonic stem cells. To this end, twelve patients with juvenile macular degeneration are to take part in a phase I / II study in which the retinal epithelial cells obtained from embryonic stem cells are implanted under the retina (subretinal). The method has already been successfully tested in various animal experiments on rats and mice, whereby the implanted cells saved the photoreceptors of the retina from destruction and saved the eyes of the animals, Dr. Robert Lanza from the biotech company Advanced Cell Technology (ACT), which produces the cells. "In rats, the stem cells showed a 100 percent improvement compared to untreated animals," said Lanza. The researchers are now hoping for similar therapeutic successes when using the new method in people with macular degeneration.
The study is aimed specifically at patients with Stargardt's disease, an inherited form of macular degeneration that leads to the destruction of the cells of the retinal pigment epithelium (RPE cells) on the retina. In most cases, only the macula, also known as the "yellow spot", the "point of sharpest vision", is affected by the disease. Stargardt's disease usually occurs for the first time between the ages of 10 and 20 and the eyesight continues to deteriorate from then on. A therapy with which the loss of vision can be counteracted has so far not existed and the patients suffer from a steadily progressing decrease in visual acuity. The central visual field is most affected. According to the researchers, around 25,000 people suffer from Stargardt's disease in the USA, and around 8,000 people in Germany.
The US scientists around Dr. Steven Schwartz of the Jules Stein Eye Institute at the University of California at Los Angeles plans to implant 50,000 to 200,000 of the RPE cells made from embryonic stem cells under the retina of twelve Stargardt patients. The researchers use the RPE cell preparation "MA09-hRPE" manufactured by ACT, which has had "orphan drug status" in the USA since the beginning of the year. In this context, ACT emphasized that although the preparation is derived from human embryonic stem cells, it no longer contains any stem cells that could increase the risk of cancer. In addition to the juvenile macular degeneration study, the company also plans a study with patients suffering from age-related dry macular degeneration, Robert Lanza said
Although the RPE cells derived from stem cells are now being used in humans for the first time, the manufacturer believes that it will still take years before the method is used more widely in the USA. Due to the extremely controversial use of human embryonic stem cells, it is questionable whether the method would even be approved in Germany. The study must first prove that the twelve participants showed an improvement in their eyesight and that there were no serious side effects. (fp)