"Elderly people losing their vision from agerelated macular degeneration httphealth.nytimes.comhealthguidesdiseasemaculardegenerationoverview.htmlinlinenytclassifier might one day have a treatment option that requires fewer injections into the eye than the standard drug now used. In testing an experimental drug being developed by Regeneron Pharmaceuticals httptopics.nytimes.comtopnewsbusinesscompaniesregeneronpharmaceuticalsincindex.htmlinlinenytorg when injected every eight weeks proved as effective as the standard treatment Lucentis from Genentech which was injected every four weeks. The findings are from two clinical trials that Regeneron is expected to announce on Monday. In a separate development Advanced Cell Technology is expected to announce Monday that it has won regulatory approval to test a therapy derived from human embryonic stem cells httptopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicsstemcellsindex.htmlinlinenytclassifier in people with Stargardts macular dystrophy another retina disease. It is only the second trial of a therapy derived from human embryonic stem cells to be cleared by the Food and Drug Administration. The first involves a treatment for spinal cord injury httphealth.nytimes.comhealthguidesdiseasespinalcordtraumaoverview.htmlinlinenytclassifier developed by Geron. Agerelated macular degeneration is the leading cause of blindness httphealth.nytimes.comhealthguidessymptomsblindnessoverview.htmlinlinenytclassifier in the elderly. Lucentis can restore a persons ability to drive and read in some cases. But the drug works best when given every four weeks which can be inconvenient for patients and doctors. Doctors often give Lucentis less frequently but even if that regimen produces good results patients must still get checkups every month to make sure their vision is not deteriorating. Regenerons drug which is called VEGF TrapEye gives us the opportunity to not have to see them monthly said Dr. Jeffrey Heier of Boston an investigator in one of the trials and a consultant to Regeneron. That would be very meaningful to patients and their families he said. Regeneron and its partner Bayer said they planned to apply for approval of the drug in the first half of . The two similar trials involved a total of  patients who were randomly chosen to receive either Lucentis every four weeks or VEGF TrapEye either every four weeks or every eight weeks. In the eightweek arm the first three doses were given every four weeks. After a year roughly  percent of the patients in all the arms of the trial maintained their vision meaning their ability to read an eye chart declined by no more than  letters or three lines. VEGF TrapEye was also noninferior to Lucentis in terms of the average change in vision after one year. Lucentis recipients had a mean gain of . letters and . letters in the two trials. Those getting Regenerons drug every eight weeks had gains of . letters and . letters. Regeneron said the two drugs were equally safe. Both VEGF TrapEye and Lucentis block a protein called vascular endothelial growth factor that causes blood vessels to grow and leak into the eye. VEGF TrapEye could become the first big product for Regeneron which was founded in  and is based in Tarrytown N.Y. It sells one drug for a rare disease and has garnered hundreds of millions of dollars from licensing deals with big pharmaceutical companies. Regenerons drug is likely to face competition from offlabel use of Genentechs cancer httphealth.nytimes.comhealthguidesdiseasecanceroverview.htmlinlinenytclassifier drug Avastin httptopics.nytimes.comtopnewshealthdiseasesconditionsandhealthtopicsavastin_drugindex.htmlinlinenytclassifier. When used in the eye Avastin costs about  a dose compared with about  for Lucentis. Still even with such lowpriced competition Lucentis has sales exceeding  billion globally. Meanwhile Advanced Cell Technology of Marlborough Mass. said it would test its stem cell therapy on  adults with severe vision loss caused by Stargardts an inherited disease. The company has turned human embryonic stem cells into retinal pigment epithelial cells which will be surgically implanted into the eye. The hope is that the implanted cells will replace those injured by the disease. Human embryonic stem cells are controversial because their creation usually entails the destruction of human embryos although Advanced Cell Technology is working on a technique to avoid that. Embryonic cells can also form tumors httphealth.nytimes.comhealthguidesdiseasetumoroverview.htmlinlinenytclassifier if injected into the body. Dr. Robert Lanza chief scientist at Advanced Cell said the company had to prove to the F.D.A. that its retinal cells contained virtually no residual embryonic stem cells. It took a year for the company to get clearance for the trial from the F.D.A. It is likely to be several years before such a treatment can reach the market if it works. Still even starting the trial could be a boost to Advanced Cell which often makes headlines but has struggled to raise money. Its shares closed at  cents on Friday. Dr. Peter J. Francis an associate professor at the Oregon Health and Science University which will be a site for the trial says the eye is a good place to test stem cell therapy because it is accessible. Also he said there is less chance of rejection of the implanted cells because the eye is shielded somewhat from the bodys immune system. There is no treatment for Stargardts which affects more than  people in the United States. The disease is usually diagnosed during childhood and it causes a loss of central vision though not usually peripheral vision. Ryan Rapoport of Newcastle Wash. who has the disease basically went from normal vision to legally blind in seven months said his father Darrin. Ryan now  cannot be in the trial because for safety reasons it is confined to adults. Still Mr. Rapoport said It gives us some hope because up until recently there was no hope."