A ray of hope! Gene tharapy provide sight to young persons!

Breaking News from the Foundation Fighting Blindness
04/28/2008
Now They SeeLandmark Gene Therapy Provides Vision to Nearly Blind Young Adults
Jean Bennett, M.D., Ph.D.,lead investigator of the study, with her husband, Albert Maguire, M.D.,the study's lead surgeon.
Three young adults with virtually no vision can now read several lineson an eye chart and see better in dimly lit settings thanks to aninnovative genetherapy aiming to reverse blindness in a severe form of retinitispigmentosa known as Leber congenital amaurosis or LCA. One person waseven able to betternavigate an obstacle course several weeks after receiving the therapy.
The three individuals are participating in a Phase I clinical trial atThe Children's Hospital of Philadelphia, which is funded in part bythe FoundationFighting Blindness.
"I am overwhelmed with delight. We are delivering vision to people whowere blind. This is the biggest advancement in the 37-year history ofthe FoundationFighting Blindness," says Gordon Gund, Co-Founder and Chairman of theFoundation Fighting Blindness. "We have achieved an incrediblemilestone in curingblindness, and this advancement will help pave the way for thedevelopment of gene therapies to treat and cure a variety of retinaldiseases including:retinitis pigmentosa, Stargardt disease, Usher syndrome, and maculardegeneration. This is a great day for the Foundation and all peopleaffected by blindingretinal diseases."
The development of the approach began when a form of LCA was linked tothe RPE65 gene in 1997. Three years later, researchers began givingvision to dogsborn blind from LCA, including the world-famous Lancelot. More than 50dogs have been treated and all continue to see well. The FoundationFighting Blindnesshas been funding this research virtually every step of the way.
Though the Phase I studies are primarily focused on safety, the firstdose used in this study resulted in improved vision. An additional sixindividualswill be enrolled in a continuation of this study to evaluate safetyand efficacy of differing doses. The vision improvement in youngadults seen so farat the lowest dose gives researchers optimism that the treatment mayprovide near-normal vision to children in Phase II studies.
Results of the clinical trials, funded in part by the Foundation, werepublished on April 28, 2008 in the New England Journal of Medicine.The journal publishedthe results of gene therapy trials taking place at CHOP and MoorfieldsEye Hospital in London. A third trial of the gene therapy, sponsoredby the NEI,is also taking place at the University of Pennsylvania and theUniversity of Florida.
Jean Bennett, M.D., Ph.D., lead investigator of the CHOP trial,reports that the team studied three participants, who ranged in agefrom 19 to 26. All threehad one eye treated.
Bennett says that all three individuals reported improved vision indimly lit environments and in visual acuity in their injected eyesstarting two weeksafter treatment. Nystagmus- the roving eye movement associated withsevere vision loss from LCA- was also reduced in all threeindividuals.
The treatment developed by this team of investigators involvesdelivery of a normal RPE65 gene to the retina to augment function ofthe defective RPE65gene that leads to one form of LCA. Twelve different genes that leadto LCA have been identified.
The gene is delivered using a therapeutic virus known as anadeno-associated vector or AAV.
Researchers believe the vision improvement from a single injectionwill last for many years. In earlier laboratory studies, a singleAAV-based gene therapyin more than 50 dogs born blind from LCA has been effective for morethan seven years.
This study is being carried out by an international team led by TheUniversity of Pennsylvania, The Children's Hospital of Philadelphia,the Second Universityof Naples and the Telethon Institute of Genetics and Medicine (both inItaly), and several other American institutions.
http://www.blindness.org/research.asp?id=326