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Archivos de Advanced Cell Technology para el uso de Stem Cells para tratar enfermedades del ojo
Advanced Cell Technology Files IND for Trial Using Stem Cells to Treat Eye
Advanced Cell Technology, Inc. (Worcester, MA), filed an Investigational New
Drug Application (IND) with the FDA to initiate the human clinical trial
evaluating the use of embryonic stem cells for the treatment of Stargardt
macular dystrophy (SMD).
The phase 2/3 study will use stem cells to recreate retinal pigment
epithelium (RPE), which supports the photoreceptors needed for vision,
according to a company news release. RPE cells are often the first to die in
patients with SMD and AMD, leading to vision loss.
Twelve patients will be enrolled in the study at three clinical sites. The
prospective, open-label, multicenter study will determine the safety and
tolerability of the RPE cells following subretinal transplantation in
patients with advanced SMD.
Informe de Stargardt de la fundación Fighting Blindness
What is Stargardt Disease?
Stargardt disease is the most common form of inherited juvenile macular degeneration. The progressive vision loss associated with Stargardt disease is caused by the death of photoreceptor cells in the central portion of the retina called the macula.
The retina is the delicate light-sensing tissue lining the back inside wall of the eye. Photoreceptor cells in the retina provide vision by conveying information from the visual field to the brain. The macula is responsible for sharp central vision — for tasks like reading, watching television, and looking at faces.
Decreased central vision is a hallmark of Stargardt disease. Side vision is usually preserved. Stargardt disease typically develops during childhood and adolescence. Also involved in Stargardt disease is a region beneath the macula called the retinal pigment epithelium.
What are the symptoms?
The symptom that brings most people to an eye doctor is a change in central vision. A doctor looking at the retina of a person with Stargardt disease will see characteristic yellowish flecks in and under the macula. The flecks might extend outward in a ring-like fashion.
The flecks are deposits of lipofuscin, a fatty byproduct of normal cell activity. In Stargardt disease, lipofuscin accumulates abnormally. The Foundation Fighting Blindness supports research studying lipofuscin build up and ways to prevent it.
A decrease in color perception also occurs in Stargardt disease. This is because photoreceptor cells involved in color perception are concentrated in the macula.
How quickly does vision fade?
The progression of symptoms in Stargardt disease is variable. Visual acuity (the ability to distinguish details and shape) may decrease slowly at first, accelerate, and then level off.
A study of 95 people with Stargardt disease showed that once a visual acuity of 20/40 is reached, there is often rapid progression of additional vision loss until it reaches 20/200. (Normal vision is 20/20. A person with 20/40 vision sees at 20 feet what someone with normal vision sees at 40 feet.) By age 50, approximately 50 percent of people in the study had visual acuities of 20/200 or worse.
Eventually, almost everyone with Stargardt disease has a visual acuity in the range of 20/200 to 20/400. The vision loss is not correctable with prescription eyeglasses, contact lenses, or refractive surgery.
Is it an inherited disease?
Stargardt disease is almost always inherited as an autosomal recessive trait. It is inherited when both parents, called carriers, have one gene for the disease paired with one normal gene. Each offspring has a 25 percent chance of inheriting two copies of the Stargardt gene (one from each parent) needed to cause the disease. Carrier parents are unaffected because they have only one copy of the gene.
Genetic counselors are an excellent resource for discussing inheritability, family planning, career choices, and other issues related to living with Stargardt disease.
In 1997, FFB-funded researchers found the gene for Stargardt disease, ABCA4, which normally causes the production of a protein involved in the visual cycle. Lipofuscin buildup appears to be related to a mutation in this gene, and the resulting production of a dysfunctional protein.
What treatment is available?
FFB is supporting several promising avenues of research, including gene and drug therapies. Researchers are planning a clinical study of a treatment that involves delivery of a healthy version of the ABCA4 gene into retinal cells to restore production of the normal protein. They are also optimistic about several drugs that may slow vision loss by reducing the buildup of lipofuscin.
Because there is some evidence that sunlight may influence lipofuscin accumulation in the retina, u-v blocking sunglasses are generally recommended for outdoors. For people who already have significant vision loss, low vision aides are available.
Are there any related diseases?
Stargardt disease is also known as Stargardt macular dystrophy or fundus flavimaculatus. In addition to recessive Stargardt disease, there are other rarer forms inherited as dominant rather than recessive traits.
See also: macular degeneration.
The Foundation Fighting Blindness is a research foundation dedicated to finding the causes, treatments and cures for retinal degenerative diseases like retinitis pigmentosa (RP), Usher syndrome and macular degeneration.
New Investment to Boost Gene Therapy Development
The National Neurovision Research Institute (NNRI), the Foundation Fighting Blindness’ clinical trial support organization, announced today that one of its key partners, biopharmaceutical company Oxford BioMedica, has established a collaboration with sanofi-aventis, a major international pharmaceutical company, to develop and commercialize gene therapy treatments for vision-robbing retinal degenerative diseases that affect tens of millions of people around the world.
The collaboration will significantly bolster the development of the following gene therapy products: StarGen™ for the treatment of Stargardt disease, a form of early-onset macular degeneration; UshStat™ for the treatment of Usher syndrome, the leading cause of deaf-blindness; and RetinoStat® for the treatment of age-related macular degeneration, the leading cause vision loss in people 55 and older in developed countries.
The development of treatments for these and other retinal degenerative diseases is a key goal of the National Neurovision Research Institute and is the basis for its partnership with Oxford BioMedica. In 2006, Paul and Diane Manning, with the National Neurovision Research Institute, established a partnership with Oxford BioMedica to advance gene therapies for these and other related retinal degenerative diseases.
“The investment from sanofi-aventis is a wonderful boost for the development of Oxford BioMedica’s gene therapy products and will greatly enhance our ability to move these emerging treatments into and through the clinical trial process,” says Stephen Rose, Ph.D., chief research officer, Foundation Fighting Blindness. “This collaboration affirms the great potential for gene therapy to treat and cure a number of retinal degenerative diseases including Stargardt disease and Usher syndrome that, as rare diseases, often do not receive the attention or investment necessary to bring about promising treatments.”
“An important goal of the Foundation, through NNRI, is to attract investment from large pharmaceutical companies for the development and production of treatments for inherited retinal disease,” says Morton Goldberg, M.D., chairman of the board of NNRI. “The NNRI-Oxford partnership is an excellent model of how NNRI collaborations can accelerate the translation of laboratory-based research into clinical trials, ultimately getting successful treatments for rare diseases like inherited retinal degenerations to the market and out to the people who need them.”
Based on the agreement, Oxford BioMedica will receive an upfront payment of $26 million and a further $24 million from sanofi-aventis over a three-year period.
The treatments will utilize Oxford BioMedica’s LentiVector® gene delivery technology to deliver healthy vision-saving genes to the retina. For more information on this technology, visit www.oxfordbiomedica.co.uk/
Newly-Published Peer-Reviewed Paper Shows Durasert Device Was Neuroprotectant In Retinitis Pigmentosa Model - - 09 Apr 2010
pSivida Corp. (NASDAQ:PSDV) (ASX:PVA), a leader in the development of ophthalmic sustained release drug delivery products, today said that a recently-published peer reviewed scientific paper showed that a sustained release Durasert drug delivery device releasing the steroid fluocinolone acetonide (FA) in the back of the eye preserved retinal function in a retinitis pigmentosa model.
Dr. Paul Ashton, CEO of pSivida Corp., who co authored the paper with Inna V. Glymbia, Alexander Kennedy and Gary Abrams of Wayne State University, Kresge Eye Institute in Detroit and Raymond Iezzi of the Mayo Clinic in Rochester, used pSivida's Durasert technology to study the neuroprotective properties of low-dose sustained-release intravitreous FA as a means of reducing retinal neuroinflammation, preventing cell death and preserving retinal function. Retinitis pigmentosa is a hereditary condition that affects approximately 100,000 individuals in the US. There is presently no known cure or effective treatment for the condition, which causes gradual loss of peripheral vision and night vision and eventually most individuals become legally blind.
"This is very encouraging," said Dr. Ashton, "and we intend to pursue further studies using our technologies for the treatment of eye diseases for which there currently are very few effective treatments." pSivida has developed two of the only three FDA approved ophthalmic sustained release drug delivery products, Retisert® for the treatment of posterior uveitis and Vitrasert® for the treatment of Aids-related CMV retinitis, both of which are licensed to Bausch & Lomb. The company's third product, Iluvien® for the treatment of diabetic macular edema is licensed to Alimera Sciences which is conducting Phase III fully recruited trials and expects to submit a New Drug Application to the FDA in the second quarter of this year. If approved, Iluvien will be the first FDA approved drug for the treatment of DME.
Article URL: http://www.medicalnewstoday.com/articles/184870.php
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