Retina specialists and ophthalmologists are encouraged by promising new scientific approaches that could have the potential to reduce the devastating effects of wet AMD for patients and offer the medical community a new paradigm of care, according to presentations made at the 2004 Annual Meeting of the American Academy of Ophthalmology in New Orleans.
Many experts consider AMD, the leading cause of blindness in Americans over age 50, as a growing public health epidemic. Diagnoses for AMD are expected to double by 2020.
"The epidemic of AMD is fueled by the aging Baby Boomers, the fact that people are living longer, and the increasing incidence of the disease," said presenter Paul Sternberg Jr., M.D., Chairman of the Vanderbilt Eye Institute. "Fortunately, new approaches to treating the disease may soon become available with several therapies in late-phase clinical trials or pending FDA approval showing great promise for stabilizing wet AMD and preserving vision."
Saving Eyes, Saving Lives: The Physical and Emotional Impact of Vision Loss
AMD is a chronic, progressive disease that results in the loss of central vision. As the disease advances, simple tasks such as reading, writing NEW ORLEANS, LA, October 25, 2004 – As more Americans age, the threat of blindness is increasing, and the search for new ways to prevent and treat diseases such as age-related macular degeneration (AMD) has become a high priority in the eye care community., recognizing faces and driving become difficult, if not impossible. The disease not only takes a physical toll on its patients, but also can have a devastating emotional impact on them, their families and caregivers.
"Even a little vision loss to a fully sighted adult can compromise function more globally than any other impairment, increasing the risk of falls and injuries, medication mix-ups, poor nutrition, social isolation and clinical depression," said presenter Lylas G. Mogk, M.D., founding director of the Visual Rehabilitation and Research Center at the Henry Ford Health System Eye Care Services. "For most people, losing both legs would actually impact our lives less than losing our central vision. So it's not a surprise that sighted Americans fear vision loss second only to loss of mental capacity."
Living with vision loss does not have to be such a lonely and isolating experience. Today, vision rehabilitation services are available to maximize independence and preserve quality of life for the hundreds of thousands of Americans living with age-related macular degeneration. Between six and ten percent of patients with AMD progress to the wet form of the disease, characterized by the growth of abnormal blood vessels. Currently only 25 percent of patients with wet AMD have a treatment option approved by the U.S. Food and Drug Administration (FDA). In addition to vision rehabilitation, innovations in biotechnology have the potential to fill the large unmet medical need by offering new treatments to wet AMD patients.
Hope on the Horizon: Anti-VEGF, Anti-Angiogenic and Angiostatic Treatments
Dr. Carmen A. Puliafito, Chairman of the Bascom Palmer Eye Institute at the University of Miami, said that a new treatment paradigm for wet macular degeneration is emerging. This new treatment paradigm is based on the use of drugs which block VEGF (vascular endothelial growth factor), the molecule which promotes the growth of abnormal blood vessels in wet macular degeneration. These drugs can be delivered directly into the eye by injection and attack abnormal VEGF in the retina and adjoining tissues in eyes with wet macular degeneration.
"There are several reasons why anti-VEGF treatment for macular degeneration is so exciting. For the first time, we will have a treatment option for all new cases of wet age-related macular degeneration; right now we only treat a limited number of angiographically defined subtypes," said Dr. Puliafito. "These agents also offer a unique strategy for restoring retinal function and structure in eyes with wet AMD."
Evaluating Emerging Wet AMD Therapies: Is a Bright Future Ahead?
Data presented at this year's American Academy of Ophthalmology meeting show that significant progress is being made to bring new therapies to wet AMD patients at the earliest possible time.
Two anti-VEGF treatments currently in development include pegaptanib sodium (to be marketed as MacugenTM by Eyetech Pharmaceuticals and Pfizer Inc), an anti-VEGF aptamer that binds to one particular form of VEGF in the eye, thereby neutralizing its activity, and ranibizumab (to be marketed as LucentisTM by Genentech Inc and Novartis Ophthalmics), an antibody fragment that also binds to VEGF and inhibits its activity. New clinical trial data on pegaptanib presented during the Retina Subspecialty symposium showed that wet AMD patients benefit from two years of treatment with pegaptanib, which demonstrates that longer-term use may be beneficial for patients suffering from this chronic disease. Pegaptanib is currently under priority review by the FDA and the agency expects to make its decision on the drug by mid-December. Genentech's ranibizumab is currently in phase III clinical trials.
Data from another investigational treatment known as anecortave acetate, an angiostatic cortisene that inhibits the abnormal growth of blood vessels, was also presented at the AAO meeting. Initial analysis of the one-year data from a comparative study of anecortave acetate versus photodynamic therapy in the treatment of wet AMD showed there was no statistical difference between the two therapies. Additional analyses of treatment interval and drug reflux, two controllable factors that some say negatively affected the results, were presented during the meeting. The company is continuing to analyze the data and plans to submit its New Drug Application to the FDA by the end of the year.
Donald D'Amico, M.D., professor of ophthalmology at Harvard University and associate chief of ophthalmology for clinical affairs at the Massachusetts Eye and Ear Infirmary, is optimistic about the future of treatment. "The future looks brighter for people with wet AMD," said D'Amico. "Investigational therapies have the potential to usher in a new era in treatment for wet AMD and offer hope to patients where once there was little or none. Patients have been waiting for new treatment options and the data presented at this meeting show that we are getting closer to making these important new therapies available to wet AMD patients and the physicians who treat them."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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