Age-related macular degeneration (AMD)
Age-related macular degeneration – dangerous, but almost unknown
The cause is age-related macular degeneration (AMD). This dangerous disease is almost unknown to the general public. Yet it is the most common cause of severe visual impairment and blindness among people over the age of 65 in developed countries. The incidence of age-related macular degeneration will go on growing dramatically as societies continue to age. Women are more frequently affected than men.
The initial symptoms of macular degeneration
Different forms of the disease
"Dry" age-related macular degeneration (AMD) is the most common form of the disease. It only progresses slowly, so that the patients' loss of vision remains limited. The "wet" form of macular degeneration (about 10 to 15 percent of all AMD cases) causes much more serious restrictions of vision. It is caused by tissue fluid and blood seeping from pathologically changed blood vessels into the macula, leading to edemas (swellings caused by fluid accumulations). In addition, new, diseased blood vessels form in the choroid under the retina, so that thickness of the retina is an important parameter of how active the disease is. As a result, the nerve cells of the retina gradually die off, and central vision can be lost within just a few years. If there is hemorrhaging, it may even be lost completely at once.
Prospects of a new active substance against wet AMD
More and more medicines that inhibit a specific growth factor known as VEGF (vascular endothelial growth factor) are used today in the treatment of wet age-related macular degeneration. This messenger substance usually stimulates the formation of new blood vessels.
VEGF inhibition is also the basic mechanism used by a new active substance under development by Bayer HealthCare and the U.S. firm Regeneron Pharmaceuticals. Two Phase III trials are currently ongoing. This substance could prevent blindness in people with wet age-related macular degeneration (AMD). It is a protein that is injected into the eye. There, it inhibits not only VEGF, but also another messenger substance involved in the abnormal formation of new blood vessels and its fateful consequences. Progressive blindness can be stopped in this way. And not only that: because the substance causes existing edemas and pathologically formed new blood vessels in the choroid to recede, some of the photoreceptor cells that have not yet been completely destroyed can be saved – and visual acuity can even improve in some patients.
Phase III study results from the first year have been promising. They have shown that the participants' visual acuity improved significantly. Similarly, treatment with the new active substance led to a statistically significant reduction in retinal thickness after twelve weeks. The substance was also well tolerated by patients. In the second year of the studies, patients in VIEW 1 and VIEW 2 continued to be treated with the same dose per injection as in the first year but administered only every three months or more often, if any worsening of visual acuity, retinal thickness or leakage of blood and fluid occurs.
Bayer HealthCare and Regeneron are collaborating on the global development of Aflibercept (VEGF Trap-Eye). Regeneron maintains exclusive rights to Aflibercept (VEGF Trap-Eye) in the United States. Bayer HealthCare licensed the exclusive marketing rights outside the United States, where the companies will share equally the profits from any future sales of Aflibercept (VEGF Trap-Eye), except for Japan where Regeneron will receive a royalty on net sales.
Aflibercept (VEGF Trap-Eye) was already approved in the United States in Macular Edema following Central Retinal Vein Occlusion (CRVO) and in wet AMD. In 2012, Bayer has received approval for Aflibercept (VEGF Trap-Eye) for the treatment of wet AMD in several markets, including Europe, Japan, Australia, and some countries in Latin America. Submissions have been filed in this indication for marketing authorization in additional countries worldwide. In December 2012 Bayer HealthCare has requested the approval for Aflibercept (VEGF Trap-Eye) for the treatment of macular edema following Central Retinal Vein Occlusion (CRVO) at the EMA (European Medicines Agency).
Advice for patients
Every body reacts differently to medicines. Therefore it is impossible to tell which medicine works best for you. Please consult your physician.