Choroid is the part of eye that lies in between the retina (vision
sensory area) and the sclera (the outer layer of the eye), this area
consist of blood vessels that supply nutrients to the retinal part of
our eye. Choroidal NeoVascularization (CNV) is a disease, which is
characterized by the formation of new blood vessels that arise either
due to the presence of Vascular Endothelial Growth Factors (VGEF) or
due to Age-related Macular Degeneration (AMD). This results in fluid
accumulation below the retinal pigment epithelium, which can lead to
vision loss or extreme myopic vision among individuals. CNV is also
seen in individuals with diabetic retinopathy. In rare cases, it can
occur among individuals with defects in Bruch's membrane, the
innermost layer of the choroid. It has also been observed by the
American Academy of Ophthalmology and other reports that patients
with CNV in one eye have a very high probability to contract CNV in
the other eye within a short frame of time. According to the British
Journal of Ophthalmology published in 2007, age?related macular
degeneration (AMD) is one of the leading causes of irreversible sight
loss among adults registered as legally blind. Among these,
two-thirds of people with AMD have the wet form, which can progress
quickly causing irreversible sight loss within days or weeks. In
2007, approximately 250,000 people were suffering from neovascular
AMD in the U.K, with an incidence rate of 25,000 and 30,000 new cases
annually.
The only successful treatment option that is available commercially
in the market for CNVs include intravitreal (direct to the eye)
injections of anti-VEGF drugs to control the neovascularization and
reduce the fluid accumulated. The most common anti-VGEF compounds are
Ranibizumab (Trade name: Lucentis), Bevacizumab (Trade name: Avastin)
and the novel drug Pegaptanib (Trade name: Macugen). These drugs
belong to a class called anti-angiogenic drugs, their primary
objective being the inhibition of the growth of new blood vessels.
Anti angiogenic drugs are more commonly used for cancer treatment,
where cancerous cells promote angiogenesis resulting in the
proliferation of cells in large numbers, thus forming tumors.
Bevacizumab is a successfully used cost effective drug for the
treatment of cancer as well as AMD related CNVs with a very high half
life (more than twice) in comparison with Ranibizumab. However
chances of adverse effects with Bevacizumab are comparatively higher,
hence Ranibizumab (Lucentis) is now currently the most effectively
and safely used treatment for CNV. Pegaptanib on the other hand is in
Phase IV of the clinical trials wherein only 1000 patients so far
have been treated with significant success rate.
Perceive the Future Details Regarding Choroidal NeoVascularization
at: http://bit.ly/2gxDcnM
With increasing aging population throughout the world the probability
of occurrence of wet-AMD is high, especially in China and Japan where
the aging population is predicted to tip over the young adult
population. The patents for both Bevacizumab and Ranibizumab are till
2018 hence after patent expiry it is predicted that their sales shall
significantly increase, especially with the entrance of Asian drug
manufacturers.
Currently the companies that manufacture Ranibizumab are Novartis
(licensed) in global market and Genetech (patented) in the U.S.
Bevacizumab too was developed by Roche Pharma in association with
Genentech and is currently marketed by Roche internationally.
Pegaptanib is manufactured by Eyetch Inc. and marketed by Pfizer Inc.
Pegaptanib has been approved and is available only in North America,
Europe, Brazil and Australia. Ranibizumab is available under the name
Lucentis with high market share in Europe and North America and
growing in Asia-Pacific region. Bevacizumab is sold as Avastin
globally with highest growth rate observed in Asia and highest
voluminous growth seen in the North Americas and European markets.
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