MACUGEN® slows vision loss in wet AMD, receives FDA approval
MACUGEN (pegaptanib) is the first FDA-approved treatment for wet age-related macular degeneration (AMD) that inhibits the growth of unhealthy blood vessels underneath the retina. In contrast, most other available treatments for wet AMD involve procedures that destroy the blood vessels after they’ve grown. The proliferation of sub-retinal blood vessels — a process known as choroidal neovascularization (CNV) — causes substantial and rapid vision loss for people with wet AMD.
Dr. Stephen Rose, chief research officer of The Foundation Fighting Blindness, says "This is meaningful progress, because until now, we haven’t had an FDA-approved treatment for wet AMD that actually inhibits CNV. Other existing therapies are utilized after CNV is prevalent."
Availability and treatment
MACUGEN is being developed and marketed by Eyetech Pharmaceuticals, Inc. and Pfizer, Inc. The companies plan to make the treatment generally available during the first quarter of 2005.
Typically, MACUGEN is administered every six weeks as an injection into the eye (0.3 mg dose).
Efficacy — minimizing vision loss
By inhibiting the growth of new blood vessels, MACUGEN minimizes vision loss. It does not restore vision.
MACUGEN's efficacy was evaluated in two studies, each lasting two years, involving approximately 1,200 patients (892 received MACUGEN, 298 received a placebo).
After the first year, MACUGEN's efficacy was measured at 73% vs. 60% for a placebo. After the second year, efficacy was measured at 64% vs. 53% for the placebo. The drug was considered efficacious if a patient lost less than 15 letters of visual acuity after a 54 week treatment period. Patients received treatments every six weeks.
How the new treatment works
MACUGEN is a vascular endothelial growth factor (VEGF) antagonist. VEGF is a protein, which induces the growth of leaky and inflamed blood vessels underneath the retina. As a VEGF antagonist, MACUGEN blocks VEGF, thereby inhibiting the growth of deleterious blood vessels.
Other anti-angiogenic treatments on the horizon
Drugs and therapies such as MACUGEN that inhibit the growth of new blood vessels are known to be "anti-angiogenic." (The term "angiogenesis" means: formation and differentiation of blood vessels.) Researchers are studying other anti-angiogenic drugs to treat macular degeneration.
"Anti-angiogenic therapies are promising for AMD treatment, because they target the disease at an earlier point in its process, minimizing vision loss," says Rose.
Anti-angiogenics — including VEGF antagonists — are also being used and studied to treat cancer (inhibiting tumor growth), as well as other conditions and diseases.