Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. The underlying cause in most cases is the abnormal growth of leaky blood vessels beneath the retina, the nerve layer that processes light. The current standard of care is to use an antiangiogenic, or blood vessel growth inhibitor, called Lucentis (ranibuzumab) or Avastin (bevacizumab) which is administered by monthly injections directly into the eye.
A new experimental antiangiogenic drug, called VEGF Trap-Eye (aflibercept ophthalmic solution) is being tested for its ability to being benefits over these current therapies. VEGF Trap-Eye is a protein that binds to and inactivates a growth factor called VEGF (vascular endothelial growth factor) that stimulate blood vessel growth in AMD. Inhibiting these blood vessels reduces vision loss.
Two phase 3 clinical trials, called VIEW 1 and VIEW 2, have been conducted to examine the benefits of VEGF Trap-Eye. The results indicate that this new drug is just as effective as a standard therapy, but requires fewer injections into the eyes. In VIEW 1 and VIEW 2, at least 95% of patients who received the experimental medication maintained their vision during the 52-week follow-up period. Maintenance of vision was defined as losing fewer than three lines (equivalent to 15 letters) on the Early Treatment Diabetic Retinopathy Study (ETDRS) eye chart.
In the two VIEW clinical trials, all doses and schedules of VEGF Trap-Eye—0.5 mg monthly, 2 mg monthly, and 2 mg every 2 months—allowed at least 95% of patients to maintain their vision. Importantly, the every-other-month dosing of VEGF Trap was just as effective as the monthly dosing of the agent, and was slightly more effective than monthly dosing of the comparator drug, Lucentis.
Convenience of dosing is a major issue with patients receiving treatment for wet AMD. Fewer injections would be a major advance in the treatment of the disease.
The side effects of VEGF Trap-Eye across all treatment groups in the VIEW studies were generally mild. The most frequent side effects were associated with the injection procedure, the underlying disease, or the aging process. The most frequent in the treated eyes were: conjunctival hemorrhage, macular degeneration, eye pain, retinal hemorrhage, and vitreous floaters. There were no notable differences in side effects across the different study treatment arms.
Based on the favorable results from these clinical studies, the manufacturer of VEGF Trap-Eye is planning to submit regulatory applications for marketing approval for wet AMD in Europe and the U.S. in the first-half of 2011. VEGF Trap-Eye is also in clinical development for the treatment of central retinal vein occlusion (CRVO), another major cause of blindness, and diabetic macular edema (DME).