Saturday, May 21, 2011

No Difference in Anti-VEGF Drugs for Wet AMD

Researchers conducting a closely watched head-to-head study of intravitreal bevacizumab (Avastin) and ranibizumab (Lucentis) for slowing "wet" age-related macular degeneration (AMD) will report that the drugs were equally effective, according to the New York Times.
The newspaper cited anonymous investigators in the National Eye Institute-sponsored trial. The results were scheduled to be presented Sunday at the Association for Research in Vision and Ophthalmology meeting in Ft. Lauderdale, Fla. The Times also indicated that a peer-reviewed paper with details would be published simultaneously online in the New England Journal of Medicine.
Both drugs target the vascular endothelial growth factor (VEGF) pathway to inhibit angiogenesis. Neovascularization in the retina is responsible for the less common but more severe "wet" form of AMD.
The question of their respective efficacy came up because off-label bevacizumab is far less costly than ranibizumab, which is approved for this purpose and is used about as often.
Bevacizumab is currently approved for treating various solid-tumor cancers.
Many ophthalmologists have generally believed that the drugs are equally effective in wet AMD, but didn't have the systematic data to prove it.
Moreover, bevacizumab's manufacturer, Genentech, had no incentive to sponsor a comparison trial because it also sells ranibizumab, which carries a price tag 40 times higher than bevacizumab's for an intravitreal dose.
Indeed, the company has been accused of trying to sow doubts about the efficacy and safety of bevacizumab for AMD.
Another study -- sponsored by Genentech -- slated for presentation at the ophthalmology conference cites Medicare data indicating higher rates of hemorrhagic stroke and death in AMD patients receiving bevacizumab than in those receiving ranibizumab.
So in stepped the National Eye Institute to sponsor the 1,200-patient randomized trial.
According to the Times, the difference in visual acuity following one year of treatment was less than five letters on a standard chart, which was the trial's prespecified definition of noninferiority.
But one of the newspaper's sources indicated that bevacizumab was less effective than ranibizumab in reducing macular thickness, which could presage degradation in visual acuity later on.

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