FDA Panel Recommends Macular Degeneration Drug
Nov. 17, 1999 (Washington) -- Without taking a formal vote, an advisory panel to the FDA recommended laser therapy with the light-sensitive agent called Visudyne (verteporfin) to treat a particularly aggressive form of macular degeneration that can result in blindness. "The treatment is effective, but the treatment effect is very modest ... it's not penicillin," Donald Fong, MD, chair of the Ophthalmic Drugs Subcommittee, tells WebMD.
In the wet form of age-related macular degeneration (AMD), leaky blood vessels grow across the central portion of the retina, or macula, for unknown reasons and cause scarring. Laser therapy selectively destroys the abnormal blood vessels, leaving the normal vessels and tissue alone. About 200,000 cases occur in the U.S. annually, and the ability of current treatments to preserve useful vision is limited to about 20% of new cases.
Fong says about half of those treated with Visudyne still lost vision, but he termed it "a step in the right direction." Since the drug is under a priority review, it could be available in the spring, pending FDA action. If ultimately approved, Visudyne would be a new approach to treating patients with the wet form of AMD, a small percentage of people who develop AMD.
Trials for Visudyne focused on those who have the 'classical' form of the disease, which is considered the most aggressive. In two studies involving more than 600 patients, researchers compared Visudyne to placebo in patients at least 50 years old with a variety of macular-related lesions.
The treatment involves a 30-minute drug infusion, and then, 15 minutes later, a jolt of laser energy aimed into the eye 'turns on' the Visudyne. The drug then inhibits the growth of abnormal blood vessels, apparently without damaging normal tissue. According to the manufacturer, 15% more of those treated with this therapy either stabilized or showed a small loss of vision at the 12-month follow-up compared with those on placebo.
The improvement could mean the difference between 20/100 and 20/200 vision, according to drug investigator Neil Bressler, MD, ophthalmologist at Johns Hopkins University School of Medicine. This is described as clinically significant for those who have the classic type of AMD.