Avastin Works Well Against Age-Related Macular Degeneration
Madison, Wisconsin - University of Wisconsin School of Medicine and Public Health researchers call it "wonderful news" that a much less expensive cancer drug seems to work well to treat the leading cause of blindness in people over the age of 50.
Dr. Suresh Chandra, professor of ophthalmology and visual sciences, led the UW-Madison center of the national clinical trial, which released its first year's worth of results Thursday. Of 1,208 patients who participated in the trial, 26 were treated at the UW School of Medicine and Public Health.
The National Eye Institute study compared Avastin, a cancer drug that is commonly used off-label to treat age-related macular degeneration (AMD), and Lucentis, the Food and Drug Administration-approved drug for treating AMD. The Comparison of AMD Treatments Trials (CATT) found that the two drugs had similar effectiveness.
But they don't have similar prices: Avastin costs about $50 a dose, while Lucentis costs about $2,000.
"This is wonderful, it could result in billions of savings for the Medicare program," says Chandra, a retina specialist. "It also has important implications for patients in developing countries where they just can't afford Lucentis."
The study will be published online in the New England Journal of Medicine on Sunday.
The National Eye Institute (NEI), a part of the National Institutes of Health, estimates that more than 250,000 patients are treated each year for AMD, the leading cause of vision loss in older Americans. In its advanced stages, the wet form of AMD spurs the growth of abnormal blood vessels, which leak fluid and blood into the macula and obscure vision.
The macula is the central portion of the retina that allows us to look straight ahead and to perceive fine visual detail. AMD can cause loss of central vision, which can take away patients' mobility and independence as they lose the ability to drive, read, recognize faces or perform tasks that require hand-eye coordination.
Genentech, the maker of both drugs, originally developed Avastin to prevent blood-vessel growth that enables cancerous tumors to develop and spread. In 2004, the FDA approved Avastin for the systemic treatment of metastatic colon cancer. Genentech later developed Lucentis, derived from a protein similar to Avastin, specifically for injection in the eye to block blood-vessel growth in AMD.
In 2005, clinical trials established Lucentis as highly effective for the treatment of wet AMD. Before the drug became commercially available, ophthalmologists began injecting AMD patients with low doses of Avastin, due to its similarity to Lucentis and its availability
NEI launched CATT in 2008 to compare Lucentis and Avastin. The study has now reported results for 1,185 patients with AMD treated at 43 clinical centers in the United States, including Madison.
Patients were randomly assigned and treated with one of four regimens for a year. They received Lucentis or Avastin either monthly, or as needed (PRN) based on examination. Ophthalmologists did not know which study drug a patient was getting.
So far, visual acuity improvement was virtually identical (within one letter difference on an eye chart) for either drug when given monthly. In addition, no difference was found in the percentage of patients who had an important gain or loss in visual function.
Also, when each drug was given on a PRN schedule, there also was no difference (within one letter) between drugs. PRN dosing required four to five fewer injections per year than monthly treatment. Visual gains were about two letters fewer with PRN than with monthly treatment but overall visual results were still excellent.
Dr. Chandra said the researchers will continue to follow patients through a second year of treatment to study longer-term effects of the drugs on vision and safety.
Date Published: 04/29/2011