(RxWiki News) Two medications commonly used to treat age-related macular degeneration (AMD) have been found to provide equal treatment benefit in the first long-term study comparing the drugs.
Injectable drugs Avastin (bevacizumab), an off-label cancer medication most frequently used to treat AMD, and Lucentis (ranibizumab), approved to treat AMD by the U.S. Food and Drug Administration in 2006, both provided similar vision improvements at two years.
"Get regular vision exams to pinpoint vision loss early."
Maureen Maguire, PhD, corresponding author and director of the Center for Preventive Ophthalmology and Biostatistics at the Perelman School of Medicine at the University of Pennsylvania, noted that regardless of which medication is chosen, both require repeated monthly or as-needed treatments to prevent vision loss.
She said it was known that Avastin and Lucentis resulted in similar improvements short term, but that it has become clear that differences between the two drugs in the long term are almost non-existent, with both providing a nearly identical vision benefit.
AMD is the leading cause of vision loss and blindness in older adults. When it becomes advanced, the wet form of AMD causes the growth of abnormal blood vessels, which leak blood and fluid into the macula, obscuring vision and causing central vision loss.
Avastin, which is approved to treat certain cancers but not AMD, and Lucentis work by blocking the abnormal blood vessel growth and fluid leakage.
During the original, or year one, Comparison of AMD Treatment Trials (CATT), researchers followed 1,185 AMD patients with an average age of 80 treated at one of 43 U.S. medical centers.
The patients were assigned to one of four treatment groups defined by taking either Avastin or Lucentis, and receiving dosing that was either monthly or as-needed.
During the first year Lucentis was administered monthly, but in the second year researchers focused on administering it as-needed to determine whether it would produce the same long-term visual improvements.
Monthly dosage patients received injections every 28 days, while the as-needed group received treatment at the beginning of the study, then were examined every 28 days to determine their need for additional treatment. During the current year two study, 1,107 patients were followed during the second year to assess continued visual clarity improvement.
Investigators found both drugs were highly effective after two years, and vision clarity was only slightly better in patients who received monthly injections as compared to those who received as-needed treatments. In standard eye chart tests, those who received monthly injections had improved an average of half a line better than those in as-needed groups.
In addition, two thirds of patients had driving vision of 20/40 or better after two years. In previous studies only 15 percent retained 20/40 visual acuity.
"Patients who want the small extra advantage afforded with the monthly treatment should also be aware of the additional risks and costs of the monthly injections," said Maguire.
"Those in the as-needed group ultimately required 10 fewer injections over the course of two years and experienced similar visual improvements."
Serious adverse events occurred in 40 percent of patients receiving Avastin and 32 percent of those taking Lucentis, though a high rate of hospitalizations was expected from chronic or acute medical conditions common to older patients.
While more events were reported in Avastin users, they were distributed across numerous conditions, most of which were not found to be associated with the drug when evaluated in cancer trials at a significantly higher dose. The number of deaths, heart attacks, and strokes reported for both drugs was low, and the rates were similar.
"No surprise here," noted Dr. Christopher Quinn, an optometrist with Omni Eye Associates. "The reason we favor Avastin is that it costs less than 10 percent of Lucentis. This will likely not change the use habits of the drugs since it has been our clinical impression for a long time (that) the drugs are equivalent."
Lucentis costs about $2,000 a dose, while Avastin costs about $50 per dose when broken into smaller quantities to treat the eyes.
This study, funded by the National Eye Institute, was published in the current issue of Ophthalmology. First year results were published in the May 2011 issue of the New England Journal of Medicine.