Latest CATT study results published in the journal Ophthalmology show similar results for two treatments with significantly different costs
SAN FRANCISCO—The results of the second year of the Comparison of Age-related macular degeneration Treatment Trials (CATT) indicate that bevacizumab (Avastin®) is equivalent to ranibizumab (Lucentis®) in the treatment of wet age-related macular degeneration (AMD) through two years when using similar dosing regimens. The study also showed that monthly dosing produced slightly more vision gain than an as-needed regimen. The final visual results, however, were similar in all treatment groups, regardless of dosing frequency, with 60 percent or more of the patients achieving driving vision (20/40 vision or better). The study, which was supported by the National Eye Institute (NEI), was published online this week in Ophthalmology, the journal of the American Academy of Ophthalmology.
"The year-two CATT results confirm that both Avastin and Lucentis are safe and effective therapies for wet AMD," said George A. Williams, M.D., an investigator in the trial at the Oakland University William Beaumont School of Medicine in Royal Oak, Mich. "These results must be considered when ophthalmologists discuss treatment options with individual patients. The CATT Research Group is to be congratulated for this seminal work on the value of comparative effectiveness research."
AMD is the leading cause of vision loss and blindness in older Americans, with approximately nine million people in the United States over the age of 40 suffering from the disease.[i] In its advanced stages, the wet form of AMD spurs the growth of abnormal blood vessels, which leak fluid and blood into the macula, obscuring vision. The macula is the central portion of the retina that enables people to look straight ahead and to perceive fine visual detail. Accumulation of fluid and blood damages the macula, causing loss of central vision, which can severely impede mobility and independence. Without treatment, most patients become unable to drive, read, recognize faces or perform tasks that require hand-eye coordination. Before the advent of the two drugs in the CATT study, about two-thirds of wet AMD patients could expect to be legally blind within two years of developing the disease.
Lucentis was specifically designed to treat AMD, receiving U.S. Food and Drug Administration approval in 2006. Avastin, which is FDA-approved as a cancer treatment, is frequently used as a treatment for AMD as it works in a similar manner to Lucentis due to the two drugs' structural similarities. The CATT study was designed to compare the relative safety and effectiveness of the two drugs in treating wet AMD. The multicenter study enrolled 1,185 patients at 59 research and medical institutions across the United States.
"Therapies for AMD require repeated treatment to prevent vision loss," said Paul A. Sieving, M.D., Ph.D., director of the NEI. "Results of this clinical trial provide evidence that long-term treatment with either drug results in a robust and lasting improvement in vision. Patients and clinicians now have valuable information to base treatment decisions."
Year-one CATT results were published in the May 19, 2011, issue of the New England Journal of Medicine. Four treatment groups were defined by whether they received Lucentis or Avastin and whether they received treatment monthly or as-needed. In year two, patients continued to receive the same drug as in year one, but were randomly reassigned to monthly or as-needed treatment regimens.
"While CATT showed that patients treated monthly had slightly better vision improvement than those treated as-needed, the results for both regimens are strong enough to permit a retinal physician to select a treatment approach tailored to the needs of the individual patient," said Trexler Topping, M.D., chairman of the American Academy of Ophthalmology's Health Policy Committee.
Over the two years of the study the rates of serious events such as stroke, heart attack and death were similar for patients who received either drug. But, as occurred in year one, the second year results showed a higher rate of non-specific serious adverse events in patients receiving Avastin, at 40 percent, versus Lucentis at 32 percent. More events occurred in the patient group that received fewer injections, which is not the typical dose-response relationship. The researchers say the importance of the adverse events finding is unclear; however, it may be related to the fact that the median age of CATT patients was 80 years, a population in which chronic or acute medical conditions are more common and a high rate of hospitalizations is expected.
Beyond the clinical findings of the study, the cost differences between treatments may have implications for both patients and physicians. One dose of Lucentis costs approximately $2,000, while Avastin costs about $50 per dose.Both drugs are manufactured by Genentech.
"In 2010, ranibizumab (Lucentis) accounted for nearly 10 percent of the entire Medicare Part B drug budget, its single largest expenditure," wrote the authors. "As the treatment of patients continues indefinitely, the cumulative financial burden to third-party payers and patients will only increase."
About the American Academy of Ophthalmology
The American Academy of Ophthalmology is the world's largest association of eye physicians and surgeons — Eye M.D.s — with more than 32,000 members worldwide. Eye health care is provided by the three "O's" – ophthalmologists, optometrists, and opticians. It is the ophthalmologist, or Eye M.D., who can treat it all: eye diseases, infections and injuries, and perform eye surgery. For more information, visit www.aao.org . The Academy's EyeSmart® public education program works to educate the public about the importance of eye health and to empower them to preserve their healthy vision, by providing the most trusted and medically accurate information about eye diseases, conditions and injuries. Visit www.geteyesmart.org to learn more.
Ophthalmology,the official journal of the American Academy of Ophthalmology, publishes original, peer-reviewed reports of research in ophthalmology, including basic science investigations and clinical studies. Topics include new diagnostic and surgical techniques, treatment methods, instrument updates, the latest drug findings, results of clinical trials, and research findings. Ophthalmology also publishes major reviews of specific topics by acknowledged authorities.
[i] National Eye Institute Prevalence of Blindness Data (http://www.nei.nih.gov/eyedata/pbd_tables.asp)