Two popular drugs used to treat age-related macular degeneration (AMD) appear to be equally effective in improving vision, according to a new study.
The difference? One costs $2,000 per dose, but the other one costs $50 per dose.
About a fourth of patients treated with either Avastin, known generically as bevacizumab, or Lucentis, known generically as ranibizumab, had vision that was at least 20/40 after 12 months, investigators at Kaiser Permanente Southern California in Pasadena reported in the February issue of Ophthalmology.
The finding is likely to cause a ripple among clinicians and insurance companies because Lucentis, developed specifically to treat AMD, costs about 20 times as much as Avastin. The latter drug was originally developed to shrink cancer tumors, but ophthalmologists widely prescribe it off-label for AMD, a practice that has generated an ongoing controversy.
Genentech, which manufactures both drugs, has questioned the use of its less expensive drug for AMD, but in a statement regarding this study, the company stopped short of opposing it outright.
In the Kaiser study, the frequency of adverse events did not differ between treatment groups, but Avastin patients received fewer injections over the course of a year.
"What this article principally does is that it reassures patients and ophthalmologists that Avastin appears to be just as effective as Lucentis," said study author Dr. Donald Fong. "It provides more reassurance than changing practice." The two drugs are being compared in an NIH-sponsored multicenter, clinical trial, but results are not expected before 2011.
In an indirect comparison of the two drugs, Fong and coauthors reviewed the records of 452 patients treated for exudative, or wet, AMD with Avastin or Lucentis, both of which inhibit the growth of new blood vessels.
The authors reported that 22.9 percent of Avastin patients and 25.0 percent of Lucentis patients attained visual acuity better than or equal to 20/40 after a year of treatment, a difference that in this study was a statistical dead heat. Similar numbers of patients in each group also exhibited some degree of vision improvement at 12 months.
The authors addressed differences between their findings and those from two Genentech-sponsored clinical trials, which showed more data in favor of the newer, more expensive drug. Despite the differences, the authors concluded that "both treatments seem to be effective in stabilizing visual acuity loss."
In a prepared statement, Genentech officials said they still believe Lucentis "is the most appropriate medicine for people with wet age-related macular degeneration because it was specifically designed, formally studied, manufactured for intraocular delivery, and is approved by the FDA."
"At the same time," the company said, "Genentech does not interfere with doctors' prescribing choices and believes that they should be able to prescribe the treatment they believe is most appropriate for their patients."
A clinical spokesperson for the American Academy of Ophthalmology told MedPage Today that the results of the Kaiser study tend to support ophthalmologists' views about use of the two drugs to treat AMD.
"It looks like all the debate about the superiority or inferiority of one medicine over the other medicine is becoming essentially nullified," said Dr. Abdhish Bhavsar, director of clinical research at the Retina Center of Minnesota in Minneapolis.
"I think that these medicines both do a good job at treating, and I don't think that distinction in clinical practice is relevant anymore."