By Laird Harrison
Nice, France-Evaluating patients with neovascular age-related macular degeneration (AMD) for treatment every 6 weeks with bevacizumab may be less effective than evaluating them every 4 weeks for treatment with ranibizumab, according to one researcher.
But the two treatments showed very similar effects in a study presented by Prof. Vivian Wing-Man Ho, of Leighton Hospital, Crewe, United Kingdom, here at the European Society of Retina Specialists 15th EURETINA Congress.
While both drugs have been shown effective in previous research, bevacizumab is a cancer drug used off label for neovascular AMD while ranibizumab is approved for AMD.
On the other hand, ranibizumab is more expensive. So clinicians have a keen interest in knowing whether one treatment works better than the other.
To see how their patients fared on the different regimens, Dr. Ho and her colleagues looked at the records of 102 consecutive patients treated with 1.25 mg intravitreal injections of bevacizumab and 101 consecutive patients treated with 0.5 mg intravitreal injections of ranibizumab between August 2008 and October 2010.
The median age of the bevacizumab patients was 81 years. The group was 74.28% female, had a mean best corrected visual acuity (BCVA) of 38.6 letters and a central macular thickness of 405 µm.
The median age of the bevacizumab patients was 80 years. The group was 72.29% female, had a mean best corrected visual acuity (BCVA) of 40.6 letters and a central macular thickness of 424 µm.
However none of these differences between the groups were statistically significant by the traditional definition (p < 0.05).
After getting information on the two possible treatments, patients who had never before been treated chose between one protocol or the other. All the patients received 3 loading doses. After that, the bevacizumab patients visited the hospital for evaluation every 6 weeks while the ranibizumab patients visited every 4 weeks.
At each visit, those patients who had lost more than 5 letters in best-corrected visual acuity (BCVA), had gained retinal fluid on optical coherence tomography (OCT) scans or had new retinal haemorrhages received an additional injections.
Both groups gained mean visual acuity and lost mean central macular thickness, but the differences between the groups also fell short of traditional statistical significance. The bevacizumab group needed about one more injection per year, which met the traditional definition of statistical significance.
|Bevacizumab, n = 102||Ranibizumab, n = 101||P|
|Mean Change in BCVA at 1 Year, Letters||7.6||10.7||0.10|
|Mean Change in BCVA at 2 Years, Letters||7.0||9.2||0.31|
|Lost 15 Letters or More at 1 Year, %||10||2||0.054|
|Lost 15 Letters or More at 2 Years, %||12||6||0.13|
|Mean Change in CMT at 1 Year, µm||-139||-150||0.85|
|Mean Change in CMT at 2 Years, µm||-146||-160||0.72|
|Mean Number of Injections at 1 Year||6.6||5.9||< 0.001|
|Mean Number of Injections at 2 Years||11.9||10.3||0.023|
“As we all know bevacizumab and ranibizumab have significant improvement in terms of visual acuity and macular thickness reduction in neovascular AMD patients,” Dr. Ho said. “However our study could not demonstrate that bevacizumab 6 weekly as required treatment was non inferior to ranibizumab 4 weekly.”