Bevacizumab (Avastin), a bowel cancer medication which is widely used off label to prevent AMD (wet age related macular degeneration), has been shown to be safe and effective – it is a much cheaper alternative to approved drug ranibizumab (Lucentis). Several large trials comparing the two medications are currently ongoing.
Ranibizumab was not included in this study (it was not licensed for use when the trial began), results of which have been published in the BMJ (British Medical Journal). The researchers support bevacizumab’s immediate implementation in healthcare systems whose limited budgets prevent patients’ access to ranibizumab.
In most countries worldwide, where there is either no treatment or inferior therapies for wet AMD patients, the appropriate use of highly cost-effective bevacizumab would have an direct impact in reducing incident blindness from this condition, the authors write.
Wet AMD is the leading cause of visual loss/virtual blindness in people aged over 50 years in Europe and North America. Visual loss results from the progressive loss of light sensitive cells at the back of the eye caused by damage from abnormal, leaking blood vessels. Sufferers do not go blind, but find it practically impossible to read, drive, or undertake tasks that require fine, sharp, central vision.
In 2006, scientists at three UK eye centers decided to determine whether bevacizumab is an effective and safe treatment for wet AMD compared to standard NHS (National Health Service) care available at the time.
131 trial participants, all aged 50 years or more and who had wet AMD were selected randomly to either receive bevacizumab injections at six week intervals or standard care (one of 3 different treatments available on the NHS at the start of the study). Visual acuity was measured at the start of the study (baseline) and then monitored over one year (54 weeks).
At one year:
32% of patients in the bevacizumab group gained 15 or more letters from baseline visual acuity
3% in the standard care group gained 15 or more letters from baseline visual acuity
91% of those receiving bevacizumab treatment lost fewer than 15 letters of visual acuity from baseline
67% in the standard care group lost fewer than 15 letters of visual acuity from baseline
Average visual acuity rose by 7 letters in the bevacizumab group with a median of seven injections, compared to a fall of 9.7 letters in the standard care group, and the initial improvement at week 18 was sustained to week 54.
There was a low rate of serious adverse events associated with Bevacizumab treatment.
The researchers wrote that the results demonstrate that bevacizumab injections given at six weekly intervals for wet AMD are superior to the standard care available at the start of the trial.
The authors concluded:
This trial provides level-one evidence for the use of bevacizumab injections for the treatment of wet AMD, they conclude.
Professor Usha Chakravarthy from the Royal Victoria Hospital in Belfast, in an accompanying editorial writes that, although this trial fills a gap in the evidence base and shows compellingly that bevacizumab is superior to previously employed treatments, it does not tell us whether the drug is as effective as ranibizumab. And she warns that:
..the off label use of bevacizumab should not be encouraged until the large randomized trials comparing it with ranibizumab report their findings.
Research
Bevacizumab for neovascular age related macular degeneration (ABC Trial): multicentre randomised double masked study
Adnan Tufail, Praveen J Patel, Catherine Egan, Philip Hykin, Lyndon da Cruz, Zdenek Gregor, Jonathan Dowler, Mohammed A Majid, Clare Bailey, Quresh Mohamed, Robert Johnston, Catey Bunce, Wen Xing
Published 10 June 2010, doi:10.1136/bmj.c2459
BMJ 2010;340:c2459
Editorials
Bevacizumab for the treatment of neovascular age related macular degeneration
Usha Chakravarthy
Published 10 June 2010, doi:10.1136/bmj.c2834
BMJ 2010;340:c2834
View drug information on Avastin; Lucentis.