Date Posted: 02 June 2010
Commentary from the UK's Royal College of Ophthalmologists (RCO) has advised against the off-label use of Avastin (bevacizumab) for the treatment of wet age-related macular degeneration.
Controversy surrounding the off-label use of Avastin for wet AMD has been covered widely in both the specialist and general press. The drug, developed by Genentech/Roche, is a full recombinant humanized monoclonal antibody with a molecular weight of 149kDa and is licensed for the treatment of metastatic colorectal and breast cancer. Avastin binds all isoforms of vascular endothelial growth factor-A (VEGF-A), a factor known to be critical in the pathogenesis of choroidal neovascularisation in AMD. A very similar drug, Lucentis (ranibizumab), is also a humanized therapeutic monoclonal antibody fragment that binds all isoforms of VEGF-A but has a molecular weight of 48kDa. In addition to being three times smaller than Avastin, Lucentis also differs by 6 amino acids in the Fab domain and has a shorter serum and vitreous half-life than that of the larger Avastin. Both drugs were developed and marketed by the same company.
The RCO's current position on injection therapy for age-related macular degeneration is available on their website (www.rcophth.ac.uk). However, much of the controversy has focused on the very large price differential between Avastin and Lucentis - Avastin costs £230 for a 100mg vial while Lucentis costs £761 for 0.23ml. Under an arrangement with Novartis the UK NHS pays for the first 14 treatments of Lucentis at a cost of £149,800 per patient amounting to approximately £300M per annum for the Exchequer. Even with such coverage many patients are unable to afford the approved drug and so pressure for off-label use of Avastin has been significant. Head to head trials comparing the two drugs in AMD treatment are due to report in late 2011 and early 2012.
Your IP address: 38.107.191.82