The emerging vascular endothelial growth factor (VEGF) antagonists appear so far to represent a genuine breakthrough in the treatment of subretinal neovascularisation. Pegaptanib sodium (Macugen; OSI Eyetech, Melville, NY) is the first to have its efficacy and safety demonstrated by phase III clinical trials.1 Inhibiting receptor binding by attaching around amino acid 137, it is selective for the VEGF-A165 isoform. The as yet unpublished 2-year results of the phase III studies of ranibizumab (Lucentis; Genentech, South San Francisco, Calif) may be even more promising. Ranibizumab is an antibody fragment that binds to all isoforms of VEGF-A at amino acids 86-89. Bevacizumab (Avastin) is an IgG1-antibody that binds VEGF-A the same way as ranibizumab. It is available now because it was approved for the treatment of metastatic colorectal cancer in 2004, but how do we know whether it is safe and efficacious for the treatment of subretinal neovascularisation?
Gillies MC. What We Don't Know About Avastin Might Hurt Us. Arch Ophthalmol. 2006;124(10):1478-1479. doi:10.1001/archopht.124.10.1478