Pegaptanib
Pegaptanib is a 28-mer RNA aptamer covalently linked to two branched 20-kD polyethylene glycol (PEG) chains, with anti-angiogenic activity. Pegaptanib binds and blocks the activity of the extracellular vascular endothelial growth factor, specifically the 165-amino acid isoform (VEGF165). This prevents VEGF165 from binding to VEGF receptors, thereby blocking angiogenesis as well as preventing VEGF165-induced increases in vessel permeability. VEGF165 is preferentially involved in pathological ocular neovascularisation.