Pegaptanib Sodium in the Treatment of Neovascular Age-Related Macular Degeneration

Pegaptanib sodium is a polyethylene-glycolated, 28-nucleotide RNA aptamer that binds selectively to vascular endothelial growth factor (VEGF) 165 but not smaller isoforms. Preclinical studies identified VEGF 165 as an especially potent promoter of ocular neovascularization and inflammation. Following the pivotal clinical trials demonstrating the efficacy of intravitreal pegaptanib in treating all angiographic subtypes of neovascular age-related macular degeneration (NV-AMD), pegaptanib became the first anti-VEGF therapy to receive regulatory approval for this condition. In view of the importance of VEGF in a variety of tissues, including the cardiovascular system and the retina, concerns have been raised as to the risks that might accompany VEGF inhibition. It is thus of particular note that pegaptanib has proved to have a favorable safety record in treating NV-AMD, with no ocular or systemic safety signals having emerged over more than 4 years of clinical studies. Accordingly, in addition to its use as a single agent, pegaptanib has demonstrated promise in combinatorial regimens that employ nonselective anti-VEGF agents as an initial treatment followed by maintenance therapy with pegaptanib. Pegaptanib has also shown encouraging preliminary results in the treatment of diabetic macular edema, proliferative diabetic retinopathy, and macular edema secondary to retinal venous occlusive conditions.