Clinical experience with pegaptanib sodium

Pegaptanib sodium (Macugen(®)) blocks the extracellular vascular endothelial growth factor (VEGF) isoform VEGF(165), whose elevated levels are associated with the development of choroidal neovascularization (CNV). This selective inhibition prevents binding to the VEGF receptors and the development of the increased vascular permeability and the CNV associated with neovascular age-related degeneration (AMD). The VEGF Inhibition Study In Ocular Neovascularization (VISION) demonstrated that pegaptanib sodium confers clinically meaningful benefit in the treatment of all angiographic subtypes of neovascular AMD. It also has a favorable safety profile after 1 and 2 years of continuous treatment, and recent data suggest that the agent has a disease-modifying effect. Post hoc analysis of VISION suggests that treatment benefit may be greatest in patients with early lesions, in whom 80% achieved the primary endpoint of <15 letters lost, 47% maintained visual acuity (VA), and 20% gained ≥15 letters of vision. Similarly, our own clinical experience indicates that pegaptanib sodium achieves better outcomes in early lesions than in established lesions, particularly in patients with previously untreated minimally classic and occult lesions in whom VA improvement and lesion size stabilization has been recorded. Observations indicate that pegaptanib sodium has a slower mode of action than unselective VEGF inhibitors, resulting in an average of 3–4 injections being required to stabilize VA and lesion size. Pegaptanib sodium has good efficacy and safety profiles and represents a good treatment option for patients with early CNV membranes associated with neovascular AMD.