Pegaptanib, an aptamer, is an antagonist of vascular endothelial growth factor that has shown efficacy in the treatment of patients with exudative age-related macular degeneration (AMD). In two randomised, double-masked trials in patients with exudative AMD (n=1208), the proportion of responders (those losing <15 letters of visual acuity) at 54 weeks was significantly higher in intravitreous pegaptanib 0.3 mg recipients than in those receiving sham injections (70% vs 55%; p<0.001). These trials were conducted concurrently and analysed as a single study; the treatments were given every 6 weeks for 48 weeks. The improvement in visual acuity with pegaptanib was maintained in a 1-year extension of these trials. Similar favourable results with pegaptanib 0.3 mg were seen in terms of the secondary efficacy endpoints (e.g. proportion of patients experiencing severe loss of visual acuity or legal blindness in the study eye). These vision-improving effects of pegaptanib were associated with beneficial angiographic effects. Intravitreous pegaptanib 0.3-3 mg was well tolerated with most ocular adverse events being mild-to-moderate and transient. Serious injection-related adverse events occurred in <or=1.3% of patients treated with pegaptanib. There were no systemic adverse events that could be definitely attributed to pegaptanib.