A preliminary benefit-risk assessment of verteporfin in age-related macular degeneration

The prevalence of neovascular age-related macular degeneration (AMD) is expected to increase significantly during the next 20 years. New treatment alternatives to laser photocoagulation are on the horizon - the first of these, photodynamic therapy (PDT) with verteporfin, was approved by the US FDA in 2000. In this article we present a preliminary risk-benefit assessment of verteporfin in AMD, focusing on the landmark randomised, double-blind, placebo-controlled studies. The TAP (Treatment of Age-related macular degeneration with Photodynamic therapy) trial established the efficacy of PDT for classic subfoveal neovascularisation in AMD at 2 years follow-up. The VIP (Verteporfin in Photodynamic therapy) study concentrated on subfoveal occult-only lesions not included in the TAP study. After 2 years, treated eyes were less likely to experience visual loss. Exploratory analyses of TAP and VIP suggest that lesion size is a more significant predictor of the treatment benefit than either lesion composition or visual activity. The VIM (Visudyne in Minimally classic) trial altered the standard PDT light fluence rate in the treatment of subfoveal minimally classic lesions. This trial again demonstrated a beneficial effect for those receiving treatment with PDT. The VIO (Visudyne in Occult) trial, evaluating PDT in occult-only lesions as a confirmatory study of the VIP trial, did not achieve its primary end-point at 2 years. Further analyses are pending.PDT with verteporfin has an excellent safety profile that has been established with >1 million treatment applications. Cost-effectiveness data are limited but suggest that PDT may be a cost-effective treatment modality. Other FDA-approved treatments (pegaptanib, ranibizumab and bevacizumab) for neovascular AMD are discussed, as well as investigational substances such as anecortave acetate.