Verteporfin

Verteporfin, a benzoporphyrin derivative monoacid ring A, is a photosensiti sing drug for photodynamic therapy (PDT) activated by low-intensity, nonhea t-generating light of 689nm wavelength. Activation generates cytotoxic oxyg en free radicals. The specificity and uptake of verteporfin for target cells with a high expr ession of low density lipoprotein (LDL) receptors, such as tumour and neova scular endothelial cells, is enhanced by the use of a liposomal formulation and its rapid uptake by plasma LDL. Verteporfin therapy (at light doses < 150 J/cm(2)) selectively damages neov ascular endothelial cells leading to thrombus formation and specific occlus ion of choroidal neovascular vessels in subfoveal lesions in patients with age-related macular degeneration (AMD). Repeated applications of verteporfin therapy 6 mg/m(2) improved or maintain ed visual acuity in the majority of patients with some classic subfoveal ch oroidal neovascularisation (CNV) secondary to AMD at I year's follow-up in 2 large multicentre, placebo-controlled, double-blind trials. Furthermore, in a subgroup of these patients with predominantly classic CNV secondary to AMD, there was a significantly more marked visual acuity (VA) benefit with 67.3% of verteporfin-treated eyes experiencing less than a 15 -letter loss of VA versus 39.3% with placebo treatment. Multiple applications of verteporfin therapy were well tolerated in patient s with subfoveal CNV secondary to AMD. The most common adverse events were visual disturbances, injection site reactions, photosensitivity reactions a nd infusion-related back pain.