Abstract
Abstract: :
Purpose: To present the 2–year primary and secondary visual acuity efficacy data of two Phase III randomized trials evaluating SnET2–PDT in the treatment of subfoveal CNV secondary to AMD. Methods: Two parallel phase III trials evaluated a total of 920 patients. SnET2 doses of 0.50 mg/kg (N=372), 0.75 mg/kg (N=365) or placebo (N=183) were administered to patients approximately 12 minutes prior to 36 J/cm2 light activation, with re–treatment possible every 13 weeks. The primary efficacy endpoint was the proportion of patients losing less than 15 letters (ETDRS) from baseline. The secondary efficacy endpoints were the mean change in letters lost from baseline and proportion of patients losing less than 30 letters. Patients were followed for 2 years. Results: The per protocol population, identified as patients with a lesion size < 3 mm who received at least 2 treatments, was selected for primary efficacy analysis. This allowed evaluation of efficacy to be limited to patients who presented lesions that were not larger than the maximum laser spot size and who received the minimum protocol–defined exposure to the treatment. For all analyses, the response for the SnET2 0.75 mg/kg dose was less efficacious than the 0.50 mg/kg dose and was not statistically significantly different than the response seen in the placebo group. However, the VA outcome of the SnET2 0.50 mg/kg treated group (N=231) was statistically significant relative to the placebo group (N=119) in both individual studies and the pooled studies. At 2 years, 134 (58%) of 231 SnET2–treated patients lost <15 letters compared to 50 (42%) of 119 placebo–treated patients (P = .0045). The SnET2–treated patients lost 11.9 letters on average versus 17.2 letters for the placebo patients (p=0.0072) over 2 years. Efficacy with the SnET2 treatment was consistent over the 2–year study period. Conclusion:SnET2 0.50 mg/kg is more effective than placebo in preserving visual acuity over a 2–year period in patients with subfoveal CNV secondary to AMD, as demonstrated by statistically significant primary and secondary visual acuity efficacy outcomes.
Keywords: age–related macular degeneration • choroid: neovascularization • photodynamic therapy