Abstract
Abstract: :
Purpose: This multicenter phase III clinical trial evaluates the safety and efficacy of apheresis (RheopheresisTM), an extracorporeal blood filtration procedure, in subjects with pre-angiogenic ARMD. Methods:150 subjects are to be randomized into apheresis treatment or placebo control in a 2:1 ratio and followed clinically for one year among up to 12 centers. Qualified subjects have an area of soft drusen ≥ 31,000 um2, elevated blood levels of certain hemorheologic factors and ETDRS visual acuity between 20/32 and 20/125 inclusive. To date, 43 subjects have completed the 12-month follow up visit. Interim analysis includes three groups: all of the study eyes (n=43), all of the qualifying eyes that met entry criteria (study eyes and fellow eyes, n=54), and all eyes of all subjects (n=85). Statistical analysis compared treated and control groups using repeated measures ANOVA of best corrected ETDRS visual acuity acquired at 3, 6, 9, and 12 month post baseline visits. Results:The three groups of eyes demonstrate a significant treatment effect at 12 months. The mean difference between treated and control groups is 1.6 ETDRS lines in the primary group (p=0.001), 1.5 in the all qualifying eyes group (p=0.005), and 1.7 in the all eyes group (p=0.003). Subgroup analysis indicates that subjects with baseline acuity worse than 20/40 derived the greatest benefit at one year (mean difference 3.0 lines in study eyes at 12 months, p=0.001). In primary study eye group 20% of subjects have a ≷= 2.5 line improvement in acuity, compared to only 9% in the placebo control group . Adverse events from the apheresis treatment were self-limited and typical for extracorporeal therapies. Conclusion:The apheresis procedure produced significant vision benefits at one year in pre-angiogenic AMD patients. The mechanism of action remains under investigation, but may involve hemorheologic/blood flow effects in the choriocapillaris and/or removal of specific pathologic macromolecules from the plasma. These encouraging early results should stimulate further research into the basis for this treatment effect and may lead to new treatment strategies.
Keywords: 308 age-related macular degeneration • 331 blood supply • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials