Clinical research conducted by the Diabetic Retinopathy Clinical Research Network has indicated that post hoc analyses of data from the anti-VEGF treatment of DME shows superior visual acuity (VA) results for aflibercept at the 2-year time point. The analyses, led by researchers at the Feinberg School of Medicine, Northwestern University, Chicago, looked at the collated data from 660 DME patients. The study compared the efficacy and safety of intravitreal aflibercept, intravitreal bevacizumab, and intravitreal ranibizumab in the treatment of central-involved DME in eyes with visual acuity of 20/32 to 20/320. The most recent results support earlier analyses showing that patients with a baseline VA of 20/50 or worse, had greater improvement in mean VA at the end of year 1 when treated with aflibercept. The Diabetic Retinopathy Clinical Research Network (DRCR.net), funded by the US National Eye Institute (NEI), is a network of multicenter clinical research facilities supporting clincial research on diabetes-induced retinal disorders. The network comprises over 115 participating centres with over 400 supporting clinicians in the US. The well established network has published mutiple studies in the field providing high quality data that contribute to clinical guidelines
The most recent study, “Protocol T: A Comparative Effectiveness Study of Intravitreal Aflibercept, Bevacizumab and Ranibizumab for DME, Study Objective and Treatment Arms (N = 660)” was performed between August 22, 2012 and September 23, 2015. A post hoc analyses between May and June 2016 showed that for eyes with an initial VA of 20/50 or worse, visual acuity improvement was greater with aflibercept than with the other agents at 1 year but superior only to bevacizumab at 2 years. Mean (SD) letter change in visual acuity over 2 years was reported to be greater with aflibercept (+17.1 [9.7]) than with bevacizumab (+12.1 [9.4]; 95% CI, +1.6 to +7.3; P < .001) or ranibizumab (+13.6 [8.5]; 95% CI, +0.7 to +6.0; P = .009). The analyses showed that when visual acuity was 20/50 or worse at baseline, bevacizumab reduced central sub-field thickness less than the other agents at 1 year, however at 2 years the differences were reduced. Of the 660 participants, the mean [SD] age was 61 [10] years, 47% were female, 65% were white, 16% black or African American, 16% Hispanic, and 3% “other”.
The authors of the report commented that post hoc analyses “should be viewed with caution given the potential for bias”, however, the work appears to support a conclusion that “in eyes with a VA of 20/50 or worse, aflibercept has the greatest improvement in VA over 2 years”. In addition the authors stated in their research report that “for eyes with DME and worse initial VA, aflibercept continues to exhibit greater VA benefit compared with bevacizumab at 2 years, but the difference in mean VA between participants receiving ranibizumab and aflibercept was no longer statistically significant. Nevertheless, over 2 years, the mean VA improvement was greater for aflibercept compared with bevacizumab or ranibizumab.”