Comparison of the efficacy of aflibercept, ranibizumab, and bevacizumab in an RPE/choroid organ culture.

Anti-VEGF treatment is the therapy of choice in age-related macular degeneration and is also applied in diabetic macular edema or retinal vein occlusion. Recently, aflibercept has been approved for therapeutic use. In this study, we investigate the efficacy of aflibercept in comparison with the VEGF-antagonists ranibizumab and bevacizumab in RPE/choroid organ cultures. RPE/choroid organ cultures were prepared from freshly slaughtered pigs' eyes. Organ cultures were treated with 125 μg/ml aflibercept, ranibizumab, or bevacizumab, and the VEGF content of the supernatant was evaluated over the course of 7 days. Additionally, the minimal concentration of VEGF inhibition was evaluated in organ cultures, measured after 6 h of application. Aflibercept was able to completely inhibit VEGF detection for 6 h at a minimal concentration of 0.031 μg/ml, in contrast to bevacizumab (3.9 μg/ml) and ranibizumab (0.244 μg/ml). A statistically significant VEGF inhibition compared to control could be found for aflibercept and ranibizumab down to and including 0.031 μg/ml, while bevacizumab was significantly reduced compared to control down to a concentration of 0.244 μg/ml and again at 0.061 μg/ml. Inhibition of VEGF after a single aflibercept application of 125 μg/ml could be found over the course of 7 days, with some VEGF detectable at the 7th day. In contrast, VEGF was detectable after 72 h of ranibizumab treatment and some VEGF could already be found 12 h after bevacizumab treatment. In conclusion, aflibercept displays a prolonged VEGF inhibition, confirming its effectiveness but also raising concerns about possible side effects of long-term usage.