Clinical outcomes of switching to aflibercept using a pro re nata treatment regimen in patients with neovascular age-related macular degeneration who incompletely responded to ranibizumab.

Abstract

Purpose : We wanted to assess the effect of switching patients previously incompletely treated with ranibizumab (RBZ) to aflibercept (AFL) using a pro re nata (PRN) treatment strategy in neovascular age-related macular degeneration (nvAMD).

Methods : A longitudinal cohort study was conducted on patients who had persistent or recurrent intra- and/or sub-retinal fluid treated initially with RBZ and subsequently switched to AFL. The main outcome measures were best corrected visual acuity (BCVA) and central retinal thickness (CRT) measured at different stages of the study. Friedman analysis of variance and Wilcoxon test were used to examine differences in BCVA and CRT.

Results : 207 eyes from 182 patients with nvAMD were included. BCVA and CRT improved significantly initially following 3 RBZ injections with a mean gain of 3.7 letters (p<0.001) and a mean decrease of 69μm (p<0.001) respectively. Following PRN RBZ therapy and immediately prior to switching to AFL (mean 129 weeks), there was a mean loss of 6.7 letters (p<0.001) BCVA and a mean gain of 24μm (p<0.001) CRT. AFL loading resulted in a mean improvement of 0.7 letters (p=0.28) BCVA and a mean decrease of 55μm (p<0.001) CRT. At final follow-up following AFL PRN therapy (mean 85 weeks), there was a mean loss of 8.9 letters (p<0.001) BCVA and a mean gain of 12μm (p<0.05) CRT.

Conclusions : Following switch of anti-VEGF agent, AFL loading resulted in a significant anatomical improvement but no significant change in visual acuity. However, the benefits of switching were gradually lost over time with AFL PRN dosing despite an increased injection rate. The gradual reduction in vision following switch most likely represents a continued retinal degenerative process which started prior to switch and could not be halted by AFL therapy, tachyphylaxis to anti-VEGF therapy and also the result of the reactive treatment regimen in place at the time of the study.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.