Abstract
Purpose :
To perform OCT-based analysis of RPE and photoreceptor atrophy progression in patients enrolled in the FILLY trial.
Methods :
SD-OCT (Spectralis) images from the FILLY trial, a sham controlled phase 2 clinical study of geographic atrophy (GA) with intravitreal pegcetacoplan, an investigational therapy targeting complement C3, were analyzed. A-scan based manual annotation of the absence of the following bands was performed on baseline and year one SD-OCT volumes: retinal pigment epithelium (RPE), ellipsoid zone (EZ) and external limiting membrane (ELM). These manual annotations were also used to develop and validate an algorithm to automatically delineate GA areas. The growth rate of the resulting areas was calculated using the square root transformation. The difference in growth between treatment regimens (monthly injection (AM), injection every other month (AEOM), and sham (SM)) was calculated using the Kruskal-Wallis-test. Post-hoc pairwise testing was performed using Bonferroni correction for multiple testing.
Results :
145 OCT images were annotated from baseline and 115 from year 1. In total, 113 matched (38 AM, 36 AEOM, 39 SM) OCT volumes were included for analysis. Results are presented as mm change and interquartile range (IQR). Median growth of RPE-loss was 0,158 [0,057 – 0,296] in the AM group, 0,190 [0,106 – 0,336] in the AEOM group and 0,255 [0,188 – 0,359] in the SM group. The difference between AM and SM was statistically significant (p = 0,014).
Median growth of EZ-loss was 0,127 [0,041 – 0,247] in the AM group, 0,179 [0,101 – 0,293] in the AEOM group and 0,232 [0,130 – 0,349] in the SM group. Likewise to RPE-loss, the difference between AM and SM was statistically significant (p = 0,017).
There was no significant difference in ELM-loss growth between the treatment groups (p = 0,114).
Conclusions :
Analysis of SD-OCT imaging provided consistent results in the measurement of GA lesion growth compared to FAF. In addition to significantly slower growth of RPE atrophy, SD-OCT data showed significant reduction in EZ impairment, indicative of slowed disease progression in patients treated with pegcetacoplan monthly. Therefore, a combination of SD-OCT imaging and advanced analysis may be the optimal methodology for measuring disease activity and potential therapeutic efficacy in GA.
This is a 2021 ARVO Annual Meeting abstract.