Abstract
Purpose :
To measure the interleukin 6 (IL-6) levels in the aqueous humor of patients with diabetic macular edema (DME) and neovascular age-related macular degeneration (nAMD); Compare vison outcomes with anti-vascular endothelial growth factor (anti-VEGF) monotherapy between “high” and “low” IL-6 concentration groups.
Methods :
In the READ3 study 152 patients with DME were randomized 1:1 to receive 0.5 mg or 2.0 mg ranibizumab q4 for 24 months. Aqueous humor samples from 131 eyes were collected at baseline, Months 3, 6, 9 and 12. In the HARBOR study 1097 patients with nAMD were randomized 1:1:1:1 to receive 0.5 mg or 2.0 mg ranibizumab q4 or PRN for 24 months. Matching aqueous and serum samples collected at study month 2 (after the third monthly/loading ranibizumab injection) were available from 36 patients. Functional outcomes were assessed as change from baseline in BCVA (ETDRS letters). Wilcoxon rank-sum test was used to compare concentrations. Spearman rank correlation coefficient was used to evaluate correlations between IL-6 levels and functional outcomes.
Results :
IL-6 levels did not appear to be affected by VEGF inhibition. After 3 ranibizumab injections the median IL-6 concentration in aqueous humor was 24.7 pg/ml in patients with DME and 6.0 pg/ml in patients with nAMD. There was no correlation between aqueous and serum IL-6 levels in patients with nAMD. In READ3 at all time points there appears to be a negative correlation between the baseline IL-6 level and BCVA: the higher the baseline IL-6 levels rank, the lower the BCVA levels tend to rank at every time point (Figure 1). In the HARBOR trial nAMD patients with the highest aqueous IL-6 levels on average lost 9 BCVA letters by the end of the study, while the rest of patients maintained vision (Figure 2).
Conclusions :
Analyses from two different groups of patients with DME and nAMD identify potential trend of poorer vision outcomes with anti-VEGF monotherapy in patients with higher aqueous levels of IL-6.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.