Effects of Netarsudil on the Corneal Endothelium: Three-Month Findings from a Phase 3 Trial

To describe the changes in endothelial cell density (ECD), the coefficient of variation (CV), and the percent of hexagonal cells (%HEX) after 3 months of therapy with netarsudil (Rhopressa; Aerie Pharmaceuticals Inc, Durham, NC) 0.02% dosed once daily (QD) or twice daily (BID) and to compare these changes with those seen with timolol 0.5% BID in eyes with ocular hypertension (OHTN) or open-angle glaucoma (OAG). Post hoc analysis of data from a phase 3 evaluation of the intraocular pressure (IOP)-lowering efficacy and safety of netarsudil 0.02% versus timolol 0.5%. A subset of study subjects underwent corneal endothelial cell imaging by specular microscopy at baseline and after 3 months of therapy. Images were evaluated in a masked fashion at an independent reading center. The ECD, CV, and %HEX were determined using a standardized protocol for image analysis. Changes in ECD, CV, and %HEX from baseline to 3 months were compared between treatment groups using 2-sample t tests. Data from 386 subjects from whom analyzable specular microscopy images were obtained at both baseline and month 3 were included in this analysis. Mean ECD, CV, and %HEX values were comparable between groups at baseline. There were no statistically significant between-group differences in changes from baseline to month 3 in ECD, CV, or %HEX between either of the netarsudil groups and the timolol group. Within groups, CV declined in a statistically significant fashion from baseline to month 3 in all 3 groups by 1.4% to 2.1% (P < 0.001), and %HEX increased by a statistically significant amount (0.7%, P = 0.030) in the timolol group. These small changes were unlikely to be of clinical significance. No statistically significant changes in ECD were seen in any group. Netarsudil 0.02% showed no clinically significant effects on ECD, CV, or %HEX when dosed QD or BID for 3 months in eyes with OHTN or OAG.