Iontophoretic Dexamethasone Phosphate Compared to Topical Prednisolone Acetate 1% for Noninfectious Anterior Segment Uveitis

Abstract

To evaluate the safety and efficacy of dexamethasone phosphate ophthalmic solution (EGP-437) delivered by a transscleral iontophoresis delivery system (EyeGate II) compared to that of topical prednisolone acetate 1% (PA 1%) in subjects with noninfectious anterior uveitis. Prospective, randomized, double-masked, parallel group, noninferiority clinical trial. A total of 193 subjects with active noninfectious anterior uveitis (anterior chamber [AC] cell count ≥11 cells) were randomized to EGP-437 delivered by iontophoresis (days 0 and 7) or self-administered PA 1% daily (tapered schedule, days 0-28). Masking was maintained with placebo iontophoresis or eye drops. The primary efficacy endpoint was the proportion of subjects with an AC cell count of zero on day 14. Noninferiority of EGP-437 was defined if the lower limit of the confidence interval (CI) for the difference (EGP-437minus PA 1%) was less than-10%. At day 14, 32 of 96 EGP-437 subjects (33.3%) and 32 of 97 PA 1% subjects (33.0%) had an AC cell count of zero (difference, 0.34; 95% CI,-12.94 to 13.63; P= 0.064). Efficacy trended better with EGP-437 among patients with more severe baseline uveitis (AC cell count >25). Safety and tolerability were good with both treatments. EGP-437 subjects experienced fewer IOP elevations ≥6mm Hg versus PA 1% subjects (13 vs 24 incidents, respectively, through day28). Despite clinically similar response rates, statistical noninferiority of EGP-437 versus a tapered regimen of PA 1% was not achieved. Numerical trends suggesting fewer IOP elevations with EGP-437, similar efficacy overall, and possibly better efficacy in more severe disease warrant further study.