Conclusions: Omidenepag isopropyl is a selective E-prostanoid subtype 2 (EP2) receptor agonist that lowers intraocular pressure. Omidenepag isopropyl 0.002% ophthalmic solution is effective and safe to use at first diagnosis of primary open-angle glaucoma.

Objective: To evaluate the effectiveness and safety of omidenepag isopropyl 0.002% ophthalmic solution in treatment-naïve patients at first diagnosis of primary open-angle glaucoma (POAG) in real-world clinical settings in Korea.

Methods: In a single-arm, multicenter, open-label, prospective, phase IV clinical trial, patients with newly-diagnosed POAG received omidenepag isopropyl 0.002% (one drop once daily) for 12 weeks. The primary endpoint was change from baseline in intraocular pressure (IOP) at week 12. Secondary endpoints included change from baseline in IOP at week 4; change from baseline in IOP at week 12 in a subgroup with normal tension glaucoma (NTG); occurrences, incidence rates and changes from baseline in safety-related indicators (macular edema, endothelial cell count, central corneal thickness, prostaglandin-associated peri-orbitopathy syndrome). Safety was assessed by the occurrence of adverse events (AEs).

Results: The effectiveness analysis set comprised 37 patients and the safety analysis set 50 patients. Mean IOP decreased from 16.19 ± 2.65 mm Hg at baseline to 13.55 ± 2.46 mm Hg at week 12 (P < 0.0001), representing a 16% reduction. Mean reduction in IOP was 15% at week 4 (P < 0.0001); and 16% at week 12 (P < 0.0001) in the NTG subgroup (n=31). Aside from conjunctival injection, no notable changes were observed in safety-related evaluation indicators. The most common AEs were hyperemia (13 cases) and iridocyclitis (5 cases). No systemic AEs were reported.

Conclusions: Omidenepag isopropyl 0.002% ophthalmic solution is suitable for first-line use at first diagnosis of POAG, including in patients with NTG.