Topical Dexamethasone Ophthalmic Suspension OCS-01 Effective in DME Treatment

New findings suggest the topical dexamethasone ophthalmic suspension OCS-01 had a significant effect on improving central macular thickness (CMT) in patients with diabetic macular edema (DME), compared to vehicle-treated eyes.

Specifically, patients with DME with lower baseline best-corrected visual acuity (BCVA) benefited more from OCS-01 treatment, according to investigators.

“It is likely, therefore, that if entry criteria had included lower baseline BCVA, as in some studies  with  intravitreal  therapies, a larger improvement in baseline BCVA would have been seen across the study population,” wrote study author Einar Stefánsson, Ophthalmology and Physiology, University of Iceland.

Although intravitreal injections of anti-VEGF agents are the main treatment for DME and highly effective at increasing visual acuity, not all patients have access to these therapies and are often at risk of tolerance and burden issues from the injections.

Topical therapies for DME, if effective, may improve comfort and safety, accessibility, and cost. However, current topical therapies are not considered effective and none are currently approved for DME. The current randomized, vehicle-controlled Phase 2 study was designed to evaluate the efficacy of OCS-01, in terms of improvements in visual acuity and CMT, as well as the safety.

The study was conducted at 27 centers in 6 countries (Denmark, Estonia, Finland, Hungary, Latvia, and Sweden). Participants were eligible if they were 18 - 85 years of age at baseline with DME of <3 years duration and had intraretinal and/or subretinal fluid in the study eye. Other eligibility criteria included ETDRS central subfield thickness of ≥310 μm with ETDRS BCVA letter score ≤73 (Snellen 20/40) and ≥24 (Snellen 20/320) in the study eye.

Participants were randomized 2:1 to OCS-01 or matching vehicle, 1 drop at 3 times/day throughout 12 weeks. OCS-01 eye drops were noted to be a 1.5% w/v dexamethasone suspension.

Data show a higher proportion of patients in the oCS-01 group gained ≥10 ETDRS letters (14 of 99, 14%) or ≥15 ETDRS letters (5 of 99, 5%) compared to the vehicle group (4 of 45, 9% and zero, respectively). However, the between-group differences were not statistically significant.

The mean CMT showed a greater decrease from baseline with OCS-01 (n = 99) than vehicle (n = 45) at Week 12 (-53.6 vs -16.8 μm; P = .0115). It additionally showed statistically signciant differences between groups at all visits from Week 2 to Week 12.

Within an exploratory post-hoc analysis, both BCVA and CMT showed greater improvements from baseline in patients with baseline BCVA ≤65 letters. Data show the OCS-01 group improved 3.8 letters compared with 0.9 letters with vehicle.

Investigators noted OCS-01 was well-tolerated, with increased intraocular pressure (IOP) the most common adverse event, as was expected by investigators. At week 12, data show 14 of 99 (14.1%) patients in the OCS-01 group had increases of ≥10 mmHg from baseline.

“IOP decreased quickly after the end of treatment, suggesting that any IOP increase observed during OCS-01 treatment for DME should rapidly resolve after discontinuation of treatment,” Stefánsson noted.

He added that a phase 2/3 study is ongoing to confirm the findings within a larger patient population.

The study, “Topical treatment of diabetic macular edema using dexamethasone ophthalmic suspension: A randomized, double-maked, vehicle-controlled study,” was published in Acta Ophthalmologica.