Oculis Holding AG announced positive topline data from its stage 1, phase 3 study assessing the safety and efficacy of OCS-01 eye drops for the treatment of diabetic macular edema (DME).
Tell me about OCS-01.
OCS-01 is a novel, high-concentration, topical drug candidate of dexamethasone that employs Oculis’ Optireach solubilizing nanoparticle technology—a proprietary platform that can enable the formulation of drugs as non-invasive topical treatments, potentially extend their residence time on the ocular surface along with enhancing bioavailability in relevant eye tissues.
Now talk about this trial.
The phase 3 Diabetic Macular edema patients On a Drop (DIAMOND) study (NCT05066997) is a two-stage pivotal, double-masked, randomized, vehicle-controlled, multicenter (39 sites), multi-country (in the United States and Europe) study measuring OCS-01 in 148 patients with DME.
The first stage compared OCS-01 to a vehicle while the second stage will look at OCS-01 alone.
Talk about the dosing.
Patients were randomized 2:1 to receive either OCS-01 (n = 100) or vehicle (n = 49) 6 times a day for 6 weeks followed by 3 times a day for a subsequent 6-week maintenance period, according to Oculis.
And the primary objectives?
Stage 1’s primary targets included identifying an optimal dosing regimen.
Primary endpoints for both stages are the mean change in the best-corrected visual acuity “Early Treatment Diabetic Retinopathy Study” chart (BCVA ETDRS) from baseline to week 6 and to week 52.
Now the findings.
OCS-01 met its primary efficacy endpoint, demonstrating a statistically significant improvement in BCVA ETDRS score—OCS-01 = 7.2 letters vs vehicle = 3.1 letters, p = 0.007—as well as a strong visual gain in the treatment arm.
Did efficacy extend past the Week 6 point?
Yup; it sustained to week 12 with a statistical significance: OCS-01 = 7.6 letters vs vehicle = 3.7 letters, p= 0.016.
Further, a higher percentage (25.3%) of OCS-01-treated patients achieved ≥15-letter improvement in BCVA from baseline vs vehicle (9.8%) at week 6 that continued until week 12 (27.4% vs 7.5%, p = 0.009)
Anything else?
Investigators also observed a statistically significant decrease in central subfield thickness (CST) at week 6 among OCS-01 patients (-63.6 µm) vs vehicle-treated patients ( +5.5 µm, p<0.0001), which continued through to week 12 (-61.6 µm vs -16.0 µm, p=0.004).
How about adverse effects?
Overall, there were no unexpected adverse events observed in stage 1 of the study; OCS-01 was well-tolerated.
What’s next?
Oculis will move forward with stage 2 of the DIAMOND study for OCS-01; the second phase will feature two global clinical trials with an estimated 350 to 450 patients enrolled in each.
The company expects to initiate stage 2 in the second half of 2023.
And according to Clinical Trials, the complete phase 3 study is slated to conclude in August 2025.
Significance?
With this recent positive data, OCS-01 has the potential to become the first topical eye drop and noninvasive treatment for DME, possibly allowing for patients to receive quicker and easier access to treatment.
David S. Boyer, MD, co-principal Investigator for the DIAMOND trial stated that, “Since it is a topical agent, it has also the potential to be a first line treatment in DME, if approved. In short, I believe the impact of OCS-01 in DME could be a true game-changer.”