Ramin Tadayoni MD, PhD
The novel topical dexamethasone product OCS-01 showed promising results in a phase II study for the treatment of diabetic macular oedema. The compound, delivered using a proprietary nanoparticle delivery system, was more effective than vehicle in reducing macular thickness and improving vision, said Ramin Tadayoni MD, PhD, at the EURETINA 2020 Virtual meeting.
“This phase II study shows that OCS-01 has the potential to be the first clinically validated topical therapy for DME. It is also a positive proof-of-concept of topical SNP technology to develop additional topical therapies for retinal diseases,” said Dr Tadayoni, Professor of Ophthalmology, University of Paris, Paris, France.
Patients enrolled in the study all had DME for less than three years, BCVA ranging from 20/40 to 20/320, and central macular thickness (CMT) >310µm. A total of 144 patients were randomised 2:1 to three times daily use of OCS-01 or vehicle for 12 weeks. Patients were followed off-treatment until week 16.
At the primary endpoint at 12 weeks, data analyses showed differences favouring OCS-01 versus vehicle in mean change from baseline in central macular thickness (CMT; -53.68 vs -16.87µm) and BCVA (+2.9 vs +1.7 letters). Compared with the control group, higher percentages of patients treated with OCS-01 demonstrated gains of ≥10 ETDRS letters (14.1% vs 5.1%) and ≥15 ETDRS letters (5.1% vs 0%).
Treatment benefit with OCS-01 was already noted in analyses of CMT and BCVA data collected at two weeks. At the end of the four-week off-treatment observation period, the OCS-01 group maintained the BCVA improvement achieved at week 12, whereas mean CMT increased towards the level of the control group.
“These data show the power of the OCS-01 drops, the penetration of dexamethasone to the retina and proof that the decrease in CMT in the OCS-01 group was related to the drug,” Dr Tadayoni said.
The adverse event review showed 21% of patients treated with OCS-01 had an increase in IOP. Intraocular pressure increased in the OCS-01 group during the 12-week treatment period by a mean of 4.53mmHg, but it returned to the baseline level at the end of the observation period.
“Increased IOP is expected with dexamethasone, and again these data are proof that the drug penetrated to achieve a good concentration inside the eye. The return to normal IOP at study end shows we can stop the drop if a side-effect occurs. That is a benefit of the topical treatment compared with intravitreal steroid injections,” Dr Tadayoni said.
