Oculis Holding AG reported that its phase 3 DIAMOND-1 and DIAMOND-2 trials of OCS-01 eye drops for diabetic macular edema (DME) did not meet their primary endpoint. In a press release, the company said it does not plan to pursue an FDA regulatory filing for OCS-01 in DME.

The DIAMOND program consisted of 2 randomized, double-masked, multicenter phase 3 studies evaluating OCS-01, a high-concentration dexamethasone eye drop utilizing Oculis’s Optireach technology, over 52 weeks of treatment. More than 800 patients were enrolled across 119 investigational sites in the United States and several other countries.

In both trials, OCS-01 failed to achieve a statistically significant improvement in best-corrected visual acuity (BCVA), as measured by Early Treatment Diabetic Retinopathy Study (ETDRS) letter score at week 52. The key secondary endpoint assessing the proportion of patients gaining at least 15 ETDRS letters also was not met.

OCS-01 did demonstrate reductions in retinal thickness compared with vehicle, a secondary endpoint in the trial. The effect was observed at all study visits in DIAMOND-2 and at all visits except week 52 in DIAMOND-1, according to the company. Oculis also reported that OCS-01 was well tolerated, with no unexpected adverse events and a safety profile consistent with previous studies.

“We are naturally disappointed that the substantial and sustained reduction in retinal thickness observed across both trials didn’t translate into BCVA improvement at week 52,” said Riad Sherif, MD, chief executive officer of Oculis. “We thank the patients, investigators, and all clinical experts who participated in the DIAMOND program.”

Dr. Sherif said that Oculis will strategically focus resources on other late-stage programs, including the PIONEER development program for Privosegtor in optic neuropathies and the PREDICT-1 trial of Licaminlimab in dry eye disease. RP