Key Takeaways:
Oculis Holding AG (NASDAQ: OCS) said its two Phase 3 DIAMOND trials of OCS-01 in diabetic macular edema failed to meet the primary endpoint of improving best-corrected visual acuity at week 52, sending shares down more than 23% in Friday trading.
"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," Riad Sherif, M.D., chief executive officer of Oculis, said on the company's conference call.
The DIAMOND program enrolled 805 patients across 119 sites globally, with 404 in DIAMOND-1 and 401 in DIAMOND-2. Both studies randomized roughly 200 patients per treatment arm. The primary endpoint measured change in BCVA ETDRS letter score at week 52, while a key secondary endpoint tracked the percentage of patients gaining at least 15 letters. Neither was met. More than 80% of patients completed the drug portion of the 52-week study, which included a six-week induction phase and a 46-week maintenance phase.
OCS-01 did show a rapid and sustained reduction in central subfield thickness, an anatomical measure of retinal swelling, across both trials. However, that benefit did not translate into functional vision improvement. Sherif said the roughly five-letter gain seen in the vehicle arm was "more than double the best placebo response in any other trial" in DME, calling the result surprising. He said the company had cross-checked protocol execution and found no evidence of trial conduct issues, and that compliance was high and consistent with earlier-stage studies.
The safety profile was consistent with prior trials, with no unexpected findings. Elevated intraocular pressure and cataracts were higher in the OCS-01 arm, which Sherif said was expected with chronic steroid use in DME.
Based on the results, Oculis does not currently plan to pursue a U.S. Food and Drug Administration filing for OCS-01 in DME. Chief Financial Officer Sylvia Cheung said Oculis owns the OPTIREACH technology and OCS-01 candidate with no license payments tied to the program. Routine site closeout costs for DIAMOND are expected in the second quarter and early third quarter. Sherif said OCS-01 was ready for a potential filing in ocular surgery, and the company will conduct a full assessment before deciding.
Oculis will redirect resources to its late-stage pipeline, including the Privosegtor PIONEER program in optic neuropathies and the licaminlimab PREDICT-1 study in dry eye disease. The PIONEER-1 design is aligned with the FDA under a special protocol assessment, with more than 70 U.S. and international sites in various stages of activation. Sherif said the company expects to treat the first patient "in the near future." For licaminlimab, the PREDICT-1 trial plans to enroll 160 patients, with about 70% of sites in active screening. Oculis expects to provide an update later this year.
The company holds $278 million in cash, cash equivalents and short-term investments, giving it a runway into the second half of 2029. The decline puts OCS shares at their lowest level since the trial readout, testing investor confidence in the company's remaining pipeline. Investors will watch for updates on PIONEER-1 patient enrollment and PREDICT-1 screening progress in the coming months.
This article is for informational purposes only and does not constitute investment advice.
