Just days after purchasing privosegtor’s exclusive globals rights, Oculis Holding AG announced the first patient dosing in its phase 3 registrational trial evaluating the investigational neuroprotective asset for optic neuritis (ON).
Lots to unpack here … starting with privosegtor.
What it is: a novel peptoid small molecule that activates serum/glucocorticoid-regulated kinase 2 (SGK-2) and crosses both the blood-brain and blood-retinal barriers.
- How it works: by preserving the retina and improving visual function after an acute ON episode.
- Its U.S. status: The FDA has already granted it Breakthrough Therapy Designation (January 2026) and Orphan Drug Designation (October 2025).
And the big-picture potential: Privosegtor could become the first neuroprotective therapy for both acute ON (AON) and non-arteritic anterior ischemic optic neuropathy (NAION).
Now regarding that recent rights purchase—what should we know?
Basically? Oculis now has outright ownership of privosegtor (along with another asset, ACT-0), including its global development and commercial rights.
- Read up on this deal (including what Accure Therapeutics, its original owner and developer, will get in return).
Next up: this clinical trial.
Oculis’ phase 3 Privosegtor Investigation in Optic Neuropathies Efficacy Evaluation Research (PIONEER)-1 trial is the first of two pivotal studies planned for its PIONEER program on ON.
Worth noting: Just a few months ago the FDA agreed to a special protocol assessment (SPA) for the specialized study. Check out the significance of this.
So what should we know about PIONEER-1?
Its purpose: to evaluate privosegtor among a broad population of ON patients—including those with and without multiple sclerosis (MS).
Its setup: Patients will be followed for 12 months to assess privosegtor’s long-term safety and tolerability, with dosing and patient enrollment criteria replicating that of a prior phase 2 trial:
- Acute OptiC NeUrITis of DemYelinating Origin (ACUITY; NCT04762017)
- See here (for dosing) and here (for participant criteria).
Wait, why mirror that phase 2 trial?
Because privosegtor demonstrated promising results, including:
- Substantial improvements in vision at Month 3 through Month 6 (measured via low-contrast visual acuity [LCVA])
- Consistent anatomical and biological neuroprotective benefits versus placebo
See more findings from the ACUITY study (and keep in mind: this data led to the therapeutic’s aforementioned FDA BTD earlier this year).
And what are investigators evaluating?
Two clinically meaningful function endpoints for ON:
- Primary endpoint: number of patients achieving at least a 15-letter gain from baseline in LCVA at Month 3.
- Secondary endpoint: mean change in low-contrast visual acuity (LCVA) at Month 3
To note: The primary analysis will be conducted at Month 3, while patients will continue to be followed through Month 12 to track privosegtor’s long-term safety and tolerability.
So, regarding this first patient dosing … what do we know?
Per Oculis, the participant was treated “at a leading center in the U.S” as the company continues to move toward establishing a more integrated, multidisciplinary approach to treating ON.
Noted. And when can we expect data?
Per Clinical Trials, the study’s primary completion is set for December 2027—with total completion expected by December 2028.
Topline data is likely before then (so stay tuned).