Oculis Receives U.S. FDA Breakthrough Therapy Designation for Privosegtor in Optic Neuritis
Wednesday, January 07, 2026
Oculis Holding AG, a global biopharmaceutical company focused on neuro-ophthalmology and ophthalmology, has received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) for Privosegtor for the treatment of optic neuritis.
Privosegtor is a novel small-molecule therapy designed to cross both the blood–brain barrier and the retinal barrier. It is being developed as a potential neuroprotective treatment for optic neuropathies, serious conditions that can cause permanent vision loss due to nerve damage. Currently, there are no approved neuroprotective treatments for these disorders, which together represent a significant unmet medical need and a potential U.S. market of around $7 billion.
The FDA designation is supported by results from the Phase 2 ACUITY trial in optic neuritis, a rare and sight-threatening condition that is often an early sign of multiple sclerosis. In the study, Privosegtor showed meaningful improvements in visual function compared with placebo, along with consistent anatomical and biological benefits, supporting its potential role as a neuroprotective therapy.
In the ACUITY trial, patients treated with Privosegtor at a dose of 3 mg/kg/day in combination with intravenous methylprednisolone achieved an average gain of 18 letters on the low-contrast visual acuity test at three months, compared with placebo plus standard treatment. A gain of 15 letters is generally considered clinically meaningful for everyday vision. The treatment also helped preserve the structure of the retina and optic nerve, which are commonly damaged during acute optic neuritis. In addition, reduced levels of neurofilament release were observed, suggesting lower levels of nerve injury. The most common treatment-related side effects were headache and acne, each reported in a small number of patients. No serious treatment-related adverse events were reported.
Following discussions with the FDA in 2025, Oculis initiated the PIONEER clinical programme, which includes three late-stage trials designed to support regulatory submissions for Privosegtor in optic neuritis and non-arteritic anterior ischaemic optic neuropathy (NAION). These two conditions together represent a potential U.S. market exceeding $7 billion. The first study in the programme, PIONEER-1 in optic neuritis, was initiated in the fourth quarter of last year. This global trial spans three continents, with site activation underway and patient enrolment expected to begin soon.
With Privosegtor advancing through late-stage development, Oculis aims to address major unmet needs in neuro-ophthalmic diseases and position the therapy as a potential first-in-class neuroprotective option.
Source: globenewswire.com
