Oculis Holding AG announced that the US Food and Drug Administration (FDA) has granted breakthrough therapy designation to Privosegtor (formerly OCS-05) for the treatment of optic neuritis, a rare neuro-ophthalmic condition that can result in permanent vision loss. Privosegtor is a peptoid small molecule designed to cross the blood-brain and retinal barriers and is being developed as a neuroprotective therapy for optic neuropathies.

The designation is supported by results from the phase 2 ACUITY trial, in which Privosegtor was evaluated in patients with acute optic neuritis. In the study, patients receiving Privosegtor at 3 mg/kg/day in combination with intravenous methylprednisolone gained an average of 18 letters on the 2.5% ETDRS low-contrast visual acuity chart at 3 months, compared with placebo plus methylprednisolone. The trial also showed preservation of retinal and optic nerve structure and reduced neurofilament release, a biomarker associated with neuroaxonal injury. The most common drug-related adverse events were headache and acne, with no serious drug-related events reported.

Following discussions with the FDA in 2025, Oculis initiated the PIONEER program, which includes 3 pivotal trials intended to support registration of Privosegtor in optic neuritis and nonarteritic anterior ischemic optic neuropathy. The first study, PIONEER-1, began site activation late last year, with enrollment expected to start soon. RP