Privosegtor granted FDA breakthrough status for optic neuritis
Treatment for common MS symptom seeks to protect against vision loss
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Privosegtor received FDA breakthrough status for acute optic neuritis.
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Optic neuritis, a common multiple sclerosis symptom, causes vision loss due to optic nerve inflammation.
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This experimental therapy aims to protect vision and nerve structure; a global Phase 3 trial is expected to launch soon.
The U.S. Food and Drug Administration (FDA) has granted breakthrough therapy designation to privosegtor, an experimental treatment from Oculis that aims to protect the vision of people experiencing acute optic neuritis. This condition, which involves inflammation of the optic nerve, is a common and often debilitating symptom of multiple sclerosis (MS) that can lead to vision loss.
This FDA status is designed to fast-track the development and review of drugs for serious conditions. By receiving this designation, Oculis will benefit from more frequent meetings with the FDA and potential eligibility for a priority review, which could shorten the standard 10-month approval process to six months.
“Breakthrough Therapy Designation underscores Privosegtor’s significant potential as a first‑of‑its‑kind neuroprotective therapy for people living with optic neuritis, and highlights our commitment to redefining what’s possible for patients suffering from neuroaxonal loss,” Riad Sherif, MD, Oculis’ CEO, said in a company press release. Neuroaxonal loss refers to damage to axons, the nerve fibers that allow information to be transmitted between neurons.
Global Phase 3 trial to begin soon
Oculis has launched a global Phase 3 clinical trial to test privosegtor in people with optic neuritis, and whose results, if positive, are expected to be used to file for the therapy’s approval. Recruitment is expected to start soon. No further details have been provided.
MS is characterized by inflammatory attacks on the brain and spinal cord that damage myelin, a protective sheath around nerve fibers that allows fast nerve cell communication.
Up to 70% of people with MS are estimated to experience optic neuritis, a condition characterized by inflammation of the optic nerves, which carry information between the eye and the brain. Optic neuritis is often one of the first signs of MS and can lead to vision problems ranging from blurred vision to permanent vision loss.
While optic neuritis typically resolves on its own or with anti-inflammatory corticosteroid treatment, some patients may still develop vision loss.
As such, “There remains an unmet medical need for therapies that preserve vision by providing neuroprotection after an acute episode of optic neuritis,” Oculis states on its product webpage.
Privosegtor, previously known as OCS-05, is an experimental small molecule that can act as a neuroprotective agent in optic neuritis caused by MS or other diseases characterized by myelin loss.
The therapy, which has been shown to reach the brain, is believed to activate serum/glucocorticoid-regulated serum kinase 2, a molecule that elicits a range of pathways supporting nerve cell development, survival, and repair.
Privosegtor also received orphan drug designation in the U.S. and the European Union for optic neuritis. This status is meant to expedite the therapy’s clinical development and regulatory review.
In a Phase 1 clinical trial (NCT03630497) involving healthy volunteers, the therapy showed a favorable safety and pharmacological profile.
The latest FDA designation was supported by results from the Phase 2 ACUITY clinical trial (NCT04762017), which enrolled 36 people with acute optic neuritis in one eye caused by a demyelinating, myelin-damaging disorder.
A total of 33 people, mostly with MS, were randomly assigned to receive privosegtor, at doses of 2 or 3 mg/kg, or a placebo, daily for five days via intravenous (into-the-vein) infusions, on top of standard corticosteroids.
Significant improvements in visual function
Results showed that the treatment led to a substantial improvement in a test of visual function called low-contrast letter acuity, which evaluates how well a person can read faint gray letters on a white background.
Participants receiving the highest privosegtor dose were able to read a mean of 18 more letters than those on the placebo three months after completing the treatment, which is considered a clinically meaningful difference. At six months, there was still a significant difference of about 15 letters.
The treatment also preserved the structure of the optic nerve and retina (the light-sensitive tissue in the back of the eye), both of which are commonly damaged in optic neuritis. Additionally, it reduced the levels of neurofilament release, a marker of nerve damage.
The most common treatment-related adverse events included headache and acne. No serious adverse events or events leading to treatment discontinuation were reported.
“The ACUITY trial delivered truly groundbreaking results, demonstrating for the first time in a single study that a drug candidate consistently improves visual function alongside anatomical and biological evidence of neuroprotective benefit,” said Mark Kupersmith, MD, Oculis’ chief medical advisor of neuro-ophthalmology.
The company is also developing privosegtor for non-arteritic anterior ischemic optic neuropathy, a non-inflammatory condition that can cause optic nerve damage.
