Privosegtor Added to Standard IV Methylprednisolone in Patients with Optic Neuritis: Randomized Placebo‑Controlled Trial

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What is this study about?

Optic Neuritis is a rare condition in which inflammation of the optic nerve causes sudden loss of vision or blurred sight. The trial investigates the investigational drug Privosegtor (OCS-05) given by intravenous infusion as an add‑on to the standard steroid treatment IV Methylprednisolone. Participants receive either the study medication or a matching placebo solution.

The purpose of the study is to evaluate the effectiveness and safety of adding Privosegtor to standard therapy for individuals with Optic Neuritis.

Participants receive the infusion at the start of the study and are followed for three months, with clinic visits to check vision and safety. Vision is tested using low contrast visual acuity, a measure of how well a person can see faint patterns, and the eye’s structure is examined with optical coherence tomography, a non‑invasive scan that measures retinal layer thickness. A blood test for serum neurofilament light chain is performed to assess nerve damage, and questionnaires evaluate the impact of vision changes on daily life. Changes in these assessments are compared between the drug and placebo groups.

1 initial visit and baseline assessments

after joining the study, you will attend an initial visit where basic health information is recorded and a series of eye examinations are performed.

these examinations include a test of low contrast visual acuity, which measures how well you can see letters that are not very dark, and an optical coherence tomography scan, which creates a detailed picture of the layers of the retina.

2 random assignment to treatment group

based on a computer-generated random process, you will be assigned to receive either the active study drug privosegtor or a matching placebo solution.

the assignment is double‑masked, meaning neither you nor the study staff will know which product you receive.

3 pre‑infusion preparation

on the day of the infusion, a healthcare professional will calculate the dose of privosegtor based on your body weight: 3 milligrams for each kilogram you weigh.

the drug is supplied as a solution for infusion and will be mixed with a sterile saline solution that looks the same as the placebo.

4 intravenous infusion of study medication

the study medication, either privosegtor or the placebo, will be given through an intravenous (iv) line, which means the fluid is delivered directly into a vein.

the infusion is administered once during this visit; the exact duration of the infusion is determined by the study protocol.

5 concomitant iv methylprednisolone

in addition to the study medication, you will receive iv methylprednisolone, a steroid medication that is also delivered through an iv line.

the purpose of the steroid is to treat optic neuritis, the condition being studied.

6 post‑infusion monitoring

after the infusion, you will be observed for a short period to ensure there are no immediate side effects.

vital signs such as heart rate and blood pressure may be checked during this monitoring time.

7 follow‑up visits and month‑3 assessment

you will return for scheduled follow‑up visits during the study, with the most important evaluation occurring at month 3.

at the month‑3 visit, the same eye examinations performed at baseline will be repeated, including low contrast visual acuity, optical coherence tomography, and blood sampling to measure serum neurofilament light chain, a protein that can reflect nerve damage.

questionnaires such as the ne i vfq 25 (a vision‑related quality‑of‑life survey) and the nos‑10 (a symptom questionnaire) will also be completed.

Who Can Join the Study?

Be an adult (age 18‑50) man or woman who has their first episode of Optic Neuritis in the eye being studied, with loss of vision in that one eye only; having had Optic Neuritis before in the other eye is allowed.
Have started to notice vision loss no more than 12 days before receiving the first dose of the study medication.
Show a level of Low Contrast Visual Acuity (the ability to read faint letters) that is 40 letters or fewer on the test chart at the start of the trial.
Have a brain and eye MRI scan done within 12 days after the vision loss began, and the scan must show results that match an acute episode of Optic Neuritis.
Be able to sign a written informed consent form and agree to follow all study requirements.

Who Cannot Join the Study?

Having any other eye nerve disease (called optic neuropathy) that is not the study’s optic neuritis, such as infections, lack of blood flow, trauma, pressure, toxins, nutritional problems, or inherited causes, in the eye being studied.
Testing positive for special antibodies called anti‑aquaporin‑4 (AQP4) antibodies or anti‑myelin oligodendrocyte glycoprotein (MOG) antibodies at the screening visit.
Having had cancer in the past five years, except for well‑treated skin cancers like basal or squamous cell carcinoma or early‑stage cervical cancer.
Having a current or past invasive cancer of the upper face (forehead, eyes, or side of the head).
Having a major mental illness (such as severe depression, bipolar disorder, or schizophrenia) within the two years before screening.
Having abused alcohol or drugs within the two years before screening.
Having taken steroids (called corticosteroids) for the current episode of optic neuritis before joining the study.
Using medicines that the study says are not allowed at screening or planning to use them during the study.
Being allergic to the study drug, medicines that are chemically similar, or to methylprednisolone (a type of steroid).
Having received intravenous immune globulin (IVIg) within three months before the baseline visit or expecting to need it within three months after randomization.
Having a neurodegenerative disease that could affect the vision test, such as amyotrophic lateral sclerosis (ALS), Parkinson’s disease, or Alzheimer’s disease.
Having had therapeutic apheresis (a procedure called PLEX or immunoadsorption) within three months before baseline or planning to need it within three months after randomization.
Having taken drugs that block the IGF‑1 receptor (for example, teprotumumab) within the past six months.
Having taken certain heart rhythm medicines (Class Ia anti‑arrhythmic drugs like quinidine or disopyramide, or Class III drugs like amiodarone or sotalol) within three months before baseline or planning to use them during treatment.
Having another reason for vision loss, such as lazy eye (amblyopia), damage to the central retina (macula), retinal disease, infection, or genetic eye disorders.
Being unable to have an MRI scan with a contrast agent called gadolinium because of a medical reason.
Having used any other experimental drug within three months before enrollment or within five drug half‑lives (whichever is longer).
Being pregnant or breastfeeding and not willing or able to stop breastfeeding.
Being a woman who could become pregnant and not willing to use reliable birth control for at least six months after the last dose of the study drug.
Being a man who is not willing to use reliable birth control until two days after the last dose of the study drug.
Having any health problem that the investigator believes would make participation unsafe or interfere with the study.
Having current seizures or a history of seizures that needed treatment for at least one year (simple “petit mal” or fever‑related seizures are not excluded).
Having physical, travel, or personal constraints, or being unwilling to follow the study schedule for the full 12‑month period.
Planning to move to a location where there is no study site.
Being a study staff member (investigator, sub‑investigator, research assistant, pharmacist, coordinator, etc.) or a close relative directly involved in the study.
Being unwilling or unable to complete the study treatments and all required assessments.
Having a strong prescription for nearsightedness or farsightedness (a refractive error of 6.00 diopters or more).
Having a significant heart condition, abnormal heart rhythm (arrhythmia), heart block, a prolonged QT interval, or other important heart test abnormalities.
Having any abnormal findings on the screening electrocardiogram (ECG).
Showing white‑matter changes on brain MRI that suggest a non‑inflammatory optic nerve problem (such as metabolic or mitochondrial disorders).
Using strong or moderate inhibitors of the liver enzyme CYP3A4 or certain drug‑transport proteins (MATE2‑K, MRP2, OAT3, OATP1B3) within one week (or five half‑lives) before treatment, or planning to use them during or shortly after treatment.
Having a severe or poorly controlled systemic disease (such as serious liver, gastrointestinal, heart, lung, blood, kidney, endocrine, or skin disorder). Poor kidney function is defined as a glomerular filtration rate (GFR) below 60 mL/min/1.73 m². Lab thresholds that indicate poor liver function include: AST or ALT more than three times the normal upper limit, total bilirubin more than 1.5 times normal, or clotting tests (INR or aPTT) more than 1.5 times normal.
Using strong or moderate inducers of the liver enzyme CYP3A4 within two weeks (or five half‑lives) before treatment, or planning to use them during or shortly after treatment.
Having medically unstable conditions at enrollment, such as uncontrolled diabetes (type 1 or 2) or high blood pressure.
Having any systemic condition that could affect safety assessments or the ability to follow study procedures.
Having an active bacterial, viral, or fungal infection.
Having an ongoing infection that requires treatment, such as tuberculosis, HIV, hepatitis B or C, or recurrent severe infections.
Having an active immune system disease that needs ongoing therapy (for example, Sjögren’s disease, systemic lupus erythematosus, or other autoimmune disorders). Note: Multiple sclerosis, MOG‑associated disease, or neuromyelitis optica spectrum disorder are not exclusions.
Having any eye condition that could interfere with the low‑contrast visual acuity test, as defined by the study protocol.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country
Azienda Ospedaliero Universitaria Careggi	Florence	Italy
Azienda Ospedaliera Universitaria Universita’ Degli Studi Della Campania Luigi Vanvitelli	Naples	Italy
Technische Universitaet Dresden	Dresden	Germany
Hospital Universitario Y Politecnico La Fe	Valencia	Spain

Other Sites

Site Name	City	Country
Quinze-Vingts National Ophthalmology Hospital	Paris	France
Azienda Universitaria Ospedaliera Consorziale Policlinico Bari	Bari	Italy
Rheinische Friedrich-Wilhelms-Universitaet Bonn	Bonn	Germany
Hospital General Universitario Gregorio Maranon	Madrid	Spain
Hospital Del Mar	Barcelona	Spain
Fngjhegdf A Dm Rtdhchuofy	Paris	France
Uozmsbqyhp dfadx ssxou Gksuezbx Dmdqlncdhf Cyozhxnwcuaqeq Cubikt dr Swvqh e tpkufhraar aabcvzam	Chieti	Italy
Ivkhgizf Dj Cqxuhct Ek Dm Ls Mwzgxz Eyphvbbg	Paris	France
Alauyhrbfv Pljgghpw Hkrxidbv Dt Mgewmcfsv	Marseille	France
Bvkgmczc Usbvclaxua Houxmnfu Cfqxhg	Besançon	France
Ivmpm Odjvjngr Pewwsnmoigj Sqc Mkhrjvg	Genoa	Italy
Catfcl Hjicvjcykbq Uclplkzrsokoy Dt Mcahymycesk	Montpellier	France
Cqnbwm Hljttpysxtu Uvcbxoonbvxdp Df Njluu	Nimes	France
Aacnmwm Oexauzezbscqqqmjtqjozcivs Soxf Aslei	Rome	Italy
Cdsgrm Hlsghesdlmf Lkyy Sgy	Pierre Benite	France
Fihkwcyxhg Inpqxbgn Gl Gaybgw Dt Cqdvog	Cefalu'	Italy
Hksrhpig Umnywnzkqexfqv Sdwvleettc &ydmglj Hgmqgbh df Hzvdrotdsqc	STRASBOURG, Alsace	France
Uerfsatpnslyiuxycinxw Tqysbsukp Aan	Tuebingen	Germany
Cdzswuv Uqykpjvngpvunfywdvfn Byppjm Kqw	Berlin	Germany
Mafhhiv Cokabn &tehnik Uutowfckic Ot Fobjfbay	Freiburg Im Breisgau	Germany
Umtjymyqhi Mmxynyi Cgmigx Hkejsuspjluijznnk	Hamburg	Germany
Hfhtjkcd Sxiob Cbfpxcop Iaq	Salt	Spain
Hsnrgxia Cidrgz Dg Bfdpaedgi	Barcelona	Spain
Ubbsoloxkp Cpeqbkax Hpaupfnx Vwrsjk Dz Ll Arbqahoq	Murcia	Spain
Hzslkcwe Cscnokj Syq Cqozes	Madrid	Spain
Hzohxvat Ugxunekjdbwb Afltz De Vphxiwyi Dh Lm Gbnpmstr Tcmrtfgssex Dx Lcpikx	Lleida	Spain
Hmedubbv Axwxpp Cdjtqmawu	Vigo	Spain

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	30.09.2026
Germany	Not yet recruiting	30.09.2026
Italy	Not yet recruiting	30.09.2026
Spain	Not yet recruiting	30.09.2026

Trial locations

Privosegtor (also known as OCS‑05) is a new drug being tested to see if it can improve vision in people with optic neuritis. In the study it is given through an IV infusion, mixed into a liquid that is poured into a vein. Researchers are looking to find out whether adding this medication helps patients see better on a low‑contrast eye chart compared with not receiving it.

Methylprednisolone is a steroid medication that is already used to treat inflammation in optic neuritis. In this trial all participants receive an IV dose of methylprednisolone, and the researchers are testing whether adding Privosegtor to this standard treatment provides extra benefit for vision recovery.

Optic neuritis – Optic neuritis is inflammation of the optic nerve, the pathway that carries visual information from the eye to the brain. It typically starts with a sudden loss of vision or blurred vision in one eye, often with pain on eye movement. Vision usually improves over several weeks to months, but some people continue to have difficulty seeing low‑contrast images. The condition can recur, and repeated episodes may cause thinning of the nerve layer that can be seen on eye imaging. It is classified as a rare disease.

Trial ID:

2025-525075-91-00

Protocol code:

PR-5301

Trial Phase:

Therapeutic confirmatory (Phase III)

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Privosegtor Added to Standard IV Methylprednisolone in Patients with Optic Neuritis: Randomized Placebo‑Controlled Trial

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?