A Phase 2 interventional study of Clemastine and Placebo in Optic Neuritis, sponsored by University of California, San Francisco. Recruiting at 1 site in United States. Open to participants aged 18 Years to 55 Years. Per ClinicalTrials.gov, last updated 2026-03-11.
Sponsored by University of California, San Francisco · Phase 2, Interventional, and Treatment
The main purpose of this study is to assess clemastine as a remyelinating agent in patients with acute optic neuritis.The study will also evaluate the tolerability of clemastine, originally approved as first-generation antihistamine, in patients with optic neuritis. Study procedures will include assessments for evidence of remyelination in the anterior visual pathway and in the brain using electrophysiologic techniques and magnetic resonance imaging. If they are on one, patients in this study can remain on their standard disease modifying treatment during the course of the study. However, patients cannot participate in any other investigational new drug research study concurrently.
Optic neuritis is an inflammatory, demyelinating disease of the optic nerve. It is most often characterized by visual loss or blurred vision along with dyschromatopsiaaccompanied by pain (especially with eye movement) and no demonstrable evidence of an alternate diagnosis such as ischemia or retinal disease. It can also be associated with a swollen optic disc (Optic Neuritis Study Group 1991, Hutchinson, W.M. 1976) and optic nerve enhancement on MRI (Kupersmith 2002).
Functional high-throughput screening for compounds that promote remyelination presents a major unmet need in the therapeutic arsenal for multiple sclerosis and other demyelinating conditions such as optic neuritis. Screening for myelin repair is problematic, as functional remyelination requires the presence of intact neuronal axons. Standard methods are not suited for high-throughput formats. We performed a detailed screen of over 1500 FDA approved small molecule drugs to identify agents that could be promising for remyelination. Engineered with conical dimensions, our micropillar technology permitted resolution of the extent and length of membrane wrapping from a single 2-dimensional image. Confocal imaging acquired from the base to the tip of the pillars allows for the fluorescence detection of concentric wrapping observed as "rings" of myelin membrane. The platform was formatted in 96-well plates, amenable to semi-automated random acquisition and automated detection and quantification. Upon initiating a screen of 1500 bioactive molecules, we identified Clemastine as a compound that potentially enhances oligodendrocyte differentiation and remyelination. We then validated this and other drugs in preclinical assays as well as in animal models of primary myelination and remyelination after inflammatory and chemical demyelination. Together, our findings illustrate the proof of concept for a novel high-throughput screening platform for potential regenerative therapeutics in MS (Chan JR et al. 2014).
This study is intended to assess for clinical evidence of remyelination using Clemastine Fumarate in patients with acute inflammatory injury causing demyelination of the anterior visual pathway as a consequence of acute demyelinating optic neuritis. The study is designed to assess tolerability and clinical efficacy of Clemastine using outcomes intended to assess for (a) adverse events and (b) recovery of myelin. This study is complementary to an earlier study evaluating clemastine in chronic demyelinated optic neuropathy and serves as part of a proof of concept program intended to evaluate methods for conducting remyelination trials in MS.
88 studies on the registry are indexed under Optic Neuritis; 16 are open to participants now.
This study's planned enrollment of 90 is above the median of 50 across 58 interventional studies indexed under Optic Neuritis.
Browse Optic Neuritis studies →University of California, San Francisco is the lead sponsor of 2,169 studies on the registry; 372 are open to participants now.
Of its 267 completed or terminated interventional studies of FDA-regulated products, 202 (76%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive clemastine until 3 months and then will be off treatment until 9 month time point.
Drug: Clemastine
Participants will receive placebo until 3 months and then will be off treatment until 9 month time point.
Drug: Placebo
12mg (4mg 3x/day) clemastine for 7 days followed by 8mg clemastine (4mg 2x/day) until 3 months. Patients will be off treatment from 3-9 months and will be reevaluated at 9 months.
Also known as: Tavist, Clemastine fumarate, Walhist
Equivalent placebo. 12mg (4mg 3x/day) placebo for 7 days followed by 8mg placebo (4mg 2x/day) until 3 months. Patients will be off treatment from 3-9 months and will be reevaluated at 9 months.
Change in P100 latency on full-field visual evoked potential
To evaluate the efficacy of clemastine relative to placebo for reducing P100 latencies on full field transient pattern reversal visual evoked potentials. Measure will be reported as difference in P100 latency from baseline to 9 months.
Time frame: baseline, 1 week, 1 month, 3 months, 9 months
Change in low contrast visual acuity
The second primary outcome is to measure the effectiveness of clemastine relative to placebo at improving patient performance on ETDRS low contrast visual acuity chart testing (2.5% black on white) during the recovery from an acute optic neuritis. Measure will be reported as difference in ETDRS score from baseline to 9 months.
Time frame: baseline, 1 week, 1 month, 3 months, 9 months
Change in retinal nerve fiber layer thickness on optical coherence tomography
The primary outcome is to measure the effectiveness of clemastine relative to placebo at preventing the loss of retinal nerve fiber assessed via optical coherence tomography (OCT). Measure will be reported as difference in nerve fiber thickness between baseline and 9 months.
Time frame: baseline, 1 week, 1 month, 3 months, 9 months
Radiological outcomes assessed by magnetic resonance imaging
To evaluate the efficacy of clemastine relative to placebo in increasing magnetization transfer ratios and myelin water fraction derived from magnetic resonance imaging of the brain during the period of exposure to active treatment. Measures will be reported as change between baseline and 9 months.
Time frame: baseline, 9 month
Expanded Disability Status Scale score
To evaluate the efficacy of Clemastine relative to placebo in reducing the EDSS score at 9 months.The EDSS is an ordinal scale used for assessing neurological impairment of MS based on a neurological examination. It consists of scores in each of seven functional systems (FS) and an ambulation score that are then combined to determine the EDSS \[ranging from 0 (normal) to 10 (death due to MS)\]. The FSs are the Visual, Brain Stem, Pyramidal, Cerebellar, Sensory, Bowel \& Bladder, and Cerebral functions. The FSs and EDSS steps will be assessed in a standardized manner. EDSS is a widely used and accepted instrument to evaluate disability status at a given time and longitudinally, to assess disability progression in clinical studies in MS.
Time frame: baseline, 9 months
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Studies of the drug tested here: Clemastine
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