for people ages 18-55 (full criteria)
at San Francisco, California
study started
completion around
Principal Investigator
by Ari Green
Headshot of Ari Green
Ari Green



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.

Official Title

A Randomized, Double-Blind, Parallel-Group, Placebo Controlled Trial to Assess the Efficacy, Safety, Tolerability, and Pharmacokinetics of Clemastine Fumarate as a Remyelinating Agent in Acute Optic Neuritis


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.


Optic Neuritis, multiple sclerosis, eye pain, vision loss, Neuritis, Clemastine


You can join if…

Open to people ages 18-55

  • Patients diagnosed or suspected to have an acute demyelinating optic neuritis in at least one eye within 3 weeks from the onset of any visual symptom other than pain
  • Use of disease-modifying therapies is not a contraindication
  • Use of appropriate contraception during the period of trial (women)
  • Understand and sign the informed consent

You CAN'T join if...

  • Other major ophthalmologic diseases / concomitant ophthalmologic disorders (e.g. diabetes, macular degeneration, glaucoma, severe myopia, etc)
  • Disc hemorrhages in the qualifying eye
  • No light perception in qualifying eye
  • Simultaneous bilateral optic neuritis
  • Cotton wool spots in the qualifying eye
  • Macular star in the qualifying eye
  • History of significant cardiac conduction block
  • History of cancer
  • Suicidal ideation or behavior in 6 months prior to baseline
  • Pregnancy, breastfeeding or planning to become pregnant
  • Involved with other study protocols simultaneously without prior approval
  • Concomitant use of any other putative remyelinating therapy as determined by the investigator
  • Serum creatinine > 1.5 mg/dL; aspartate transaminase (AST), alanine transaminase (ALT), or alkaline phosphatase > 2 times the upper limit of normal
  • History of drug or alcohol abuse within the past year
  • Untreated B12 deficiency (as determined by B12 serological assessments and metabolites including methylmalonic acid (MMA) and homocysteine) or untreated hypothyroidism
  • Clinically significant cardiac, metabolic, hematologic, hepatic, immunologic, urologic, endocrinologic, neurologic, pulmonary, psychiatric, dermatologic, allergic, renal, or other major diseases that, in the PI's judgment, may affect the interpretation of study results or patient safety
  • History or presence of clinically significant medical illness or laboratory abnormality that, in the opinion of the investigator would preclude participation in the study.
  • Positive for NMO antibody discovered within the first 2 weeks after randomization.


  • UCSF accepting new patients
    San Francisco California 94158 United States

Lead Scientist at UCSF

  • Ari Green
    Dr. Ari J Green is the Chief of the Division of Neuroimmunology and Glial Biology in the Department of Neurology at the University of California at San Francisco. His team consists of more than 20 laboratories and groups dedicated to discovering the causes of Multiple Sclerosis and related disorders; and to developing treatments as well as cures for these conditions.


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Phase 2 Optic Neuritis Research Study
Study Type
Expecting 90 study participants
Last Updated