Assessing Changes in Multi-parametric MRI in MS Patients Taking Clemastine Fumarate as a Myelin Repair Therapy

Treatments capable of remyelination are a major unmet need for multiple sclerosis and other diseases that involve myelin damage, loss, or dysfunction in the central nervous system (CNS). Chronic demyelination of axons is believed to be injurious to neurons and serves as a major contributor to irreversible cell loss that underlies permanent disability. Available MS treatments are primarily immunosuppressing, without directly addressing or fully preventing axonal degeneration and disability. Clemastine fumarate was identified along with a series of other antimuscarinic medications as a potential remyelinating agent using the micropillar screen (BIMA) developed at UCSF. The screen demonstrated that clemastine promoted the differentiation of the endogenous oligodendrocyte precursor cells (OPCs) into mature myelinating oligodendrocytes. Following in vivo validation, an FDA investigational new drug (IND) exemption was granted to investigate clemastine for the treatment of multiple sclerosis in the context of chronic optic neuropathy. That pilot study was recently completed and is the first randomized control trial documenting efficacy for a putative remyelinating agent for the treatment of MS. The preselected primary efficacy endpoint (visual evoked potential) was met and a strong trend to benefit was seen for the principal secondary endpoint assessing function (low contrast visual acuity). That trial number was 13-11577. This clinical trial is intended to assess magnetic resonance imaging evidence of remyelination using Clemastine Fumarate in patients with chronic demyelinated lesions. Specifically speaking, the primary objective will assess various multi-parametric MRI sequences on the corpus callosum region, a region that animal models studies identified as a promising candidate for assessing remyelination. The aim was to help define the potential for MRI in measuring remyelination in MS, determine the optimal sequences and location for measuring myelin recovery, and help guide trial design for future remyelinating trials. Finally, 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.