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.
The clinical trial is intended to assess for clinical evidence of Clemastine Fumarate as a myelin repair therapy in patients with chronic inflammatory injury-causing demyelination as measured by multi-parametric MRI assessments.~No reparative therapies exist for the treatment of multiple sclerosis. Clemastine fumarate was identified along with a series of other antimuscarinic medications as a potential remyelinating agent using the micropillar screen (BIMA) developed at the University of California, San Francisco (UCSF). Following in vivo validation, an FDA 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 study seeks to follow up on that study and examine clemastine fumarate's protective and reparative effects in the context of chronic demyelinating brain lesions as imaged by multi-parametric MRI assessments. The investigators will be assessing the effects of clemastine fumarate as a remyelinating therapy and assessing its effect on MRI metrics of chronic lesions found in patients with a confirmed diagnosis of relapsing-remitting multiple sclerosis.~In addition to using conventional multi-parametric MRI assessments, this study will also evaluate a new MRI technique called Ultrashort Echo Time (UTE) MRI to assess the effects of clemastine fumarate as a remyelinating therapy of chronic lesions found in patients with a confirmed diagnosis of relapsing-remitting multiple sclerosis and compare it to the other assessments.