Development of a Population Pharmacokinetic Model for the Diroximel Fumarate Metabolites Monomethyl Fumarate and 2-Hydroxyethyl Succinimide Following Oral Administration of Diroximel Fumarate in Healthy Participants and Patients with Multiple Sclerosis

The Evolving Role of Monomethyl Fumarate Treatment as Pharmacotherapy for Relapsing-Remitting Multiple Sclerosis

Multiple sclerosis is the most common autoimmune disease affecting the central nervous system (CNS) worldwide. Multiple sclerosis involves inflammatory demyelination of nerve fibers in the CNS, often presenting with recurrent episodes of focal sensory or motor deficits associated with the region of the CNS affected. The prevalence of this disease has increased rapidly over the last decade. Despite the approval of many new pharmaceutical therapies in the past 20 years, there remains a growing need for alternative therapies to manage the course of this disease. Treatments are separated into two main categories: management of acute flare versus long-term prevention of flares via disease-modifying therapy. Primary drug therapies for acute flare include corticosteroids to limit inflammation and symptomatic management, depending on symptoms. Several different drugs have been recently approved for use in modifying the course of the disease, including a group of medications known as fumarates (e.g., dimethyl fumarate, diroximel fumarate, monomethyl fumarate) that have been shown to be efficacious and relatively safe. In the present investigation, we review available evidence focused on monomethyl fumarate, also known as Bafiertam®, along with bioequivalent fumarates for the long-term treatment of relapsing-remitting multiple sclerosis.

Diroximel Fumarate as a Novel Oral Immunomodulating Therapy for Relapsing Forms of Multiple Sclerosis: A Review on the Emerging Data

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating and neurodegenerative disorder of the central nervous system. Disease-modifying drugs (DMDs) and subsequent adherence are crucial for preventing reversible episodes of neurological dysfunction and delayed onset of progressive accumulation of irreversible deficits. Yet, side effects may limit their usage in clinical practice. Gastrointestinal (GI) side effects are a significant limitation of the use of dimethyl fumarate (DMF), the most frequently prescribed oral DMD in MS worldwide. Diroximel fumarate (DRF) is a second-generation oral fumaric acid ester (FAE) that was developed as a formulation with better GI tolerability. The improved tolerability is assumed to be related to a lower synthesis of gut-irritating methanol. Other explanations for DRF’s lower extent of GI irritation include a more modest off-target activity due to its chemical structure. The superior GI tolerability of DRF compared to DMF could be proven in clinical trials and lead to approval of DRF for the treatment of relapsing forms of MS/relapsing-remitting MS (United States Food and Drug Administration and European Medicines Agency, respectively). Here, we summarize the mode of action of oral FAE and compare the chemical and physiological characteristics of DMF and DRF. Moreover, we discuss the adverse effects of FAE and introduce the emerging preclinical and trial data leading to the approval of DRF in MS. This article additionally reviews our current understanding of coronavirus disease 2019 (COVID-19) and the efficacy of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination in people treated with FAE.