Progressive multifocal leukoencephalopathy outcomes in patients with multiple sclerosis treated with dimethyl fumarate

Escalation to Anti-CD20 Treatment for Multiple Sclerosis Following Natalizumab-Associated Progressive Multifocal Leukoencephalopathy

Objectives

Disease-modifying therapy (DMT) for multiple sclerosis (MS) after natalizumab-associated progressive multifocal leukoencephalopathy (PML) is controversial due to concern for recurrent PML. We describe DMT utilization for over a decade in a patient with MS who survived PML.

Methods

Case report.

Results

A 36-year-old woman was diagnosed with MS in 2002 and treated with interferon beta-1a until 2006, when she transitioned to natalizumab due to relapses. She presented in 2012 with 2 months of progressive cognitive and gait concerns and was diagnosed with PML by positive CSF JC virus testing with concordant clinical and MRI findings. She was treated with plasma exchange and then corticosteroids for PML immune reconstitution inflammatory syndrome before starting glatiramer acetate for DMT. She transitioned to dimethyl fumarate in 2013 after MS activity on MRI with negative CSF JC virus testing. Owing to worsening footdrop consistent with progression, she transitioned to ocrelizumab in 2017 and then to ofatumumab in 2020 due to logistics of medication administration. There has been no clinicoradiographic or CSF evidence of recurrent PML.

Discussion

DMT selection is challenging for patients with MS who survive PML. We used an escalation approach extending to ocrelizumab and ofatumumab due to MS progression. Anti-CD20 DMTs are a high-efficacy option post-PML.

Classification of Evidence

This provides Class IV evidence. It is a single observational study without controls.

Lymphopenia is Not the Primary Therapeutic Mechanism of Diroximel Fumarate in Relapsing-Remitting Multiple Sclerosis: Subgroup Analyses of the EVOLVE-MS-1 Study

INTRODUCTION

In EVOLVE-MS-1 (NCT02634307), mean absolute lymphocyte count (ALC) on diroximel fumarate (DRF) declined from baseline by approximately 28% in year 1, then stabilized, similar to ALC decline observed with dimethyl fumarate (DMF). Prior studies reported that clinical efficacy of DMF was not substantially different in patients with and without lymphopenia.

METHODS

EVOLVE-MS-1-an open-label, 96-week, phase 3 study-assessed DRF safety and exploratory efficacy in patients with relapsing-remitting multiple sclerosis. This study analyzes efficacy-related outcomes comparing (1) patients with lymphopenia (≥ 1 ALC below lower limit of normal [LLN]) and without (all ALCs ≥ LLN); (2) across quartiles stratified by week 96 ALC decline from baseline: Q1 (≥ 47% decline); Q2 (30% to < 47% decline); Q3 (12% to < 30% decline); Q4 (< 12% decline).

RESULTS

Baseline characteristics were similar between patients without (n = 593) and with lymphopenia (n = 452). At week 96, adjusted annualized relapse rate (ARR; 95% confidence interval) was 0.14 (0.11-0.17) without lymphopenia and 0.12 (0.09-0.15) with lymphopenia. Estimated proportions with 12-week confirmed disability progression (CDP12) at week 96 were 10.2% without and 9.3% with lymphopenia. When stratified by quartiles (Q1-Q4), ARR at week 96 was 0.11 (Q1), 0.09 (Q2), 0.13 (Q3), and 0.17 (Q4). Estimated proportions with CDP12 at week 96 were 9.6% (Q1), 10.2% (Q2), 5.7% (Q3), and 10.9% (Q4). At week 96, no evidence of disease activity was achieved by 47.2% (Q1), 47.8% (Q2), 45.4% (Q3), and 37.3% (Q4) of patients.

CONCLUSION

In DRF-treated patients in EVOLVE-MS-1, clinical and radiological measurements indicated reduced disease activity regardless of lymphopenia or magnitude of ALC decline from baseline; however, patients who had greater ALC declines appeared to have numerically lower ARR and higher proportions free from relapses and gadolinium-enhancing lesions compared with those with smallest decline. This supports prior evidence that, while lymphopenia may contribute to fumarate efficacy outcomes, it is not the primary mechanism of action.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02634307.

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.

Identification of key neuronal mechanisms triggered by dimethyl fumarate in SH-SY5Y human neuroblastoma cells through a metabolomic approach

Dimethyl fumarate (DMF) is an old drug used for psoriasis treatment that has recently been repurposed to treat relapse-remitting multiple sclerosis, mostly due to its neuro- and immunomodulatory actions. However, mining of a pharmacovigilance database recently ranked DMF as the second pharmaceutical most associated with cognitive adverse events. To our best knowledge, the signaling mechanisms underlying its therapeutic and neurotoxic outcomes remain mostly undisclosed. This work thus represents the first-hand assessment of DMF-induced metabolic changes in undifferentiated SH-SY5Y human neuroblastoma cells, through an untargeted metabolomic approach using gas chromatography-mass spectrometry (GC-MS). The endometabolome was analyzed following 24 h and 96 h of exposure to two pharmacologically relevant DMF concentrations (0.1 and 10 μM). None of these conditions significantly reduced metabolic activity (MTT reduction assay). Our data showed that 24 h-exposure to DMF at both concentrations tested mainly affected metabolic pathways involved in mitochondrial activity (e.g., citric acid cycle, de novo triacylglycerol biosynthesis), and the synthesis of catecholamines and serotonin by changing the levels of their respective precursors, namely phenylalanine (0.68-fold decrease for 10 μM DMF vs vehicle), and tryptophan (1.36-fold increase for 0.1 μM DMF vs vehicle). Interestingly, taurine, whose levels can be modulated via Nrf2 signaling (DMF's primary target), emerged as a key mediator of DMF's neuronal action, displaying a 3.86-fold increase and 0.27-fold decrease for 10 μM DMF at 24 h and 96 h, respectively. A 96 h-exposure to DMF seemed to mainly trigger pathways associated with glucose production (e.g., gluconeogenesis, glucose-alanine cycle, malate-aspartate shuttle), possibly related to the metabolism of DMF into monomethyl fumarate and its further conversion into glucose via activation of the citric acid cycle. Overall, our data contribute to improving the understanding of the events associated with neuronal exposure to DMF.