Time course of clinical and neuroradiological effects of delayed-release dimethyl fumarate in multiple sclerosis

Whole blood miRNAs in relapsing MS patients treated with dimethyl fumarate in the phase 4 TREMEND trial

We investigated the impact of dimethyl fumarate (DMF), an oral therapy for relapsing multiple sclerosis (MS), on blood microRNA (miRNA) signatures and neurofilament light (NFL) levels. DMF normalized miR-660-5p and modulated various miRNAs associated with the NF-kB pathway. These alterations reached a peak 4-7 months after treatment. Notably, particular miRNAs correlated with high or low NFL levels, implying their potential role as markers of treatment efficacy. Our findings broaden the understanding of DMF's immunomodulatory effects and may aid in predicting treatment responses.

Lessons from immunotherapies in multiple sclerosis

The improved understanding of multiple sclerosis (MS) neurobiology alongside the development of novel markers of disease will allow precision medicine to be applied to MS patients, bringing the promise of improved care. Combinations of clinical and paraclinical data are currently used for diagnosis and prognosis. The addition of advanced magnetic resonance imaging and biofluid markers has been strongly encouraged, since classifying patients according to the underlying biology will improve monitoring and treatment strategies. For example, silent progression seems to contribute significantly more than relapses to overall disability accumulation, but currently approved treatments for MS act mainly on neuroinflammation and offer only a partial protection against neurodegeneration. Further research, involving traditional and adaptive trial designs, should strive to halt, repair or protect against central nervous system damage. To personalize new treatments, their selectivity, tolerability, ease of administration, and safety must be considered, while to personalize treatment approaches, patient preferences, risk-aversion, and lifestyle must be factored in, and patient feedback used to indicate real-world treatment efficacy. The use of biosensors and machine-learning approaches to integrate biological, anatomical, and physiological parameters will take personalized medicine a step closer toward the patient's virtual twin, in which treatments can be tried before they are applied.

Gut microbiota composition as a candidate risk factor for dimethyl fumarate-induced lymphopenia in multiple sclerosis

Mounting evidence points towards a pivotal role of gut microbiota in multiple sclerosis (MS) pathophysiology. Yet, whether disease-modifying treatments alter microbiota composition and whether microbiota shape treatment response and side-effects remain unclear. In this prospective observational pilot study, we assessed the effect of dimethyl fumarate (DMF) on gut microbiota and on host/microbial metabolomics in a cohort of 20 MS patients. Combining state-of-the-art microbial sequencing, metabolome mass spectrometry, and computational analysis, we identified longitudinal changes in gut microbiota composition under DMF-treatment and an increase in citric acid cycle metabolites. Notably, DMF-induced lymphopenia, a clinically relevant safety concern, was correlated with distinct baseline microbiome signatures in MS patients. We identified gastrointestinal microbiota as a key therapeutic target for metabolic properties of DMF. By characterizing gut microbial composition as a candidate risk factor for DMF-induced lymphopenia, we provide novel insights into the role of microbiota in mediating clinical side-effects.

Inflammation and Nitro-oxidative Stress as Drivers of Endocannabinoid System Aberrations in Mood Disorders and Schizophrenia

The endocannabinoid system (ECS) is composed of the endocannabinoid ligands anandamide (AEA) and 2-arachidonoylgycerol (2-AG), their target cannabinoid receptors (CB₁ and CB₂) and the enzymes involved in their synthesis and metabolism (N-acyltransferase and fatty acid amide hydrolase (FAAH) in the case of AEA and diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL) in the case of 2-AG). The origins of ECS dysfunction in major neuropsychiatric disorders remain to be determined, and this paper explores the possibility that they may be associated with chronically increased nitro-oxidative stress and activated immune-inflammatory pathways, and it examines the mechanisms which might be involved. Inflammation and nitro-oxidative stress are associated with both increased CB₁ expression, via increased activity of the NADPH oxidases NOX4 and NOX1, and increased CNR1 expression and DNA methylation; and CB₂ upregulation via increased pro-inflammatory cytokine levels, binding of the transcription factor Nrf2 to an antioxidant response element in the CNR2 promoter region and the action of miR-139. CB₁ and CB₂ have antagonistic effects on redox signalling, which may result from a miRNA-enabled negative feedback loop. The effects of inflammation and oxidative stress are detailed in respect of AEA and 2-AG levels, via effects on calcium homeostasis and phospholipase A₂ activity; on FAAH activity, via nitrosylation/nitration of functional cysteine and/or tyrosine residues; and on 2-AG activity via effects on MGLL expression and MAGL. Finally, based on these detailed molecular neurobiological mechanisms, it is suggested that cannabidiol and dimethyl fumarate may have therapeutic potential for major depressive disorder, bipolar disorder and schizophrenia.

Effects of Dimethyl Fumarate on Brain Atrophy in Relapsing-Remitting Multiple Sclerosis: Pooled Analysis Phase 3 DEFINE and CONFIRM Studies

Objective

In the pivotal DEFINE and CONFIRM trials for dimethyl fumarate (DMF), patterns of brain volume changes were different, potentially due to low sample sizes and because MRIs were analyzed at two different reading centers. We evaluated effects of DMF on brain volume change in patients with multiple sclerosis (MS) through reanalysis of pooled images from DEFINE/CONFIRM trials in one reading center.

Methods

MRIs from DEFINE/CONFIRM at weeks 0, 24, 48, and 96 from patients randomized to twice-daily DMF or placebo (PBO) were reanalyzed at the Cleveland Clinic to measure brain parenchymal fraction (BPF). To account for pseudoatrophy, brain volume estimates were re-baselined to calculate changes for weeks 48–96.

Results

Across studies, 301 and 314 patients receiving DMF and PBO, respectively, had analyzable MRIs. In weeks 0–48, mean ± SE percentage change in BPF was −0.44 ± 0.04 vs. −0.34 ± 0.04% in DMF vs. PBO, respectively, whereas in weeks 48–96, mean ± SE percentage change in BPF was −0.27 ± 0.03 vs. −0.41 ± 0.04% in DMF vs. PBO, respectively. The mixed-effect model for repeated measures showed similar results: in weeks 48–96, estimated change (95% confidence interval) in BPF was −0.0021 (−0.0027, −0.0016) for DMF vs. −0.0033 (−0.0039, −0.0028) for PBO (35.9% reduction; p = 0.0025).

Conclusions

The lower rate of whole brain volume loss with DMF in this pooled BPF analysis in the second year vs. PBO is consistent with its effects on relapses, disability, and MRI lesions. Brain volume changes in the first year may be explained by pseudoatrophy effects also described in other MS clinical trials.

Interleukin-1 promotes autoimmune neuroinflammation by suppressing endothelial heme oxygenase-1 at the blood-brain barrier

The proinflammatory cytokine interleukin 1 (IL-1) is crucially involved in the pathogenesis of multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Herein, we studied the role of IL-1 signaling in blood-brain barrier (BBB) endothelial cells (ECs), astrocytes and microglia for EAE development, using mice with the conditional deletion of its signaling receptor IL-1R1. We found that IL-1 signaling in microglia and astrocytes is redundant for the development of EAE, whereas the IL-1R1 deletion in BBB-ECs markedly ameliorated disease severity. IL-1 signaling in BBB-ECs upregulated the expression of the adhesion molecules Vcam-1, Icam-1 and the chemokine receptor Darc, all of which have been previously shown to promote CNS-specific inflammation. In contrast, IL-1R1 signaling suppressed the expression of the stress-responsive heme catabolizing enzyme heme oxygenase-1 (HO-1) in BBB-ECs, promoting disease progression via a mechanism associated with deregulated expression of the IL-1-responsive genes Vcam1, Icam1 and Ackr1 (Darc). Mechanistically, our data emphasize a functional crosstalk of BBB-EC IL-1 signaling and HO-1, controlling the transcription of downstream proinflammatory genes promoting the pathogenesis of autoimmune neuroinflammation.

Delay from treatment start to full effect of immunotherapies for multiple sclerosis

In multiple sclerosis, treatment start or switch is prompted by evidence of disease activity. Whilst immunomodulatory therapies reduce disease activity, the time required to attain maximal effect is unclear. In this study we aimed to develop a method that allows identification of the time to manifest fully and clinically the effect of multiple sclerosis treatments (‘therapeutic lag’) on clinical disease activity represented by relapses and progression-of-disability events. Data from two multiple sclerosis registries, MSBase (multinational) and OFSEP (French), were used. Patients diagnosed with multiple sclerosis, minimum 1-year exposure to treatment, minimum 3-year pretreatment follow-up and yearly review were included in the analysis. For analysis of disability progression, all events in the subsequent 5-year period were included. Density curves, representing incidence of relapses and 6-month confirmed progression events, were separately constructed for each sufficiently represented therapy. Monte Carlo simulations were performed to identify the first local minimum of the first derivative after treatment start; this point represented the point of stabilization of treatment effect, after the maximum treatment effect was observed. The method was developed in a discovery cohort (MSBase), and externally validated in a separate, non-overlapping cohort (OFSEP). A merged MSBase-OFSEP cohort was used for all subsequent analyses. Annualized relapse rates were compared in the time before treatment start and after the stabilization of treatment effect following commencement of each therapy. We identified 11 180 eligible treatment epochs for analysis of relapses and 4088 treatment epochs for disability progression. External validation was performed in four therapies, with no significant difference in the bootstrapped mean differences in therapeutic lag duration between registries. The duration of therapeutic lag for relapses was calculated for 10 therapies and ranged between 12 and 30 weeks. The duration of therapeutic lag for disability progression was calculated for seven therapies and ranged between 30 and 70 weeks. Significant differences in the pre- versus post-treatment annualized relapse rate were present for all therapies apart from intramuscular interferon beta-1a. In conclusion we have developed, and externally validated, a method to objectively quantify the duration of therapeutic lag on relapses and disability progression in different therapies in patients more than 3 years from multiple sclerosis onset. Objectively defined periods of expected therapeutic lag allows insights into the evaluation of treatment response in randomized clinical trials and may guide clinical decision-making in patients who experience early on-treatment disease activity. This method will subsequently be applied in studies that evaluate the effect of patient and disease characteristics on therapeutic lag.

Current Landscape of NRF2 Biomarkers in Clinical Trials

The transcription factor NF-E2 p45-related factor 2 (NRF2; encoded by NFE2L2) plays a critical role in the maintenance of cellular redox and metabolic homeostasis, as well as the regulation of inflammation and cellular detoxication pathways. The contribution of the NRF2 pathway to organismal homeostasis is seen in many studies using cell lines and animal models, raising intense attention towards targeting its clinical promise. Over the last three decades, an expanding number of clinical studies have examined NRF2 inducers targeting an ever-widening range of diseases. Full understanding of the pharmacokinetic and pharmacodynamic properties of drug candidates rely partly on the identification, validation, and use of biomarkers to optimize clinical applications. This review focuses on results from clinical trials with four agents known to target NRF2 signaling in preclinical studies (dimethyl fumarate, bardoxolone methyl, oltipraz, and sulforaphane), and evaluates the successes and limitations of biomarkers focused on expression of NRF2 target genes and others, inflammation and oxidative stress biomarkers, carcinogen metabolism and adduct biomarkers in unavoidably exposed populations, and targeted and untargeted metabolomics. While no biomarkers excel at defining pharmacodynamic actions in this setting, it is clear that these four lead clinical compounds do touch the NRF2 pathway in humans.

Dimethyl Fumarate: A Review in Relapsing-Remitting MS

Dimethyl fumarate (Tecfidera^®) is approved for the treatment of relapsing forms of multiple sclerosis (MS). Based on evidence from the clinical trial and real-world settings, dimethyl fumarate is an effective treatment in this patient population, with benefits maintained over the longer term. In the pivotal, placebo-controlled phase III DEFINE and CONFIRM trials in adults with relapsing-remitting multiple sclerosis (RRMS), twice-daily dimethyl fumarate reduced clinical relapse and MRI measures of disease activity and improved some aspects of health-related quality of life (HR-QoL). Reduced disability progression was also observed with dimethyl fumarate in DEFINE. Results in predominantly East Asian patients (APEX trial) were reflective of those seen in DEFINE and CONFIRM. Dimethyl fumarate had an acceptable tolerability profile. The most common adverse events were flushing and gastrointestinal events, which were of mild or moderate severity and appear to be largely manageable. Thus twice-daily dimethyl fumarate remains an effective treatment option for use in patients with RRMS, with the convenience of oral administration.

Lymphocyte reconstitution after DMF discontinuation in clinical trial and real-world patients with MS

Background

Delayed-release dimethyl fumarate (DMF) has demonstrated robust efficacy in treating patients with relapsing-remitting multiple sclerosis. Decreases in absolute lymphocyte count (ALC) are a well-known pharmacodynamic effect of DMF treatment, but lymphocyte recovery dynamics are not well characterized after discontinuation of DMF.

Methods

Data sources included the Biogen DMF integrated clinical trial data set, a retrospective US chart abstraction study, and data from MSBase. We assessed rate and time course of lymphocyte reconstitution after DMF discontinuation.

Results

The majority of patients who developed lymphopenia while treated with DMF and subsequently discontinued treatment experienced ALC reconstitution. The median time to reach ALC ≥0.8 × 10⁹/L was 2-4 months after discontinuation for patients treated in real-world data sets; the median time to reach ALC ≥0.91 × 10⁹/L was 2 months after discontinuation in DMF clinical trials. Severity of lymphopenia on treatment and decline in ALC within the first 6 months did not affect the ALC reconstitution rate after DMF discontinuation; rather, on-treatment lymphopenia duration influenced the reconstitution rate. In patients with severe, prolonged lymphopenia for ≥3 years, lymphocyte reconstitution to ≥0.91 × 10⁹/L was 12-18 months vs 2-3 months in patients with lymphopenia persisting <6 months.

Conclusions

The majority of patients who discontinued DMF due to lymphopenia experienced ALC reconstitution within 2-4 months following DMF discontinuation. This may help guide clinicians in managing patients who develop lymphopenia during DMF treatment. Prolonged lymphopenia on DMF treatment is associated with slow lymphocyte recovery after DMF discontinuation.

Onset of clinical and MRI efficacy of ocrelizumab in relapsing multiple sclerosis

Objective

To assess the onset of ocrelizumab efficacy on brain MRI measures of disease activity in the phase II study in relapsing-remitting multiple sclerosis (RRMS), and relapse rate in the pooled phase III studies in relapsing multiple sclerosis (RMS).

Methods

Brain MRI activity was determined in the phase II trial at monthly intervals in patients with RRMS receiving placebo, ocrelizumab (600 mg), or intramuscular interferon (IFN) β-1a (30 μg). Annualized relapse rate (ARR; over various epochs) and time to first relapse were analyzed in the pooled population of the phase III OPERA (A Study of Ocrelizumab in Comparison With Interferon Beta-1a [Rebif] in Participants With Relapsing Multiple Sclerosis) I and OPERA II trials in patients with RMS receiving ocrelizumab (600 mg) or subcutaneous IFN-β-1a (44 μg).

Results

In patients with RRMS, ocrelizumab reduced the number of new T1 gadolinium-enhancing lesions by week 4 vs placebo (p = 0.042) and by week 8 vs intramuscular IFN-β-1a (p < 0.001). Ocrelizumab also reduced the number of new or enlarging T2 lesions appearing between weeks 4 and 8 vs both placebo and IFN-β-1a (both p < 0.001). In patients with RMS, ocrelizumab significantly reduced ARR (p = 0.005) and the probability of time to first protocol-defined relapse (p = 0.014) vs subcutaneous IFN-β-1a within the first 8 weeks.

Conclusion

Epoch analysis of MRI-measured lesion activity in the phase II study and relapse rate in the phase III studies consistently revealed a rapid suppression of acute MRI and clinical disease activity following treatment initiation with ocrelizumab in patients with RRMS and RMS, respectively.

Classification of evidence

This study provides Class II evidence that for patients with RRMS and RMS, ocrelizumab suppressed MRI activity within 4 weeks and clinical disease activity within 8 weeks.

A randomized, subject and rater-blinded, placebo-controlled trial of dimethyl fumarate for obstructive sleep apnea

Study Objectives

To investigate the therapeutic effect of dimethyl fumarate (DMF, an immunomodulatory agent) on obstructive sleep apnea (OSA), and potential influence of any such effect by selected proinflammatory molecules.

Methods

Patients with OSA who deferred positive airway pressure therapy were randomized (2:1) to receive DMF or placebo for 4 months. Participants underwent polysomnography before randomization and at 4 months. Blood was collected monthly. The primary outcome was the mean group change in respiratory disturbance index (δ-RDI). Secondary analyses focused on the association between treatment effect of DMF (on RDI) and expression of plasma cytokines and chemokines, or nuclear factor κ-B (NFκB) signaling molecules in peripheral blood mononuclear cells.

Results

N = 65 participants were randomized. N = 50 participants (DMF = 35, placebo = 15) had complete data for final analyses. The mean difference in δ-RDI between groups was 13.3 respiratory events/hour of sleep: -3.1+/-12.9 vs. 10.2+/-13.1 in DMF and placebo groups, respectively (mixed-effects model treatment effect: β = -0.14, SE = 0.062, p = 0.033). Plasma levels of TNF-α showed only nonsignificant decreases, and IL-10 and IL-13 only nonsignificant increases, in DMF-treated participants compared with placebo. No significant interaction or main effect on RDI for selected cytokines and chemokines was found. Participants with a therapeutic response to DMF did experience significant reductions in intracellular NFκB signaling molecules at 4 months. Overall, DMF was well-tolerated.

Conclusions

The immunomodulatory drug DMF partially ameliorates OSA severity. Suppression of systemic inflammation through reduction of NFκB signaling may mediate this effect.

Clinical Trials

ClinicalTrials.gov, NCT02438137, https://clinicaltrials.gov/ct2/show/NCT02438137?term=NCT02438137&rank=1.

A randomized placebo-controlled trial of delayed-release dimethyl fumarate in patients with relapsing-remitting multiple sclerosis from East Asia and other countries

Background

Delayed-release dimethyl fumarate (DMF) has demonstrated efficacy and a favorable benefit-risk profile in phase 2 and 3 studies that enrolled predominantly white patients with relapsing-remitting multiple sclerosis (RRMS). In this study (APEX, Part I), we evaluated the efficacy/safety outcomes of DMF in a predominantly East Asian population of patients with RRMS.

Methods

In this 24-week, randomized, double-blind, placebo-controlled phase 3 study, 225 patients, 142 of which were East Asian (63.4%), were enrolled: Japan (n = 114), South Korea (n = 20), Taiwan (n = 8), the Czech Republic (n = 42), and Poland (n = 40). Key exclusion criteria included diagnosis of neuromyelitis optica spectrum disorder. Stratified by country, patients were randomized 1:1 to receive DMF 240 mg twice daily or placebo. Clinical assessments, including neurological examination and EDSS scoring, were conducted at baseline and at weeks 12 and 24.

Results

A total of 213 patients (95.1%) completed the study. From weeks 12 – 24, the total number of new gadolinium-enhancing (Gd⁺) lesions was reduced by 84% (p < 0.0001) in DMF compared with placebo. For the secondary endpoint, from baseline to week 24, the total number of new Gd⁺ lesions was reduced by 75% and the mean number of new/newly enlarging T2 hyperintense lesions was reduced by 63% (both p < 0.0001). Flushing and flushing-related symptoms, and gastrointestinal events were adverse events related to DMF treatment. Efficacy and safety results in the Japanese subgroup and the East Asian subgroup (which included patients from Japan, Taiwan, and South Korea) were consistent with the overall study population.

Conclusion

The strong efficacy and favorable benefit-risk profile of DMF extends to Japanese, and more broadly, East Asian patients with RRMS.

Trial registration

This trial is registered on ClinicalTrials.gov (identifier: NCT01838668), April 20, 2013 (retrospectively registered). The registration can be found at the following URL: https://clinicaltrials.gov/ct2/show/NCT01838668

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1220-3) contains supplementary material, which is available to authorized users.

Clinical evaluation of dimethyl fumarate for the treatment of relapsing-remitting multiple sclerosis: efficacy, safety, patient experience and adherence

Dimethyl fumarate (DMF) is an oral disease-modifying therapy approved for management of relapsing-remitting multiple sclerosis patients. Results from phase 3 clinical trials (DEFINE, CONFIRM) and follow-up study (ENDORSE) have provided good evidence for its efficacy and safety profile. Patient-reported outcomes (PROs) assessment revealed stabilization or boost in health-related quality of life and work productivity of patients treated with DMF compared to placebo reflecting a higher patient satisfaction to therapy. Being an oral agent with relatively favorable risk versus benefit profile DMF is commonly prescribed first-line agent. However, literature suggests that intolerance to side effects, especially gastrointestinal adverse effects and flushing is one of the major causes to compromised therapeutic compliance. An increase in the real-world incidence of progressive multifocal leukoencephalopathy and liver abnormality cases is also concerning. Several prevention and mitigation strategies like patient counseling, dose up-titration, pretreatment with aspirin, use of symptomatic therapy and frequent blood monitoring have demonstrated to be effective in tackling these adverse effects and promoting adherence to DMF. In this article, we review the efficacy, safety, PROs and patient adhere data, along with various measures to manage adverse events and promote compliance.

Safety and Efficacy of Dimethyl Fumarate in Multiple Sclerosis: An Italian, Multicenter, Real-World Study

BACKGROUND

Two phase III trials have demonstrated the clinical and radiological efficacy of delayed-release dimethyl fumarate (DMF) in relapsing-remitting multiple sclerosis (RRMS). However, data on its safety and effectiveness in real-world practice are still limited.

OBJECTIVES

The aim of our study was to explore the safety and tolerability profile of DMF in RRMS. We also tried to identify individual variables associated with better clinical and radiological outcomes.

METHODS

We collected the clinical and magnetic resonance imaging (MRI) data of patients with RRMS who started DMF between 2012 and 2017 in seven MS clinics in central Italy. We first evaluated DMF discontinuation rates and the incidence of adverse events and side effects. We then assessed the annualized relapse rate (ARR), the number of patients with clinical relapses or disability worsening and the presence of radiological activity. Third, we investigated which baseline variables were associated with clinical and radiological outcomes.

RESULTS

We collected data for 1089 patients with a mean on-treatment follow-up of 17 ± 8 months; 331 (30.4%) of these patients were treatment naïve. In total, 210 (19.5%) patients discontinued DMF mainly because of poor tolerability (n = 103) and disease activity (n = 63), and 166 (16.5%) patients presented with lymphopenia. The ARR reduced from 0.55 to 0.13. Mean change in Expanded Disability Status Scale (EDSS) score was 0.08 ± 0.44 per year. The occurrence of clinical and/or radiological activity during follow-up was associated with younger age [hazard ratio (HR) 0.97; p < 0.001], higher EDSS score (HR 1.18; p < 0.001), greater number of Gd-enhancing lesions at baseline scan (HR 1.14; p = 0.003) and prior exposure to MS treatments (HR 1.43; p = 0.02).

CONCLUSION

This post-marketing data confirms the short-term safety, tolerability and effectiveness of DMF, supporting its use as an early treatment in MS.

Multiple Immune-Inflammatory and Oxidative and Nitrosative Stress Pathways Explain the Frequent Presence of Depression in Multiple Sclerosis

Patients with a diagnosis of multiple sclerosis (MS) or major depressive disorder (MDD) share a wide array of biological abnormalities which are increasingly considered to play a contributory role in the pathogenesis and pathophysiology of both illnesses. Shared abnormalities include peripheral inflammation, neuroinflammation, chronic oxidative and nitrosative stress, mitochondrial dysfunction, gut dysbiosis, increased intestinal barrier permeability with bacterial translocation into the systemic circulation, neuroendocrine abnormalities and microglial pathology. Patients with MS and MDD also display a wide range of neuroimaging abnormalities and patients with MS who display symptoms of depression present with different neuroimaging profiles compared with MS patients who are depression-free. The precise details of such pathology are markedly different however. The recruitment of activated encephalitogenic Th17 T cells and subsequent bidirectional interaction leading to classically activated microglia is now considered to lie at the core of MS-specific pathology. The presence of activated microglia is common to both illnesses although the pattern of such action throughout the brain appears to be different. Upregulation of miRNAs also appears to be involved in microglial neurotoxicity and indeed T cell pathology in MS but does not appear to play a major role in MDD. It is suggested that the antidepressant lofepramine, and in particular its active metabolite desipramine, may be beneficial not only for depressive symptomatology but also for the neurological symptoms of MS. One clinical trial has been carried out thus far with, in particular, promising MRI findings.

Nitro-fatty acids: New drug candidates for chronic inflammatory and fibrotic diseases

Nitrated oleic acid (NO₂-OA) was first identified in 2003, and after the characterization of its formation and thiol reactivity, it was used as a prototypical molecule to investigate the physiological actions of endogenous nitrated fatty acids (NO₂-FA). Based on in vitro observations showing significant activation of cytoprotective and anti-inflammatory signaling responses by NO₂-FA, experiments were designed to determine their pharmacological potential. Supported by strong intellectual protection and favorable pharmacokinetic and pharmacodynamic data, 10-NO₂-OA (CXA-10) underwent pharmaceutical development as a drug to treat fibrotic and inflammatory diseases. NO₂-FA are at the intersection of three unconventional drug candidate classes that include 1) fatty acids, 2) metabolic intermediates and 3) electrophilic molecules. These three groups use different scaffolds for drug development, are characterized by broad activities and are individually gaining traction as alternatives to mono-target drug therapies. In particular, NO₂-FA share key characteristics with currently approved pharmacological agents regarding reactivity, distribution, and mechanism of action. This review first presents the characteristics, liabilities, and opportunities that these different drug candidate classes display, and then discusses these issues in the context of current progress in the preclinical and clinical development of NO₂-FA as drugs. Lessons learned from the novel approaches presented herein were considered early on during development to structurally define and improve NO₂-FA and their disease targets.

Multiple Sclerosis: Epidemiologic, Clinical, and Therapeutic Aspects

Multiple sclerosis (MS) is a chronic autoimmune and degenerative disease of the central nervous system that affects young people. MS develops in genetically susceptible individuals exposed to different unknown triggering factors. Different phenotypes are described. About 15% of patients present with a primary progressive course and 85% with a relapsing-remitting course. An increasing number of disease-modifying treatments has emerged. Although encouraging, the number of drugs challenges the neurologist because each treatment has its own risk-benefit profile. Patients should be involved in the decision-making process to ensure good treatment and safety monitoring adherence.

Clinical outcomes in patients with relapsing-remitting multiple sclerosis who switch from natalizumab to delayed-release dimethyl fumarate: A multicenter retrospective observational study (STRATEGY)

BACKGROUND

Delayed-release dimethyl fumarate (DMF) may be a therapeutic option for patients with relapsing-remitting multiple sclerosis (RRMS) who are treated with natalizumab and require a change in therapy. However, there is limited information regarding predictors of favorable treatment outcomes in patients switching from natalizumab to DMF. Clinical practices and sequencing protocols vary. Herein, we present the clinical results, including annualized relapse rate (ARR) and risk of relapse, of a phase 4 retrospective observational study of patients with RRMS who switched from natalizumab to DMF in a community practice setting (STRATEGY).

METHODS

STRATEGY was performed through a single time point medical record abstraction; no study visits or procedures were required. Key inclusion criteria included age ≥ 18 years, RRMS diagnosis (McDonald criteria, 2010 revised), ≥ 12 months of continuous treatment with natalizumab monotherapy before DMF initiation, and initiation of DMF ≥ 12 months before enrollment. Patients were eligible to enroll regardless of current DMF use.

RESULTS

A total of 530 patients at 45 US sites enrolled, and 506 met the inclusion criteria and were included in the modified evaluable population for analysis. Mean (SD) age at DMF initiation was 47.0 (10.9) years, with a mean (SD) of 12.7 (7.2) years since MS diagnosis. The mean (SD) duration of natalizumab treatment was 3.4 (1.9) years, and the mean (SD) washout from natalizumab discontinuation to DMF initiation (n = 502) was 101.6 (164.0) days. Overall risk of relapse 12 months after DMF initiation was 19.6%. Overall unadjusted ARR was higher during the 12 months following initiation of DMF treatment compared with the 12 months following initiation of natalizumab treatment (rate ratio, 2.32 [95% CI, 1.69-3.18]; p < 0.0001), but was lower compared with that observed in the year before initiation of natalizumab (rate ratio, 0.51 [95% CI, 0.40-0.64]; p < 0.0001). At 1 year following initiation of DMF treatment, the relapse rate was lower for patients who did not experience a relapse during 1 year following initiation of natalizumab treatment than for those who did (rate ratio for relapse rate, 0.47 [95% CI, 0.16-1.38]; p = 0.1664). The relapse rate for patients who did not relapse during natalizumab treatment was significantly lower with a washout period of ≤ 90 days as compared with a washout period of > 90 days (rate ratio for relapse rate, 0.49 [95% CI, 0.26-0.90]; p = 0.0216). A total of 42 (8%) patients reported ≥ 1 adverse event leading to DMF discontinuation during the study; the most commonly reported events were gastrointestinal disorders (n = 21; 4%).

CONCLUSIONS

Results from this multicenter retrospective observational study suggest that DMF may be an effective treatment option for patients who discontinue natalizumab in routine clinical practice. ARR was lower in patients who initiated DMF within 90 days of natalizumab discontinuation compared with patients who initiated DMF after 90 days of natalizumab discontinuation.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier NCT02159573.

Efficacy and Tolerability of Delayed-release Dimethyl Fumarate in Black, Hispanic, and Asian Patients with Relapsing-Remitting Multiple Sclerosis: Post Hoc Integrated Analysis of DEFINE and CONFIRM

Introduction

Clinical course and treatment response may vary according to race/ethnicity in multiple sclerosis (MS) patients. Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) demonstrated significant efficacy and a favorable benefit–risk profile in relapsing-remitting MS (RRMS) patients in the 2-year phase III DEFINE/CONFIRM studies.

Methods

In this post hoc analysis of integrated data from DEFINE/CONFIRM, we assessed clinical efficacy and safety/tolerability in black, Hispanic, and Asian patients treated with DMF 240 mg twice daily (approved dosage) or placebo. Eligible patients were 18–55 years of age with an Expanded Disability Status Scale score of 0–5.0. In the integrated intention-to-treat population, 769 and 771 patients were treated with DMF or placebo, respectively, of whom 10 and 19 were black, 31 and 23 were Hispanic, and 66 and 70 were Asian.

Results

In the black, Hispanic, and Asian subgroups, DMF was associated with lower annualized relapse rates at 2 years compared with placebo [rate ratio (95% confidence interval (CI)), 0.05 (0.00–1.07); 0.31 (0.10–0.95); and 0.64 (0.30–1.34), respectively]. The percentage of black, Hispanic, and Asian patients with 12-week confirmed disability progression was lower with DMF (43%, 8%, and 20%, respectively) compared with placebo [57%, 30%, and 25%, respectively; hazard ratio (95% CI), 0.53 (0.02–1.39); 0.17 (0.00–0.60); and 0.71 (0.32–1.58), respectively]. The safety/tolerability profile of DMF was generally consistent with that in the overall population of DEFINE/CONFIRM. The incidence of adverse events leading to treatment discontinuation in black, Hispanic, and Asian patients was 2/10, 2/31, and 3/66, respectively, with DMF, and 2/19, 1/23, and 8/70, respectively, with placebo.

Conclusion

DMF may be an efficacious treatment with a favorable benefit–risk profile in black, Hispanic, and Asian patients with RRMS. Further clinical studies are needed to characterize differences in MS presentation and treatment outcomes across ethnic and racial groups.

Funding

Biogen.

Trial Registration

DEFINE: ClinicalTrials.gov identifier NCT00420212; CONFIRM ClinicalTrials.gov identifier NCT00451451.

Treatment response to dimethyl fumarate is characterized by disproportionate CD8+ T cell reduction in MS

BACKGROUND

The effect of dimethyl fumarate (DMF) on circulating lymphocyte subsets and their contribution as predictors of clinical efficacy have not yet been investigated in multiple sclerosis (MS).

OBJECTIVE

To evaluate lymphocytes and lymphocyte subsets (analyzed 6 months after DMF start) in MS patients with and without disease activity after 1 year of treatment in a retrospective study.

METHODS

Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Untreated MS patients ( n = 40) were compared to those 6 months after onset of DMF treatment ( n = 51). Clinical and magnetic resonance imaging (MRI) disease activity of DMF-treated patients were assessed in the first year under treatment.

RESULTS

Stable patients showed significantly lower lymphocytes, CD4+ and CD8+ T cells as well as CD19+ B cells compared to active patients under DMF treatment. Furthermore, an increased CD4/CD8 ratio ( p < 0.025) in stable patients indicated a disproportionate reduction of CD8+ T cells relative to CD4+ T cells. Reduced lymphocytes, CD8+ T cells, and CD19+ B cells 6 months after DMF start allowed prediction of the treatment response in the first year.

CONCLUSION

DMF treatment response is reflected by lower circulating lymphocytes and specific lymphocyte subsets. Changes in the cellular immune profiles under DMF treatment are clinically relevant and might serve as a surrogate marker of treatment response.

Dimethyl Fumarate and Monomethyl Fumarate Promote Post-Ischemic Recovery in Mice

Oxidative stress plays an important role in cerebral ischemia-reperfusion injury. Dimethyl fumarate (DMF) and its primary metabolite monomethyl fumarate (MMF) are antioxidant agents that can activate the nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway and induce the expression of antioxidant proteins. Here, we evaluated the impact of DMF and MMF on ischemia-induced brain injury and whether the Nrf2 pathway mediates the effects provided by DMF and MMF in cerebral ischemia-reperfusion injury. Using a mouse model of transient focal brain ischemia, we show that DMF and MMF significantly reduce neurological deficits, infarct volume, brain edema, and cell death. Further, DMF and MMF suppress glial activation following brain ischemia. Importantly, the protection of DMF and MMF was mostly evident during the subacute stage and was abolished in Nrf2-/- mice, indicating that the Nrf2 pathway is required for the beneficial effects of DMF and MMF. Together, our data indicate that DMF and MMF have therapeutic potential in cerebral ischemia-reperfusion injury and their protective role is likely mediated by the Nrf2 pathway.

Nrf2 signaling pathway: Pivotal roles in inflammation

Inflammation is the most common feature of many chronic diseases and complications, while playing critical roles in carcinogenesis. Several studies have demonstrated that Nrf2 contributes to the anti-inflammatory process by orchestrating the recruitment of inflammatory cells and regulating gene expression through the antioxidant response element (ARE). The Keap1 (Kelch-like ECH-associated protein)/Nrf2 (NF-E2 p45-related factor 2)/ARE signaling pathway mainly regulates anti-inflammatory gene expression and inhibits the progression of inflammation. Therefore, the identification of new Nrf2-dependent anti-inflammatory phytochemicals has become a key point in drug discovery. In this review, we discuss the members of the Keap1/Nrf2/ARE signal pathway and its downstream genes, the effects of this pathway on animal models of inflammatory diseases, and crosstalk with the NF-κB pathway. In addition we also discuss about the regulation of NLRP3 inflammasome by Nrf2. Besides this, we summarize the current scenario of the development of anti-inflammatory phytochemicals and others that mediate the Nrf2/ARE signaling pathway.

Fumarate modulates the immune/inflammatory response and rescues nerve cells and neurological function after stroke in rats

BACKGROUND

Dimethyl fumarate (DMF), working via its metabolite monomethylfumarate (MMF), acts as a potent antioxidant and immunomodulator in animal models of neurologic disease and in patients with multiple sclerosis. These properties and their translational potential led us to investigate whether DMF/MMF could also protect at-risk and/or dying neurons in models of ischemic stroke in vitro and in vivo. Although the antioxidant effects have been partially addressed, the benefits of DMF immunomodulation after ischemic stroke still need to be explored.

METHODS

In vitro neuronal culture with oxygen-glucose deprivation and rats with middle cerebral artery occlusion were subjected to DMF/MMF treatment. Live/dead cell counting and LDH assay, as well as behavioral deficits, plasma cytokine assay, western blots, real-time PCR (Q-PCR) and immunofluorescence staining, were used to evaluate the mechanisms and neurological outcomes.

RESULTS

We found that MMF significantly rescued cortical neurons from oxygen-glucose deprivation (OGD) in culture and suppressed pro-inflammatory cytokines produced by primary mixed neuron/glia cultures subjected to OGD. In rats, DMF treatment significantly decreased infarction volume by nearly 40 % and significantly improved neurobehavioral deficits after middle cerebral artery occlusion (MCAO). In the acute early phase (72 h after MCAO), DMF induced the expression of transcription factor Nrf2 and its downstream mediator HO-1, important for the protection of infarcted cells against oxidative stress. In addition to its antioxidant role, DMF also acted as a potent immunomodulator, reducing the infiltration of neutrophils and T cells and the number of activated microglia/macrophages in the infarct region by more than 50 % by 7-14 days after MCAO. Concomitantly, the levels of potentially harmful pro-inflammatory cytokines were greatly reduced in the plasma and brain and in OGD neuron/glia cultures.

CONCLUSIONS

We conclude that DMF is neuroprotective in experimental stroke because of its potent immunomodulatory and antioxidant effects and thus may be useful as a novel therapeutic agent to treat stroke in patients.

MRI utility in the detection of disease activity in clinically stable patients with multiple sclerosis: a retrospective analysis of a community based cohort

BACKGROUND

Since the application of MRI scanning to the diagnosis and treatment of multiple sclerosis, it has been recognized that only a small fraction of lesions seen on MRI scans produce recognizable symptoms or neurological findings. Because new lesions may occur without clinical detection, the recommendation has been made that MRI scanning be performed on a routine scheduled basis, usually yearly, even in patients who are clinically stable.

METHODS

A retrospective chart review study was conducted on MS patients who had MRI scans of the central nervous system between 2009 and 2012 at Providence Multiple Sclerosis Center. Inclusion criteria were patients with relapsing MS who had been treated with interferon beta or glatiramer acetate for 6 months or longer. Information on type, indication, and result of MRI and whether a change in disease modifying therapy occurred as a result of the scan was collected.

RESULTS

Of the 436 clinically stable patients who had routine MRI, 16.7 % of subjects had scans revealing new, enlarged or active lesions, yet in only 4.4 % patients was there a change in therapy based upon MRI results. Subjects who had MRI changes were found to be younger (50.15 vs 53.43, p = 0.02) but there was no significant difference in other demographic or clinical characteristics when compared with the subjects who did not have MRI changes. Thirty-six percent of patients with MRI changes did not change DMT due to patient request.

CONCLUSIONS

This study provides data on the likelihood of detecting MRI-documented disease activity, in patients demonstrating longer term sustained clinical stability while receiving DMTs. These results may materially assist in the decision whether or not to perform yearly MRI scanning of such patients. The potential clinical impact of the results of routine MRI scanning must be weighed against the consideration of considerable expense of frequent MRI scanning, and the yet unknown adverse impact of retained gadolinium in patients repeatedly receiving this contrast agent. The long-term clinical impact of not changing DMTs in patients in whom MRI changes were observed will be addressed in future studies of this cohort.

Dimethyl fumarate in multiple sclerosis: latest developments, evidence and place in therapy

Dimethyl fumarate (DMF) is one of the newer additions to the armamentarium of potent immunomodulators for the treatment of relapsing-remitting multiple sclerosis (RRMS). After more than 2 years of real-world experience and more than 190,000 patients currently treated with DMF worldwide, it is a good timepoint to review the experience gathered so far and to re-evaluate the potential of this first-line oral multiple sclerosis (MS) drug. Post-hoc analyses of clinical and magnetic resonance imaging (MRI) data, some comprising more than 6 years of drug exposure including patients from the clinical trials, and the overall notion in clinical practice widely confirm the good efficacy of DMF in RRMS. Despite an overall good safety profile, it became also clear that the necessary clinical vigilance while using DMF may not be neglected. So far, four reported cases of progressive multifocal leukoencephalopathy (PML), a towering shadow over many MS therapies, warrant proper attention in newly-updated risk management plans. This review recapitulates efficacy and safety aspects of DMF therapy in relation to reported data from the pivotal clinical trials. In addition, we summarize recent insights into DMF mechanisms of action drawn from the field of basic research which may have important implications for clinical practice.

Safety and Tolerability of Delayed-Release Dimethyl Fumarate Administered with Interferon Beta or Glatiramer Acetate in Relapsing-Remitting Multiple Sclerosis

BACKGROUND

Delayed-release dimethyl fumarate (DMF; also known as gastroresistant DMF) is indicated for relapsing multiple sclerosis (MS). The objective of this study was to explore the safety and tolerability of DMF when administered with interferon beta (IFNβ) or glatiramer acetate (GA).

METHODS

Patients with relapsing-remitting MS receiving established therapy with the same dose of IFNβ or GA for at least 12 months continued their prescribed therapy for 2 months (monotherapy period) and then received DMF 240 mg three times daily in addition to their prescribed MS therapy for 6 months (add-on therapy period). Safety and magnetic resonance imaging outcomes were monitored monthly.

RESULTS

During the add-on therapy period, in the DMF+IFNβ (n = 57) and DMF+GA (n = 47) groups, the overall incidence of adverse events was 95% and 100%, respectively; the most common adverse events were flushing, diarrhea, and abdominal pain. In both groups, mean lymphocyte counts decreased but remained within normal limits, and hepatic transaminase levels increased transiently; no case met Hy's law criteria. There was no overall increased risk of infection. In both groups, gadolinium-enhancing lesion activity and new/enlarging T2 lesions decreased compared with the monotherapy period (exploratory endpoints).

CONCLUSIONS

The safety profile of DMF taken with IFNβ or GA was acceptable and consistent with the known safety profile of DMF monotherapy.

Relapse frequency in transitioning from natalizumab to dimethyl fumarate: assessment of risk factors

Risk of relapse after natalizumab (NAT) cessation and switch to dimethyl fumarate (DMF) is unknown. The objective of this paper is to identify the risk and associated risk factors for relapse after switching from NAT to DMF in relapsing-remitting multiple sclerosis. Patients (n = 30) were treated with NAT for ≥12 months and then switched to DMF in a mean of 50 days. Patient age, annualized relapse rates (ARR), Expanded Disability Status Scale scores (EDSS), and lymphocyte counts were assessed. Overall, eight patients (27 %) had relapses after switching to DMF. Five patients (17 %) suffered severe relapses with multifocal clinical and radiological findings. New lesions by MRI (T2 hyperintense or enhancing) were observed in 35 % of patients. Relapses occurred at a mean of 3.5 months after NAT cessation. Patient age and elevated ARR prior to NAT use were significantly associated with risk of relapse after switch to DMF. Once on DMF for 4 months prior to relapse, lymphocyte count decreased more significantly in patients without relapses than those with relapses. Switching from NAT to DMF correlated with increased relapses. Young patient age, high ARR and stability of lymphocyte counts were risk factors for relapse after transition from NAT to DMF.

Onset of clinical and MRI efficacy occurs early after fingolimod treatment initiation in relapsing multiple sclerosis

To minimize the clinical burden associated with multiple sclerosis (MS), early control of focal and diffuse CNS disease activity is a treatment priority. A post hoc analysis was conducted to evaluate the onset of efficacy of fingolimod treatment in patients with relapsing MS. Data from patients who received fingolimod 0.5 mg or placebo during either of two 24-month, double-blind, randomized, parallel-group clinical trials (FREEDOMS and FREEDOMS II) were pooled for analysis. Efficacy outcomes were: time to first confirmed relapse; annualized relapse rate (ARR); proportions of patients free from T1 gadolinium-enhancing lesions or new/newly enlarged T2 lesions; percentage brain volume loss (BVL); and change in Multiple Sclerosis Functional Composite (MSFC) z-score from baseline to 6 months. An early benefit was seen with fingolimod (N = 783) vs. placebo (N = 773) for ARR at both 3 and 6 months (3 months, 0.32 vs. 0.52, p = 0.0015; 6 months, 0.21 vs. 0.45, p < 0.0001). Time to first relapse was also delayed with fingolimod vs. placebo from day 48 onwards. At 6 months, more patients in the fingolimod group than in the placebo group were free from new MRI activity (65.3 vs. 40.5%, p < 0.0001) and had less BVL (37.1% reduction vs. placebo, p < 0.001). MSFC z-score favored fingolimod over placebo at 6 months, with improvements noted in 9-Hole Peg Test and Paced Auditory Serial Addition Test scores. Improvements in outcomes related to relapses, MRI, disability, cognition, and BVL occurred within 6 months of treatment initiation with fingolimod.