Dimethyl fumarate (DMF) vs. monoethyl fumarate (MEF) salts for the treatment of plaque psoriasis: a review of clinical data

Nrf2 activation by hydroxytyrosol and dimethyl fumarate ameliorates skin tissue repair in high-fat diet-fed mice by promoting M2 macrophage polarization and normalizing inflammatory response and oxidative damage

Hydroxytyrosol (HT) or dimethyl fumarate (DMF), activators of nuclear factor erythroid 2-related factor 2 (Nrf2), may reduce obesity in high-fat diet (HFD)-fed animals; nevertheless, the role of these activators on skin tissue repair of HFD-fed animals was not reported. This study investigated whether HT or DMF could improve skin wound healing of HFD-fed obese animals. Mice were fed with an HFD, treated with HT or DMF, and full-thickness skin wounds were created. Macrophages isolated from control and obese animals were treated in vitro with HT. DMF, but not HT, reduced the body weight of HFD-fed mice. Collagen deposition and wound closure were improved by HT or DMF in HFD-fed animals. HT or DMF increased anti-inflammatory macrophage phenotype and protein Nrf2 levels in wounds of HFD-fed mice. Lipid peroxidation and protein tumor necrosis factor-α levels were reduced by HT or DMF in wounds of HFD-fed animals. In in vitro, HT stimulated Nrf2 activation in mouse macrophages isolated from obese animals. In conclusion, HT or DMF improves skin wound healing of HFD-fed mice by reducing oxidative damage and inflammatory response. HT or DMF may be used as a therapeutic strategy to improve the skin healing process in individuals with obesity.

Novel potential pharmacological applications of dimethyl fumarate-an overview and update

Dimethyl fumarate (DMF) is an FDA-approved drug for the treatment of psoriasis and multiple sclerosis. DMF is known to stabilize the transcription factor Nrf2, which in turn induces the expression of antioxidant response element genes. It has also been shown that DMF influences autophagy and participates in the transcriptional control of inflammatory factors by inhibiting NF-κB and its downstream targets. DMF is receiving increasing attention for its potential to be repurposed for several diseases. This versatile molecule is indeed able to exert beneficial effects on different medical conditions through a pleiotropic mechanism, in virtue of its antioxidant, immunomodulatory, neuroprotective, anti-inflammatory, and anti-proliferative effects. A growing number of preclinical and clinical studies show that DMF may have important therapeutic implications for chronic diseases, such as cardiovascular and respiratory pathologies, cancer, eye disorders, neurodegenerative conditions, and systemic or organ specific inflammatory and immune-mediated diseases. This comprehensive review summarizes and highlights the plethora of DMF's beneficial effects and underlines its repurposing opportunities in a variety of clinical conditions.

Dimethyl Fumarate as Potential Treatment for Alzheimer's Disease: Rationale and Clinical Trial Design

Alzheimer's Disease (AD) is a debilitating disease that leads to severe cognitive impairment and functional decline. The role of tau hyperphosphorylation and amyloid plaque deposition in the pathophysiology of AD has been well described; however, neuroinflammation and oxidative stress related to sustained microglial activation is thought to play a significant role in the disease process as well. NRF-2 has been identified in modulating the effects of inflammation and oxidative stress in AD. Activation of NRF-2 leads to an increased production of antioxidant enzymes, including heme oxygenase, which has been shown to have protective effects in neurodegenerative disorders such as AD. Dimethyl fumarate and diroximel fumarate (DMF) have been approved for the use in relapsing-remitting multiple sclerosis. Research indicates that they can modulate the effects of neuroinflammation and oxidative stress through the NRF-2 pathway, and as such, could serve as a potential therapeutic option in AD. We propose a clinical trial design that could be used to assess DMF as a treatment option for AD.

MMF induces antioxidative and anaplerotic pathways and is neuroprotective in hyperexcitability in vitro

Hyperexcitability-induced neuronal damage plays a role both in epilepsy as well as in inflammatory brain diseases such as multiple sclerosis (MS) and as such represents an important disease pathway which potentially can be targeted to mitigate neuronal damage. Dimethyl fumarate (DMF) and its pharmacologically active metabolite monomethyl fumarate (MMF) are FDA-approved therapeutics for MS, which can induce immunosuppressive and antioxidant pathways, and their neuroprotective capacity has been demonstrated in other preclinical neurological disease models before. In this study, we used an unbiased proteomic approach to identify potential new targets upon the treatment of MMF in glio-neuronal hippocampal cultures. MMF treatment results in induction of antioxidative (HMOX1, NQO1) and anaplerotic metabolic (GAPDH, PC) pathways, which correlated with reduction in ROS production, increased mitochondrial NADH-redox index and decreased NADH pool, independent of glutathione levels. Additionally, MMF reduced glycolytic capacity indicating individual intra-cellular metabolic programs within different cell types. Furthermore, we demonstrate a neuroprotective effect of MMF upon hyperexcitability in vitro (low magnesium model), where MMF prevents glio-neuronal death via reduced ROS production. These results highlight MMF as a potential new therapeutic opportunity in hyperexcitability-induced neurodegeneration.

The Challenge of Dimethyl Fumarate Repurposing in Eye Pathologies

Dimethyl fumarate (DMF) is a small molecule currently approved and used in the treatment of psoriasis and multiple sclerosis due to its immuno-modulatory, anti-inflammatory, and antioxidant properties. As an Nrf2 activator through Keap1 protein inhibition, DMF unveils a potential therapeutical use that is much broader than expected so far. In this comprehensive review we discuss the state-of-art and future perspectives regarding the potential repositioning of this molecule in the panorama of eye pathologies, including Age-related Macular Degeneration (AMD). The DMF's mechanism of action, an extensive analysis of the in vitro and in vivo evidence of its beneficial effects, together with a search of the current clinical trials, are here reported. Altogether, this evidence gives an overview of the new potential applications of this molecule in the context of ophthalmological diseases characterized by inflammation and oxidative stress, with a special focus on AMD, for which our gene-disease (KEAP1-AMD) database search, followed by a protein-protein interaction analysis, further supports the rationale of DMF use. The necessity to find a topical route of DMF administration to the eye is also discussed. In conclusion, the challenge of DMF repurposing in eye pathologies is feasible and worth scientific attention and well-focused research efforts.

New and Old Horizons for an Ancient Drug: Pharmacokinetics, Pharmacodynamics, and Clinical Perspectives of Dimethyl Fumarate

(1) Background: In their 60-year history, dimethyl fumarate and other salts of fumaric acid have been used for the treatment of psoriasis and other immune-mediated diseases for their immune-modulating properties. Over the years, new mechanisms of action have been discovered for this evergreen drug that remains a first-line treatment for several different inflammatory diseases. Due to its pleiotropic effects, this molecule is still of great interest in varied conditions, not exclusively inflammatory diseases. (2) Methods: The PubMed database was searched using combinations of the following keywords: dimethyl fumarate, pharmacokinetics, pharmacodynamics, adverse effects, psoriasis, multiple sclerosis, and clinical indications. This article reviews and updates the pharmacokinetics, mechanisms of action, and clinical indications of dimethyl fumarate. (3) Conclusions: The pharmacology of dimethyl fumarate is complex, fascinating, and not fully known. Progressive insights into the molecule's mechanisms of action will make it possible to maximize its clinical efficacy, reduce concerns about adverse effects, and find other possible areas of application.

Advances in the modulation of ROS and transdermal administration for anti-psoriatic nanotherapies

Reactive oxygen species (ROS) at supraphysiological concentration have a determinate role in contributing to immuno-metabolic disorders in the epithelial immune microenvironment (EIME) of psoriatic lesions. With an exclusive focus on the gene-oxidative stress environment interaction in the EIME, a comprehensive strategy based on ROS-regulating nanomedicines is greatly anticipated to become the mainstay of anti-psoriasis treatment. This potential therapeutic modality could inhibit the acceleration of psoriasis via remodeling the redox equilibrium and reshaping the EIME. Herein, we present a marked overview of the current progress in the pathomechanisms of psoriasis, with particular concerns on the potential pathogenic role of ROS, which significantly dysregulates redox metabolism of keratinocytes (KCs) and skin-resident or -infiltrating cells. Meanwhile, the emergence of versatile nanomaterial-guided evolution for transdermal drug delivery has been attractive for the percutaneous administration of antipsoriatic therapies in recent years. We emphasize the underlying molecular mechanism of ROS-based nanoreactors for improved therapeutic outcomes against psoriasis and summarize up-to-date progress relating to the advantages and limitations of nanotherapeutic application for transdermal administration, as well as update an insight into potential future directions for nanotherapies in ROS-related skin diseases.

Long-Term Treatment with Dimethyl Fumarate for Plaque Psoriasis in Routine Practice: Good Overall Effectiveness and Positive Effect on Impactful Areas

INTRODUCTION

Dimethyl fumarate (DMF) is an oral compound to treat plaque psoriasis. Data on the treatment of patients with psoriasis affecting impactful areas are scarce. In this interim analysis of the prospective, noninterventional SKILL study, we summarized results of DMF treatment regarding effectiveness (overall and in impactful areas) and safety.

METHODS

Data from 676 patients suffering from moderate-to-severe plaque psoriasis were analyzed after 52 weeks of DMF treatment. Of these, 257 had data available after 52 weeks. The considered impactful areas were nails, palms, soles, and scalp. Data analysis included observed cases (OC) and last observation carried forward (LOCF).

RESULTS

All effectiveness parameters improved after 52 weeks. The Psoriasis Area and Severity Index score was reduced by 79.5% (OC) and 65.7% (LOCF). Compared with baseline, improvements were shown for 70.2% of the patients in their nail psoriasis [nail-Physician Global Assessment (PGA)] and for 57.3% in palmoplantar disease (palmoplantar-PGA). The proportion of patients with scalp-PGA 0/1 (clear/almost clear) increased significantly to 79.8% (OC) and 69.3% (LOCF, both p < 0.001) (versus 37.5% and 36.6% at baseline, respectively). Significant reduction of pruritus (p < 0.001) was also observed. No unexpected adverse drug reactions were observed.

CONCLUSION

Long-term treatment with DMF in routine practice showed good overall effectiveness and safety, and a positive effect on plaque-psoriasis-affected impactful areas.

Repurposing Dimethyl Fumarate for Cardiovascular Diseases: Pharmacological Effects, Molecular Mechanisms, and Therapeutic Promise

Dimethyl fumarate (DMF) is a small molecule that has been shown to assert potent in vivo immunoregulatory and anti-inflammatory therapeutic actions. The drug has been approved and is currently in use for treating multiple sclerosis and psoriasis in the USA and Europe. Since inflammatory reactions have been significantly implicated in the etiology and progression of diverse disease states, the pharmacological actions of DMF are presently being explored and generalized to other diseases where inflammation needs to be suppressed and immunoregulation is desirable, either as a monotherapeutic agent or as an adjuvant. In this review, we focus on DMF, and present an overview of its mechanism of action while briefly discussing its pharmacokinetic profile. We further discuss in detail its pharmacological uses and highlight its potential applications in the treatment of cardiovascular diseases. DMF, with its unique combination of anti-inflammatory and vasculoprotective effects, has the potential to be repurposed as a therapeutic agent in patients with atherosclerotic cardiovascular disease. The clinical studies mentioned in this review with respect to the beneficial effects of DMF in atherosclerosis involve observations in patients with multiple sclerosis and psoriasis in small cohorts and for short durations. The findings of these studies need to be assessed in larger prospective clinical trials, ideally with a double-blind randomized study design, investigating the effects on cardiovascular endpoints as well as morbidity and mortality. The long-term impact of DMF therapy on cardiovascular diseases also needs to be confirmed.

Bioactive potentials of endophyte (Fusarium redolens) isolated from Olea europaea

During past few decades, endophytes have gained importance due their ability to produce bioactive compounds. Many medicinal plants are being exploited for the endophytic isolation to obtain drugs of interest. This study explored the fungal endophytes of Olive (Olea europaea L.) stem from which Fusarium redolens was selected for investigation of bioactive potential. The endophyte was identified using morphological characteristics and internal transcribed spacer ribosomal-deoxyribonucleic acid (ITS-rDNA) sequence analysis. The GCMS analysis of the crude extract yielded chrysophanol and fumaric acid. The culture filtrate of ethyl acetate extract showed significant cytotoxic potential against HepG2 cells, respectively. Furthermore, the screening of antioxidant potential of the ethyl acetate fungal extract using DPPH scavenging assay showed that Fusarium redolens extract exhibited potential activity with a significant EC50 value of 144.7 µg/mL.

Emerging Therapeutic Applications for Fumarates

Fumarates are successfully used for the treatment of psoriasis and multiple sclerosis. Their antioxidative, immunomodulatory, and neuroprotective properties make fumarates attractive therapeutic candidates for other pathologies. The exact working mechanisms of fumarates are, however, not fully understood. Further elucidation of the mechanisms is required if these drugs are to be successfully repurposed for other diseases. Towards this, administration route, dosage, and treatment timing, frequency, and duration are important parameters to consider and optimize with clinical paradigms in mind. Here, we summarize the rapidly expanding literature on the pharmacokinetics and pharmacodynamics of fumarates, including a discussion on two recently FDA-approved fumarates VumerityTM and BafiertamTM. We review emerging applications of fumarates, focusing on neurological and cardiovascular diseases.

Calming the (Cytokine) Storm: Dimethyl Fumarate as a Therapeutic Candidate for COVID-19

COVID-19 has rapidly spread worldwide and incidences of hospitalisation from respiratory distress are significant. While a vaccine is in the pipeline, there is urgency for therapeutic options to address the immune dysregulation, hyperinflammation and oxidative stress that can lead to death. Given the shared pathogenesis of severe cases of COVID-19 with aspects of multiple sclerosis and psoriasis, we propose dimethyl fumarate as a viable treatment option. Currently approved for multiple sclerosis and psoriasis, dimethyl fumarate is an immunomodulatory, anti-inflammatory and anti-oxidative drug that could be rapidly implemented into the clinic to calm the cytokine storm which drives severe COVID-19.

Efficacy and safety of fumaric acid esters in young patients aged 10-17 years with moderate-to-severe plaque psoriasis: a randomized, double-blinded, placebo-controlled trial

BACKGROUND

Apart from biologics, no systemic drugs are approved in Europe for children with moderate-to-severe psoriasis. Retrospective observational studies have shown promising results for fumaric acid esters (FAE) in this setting.

OBJECTIVES

To show superiority of FAE over placebo in terms of treatment response after 20 weeks in children and adolescents aged 10-17 years.

METHODS

In a multicentre, randomized, double-blind, placebo-controlled phase IIIb study, patients aged 10-17 years with moderate-to-severe plaque psoriasis requiring systemic therapy were randomized 2 : 1 to receive FAE (n = 91) or placebo (n = 43) over 20 weeks, followed by an open-label FAE treatment phase. The coprimary endpoints were ≥ 75% improvement in Psoriasis Area and Severity Index (PASI 75) and Physician's Global Assessment (PGA) score of 0 or 1 (clear or almost clear) at week 20. The study was registered with EudraCT number 2012-000035-82.

RESULTS

At week 20, 55% [95% confidence interval (CI) 0·44-0·65] of FAE-treated patients achieved a PASI 75 response vs. 19% (95% CI 0·08-0·33) in the placebo group (absolute difference 36%, 95% CI 0·20-0·53; P < 0·001). In total, 42% (95% CI 0·32-0·53) in the FAE group vs. 7% (95% CI 0·01-0·19) in the placebo group achieved a PGA score of 0 or 1 at week 20 (absolute difference 35%, 95% CI 0·21-0·49; P < 0·001). During the double-blind period, drug-related adverse events occurred more frequently in patients receiving FAE compared with placebo (76% vs. 47%). Gastrointestinal disorders were the most common adverse events.

CONCLUSIONS

FAE administered over a period of 20 weeks demonstrated a better response than placebo; the difference was statistically significant and clinically meaningful. Application up to 40 weeks was generally well tolerated. However, further studies are required.

Dimethyl Fumarate and Its Esters: A Drug with Broad Clinical Utility?

Fumaric acid esters (FAEs) are small molecules with anti-oxidative, anti-inflammatory and immune-modulating effects. Dimethyl fumarate (DMF) is the best characterised FAE and is approved and registered for the treatment of psoriasis and Relapsing-Remitting Multiple Sclerosis (RRMS). Psoriasis and RRMS share an immune-mediated aetiology, driven by severe inflammation and oxidative stress. DMF, as well as monomethyl fumarate and diroximel fumarate, are commonly prescribed first-line agents with favourable safety and efficacy profiles. The potential benefits of FAEs against other diseases that appear pathogenically different but share the pathologies of oxidative stress and inflammation are currently investigated.

Exploring the Use of Dimethyl Fumarate as Microglia Modulator for Neurodegenerative Diseases Treatment

The maintenance of redox homeostasis in the brain is critical for the prevention of the development of neurodegenerative diseases. Drugs acting on brain redox balance can be promising for the treatment of neurodegeneration. For more than four decades, dimethyl fumarate (DMF) and other derivatives of fumaric acid ester compounds have been shown to mitigate a number of pathological mechanisms associated with psoriasis and relapsing forms of multiple sclerosis (MS). Recently, DMF has been shown to exert a neuroprotective effect on the central nervous system (CNS), possibly through the modulation of microglia detrimental actions, observed also in multiple brain injuries. In addition to the hypothesis that DMF is linked to the activation of NRF2 and NF-kB transcription factors, the neuroprotective action of DMF may be mediated by the activation of the glutathione (GSH) antioxidant pathway and the regulation of brain iron homeostasis. This review will focus on the role of DMF as an antioxidant modulator in microglia processes and on its mechanisms of action in the modulation of different pathways to attenuate neurodegenerative disease progression.

Diroximel fumarate in the treatment of multiple sclerosis

Diroximel fumarate (DRF) is a new emerging therapy for patients with multiple sclerosis. The levels of its active metabolite, monomethyl fumarate, are bioequivalent to the levels generated from dimethyl fumarate (DMF) treatment. The efficacy and safety profiles of DRF are expected to be similar to the well-established profiles of DMF. The metabolism of DRF leads to lower concentration of methanol in the small intestine than with DMF and thus reduced severity and frequency of gastrointestinal adverse events. DRF seems a promising alternative to DMF and other first-line therapies for multiple sclerosis. The current review is based on the two existing Phase III trials of DRF: the interim analysis of the EVOLVE-MS-1 trial and the completed EVOLVE-MS-2 trial.

[Management of plaque psoriasis in adults]

In Germany, approximately 2% of the population suffers from psoriasis, which is no longer considered only a cutaneous, but rather a systemic disease. Accordingly, common comorbidities and potential joint involvement in psoriasis must be recorded. If necessary, interdisciplinary patient care has to be organized. The use of validated scores is recommended to complete the patient's medical history. The individual treatment should include intensified topical therapies as well as short-term phototherapy in case of an acute phase. In addition to conventional systemic therapies (e.g., fumarates, methotrexate), a number of new therapeutics for psoriasis are in development. Apart from the PDE‑4 inhibitor apremilast, targeted therapies are currently available to block TNF-alpha, IL-17A, the IL-17 receptor and IL-23. Decisions on individualized, patient-centered psoriasis management should be based on assessment of disease severity and the existence of comorbidities. Furthermore, economic aspects should be taken into account.

Electrophiles Against (Skin) Diseases: More Than Nrf2

The skin represents an indispensable barrier between the organism and the environment and is the first line of defense against exogenous insults. The transcription factor NRF2 is a central regulator of cytoprotection and stress resistance. NRF2 is activated in response to oxidative stress by reactive oxygen species (ROS) and electrophiles. These electrophiles oxidize specific cysteine residues of the NRF2 inhibitor KEAP1, leading to KEAP1 inactivation and, subsequently, NRF2 activation. As oxidative stress is associated with inflammation, the NRF2 pathway plays important roles in the pathogenesis of common inflammatory diseases and cancer in many tissues and organs, including the skin. The electrophile and NRF2 activator dimethyl fumarate (DMF) is an established and efficient drug for patients suffering from the common inflammatory skin disease psoriasis and the neuro-inflammatory disease multiple sclerosis (MS). In this review, we discuss possible molecular mechanisms underlying the therapeutic activity of DMF and other NRF2 activators. Recent evidence suggests that electrophiles not only activate NRF2, but also target other inflammation-associated pathways including the transcription factor NF-κB and the multi-protein complexes termed inflammasomes. Inflammasomes are central regulators of inflammation and are involved in many inflammatory conditions. Most importantly, the NRF2 and inflammasome pathways are connected at different levels, mainly antagonistically.

Structural Study of Monomethyl Fumarate-Bound Human GAPDH

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a core enzyme of the aerobic glycolytic pathway with versatile functions and is associated with cancer development. Recently, Kornberg et al . published the detailed correlation between GAPDH and di- or monomethyl fumarate (DMF or MMF), which are well-known GAPDH antagonists in the immune system. As an extension, herein, we report the crystal structure of MMF-bound human GAPDH at 2.29 Å. The MMF molecule is covalently linked to the catalytic Cys152 of human GAPDH, and inhibits the catalytic activity of the residue and dramatically reduces the enzymatic activity of GAPDH. Structural comparisons between NAD+bound GAPDH and MMF-bound GAPDH revealed that the covalently linked MMF can block the binding of the NAD+ cosubstrate due to steric hindrance of the nicotinamide portion of the NAD+ molecule, illuminating the specific mechanism by which MMF inhibits GAPDH. Our data provide insights into GAPDH antagonist development for GAPDH-mediated disease treatment.

Role of dimethyl fumarate in the treatment of glioblastoma multiforme: A review article

Glioblastoma multiforme (GBM), the most frequent malignant and aggressive primary brain tumor, is characterized by genetically unstable heterogeneous cells, diffused growth pattern, microvascular proliferation, and resistance to chemotherapy. Extensive investigations are being carried out to identify the molecular origin of resistance to chemo- and radio-therapy in GBM and find novel targets for therapy to improve overall survival rate. Dimethyl fumarate (DMF) has been shown to be a safe drug with limited short and long-term side effects, and fumaric acid esters (FAEs), including DMF, present both anti-oxidative and anti-inflammatory activity in different cell types and tissues. DMF has also anti-tumoral and neuroprotective effects and so it could be repurposed in the treatment of this invasive tumor in the future. Here, we have reviewed DMF pharmacokinetics and different mechanisms by which DMF could have therapeutic effects on GBM.

Switch of psoriasis therapy from a fumaric acid ester mixture to dimethyl fumarate monotherapy: Results of a prospective study

BACKGROUND

Fumaric acid esters (FAEs) are used for systemic therapy of moderate to severe psoriasis. Until recently, only a mixture of dimethyl fumarate (DMF) and three salts of ethyl hydrogen fumarate was available. However, a drug containing DMF as the sole ingredient was registered for the same indication in 2017. This prospective study aimed to investigate the switch from the currently used FAE mixture to DMF alone.

PATIENTS AND METHODS

Forty patients were consecutively recruited, for whom the FAE mixture was switched to DMF alone on the basis of the last DMF-equivalent dose without interrupting treatment. At the first check-up after switching, the efficacy and tolerability of the DMF drug was compared with that of the previous treatment.

RESULTS

The data show that the efficacy remained unchanged in the majority of patients. Tolerability (e.g. gastrointestinal complaints and flushing) of the DMF drug was rated equal or better in most patients than with the previous treatment.

CONCLUSIONS

The results show that it is possible to switch psoriasis patients under stable therapy with the FAE mixture to the DMF drug directly and without interruption.