The Pharmacokinetics of Fumaric Acid Esters Reveal Their In Vivo Effects

Pharmacological modulation of inflammatory oligodendrocyte progenitor cells using three multiple sclerosis disease modifying therapies in vitro

Preclinical studies of pro-remyelinating therapies for multiple sclerosis tend to neglect the effect of the disease-relevant inflammatory milieu. Interferon-gamma (IFN-γ) is known to suppress oligodendrocyte progenitor cell (OPC) differentiation and induce a recently described immune OPC (iOPC) phenotype characterized by expression of major histocompatibility complex (MHC) molecules. We tested the effects of cladribine (CDB), dimethylfumarate (DMF), and interferon-beta (IFN-β), existing anti-inflammatory therapies for MS, on the IFN-γ-induced iOPC formation and OPC differentiation block. In line with previous reports, we demonstrate that IFN-β and DMF inhibit OPC proliferation, while CDB had no effect. None of the drugs exhibited cytotoxic effects at the physiological concentrations tested in vitro. In a differentiation assay, none of the drugs were able to promote differentiation, under inflammatory or basal conditions. To study drug effects on iOPCs, we monitored MHC expression in vitro with live cell imaging using cells isolated from MHC reporter mice. IFN-β suppressed induction of MHC class II, and DMF led to suppression of both class I and II. CDB had no effect on MHC induction. We conclude that promoting proliferation and differentiation and suppressing iOPC induction under inflammatory conditions may require separate therapeutic strategies and must be balanced for maximal repair. Our in vitro MHC screening assay can be leveraged across cell types to test the effects of drug candidates and disease-related stimuli.

Selective activation of cellular stress response pathways by fumaric acid esters

The cellular response to oxidants or xenobiotics comprises two key pathways, resulting in modulation of NRF2 and FOXO transcription factors, respectively. Both mount a cytoprotective response, and their activation relies on crucial protein thiol moieties. Using fumaric acid esters (FAEs), known thiol-reactive compounds, we tested for activation of NRF2 and FOXO pathways in cultured human hepatoma cells by dimethyl/diethyl as well as monomethyl/monoethyl fumarate. Whereas only the diesters caused acute glutathione depletion and activation of the stress kinase p38MAPK, all four FAEs stimulated NRF2 stabilization and upregulation of NRF2 target genes. However, no significant FAE-induced activation of FOXO-dependent target gene expression was observed. Therefore, while both NRF2 and FOXO pathways are responsive to oxidants and xenobiotics, FAEs selectively activate NRF2 signaling.

Review: A Contemporary, Multifaced Insight into Psoriasis Pathogenesis

Psoriasis is a chronic recurrent inflammatory autoimmune pathology with a significant genetic component and several interferences of immunological cells and their cytokines. The complex orchestration of psoriasis pathogenesis is related to the synergic effect of immune cells, polygenic alterations, autoantigens, and several other external factors. The major act of the IL-23/IL-17 axis, strongly influencing the inflammatory pattern established during the disease activity, is visible as a continuous perpetuation of the pro-inflammatory response and keratinocyte activation and proliferation, leading to the development of psoriatic lesions. Genome-wide association studies (GWASs) offer a better view of psoriasis pathogenic pathways, with approximately one-third of psoriasis's genetic impact on psoriasis development associated with the MHC region, with genetic loci located on chromosome 6. The most eloquent genetic factor of psoriasis, PSORS1, was identified in the MHC I site. Among the several factors involved in its complex etiology, dysbiosis, due to genetic or external stimulus, induces a burst of pro-inflammatory consequences; both the cutaneous and gut microbiome get involved in the psoriasis pathogenic process. Cutting-edge research studies and comprehensive insights into psoriasis pathogenesis, fostering novel genetic, epigenetic, and immunological factors, have generated a spectacular improvement over the past decades, securing the path toward a specific and targeted immunotherapeutic approach and delayed progression to inflammatory arthritis. This review aimed to offer insight into various domains that underline the pathogenesis of psoriasis and how they influence disease development and evolution. The pathogenesis mechanism of psoriasis is multifaceted and involves an interplay of cellular and humoral immunity, which affects susceptible microbiota and the genetic background. An in-depth understanding of the role of pathogenic factors forms the basis for developing novel and individualized therapeutic targets that can improve disease management.

Analysis of the contributing role of drug transport across biological barriers in the development and treatment of chemotherapy-induced peripheral neuropathy

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) represents a major unmet medical need that currently has no preventive and/or curative treatment. This is, among others, driven by a poor understanding of the contributive role of drug transport across biological barriers to target-site exposure.

METHODS

Here, we systematically investigated the transport of 11 small-molecule drugs, both, associated and not with CIPN development, at conventional (dorsal root ganglia, sciatic nerve) and non-conventional (brain, spinal cord, skeletal muscle) CIPN sites. We developed a Combinatory Mapping Approach for CIPN, CMA-CIPN, combining in vivo and in vitro elements.

RESULTS

Using CMA-CIPN, we determined the unbound tissue-to-plasma concentration ratio (Kp,uu) and the unbound intracellular-to-extracellular concentration ratio (Kp,uu,cell), to quantitatively assess the extent of unbound drug transport across endothelial interfaces and parenchymal cellular barriers of investigated CIPN-sites, respectively, in a rat model. The analysis revealed that unique pharmacokinetic characteristics underly time-dependent accumulation of the CIPN-positive drugs paclitaxel and vincristine at conventional (dorsal root ganglia and sciatic nerve) and non-conventional (skeletal muscle) CIPN sites. Investigated CIPN-positive drugs displayed intracellular accumulation contrary to CIPN-negative drugs nilotinib and methotrexate, which lacked this feature in all investigated tissues.

CONCLUSIONS

Hence, high unbound drug intracellular and extracellular exposure at target sites, driven by an interplay of drug transport across the endothelial and parenchymal cellular barriers, is a predisposing factor to CIPN development for CIPN-positive drugs. Critical drug-specific features of unbound drug disposition at various CIPN- sites provide invaluable insights into understanding the pharmacological/toxicological effects at the target-sites which will inform new strategies for monitoring and treatment of CIPN.

Oxidative Stress and the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) Pathway in Multiple Sclerosis: Focus on Certain Exogenous and Endogenous Nrf2 Activators and Therapeutic Plasma Exchange Modulation

The pathogenesis of multiple sclerosis (MS) suggests that, in genetically susceptible subjects, T lymphocytes undergo activation in the peripheral compartment, pass through the BBB, and cause damage in the CNS. They produce pro-inflammatory cytokines; induce cytotoxic activities in microglia and astrocytes with the accumulation of reactive oxygen species, reactive nitrogen species, and other highly reactive radicals; activate B cells and macrophages and stimulate the complement system. Inflammation and neurodegeneration are involved from the very beginning of the disease. They can both be affected by oxidative stress (OS) with different emphases depending on the time course of MS. Thus, OS initiates and supports inflammatory processes in the active phase, while in the chronic phase it supports neurodegenerative processes. A still unresolved issue in overcoming OS-induced lesions in MS is the insufficient endogenous activation of the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) pathway, which under normal conditions plays an essential role in mitochondria protection, OS, neuroinflammation, and degeneration. Thus, the search for approaches aiming to elevate endogenous Nrf2 activation is capable of protecting the brain against oxidative damage. However, exogenous Nrf2 activators themselves are not without drawbacks, necessitating the search for new non-pharmacological therapeutic approaches to modulate OS. The purpose of the present review is to provide some relevant preclinical and clinical examples, focusing on certain exogenous and endogenous Nrf2 activators and the modulation of therapeutic plasma exchange (TPE). The increased plasma levels of nerve growth factor (NGF) in response to TPE treatment of MS patients suggest their antioxidant potential for endogenous Nrf2 enhancement via NGF/TrkA/PI3K/Akt and NGF/p75NTR/ceramide-PKCζ/CK2 signaling pathways.

Chemical modulation of gasdermin D activity: Therapeutic implications and consequences

The gasdermin family of proteins are central effectors of the inflammatory, lytic cell death modality known as pyroptosis. Characterized in 2015, the most well-studied member gasdermin D can be proteolyzed, typically by caspases, to generate an active pore-forming N-terminal domain. At least well-studied three pharmacological inhibitors (necrosulfonamide, disulfiram, dimethyl fumarate) since 2018 have been shown to affect gasdermin D activity either through modulation of processing or interference with pore formation. A multitude of murine in vivo studies have since followed. Here, we discuss the current state of research surrounding these three inhibitors, caveats to their use, and a set of guiding principles that researchers should consider when pursuing further studies of gasdermin D inhibition.

Exploring Psoriasis Inflammatory Microenvironment by NanoString Technologies

Psoriasis is a chronic inflammatory skin disease whose molecular mechanisms and microenvironment are poorly understood. We performed gene expression analysis through the nCounter® PanCancer Immune Profiling Panel (NanoString Technologies, Seattle, WA, USA) on 22 FFPE punch biopsies from 19 psoriasis-affected patients. A subset of five cases was analyzed before (T0) and after 6 months (T6) of treatment with dimethyl fumarate (DMF) to address immune microenvironment changes. Molecular comparisons according to biopsy site and age of onset showed a different distribution of innate immune cells (mast cells, macrophages, NK cells, and DC cells) and pathways (complement regulation and transporter functions). The analysis according to PASI (Psoriasis Area and Severity Index) led to non-significant results, suggesting no link between molecular expression profile and clinical amount of skin disease. In DMF-treated patients, we observed a strong immunomodulatory effect after treatment: A subversion of exhausted CD8 T cells, NK CD56dim cells, Tregs, neutrophils, CD45+ cells, T cells, B cells, and macrophages was reported between the two analyzed time-points, as well as the reduction in pro-inflammatory pathways and molecules, including cytotoxicity, pathogen defense, antigen processing, adhesion, cell cycle, chemokines, cytokines, and interleukins. The inflammatory psoriatic microenvironment can be modulated using DMF with encouraging results, achieving an immune-tolerant and non-inflammatory condition through the regulation of both innate and adaptive immunity.

Immune cell targeted fumaric esters support a role of GPR109A as a primary target of monomethyl fumarate in vivo

Dimethyl fumarate (DMF) is approved as a treatment for multiple sclerosis (MS), however, its mode of action remains unclear. One hypothesis proposes that Michael addition to thiols by DMF, notably glutathione is immunomodulatory. The alternative proposes that monomethyl fumarate (MMF), the hydrolysis product of DMF, is a ligand to the fatty acid receptor GPR109A found in the lysosomes of immune cells. We prepared esters of MMF and macrolides derived from azithromycin, which were tropic to immune cells by virtue of lysosomal trapping. We tested the effects of these substances in an assay of response to Lipopolysaccharide (LPS) in freshly isolated human peripheral blood mononuclear cells (PBMCs). In this system, we observed that the 4'' ester of MMF (compound 2 and 3) reduced levels of Interleukins (IL)-1β, IL-12 and tumor necrosis factor alpha (TNFα) significantly at a concentration of 1 µM, while DMF required about 25 µM for the same effect. The 2' esters of MMF (compound 1 and 2) were, like MMF itself, inactive in vitro. The 4'' ester formed glutathione conjugates rapidly while the 2' conjugates did not react with thiols but did hydrolyze slowly to release MMF in these cells. We then tested the substances in vivo using the imiquimod/isostearate model of psoriasis where the 2' ester was the most active at 0.06-0.12 mg/kg (approximately 0.1 µmol/kg), improving skin score, body weight and cytokine levels (TNFα, IL-17A, IL-17F, IL-6, IL-1β, NLRP3 and IL-23A). In contrast, the thiol reactive 4'' ester was less active than the 2' ester while DMF was ca. 300-fold less active. The thiol reactive 4'' ester was not easily recovered from either plasma or organs while the 2' ester exhibited conventional uptake and elimination. The 2' ester also reduced levels of IL-6 in acute monosodium urate (MSU) induced inflammation. These data suggest that mechanisms that are relevant in vivo center on the release of MMF. Given that GPR109A is localized to the lysosome, and that lysosomal trapping increases 2' ester activity by > 300 fold, these data suggest that GPR109A may be the main target in vivo. In contrast, the effects associated with glutathione (GSH) conjugation in vitro are unlikely to be as effective in vivo due to the much lower dose in use which cannot titrate the more concentrated thiols. These data support the case for GPR109A modulation in autoimmune diseases.

Bacterial Metabolites: A Link between Gut Microbiota and Dermatological Diseases

Dysbiosis has been identified in many dermatological conditions (e.g., psoriasis, atopic dermatitis, systemic lupus erythematosus). One of the ways by which the microbiota affect homeostasis is through microbiota-derived molecules (metabolites). There are three main groups of metabolites: short-chain fatty acids (SCFAs), tryptophan metabolites, and amine derivatives including trimethylamine N-oxide (TMAO). Each group has its own uptake and specific receptors through which these metabolites can exert their systemic function. This review provides up-to-date knowledge about the impact that these groups of gut microbiota metabolites may have in dermatological conditions. Special attention is paid to the effect of microbial metabolites on the immune system, including changes in the profile of the immune cells and cytokine disbalance, which are characteristic of several dermatological diseases, especially psoriasis and atopic dermatitis. Targeting the production of microbiota metabolites may serve as a novel therapeutic approach in several immune-mediated dermatological diseases.

Short-term exposure to dimethyl fumarate (DMF) inhibits LPS-induced IκBζ expression in macrophages

Background: The pharmacological activity of dimethyl fumarate (DMF) in treating psoriasis and multiple sclerosis (MS) is not fully understood. DMF is hydrolysed to monomethyl fumarate (MMF) in vivo, which is believed to account for the therapeutic effects of DMF. However, previous studies have provided evidence that DMF also enters the circulation. Given that DMF is short-lived in the blood, whether DMF has a therapeutic impact is still unclear. Methods: Lipopolysaccharide (LPS)-mediated RAW264.7 cell activation was used as a model of inflammation to explore the anti-inflammatory effects of short-term DMF exposure in vitro. Whole blood LPS stimulation assay was applied to compare the anti-inflammatory effects of DMF and MMF in vivo. Griess assay was performed to examined nitrite release. The expression of pro-inflammatory cytokines and transcription factors were measured by quantitative PCR (qPCR), ELISA and Western blot. Depletion of intracellular glutathione (GSH) was evaluated by Ellman's assay. Luciferase reporter assays were performed to evaluate DMF effects on Nrf2-ARE pathway activation, promoter activity of Nfkbiz and mRNA stability of Nfkbiz. Binding of STAT3 to the IκBζ promoter were examined using Chromatin immunoprecipitation (ChIP) assay. Results: Short-term exposure to DMF significantly inhibited the inflammatory response of RAW264.7 cells and suppressed LPS-induced IκBζ expression. Importantly, oral DMF but not oral MMF administration significantly inhibited IκBζ transcription in murine peripheral blood cells. We demonstrated that the expression of IκBζ is affected by the availability of intracellular GSH and regulated by the transcription factor Nrf2 and STAT3. DMF with strong electrophilicity can rapidly deplete intracellular GSH, activate the Nrf2-ARE pathway, and inhibit the binding of STAT3 to the IκBζ promoter, thereby suppressing IκBζ expression in macrophages. Conclusion: These results demonstrate the rapid anti-inflammatory effects of DMF in macrophages, providing evidence to support the direct anti-inflammatory activity of DMF.

Response to fumaric acid esters for plaque type psoriasis in real-world practice is largely independent of patient characteristics at baseline - a multivariable regression analysis from the German psoriasis registry PsoBest

OBJECTIVES

Fumaric acid esters (FAEs) are a well-established treatment option for long-term therapy of moderate to severe plaque psoriasis. This study examines effectiveness of FAEs for the treatment of plaque psoriasis in real-world practice at 12 months and if patient characteristics affect the odds of clinical response.

METHODS

A descriptive, multivariable logistic regression analysis was conducted in a cohort drawn from the German registry PsoBest. Baseline patient characteristics were assessed as potential treatment effect modifiers.

RESULTS

444 patients (mean age 47.0 years, 39.0% female) were eligible for response analysis using nonresponder imputation at month 12. Of these, 39.6% achieved clinical response, i.e., Psoriasis Area and Severity Index (PASI) ≤3 or skin clearance. In logistic regression analysis (R² = 0.114), only baseline PASI was a significant factor: patients with PASI <10 had a 4 times higher odds (p ≤ 0.001, OR 4.088), patients with PASI of 10-20 a twofold higher odds of response (p ≤ 0.044, OR 1.961) compared to those with PASI >20. Neither sex, age, body weight, disease duration, comorbidity nor pre-treatment had an impact on the odds of response (p > 0.05).

CONCLUSIONS

FAEs showed a favorable response at 12 months, largely independent of patient characteristics.

Nrf2-mediated anti-inflammatory polarization of macrophages as therapeutic targets for osteoarthritis

Macrophages are the most abundant immune cells within the synovial joints, and also the main innate immune effector cells triggering the initial inflammatory responses in the pathological process of osteoarthritis (OA). The transition of synovial macrophages between pro-inflammatory and anti-inflammatory phenotypes can play a key role in building the intra-articular microenvironment. The pro-inflammatory cascade induced by TNF-α, IL-1β, and IL-6 is closely related to M1 macrophages, resulting in the production of pro-chondrolytic mediators. However, IL-10, IL1RA, CCL-18, IGF, and TGF are closely related to M2 macrophages, leading to the protection of cartilage and the promoted regeneration. The inhibition of NF-κB signaling pathway is central in OA treatment via controlling inflammatory responses in macrophages, while the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway appears not to attract widespread attention in the field. Nrf2 is a transcription factor encoding a large number of antioxidant enzymes. The activation of Nrf2 can have antioxidant and anti-inflammatory effects, which can also have complex crosstalk with NF-κB signaling pathway. The activation of Nrf2 can inhibit the M1 polarization and promote the M2 polarization through potential signaling transductions including TGF-β/SMAD, TLR/NF-κB, and JAK/STAT signaling pathways, with the regulation or cooperation of Notch, NLRP3, PI3K/Akt, and MAPK signaling. And the expression of heme oxygenase-1 (HO-1) and the negative regulation of Nrf2 for NF-κB can be the main mechanisms for promotion. Furthermore, the candidates of OA treatment by activating Nrf2 to promote M2 phenotype macrophages in OA are also reviewed in this work, such as itaconate and fumarate derivatives, curcumin, quercetin, melatonin, mesenchymal stem cells, and low-intensity pulsed ultrasound.

Antioxidant Therapy in Cancer: Rationale and Progress

Cancer is characterized by increased oxidative stress, an imbalance between reactive oxygen species (ROS) and antioxidants. Enhanced ROS accumulation, as a result of metabolic disturbances and signaling aberrations, can promote carcinogenesis and malignant progression by inducing gene mutations and activating pro-oncogenic signaling, providing a possible rationale for targeting oxidative stress in cancer treatment. While numerous antioxidants have demonstrated therapeutic potential, their clinical efficacy in cancer remains unproven. Here, we review the rationale for, and recent advances in, pre-clinical and clinical research on antioxidant therapy in cancer, including targeting ROS with nonenzymatic antioxidants, such as NRF2 activators, vitamins, N-acetylcysteine and GSH esters, or targeting ROS with enzymatic antioxidants, such as NOX inhibitors and SOD mimics. In addition, we will offer insights into prospective therapeutic options for improving the effectiveness of antioxidant therapy, which may expand its applications in clinical cancer treatment.

Microglia in the Neuroinflammatory Pathogenesis of Alzheimer's Disease and Related Therapeutic Targets

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide, characterized by progressive neuron degeneration or loss due to excessive accumulation of β-amyloid (Aβ) peptides, formation of neurofibrillary tangles (NFTs), and hyperphosphorylated tau. The treatment of AD has been only partially successful as the majority of the pharmacotherapies on the market may alleviate some of the symptoms. In the occurrence of AD, increasing attention has been paid to neurodegeneration, while the resident glial cells, like microglia are also observed. Microglia, a kind of crucial glial cells associated with the innate immune response, functions as double-edge sword role in CNS. They exert a beneficial or detrimental influence on the adjacent neurons through secretion of both pro-inflammatory cytokines as well as neurotrophic factors. In addition, their endocytosis of debris and toxic protein like Aβ and tau ensures homeostasis of the neuronal microenvironment. In this review, we will systematically summarize recent research regarding the roles of microglia in AD pathology and latest microglia-associated therapeutic targets mainly including pro-inflammatory genes, anti-inflammatory genes and phagocytosis at length, some of which are contradictory and controversial and warrant to further be investigated.

Hitting the Bullseye: Endogenous Electrophiles Show Remarkable Nuance in Signaling Regulation

Our bodies produce a host of electrophilic species that can label specific endogenous proteins in cells. The signaling roles of these molecules are under active debate. However, in our opinion, it is becoming increasingly likely that electrophiles can rewire cellular signaling processes at endogenous levels. Attention is turning more to understanding how nuanced electrophile signaling in cells is. In this Perspective, we describe recent work from our laboratory that has started to inform on different levels of context-specific regulation of proteins by electrophiles. We discuss the relevance of these data to the field and to the broader application of electrophile signaling to precision medicine development, beyond the traditional views of their pleiotropic cytotoxic roles.

The Modulatory Effects of DMF on Microglia in Aged Mice Are Sex-Specific

There is a striking sex-related difference in the prevalence of many neurodegenerative diseases, highlighting the need to consider whether treatments may exert sex-specific effects. A change in microglial activation state is a common feature of several neurodegenerative diseases and is considered to be a key factor in driving the inflammation that characterizes these conditions. Among the changes that have been described is a switch in microglial metabolism towards glycolysis which is associated with production of inflammatory mediators and reduced function. Marked sex-related differences in microglial number, phenotype and function have been described in late embryonic and early postnatal life in rodents and some reports suggest that sexual dimorphism extends into adulthood and age and, in models of Alzheimer’s disease, the changes are more profound in microglia from female, compared with male, mice. Dimethyl fumarate (DMF) is a fumaric acid ester used in the treatment of psoriasis and relapsing remitting multiple sclerosis and, while its mechanism of action is unclear, it possesses anti-inflammatory and anti-oxidant properties and also impacts on cell metabolism. Here we treated 16–18-month-old female and male mice with DMF for 1 month and assessed its effect on microglia. The evidence indicates that it exerted sex-specific effects on microglial morphology and metabolism, reducing glycolysis only in microglia from female mice. The data suggest that this may result from its ability to inactivate glyceraldehyde-3-phosphate dehydrogenase (GAPDH).

Beneficial effects of Ilex paraguariensis in the prevention of obesity-associated metabolic disorders in mice

Obesity is a chronic condition involving inflammation and oxidative stress that commonly predisposes affected individuals to develop metabolic disorders. We hypothesize that Ilex paraguariensis (IP) can modulate oxidative stress and inflammation underpinning metabolic disorders caused by obesity. C57BL/6 mice were fed a high-fat diet (HFD group) for 12 weeks. Concomitantly, some mice were treated with roasted IP (15 mg/ml - HFD + IP) or dimethyl fumarate (DMF) as a positive control (2 mg/ml - HFD + DMF). The control group received standard chow and water ad libitum. Histological analyses of fat tissue and liver, and quantification of mediators related to oxidative stress (Kelch-like ECH-associated protein 1/NF-E2-related factor 2, NADP(H) quinone oxidoreductase-1 [NQO1], heme oxygenase 1 [HO1], and superoxide dismutase) as well as metabolic profile blood biomarkers (glucose, leptin, resistin, high-density lipoproteins [HDLs], and triglycerides) were performed. Metabolic disorders were prevented in mice treated with IP, as evidenced by the observation that glucose, HDL, and resistin levels were similar to those assessed in the control group. Morphological analyses showed that both IP and DMF treatments prevented hepatic steatosis and adipocyte hypertrophy in visceral adipose tissue. Finally, although the antioxidant response stimulated by IP was quite limited, significant effects were found on NQO1 and HO1 expression. In conclusion, IP has promising preventative effects on the development of metabolic disorders caused by obesity.

Introducing a simplified titration scheme for dimethylfumarate (DMF) in patients with moderate-to-severe psoriasis: a case series

Dimethylfumarate (DMF) is approved for the treatment of moderate to severe psoriasis. In clinical practice, DMF tolerability is improved by slowly up-titrating the dose. Time-to-onset of gastrointestinal complaints (a common adverse event [AE]) is ∼4 weeks, coinciding with the increase in dose to one 120-mg tablet. The average DMF dose during maintenance treatment is also often lower than the maximum indicated dose of 720 mg/day. Here, a simplified dose-escalation strategy is described, where twice-daily DMF was up-titrated to a maximum of 720 mg/day (if required) in week 7. Ten patients received DMF according to the new scheme (maximum dose: 720 mg/day [n = 5], 480 mg/day [n = 3; escalation halted early due to good efficacy], and ≤240 mg/day [n = 2] by week 12). Mean Psoriasis Area Severity Index (PASI) decreased from 7.2 to 0.9 between weeks 0 and 24. Absolute Psoriasis Area Severity Index (aPASI) was ≤3 for 7 and 6 patients at weeks 12 and 24, respectively. Affected BSA and DLQI demonstrated similar improvements. Treatment was terminated in 3 patients due to AEs (diarrhea and lymphopenia). In this case series, simplified DMF dosing was largely well-tolerated and provided similar efficacy to the current scheme. Higher doses were reached more quickly and the dosing regimen was simpler for patients (twice instead of three times daily).

Dimethyl fumarate treatment for psoriasis in a real-life setting: A multicentric retrospective study

Dimethyl fumarate (DMF) is a fumaric acid esters derivate approved for plaque psoriasis as first‐line systemic therapy. It has been available in Italy since 2017 and an increasing number of patients are treated with this drug. To evaluate DMF effectiveness, side effects and drug survival in a dermatological real‐life setting. We performed a retrospective multi‐center study in five dermatologic clinics in Emilia‐Romagna, Northern Italy, which included all consecutive patients affected by moderate–severe psoriasis treated with DMF. We assessed effectiveness (in terms of PASI50 and PASI75 in an intention to treat observation) and safety (occurrence of side effects) of DMF and their association with demographic and disease characteristics, mean daily dose taken and treatment discontinuation. We included 103 patients, 78 (75.72%) had at least one comorbidity including 19 (18.44%) with a history of cancer; the mean treatment duration was 23.61 ± 17.99 weeks (min 4, max 130) and the mean daily dose was 262.13 ± 190.94 mg. Twenty‐four patients (23.30%) reached PASI75 at week 12, while a further 18 patients (17.47%) reached it at week 26. Side effects occurred in 63 patients (61.16%), the most frequent were diarrhea, epigastric discomfort, nausea, and flushing. Sixteen patients (15.53%) showed an alteration of laboratory tests. In some cases side effects were transitory, while in 53 patients (51.45%) they led to cessation of therapy. The median daily dose showed a direct association with PASI50 achievement and an indirect association with treatment discontinuation. Our study shows the peculiarities of DMF in a real‐world setting: effectiveness is often reached after 12 weeks of treatment and side effects could limit the continuation of the therapy but, at the same time, DMF has no major contraindications and, due to the wide range of dosage, it can allow both to manage side effects and to personalize the prescription for each patient.

Dimethyl fumarate does not mitigate cognitive decline and β-amyloidosis in female APPPS1 mice

INTRODUCTION

Alzheimer's disease (AD) is the leading cause of dementia and a major global health issue. Currently, only limited treatment options are available to patients. One possibility to expand the treatment repertoire is repurposing of existing drugs such as dimethyl fumarate (DMF). DMF is approved for treatment of multiple sclerosis and previous animal studies have suggested that DMF may also have a beneficial effect for the treatment of AD.

METHODS

We used an APPPS1 transgenic model of senile β-amyloidosis and treated female mice orally with DMF in two treatment paradigms (pre and post onset). We quantified learning and memory parameters, β-amyloidosis, and neuroinflammation to determine the potential of DMF as AD therapeutics.

RESULTS

Treatment with DMF had no influence on water maze performance, β-amyloid accumulation, plaque formation, microglia activation, and recruitment of immune cells to the brain. Compared to vehicle-treated animals, oral DMF treatment could not halt or retard disease progression in the mice.

DISCUSSION

Our results do not favour the use of DMF as treatment for AD. While our results stand in contrast to previous findings in other models, they emphasize the importance of animal model selection and suggest further studies to elucidate the mechanisms leading to conflicting results.

Dexamethasone and Fumaric Acid Ester Conjugate Synergistically Inhibits Inflammation and NF-κB in Macrophages

Macrophage-mediated inflammation drives autoimmune and chronic inflammatory diseases. Treatment with anti-inflammatory agents can be an effective strategy to reduce this inflammation; however, high concentrations of these agents can have immune-dampening and other serious side effects. Synergistic combination of anti-inflammatory agents can mitigate dosing by requiring less drug. Multiple anti-inflammatory agents were evaluated in combination for synergistic inhibition of macrophage inflammation. The most potent synergy was observed between dexamethasone (DXM) and fumaric acid esters (e.g., monomethyl fumarate (MMF)). Furthermore, this combination was found to synergistically inhibit inflammatory nuclear factor κB (NF-κB) transcription factor activity. The optimal ratio for synergy was determined to be 1:1, and DXM and MMF were conjugated by esterification at this molar ratio. The DXM-MMF conjugate displayed improved inhibition of inflammation over the unconjugated combination in both murine and human macrophages. In the treatment of human donor monocyte-derived macrophages, the combination of DXM and MMF significantly inhibited inflammatory gene expression downstream of NF-κB and overall performed better than either agent alone. Further, the DXM-MMF conjugate significantly inhibited expression of NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome-associated genes. The potent anti-inflammatory activity of the DXM-MMF conjugate in human macrophages indicates that it may have benefits in the treatment of autoimmune and inflammatory diseases.

Nrf2/ARE Activators Improve Memory in Aged Mice via Maintaining of Mitochondrial Quality Control of Brain and the Modulation of Gut Microbiome

Aging is one of the most serious factors for central nervous dysfunctions, which lead to cognitive impairment. New highly effective drugs are required to slow the development of cognitive dysfunction. This research studied the effect of dimethyl fumarate (DMF), methylene blue (MB), and resveratrol (RSV) on the cognitive functions of 15-month-old mice and their relationship to the maintenance of mitochondrial quality control in the brain and the bacterial composition of the gut microbiome. We have shown that studied compounds enhance mitochondrial biogenesis, mitophagy, and antioxidant defense in the hippocampus of 15-month-old mice via Nrf2/ARE pathway activation, which reduces the degree of oxidative damage to mtDNA. It is manifested in the improvement of short-term and long-term memory. We have also shown that memory improvement correlates with levels of Roseburia, Oscillibacter, ChristensenellaceaeR-7, Negativibacillus, and Faecalibaculum genera of bacteria. At the same time, long-term treatment by MB induced a decrease in gut microbiome diversity, but the other markers of dysbiosis were not observed. Thus, Nrf2/ARE activators have an impact on mitochondrial quality control and are associated with a positive change in the composition of the gut microbiome, which together lead to an improvement in memory in aged mice.

Efficacy of dimethyl fumarate treatment for moderate-to-severe plaque psoriasis: presentation extracts from the 29th EADV virtual congress, 29-31 October 2020

Background: The 29th EADV Virtual Congress took place between the 29th-31st of October 2020. On October 29th, there was a Session on systemic treatment in which Professors Ulrich Mrowietz and Mar Llamas-Velasco presented the latest research on the efficacy of dimethyl fumarate (DMF) treatment for moderate-to-severe plaque psoriasis (BRIDGE and DIMESKIN 1 studies, respectively). The accepted DMF abstract from Professor Matthias Augustin, on the SKILL study, is also presented here. Results: Data from either prospective interventional (BRIDGE) or non-interventional (DIMESKIN 1, SKILL) studies among patients with moderate-to-severe psoriasis showed that DMF provides a positive efficacy profile in all four body regions included in the Psoriasis Area and Severity Index assessment (head and neck, trunk, upper and lower extremities) and a particularly interesting profile (strong efficacy) in the head and neck region. These findings may be of special interest to patients with scalp psoriasis who have been using topical therapies for a long time. Patient-reported outcomes (quality of life, pruritus) also improved during the 24 weeks of DMF treatment. The safety profile of DMF was similar to the previously described with fumaric acid esters. Conclusions: In summary, these results confirm the favorable efficacy and safety profile of DMF in long-term treatment.

Oral dimethyl fumarate induces changes within the peripheral neutrophil compartment of patients with psoriasis that are linked with skin improvement

BACKGROUND

Dimethyl fumarate (DMF) is a treatment for moderate-to-severe psoriasis and multiple sclerosis. DMF therapy typically improves skin inflammation within the first 3 months of treatment. DMF is a prodrug that generates the hydroxycarboxylic acid receptor 2 (HCA2) agonist, monomethyl fumarate (MMF). Despite widespread clinical use, DMF's mechanism of action is not fully understood.

OBJECTIVES

We wished to characterize the changes induced by DMF in peripheral neutrophils within the first 3 months of treatment to better understand its early antipsoriatic effects.

METHODS

Flow cytometry was used to assess T-cell and neutrophil frequencies, apoptosis and activation phenotype. In vitro culture of neutrophils with DMF and MMF was used to evaluate apoptosis and HCA2 internalization. Serum levels of neutrophil degranulation products were measured by enzyme-linked immunosorbent assay.

RESULTS

Patients with psoriasis had significantly higher leucocyte counts at baseline compared with controls, with a large population of pro-inflammatory CD62L^lo  CD11b^bright neutrophils. Analysis revealed that DMF treatment reduced the frequency of CD62L^lo  CD11b^bright neutrophils and serum levels of neutrophil activation markers. This reduction was not linked to increased apoptosis.

CONCLUSIONS

Our results reveal a novel in vivo effect of DMF therapy on pro-inflammatory neutrophils that likely contributes to this treatment's antipsoriatic efficacy.

A phase 4, randomized, head-to-head trial comparing the efficacy of subcutaneous injections of brodalumab to oral administrations of fumaric acid esters in adults with moderate-to-severe plaque psoriasis (CHANGE)

BACKGROUND

Brodalumab is a fully human monoclonal immunoglobulin IgG2 antibody that binds to the human IL-17 receptor subunit A and by that inhibits the biologic action of IL-17A, IL-17F, IL-17C and IL-17E. Therapy with fumaric acid esters (FAE) is a well established and widely used first-line systemic treatment for subjects with moderate-to-severe plaque psoriasis.

OBJECTIVES

To compare brodalumab to FAE in terms of clinical efficacy, patient-reported outcomes and safety in subjects with moderate-to-severe plaque psoriasis who were naïve to systemic treatment.

METHODS

Eligible subjects were randomized 1 : 1 to 210 mg brodalumab injections or oral FAE according to product label in this 24-week, open-label, assessor-blinded, multi-centre, head-to-head phase 4 trial. The primary endpoints were having PASI75 and having sPGA score of 0 or 1 (sPGA 0/1). Subjects with missing values for the primary endpoints were considered non-responders.

RESULTS

A total of 210 subjects were randomized. 91/105 subjects completed brodalumab treatment and 58/105 subjects completed FAE treatment. At Week 24, significantly more subjects in the brodalumab group compared to the FAE group had PASI75 (81.0% vs. 38.1%, P < 0.001) and sPGA 0/1 (64.8% vs. 20.0%, P < 0.001). In the brodalumab group, the median time to both PASI75 and to PASI90 was significantly shorter than in the FAE group (4.1 weeks vs. 16.4 weeks, and 7.4 weeks vs. 24.4 weeks, respectively, P < 0.0001 for both). The rate of adverse events was lower in subjects treated with brodalumab compared to subjects treated with FAE (616.4 vs. 1195.8 events per 100 exposure years). No new safety signals were detected for brodalumab.

CONCLUSIONS

Brodalumab was associated with rapid and significant improvements in signs and symptoms of moderate-to-severe plaque psoriasis, with a superior efficacy profile to what was observed with FAE in systemic-naïve subjects over 24 weeks.

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 induced lymphopenia in multiple sclerosis: A review of the literature

Dimethyl fumarate (DMF) is a first line medication for multiple sclerosis. It has a favourable safety profile, however, there is concern regarding the occurrence of moderate-severe and sustained lymphopenia and the associated risk of progressive multifocal leukoencephalopathy. We carried out an extensive literature review to understand the molecular mechanisms underlying this adverse reaction. Dynamic changes in certain components of the immune system are likely to be important for the therapeutic effects of DMF, including depletion of memory T cells and decrease in activated T cells together with expansion of naïve T cells. Similar modifications were reported for the B cell components. CD8⁺ T cells are particularly susceptible to DMF-induced cell death, with marked reductions observed in lymphopenic subjects. The reasons underlying such increased sensitivity are not known, nor it is known how expansion of other lymphocyte subsets occurs. Understanding the molecular mechanisms underlying DMF action is challenging: in vivo DMF is rapidly metabolized to monomethyl fumarate (MMF), a less potent immunomodulator in vitro. Pharmacokinetics indicate that MMF is the main active species in vivo. However, the relative importance of DMF and MMF in toxicity remains unclear, with evidence presented in favour of either of the compounds as toxic species. Pharmacogenetic studies to identify genetic predictors of DMF-induced lymphopenia are limited, with inconclusive results. A role of the gut microbiome in the pharmacological effects of DMF is emerging. It is clear that further investigations are necessary to understand the mechanisms of DMF-induced lymphopenia and devise preventive strategies. Periodic monitoring of absolute lymphocyte counts, currently performed in clinical practise, allows for the early detection of lymphopenia as a risk-minimization strategy.

Electrophilic Nrf2 activators and itaconate inhibit inflammation at low dose and promote IL-1β production and inflammatory apoptosis at high dose

Controlling inflammation is critical for preventing many diseases including cancer, autoimmune disorders and hypersensitivity reactions. NF-E2-related factor 2 (Nrf2) is a key transcription factor that controls the cellular antioxidant and cytoprotective response. Moreover, Nrf2 has been implicated in the regulation of inflammatory processes, although the ultimate mechanism by which this is achieved is unknown. Here, we investigated mechanisms of inflammation and cell death pathways induced by a variety of Nrf2 activators including dimethyl fumarate (DMF) and the endogenous metabolite itaconate. We found that exposure of bone marrow-derived dendritic cells (BMDCs) to low concentrations of a variety of electrophilic Nrf2 activators including itaconate prior to Toll-like receptor (TLR) stimulation inhibits transcription of pro-inflammatory cytokines (such as interleukin [IL]-12 and IL-1β) by activation of Nrf2. By contrast, high doses of these electrophilic compounds after TLR activation promote inflammatory apoptosis and caspase-8-dependent IL-1β processing and release independently of Nrf2. Interestingly, tert-butylhydroquinone (tBHQ), a non-electrophilic Nrf2-activator, failed to induce IL-1β production. These results have important implications for clinical application of electrophilic compounds.

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.

Long-term Safety of Oral Systemic Therapies for Psoriasis: A Comprehensive Review of the Literature

Oral systemic therapies are important treatment options for patients with moderate-to-severe psoriasis, either as monotherapy or in therapy-recalcitrant cases as combination therapy with phototherapy, other oral systemics or biologics. Long-term treatment is needed to maintain sufficient disease control in psoriasis, but continuous use of systemic treatments is limited by adverse events (AEs) and cumulative toxicity risks. The primary aim of this comprehensive literature review was to examine the long-term safety profiles of oral agents commonly used in the treatment of adults with psoriasis. Searches were conducted in EMBASE and PubMed up to November 2018, and 157 relevant publications were included. Long-term treatment with acitretin could be associated with skeletal toxicity and hepatotoxicity, although evidence for skeletal toxicity is mixed and hepatotoxicity is rare, particularly at low doses. Other safety issues include hyperlipidaemia and potential for teratogenicity up to 2-3 years after discontinuation of treatment. There is a paucity of data on long-term treatment with apremilast. Continued exposure to apremilast does not seem to increase the incidence of common AEs, such as gastrointestinal (GI) AEs, upper respiratory tract infections and headache, while the long-term risks for depression, suicidal thoughts and weight loss are unknown. Long-term ciclosporin treatment is associated with renal toxicity, hypertension, non-melanoma skin cancer, neurological AEs and GI AEs. Long-term methotrexate treatment is associated with hepatotoxicity, GI AEs, haematological toxicity, renal toxicity and alopecia. Finally, long-term treatment with fumaric acid esters (FAE) is associated with GI AEs, flushing, lymphocytopenia, proteinuria and elevated liver enzymes. Median drug survival estimates varied considerably: ~  2.9-9.7 months for apremilast; ~ 5.4 months for ciclosporin; ~ 8.6 months for acitretin; ~ 12.1-21.6 months for methotrexate; and ~  54.8 months for FAE. These long-term safety profiles may help to guide clinicians to select the optimal oral systemic treatment for the long-term treatment of psoriasis in adults.

Dimethyl fumarate suppresses metastasis and growth of melanoma cells by inhibiting the nuclear translocation of NF-κB

BACKGROUND

Malignant melanoma is among the deadliest forms of skin cancers, and its incidence has been increasing over the past decades. In malignant melanoma, activation of the nuclear factor kappa B (NF-κB) promotes survival, migration, and invasion of cancer cells. Anti-NF-κB agents for treating metastatic melanoma would be beneficial, but no such drug is approved as either monotherapy or adjuvant therapy. Dimethyl fumarate (DMF) is an approved anti-inflammatory drug already in clinical use for psoriasis and multiple sclerosis.

OBJECTIVE

We investigated the anti-tumour effect of DMF treatment in metastatic melanoma in vitro and in vivo.

METHODS

The cell viability was assessed via trypan blue exclusion assay. The migration and invasion was analyzed in a Boyden chamber assay. The anti-metastatic effects and anti-tumour activity of DMF was determined in an in-vivo model. The expressions of NF-κB pathway and NF-κB regulatory proteins were detected via western blotting.

RESULTS

DMF decreased the cell viability, migration and invasion in vitro. In addition, DMF inhibited spontaneous metastasis and tumour growth. Mechanistically, DMF prevented the nuclear translocation of NF-κB, whereas no changes were observed in the phosphorylation levels of inhibitor of kappa B (IκB). In addition, DMF inhibited the expression of matrix metalloproteinases (MMPs) and very late antigens (VLAs). Furthermore, DMF treatment decreased the expression of Survivin and Bcl-extra large (Bcl-XL) proteins.

CONCLUSION

Our results suggest that DMF as a novel inhibitor of NF-κB may be a potential therapeutic agent for metastatic melanoma.

Disparate effects of adalimumab and fumaric acid esters on cardiovascular risk factors in psoriasis patients: results from a prospective, randomized, observer-blinded head-to-head trial

BACKGROUND

The effect of adalimumab and fumaric acid esters (FAE) on the cardiovascular risk associated with psoriasis has only been investigated scarcely in randomized controlled studies.

OBJECTIVE

The aim of this prospective, randomized controlled head-to-head trial was to compare the influence of adalimumab and FAE on cardiovascular disease markers in psoriasis patients.

METHODS

Sixty-five patients with moderate to severe plaque psoriasis were randomly assigned to adalimumab or FAE treatment for 6 months. Cardiovascular haemodynamic parameters [flow-mediated dilation (FMD), nitro-glycerine mediated dilation (NMD) and carotid intima-media thickness (CIMT), blood pressure] were assessed at baseline (v0) and after 6 months (v6). Cutaneous disease severity, inflammatory and lipid cardiovascular risk markers were analysed at baseline(v0), after 3 (v3) and 6 months (v6).

RESULTS

After 6 months of treatment FMD in the adalimumab group increased significantly [v0 5.9% (6.4% SD), v6 8.0% (4.8% SD), P = 0.048) but not in the FAE group. (v0 7.0% (4.1% SD), v6 8.4% (6.1% SD), P = 0.753]. This was paralleled by a significant decrease of high sensitive C-reactive protein (hsCRP) in the adalimumab group in comparison to the FAE group (v0: 0.39 mg/dL (0.38 SD), v6: 0.39 mg/dL (0.48 SD), P = 0.043). No significant changes were observed in any other haemodynamic parameters. FAE, however, additionally decreased total cholesterol (P = 0.046) and apolipoprotein B (P = 0.041) levels compared to adalimumab. Mean Psoriasis Area and Severity Index (psoriasis area severity score) reduction was greater but not significant (P = 0.116) under adalimumab treatment compared to FAE treatment [-71.1% (29.9 SD) vs. -54.6% (45.7%)].

CONCLUSION

In our study, both treatments were documented to exert effects on the cardiovascular system. While adalimumab showed anti-inflammatory effects and improved FMD, FAE interacted favourably with the cholesterol metabolism.

Dimethyl Fumarate Targets MSK1, RSK1, 2 and IKKα/β Kinases and Regulates NF-κB /p65 Activation in Psoriasis: A Demonstration of the Effect on Peripheral Blood Mononuclear Cells, Drawn from Two Patients with Severe Psoriasis Before and After Treatment with Dimethyl Fumarate

Background

Dimethyl fumarate (DMF) has an inhibitory effect on the production of pro-inflammatory proteins from different cells which participate in the immune reaction in psoriatic skin. Most recently it was shown that DMF is an allosteric covalent inhibitor of the p90 ribosomal S6 kinases (RSK1, 2), determined by X-ray crystallography. DMF binds to a specific cysteine residue in RSK2 and in the closely related mitogen and stress-activated kinases 1 (MSK1) which inhibits further downstream activation.

Objectives

The aim of this study was to review the literature on the effects of DMF on activation of MSK1, RSK1, 2 kinases, and downstream transcription factors NF-κB/p65 and IκBα in cells contributing to the pathogenesis of psoriasis. We also hypothesized and studied if treatment with DMF would inhibit the activation of MSK1, RSK1, 2 kinases in peripheral blood mononuclear cells (PBMCs) in psoriatic patients.

Methods

PBMCs were purified from patients with severe psoriasis before and after 90 days of treatment with DMF. Cells were stimulated with anisomycin, IL-1β or EGF for 10 and 20 minutes. The levels of phosphorylation of MSK1, RSK1, 2 or NF-κB/p65, IκBα were analyzed by Western blotting.

Results

Our case study showed that treatment with DMF inhibited the activation of MSK1 and RSK1, 2 kinases in PBMCs in patients. This supports that DMF is the active metabolite in vivo in psoriatic patients during DMF treatment.

Conclusion

Pro-inflammatory proteins are induced through activation of MSK1 and NF-κB/p65 at (S276). The extracellular signal-regulated kinases (ERK1/2) control cell survival by activating both MSK1 and RSK1, 2 kinases. P-RSK1, 2 activates P-κBα and NF-κB/p65 at (S536). The phosphorylation of NF-κB/p65 at (S276) and (S536) controls different T cell and dendritic cell functions. DMF´s inhibitory effect on MSK1 and RSK1, 2 kinase activations reduces multiple immune reactions in psoriatic patients.

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.

Electrophile Signaling and Emerging Immuno- and Neuro-modulatory Electrophilic Pharmaceuticals

With a lipid-rich environment and elevated oxygen consumption, the central nervous system (CNS) is subject to intricate regulation by lipid-derived electrophiles (LDEs). Investigations into oxidative damage and chronic LDE generation in neural disorders have spurred the development of tools that can detect and catalog the gamut of LDE-adducted proteins. Despite these advances, deconstructing the precise consequences of individual protein-specific LDE modifications remained largely impossible until recently. In this perspective, we first overview emerging toolsets that can decode electrophile-signaling events in a protein/context-specific manner, and how the accumulating mechanistic insights brought about by these tools have begun to offer new means to modulate pathways relevant to multiple sclerosis (MS). By surveying the latest data surrounding the blockbuster MS drug dimethyl fumarate that functions through LDE-signaling-like mechanisms, we further provide a vision for how chemical biology tools probing electrophile signaling may be leveraged toward novel interventions in CNS disease.

Recent progress in the development of small molecule Nrf2 activators: a patent review (2017-present)

Introduction: The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is the first line of defense against a plethora of environmental or endogenous deviations in redox metabolism, proteostasis, inflammation, etc. Therefore, pharmacological activation of Nrf2 is a potential therapeutic approach for several diseases related to oxidative stress and inflammation, such as cancer, cardiovascular, and neurodegenerative diseases.Areas covered: The authors first describe the biological function of Nrf2 and the molecular regulatory mechanism of Keap1-Nrf2-ARE ((Kelch-like ECH-Associating protein 1)-Nrf2-(antioxidant response element)). Then, they review recent progress of covalent activators and non-covalent Keap1-Nrf2 protein-protein interaction (PPI) inhibitors from patents and publications in 2017-present, consisting of new chemical molecules, structure optimization of reported activators and progress in preclinical or clinical trials.Expert opinion: Despite significant achievements in the development of Nrf2 activators, the selectivity is the primary consideration. Due to reacting with redox-sensitive cysteines in proteins except for Keap1, electrophilic activators often exhibit off-target effects. For Keap1-Nrf2 PPI inhibitors, how to enhance in vivo efficacy and/or penetrate blood-brain barrier (BBB) to reach central nervous system (CNS) is also challenging. Fragment-based drug discovery (FBDD), carboxylic acid bioisosteric replacement and prodrug approach might be used to circumvent this challenge. Moreover, the possibility of cancer risk caused by Nrf2 activation needs to be considered carefully.

A 24-week multicentre, randomized, open-label, parallel-group study comparing the efficacy and safety of ixekizumab vs. fumaric acid esters and methotrexate in patients with moderate-to-severe plaque psoriasis naive to systemic treatment

Background

Interleukin‐17 antagonists have received a first‐line label for moderate‐to‐severe plaque psoriasis.

Objectives

We conducted the first head‐to‐head trial between the two most commonly used first‐line therapies in Germany, fumaric acid esters (FAEs) and methotrexate, and the interleukin‐17A antagonist, ixekizumab.

Methods

Systemic‐naive patients were randomized in this parallel‐group, active‐comparator, open‐label, rater‐blinded trial (each group n = 54). The primary outcome was the proportion of patients achieving ≥ 75% improvement in Psoriasis Area and Severity Index (PASI 75) at 24 weeks. Key secondary outcomes included 24‐week PASI 90 and 100, static Physician's Global Assessment (sPGA) score of 0 or 1, and Dermatology Life Quality Index (DLQI) score of 0 or 1. Safety events at week 24 were analysed using Fisher's exact test. Missing data were imputed using nonresponder imputation. The trial was registered at ClinicalTrials.gov (NCT02634801) and EudraCT (2015‐002649‐69).

Results

At week 24, more ixekizumab‐treated patients achieved PASI 75 [91% vs. 22% FAEs (P < 0·001) and 70% methotrexate (P = 0·014)], PASI 90 [80% vs. 9% FAEs (P < 0·001) and 39% methotrexate (P < 0·001)] and PASI 100 [41% vs. 4% FAEs (P < 0·001) and 13% methotrexate (P = 0·0041)], as well as sPGA (0,1) and DLQI (0,1).

Conclusions

Ixekizumab was superior in inducing PASI 75/90/100, sPGA (0,1) and DLQI (0,1) responses at week 24 compared with methotrexate and FAEs. Safety profiles for all treatments were consistent with prior studies.

What's already known about this topic?

Fumaric acid esters (FAEs) and methotrexate are two frequently used conventional systemic therapies for chronic plaque psoriasis.

A recent meta‐analysis of methotrexate showed a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) rate of 45·2% from primary end points at either 12 or 16 weeks.

Until recently, FAEs were licensed for psoriasis only in Germany, but were used in many other European countries as off‐label treatment of psoriasis. In 2017, the European Medicines Agency approved dimethyl fumarate, presumed to be the main active ingredient of FAEs, for the treatment of adult patients with moderate‐to‐severe chronic plaque psoriasis.

What does this study add?

This study is the first randomized, head‐to‐head trial comparing a biologic treatment with these therapies in a systemic‐treatment‐naive patient population.

This study shows the low tolerability of FAEs leading to a significant discontinuation rate, the better tolerability and moderate efficacy of methotrexate, and the good tolerability, fast onset of action and high efficacy of ixekizumab in an unbiased comparison.

Our findings reinforce the favourable risk–benefit profile of ixekizumab shown previously and provide further evidence of its efficacy at 24 weeks.

https://doi.org/10.1111/bjd.18905 available online

Improving the Gastrointestinal Tolerability of Fumaric Acid Esters: Early Findings on Gastrointestinal Events with Diroximel Fumarate in Patients with Relapsing-Remitting Multiple Sclerosis from the Phase 3, Open-Label EVOLVE-MS-1 Study

INTRODUCTION

Diroximel fumarate (DRF) is a novel oral fumarate in development for patients with relapsing forms of multiple sclerosis (MS). Clinical findings from the DRF development program suggest that rates of gastrointestinal (GI) treatment-emergent adverse events (TEAEs) and discontinuation due to GI TEAEs are low, based on clinical and real-world observations of other fumaric acid esters, including dimethyl fumarate (DMF). The incidence of GI TEAEs varies from 40 to 88% in clinical and real-world studies of DMF. The objective of this study is to present GI tolerability findings from the EVOLVE-MS-1 study and present biologic hypotheses for the improved GI properties of DRF.

METHODS

GI TEAEs and treatment discontinuation because of GI TEAEs were assessed in DRF-treated patients with relapsing-remitting MS who were participating in the ongoing, 96-week, open-label, phase 3 EVOLVE-MS-1 study.

RESULTS

As of March 30, 2018, a total of 696 patients were enrolled in EVOLVE-MS-1. GI TEAEs were reported in 30.9% (215/696) of patients; the vast majority (96%; 207/215) experienced events that were mild or moderate in severity. When GI AEs did occur, they occurred early in treatment, resolved (88.8%; 191/215), and were of short duration [median 7.5 (range 1-87) days] in most patients. GI TEAEs led to < 1% of patients discontinuing treatment.

CONCLUSIONS

We suggest that the distinct chemical structure of DRF contributes to the observed low rates of GI TEAEs and GI-associated treatment discontinuations, possibly due to a combination of several factors. We hypothesize that these factors may include less reactivity with off-target proteins and/or lower production of a methanol leaving group that may contribute to GI irritation. A direct comparison of GI tolerability with DRF versus DMF is being evaluated in the EVOLVE-MS-2 study.

TRIAL REGISTRATION

ClinicalTrials.gov number NCT02634307.

FUNDING

Alkermes Inc. (Waltham, MA, USA) and Biogen (Cambridge, MA, USA).

From bench to bedside: evolving therapeutic targets in autoimmune blistering disease

Autoimmune blistering diseases comprise a group of heterogenous conditions characterized by the loss of tolerance and subsequent development of autoantibodies targeting epidermal and subepidermal adhesion proteins. Blisters and erosions form on the skin and mucous membranes leading to significant morbidity and mortality. Traditional therapies rely on systemic immunosuppression. Advancements in our understanding of the pathophysiology of pemphigus and pemphigoid have led to the development of molecules which target specific pathways involved in induction and perpetuation of disease. In this review, we outline the novel therapeutic strategies including B-cell depletion, T-regulatory cell repletion, cell signalling inhibitors and small molecular inhibitors, inhibitory monoclonal antibodies, as well as complement inhibition. We additionally review their current level of clinical evidence. We lastly review therapeutics targets gleaned from the experimental epidermolysis bullosa acquisita mouse model. These emerging treatments offer an exciting progression from basic science discoveries that have the potential to transform the treatment paradigm in autoimmune blistering diseases.