Bis(4-acetoxy-N-ethyl-N-n-propyl-tryptammonium) fumarate-fumaric acid (1/1)

The solid-state structure of the title salt/adduct (systemic name: bis-{[2-(4-acet-yloxy-1H-indol-3-yl)eth-yl](eth-yl)propyl-aza-nium} but-2-enedioate-(E)-butenedioic acid (1/1)), 2C17H25N2O2 +·C4H2O4 2-·C4H4O4, was determined by single-crystal X-ray diffraction. The asymmetric unit consists of a singly protonated tryptammonium cation, one half of a fumarate dianion and one half of a fumaric acid mol-ecule. In the crystal, the ions and mol-ecules are linked together in infinite chains propagating along [001] through a series of N-H⋯O and O-H⋯O hydrogen bonds.

Vaccine response in people with multiple sclerosis treated with fumarates

People with multiple sclerosis (pwMS) have an increased risk of infection. As disease-modifying therapies (DMTs) and other treatments may interact with the immune system, there may be concerns about vaccine efficacy and safety. Therefore, it is important to evaluate possible interactions between DMTs and vaccines. The fumarates, dimethyl fumarate, diroximel fumarate, and monomethyl fumarate, are approved for the treatment of relapsing multiple sclerosis. This review assesses the evidence on vaccine response in pwMS treated with fumarates, with a particular focus on COVID-19 vaccines. Treatment with fumarates does not appear to result in blunting of humoral responses to vaccination; for COVID-19 vaccines, particularly RNA-based vaccines, evidence indicates antibody responses similar to those of healthy recipients. While data on the effect of fumarates on T-cell responses are limited, they do not indicate any significant blunting. COVID-19 vaccines impart a similar degree of protection against severe COVID-19 infection for pwMS on fumarates as in the general population. Adverse reactions following vaccination are generally consistent with those observed in the wider population; no additional safety signals have emerged in those on fumarates. Additionally, no increase in relapse has been observed in pwMS following vaccination. In pwMS receiving fumarates, vaccination is generally safe and elicits protective immune responses.

MiR-142-3p regulates synaptopathy-driven disease progression in multiple sclerosis

Aim

We recently proposed miR‐142‐3p as a molecular player in inflammatory synaptopathy, a new pathogenic hallmark of multiple sclerosis (MS) and of its mouse model experimental autoimmune encephalomyelitis (EAE), that leads to neuronal loss independently of demyelination. MiR‐142‐3p seems to be unique among potential biomarker candidates in MS, since it is an inflammatory miRNA playing a dual role in the immune and central nervous systems. Here, we aimed to verify the impact of miR‐142‐3p circulating in the cerebrospinal fluid (CSF) of MS patients on clinical parameters, neuronal excitability and its potential interaction with disease modifying therapies (DMTs).

Methods and Results

In a cohort of 151 MS patients, we found positive correlations between CSF miR‐142‐3p levels and clinical progression, IL‐1β signalling as well as synaptic excitability measured by transcranial magnetic stimulation. Furthermore, therapy response of patients with ‘low miR‐142‐3p’ to dimethyl fumarate (DMF), an established disease‐modifying treatment (DMT), was superior to that of patients with ‘high miR‐142‐3p’ levels. Accordingly, the EAE clinical course of heterozygous miR‐142 mice was ameliorated by peripheral DMF treatment with a greater impact relative to their wild type littermates. In addition, a central protective effect of this drug was observed following intracerebroventricular and ex vivo acute treatments of EAE wild type mice, showing a rescue of miR‐142‐3p‐dependent glutamatergic alterations. By means of electrophysiology, molecular and biochemical analysis, we suggest miR‐142‐3p as a molecular target of DMF.

Conclusion

MiR‐142‐3p is a novel and potential negative prognostic CSF marker of MS and a promising tool for identifying personalised therapies.

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.

Psilacetin derivatives: fumarate salts of the meth-yl-ethyl, meth-yl-allyl and diallyl variants of the psilocin prodrug

The solid-state structures of the salts of three psilacetin derivatives, namely, 4-acet-oxy-N-eth-yl-N-methyl-tryptammonium (4-AcO-MET) hydro-fumarate {sys-tematic name: [2-(4-acet-yloxy-1H-indol-3-yl)eth-yl](meth-yl)ethyl-aza-nium 3-carb-oxy-prop-2-enoate}, C15H21N2O2 +·C4H3O4 -, 4-acet-oxy-N-allyl-N-methyl-tryptammonium (4-AcO-MALT) hydro-fumarate {systematic name: [2-(4-acet-yl-oxy-1H-indol-3-yl)eth-yl](meth-yl)prop-2-enyl-aza-nium 3-carb-oxy-prop-2-eno-ate}, C16H21N2O2 +·C4H3O4 -, and 4-acet-oxy-N,N-di-allyl-tryptammonium (4-AcO-DALT) fumarate-fumaric acid (1/1) (systematic name: bis-{[2-(4-acet-yloxy-1H-indol-3-yl)eth-yl]diprop-2-enyl-aza-nium} but-2-enedioate-(E)-butenedioic acid (1/1)), 2C18H23N2O2 +·C4H2O4 2-·C4H4O4, are reported. All three salts possess a protonated tryptammonium cation. The 4-AcO-MET and 4-AcO-MALT compounds are charge-balanced by 3-carb-oxy-acrylate (hydro-fumarate) anions. The 4-AcO-DALT complex crystallizes as a two-to-one tryptammonium-to-fumarate salt, which co-crystallizes with a fumaric acid mol-ecule. Each structure is consolidated by N-H⋯O and O-H⋯O hydrogen bonds.

Distinct Nrf2 Signaling Mechanisms of Fumaric Acid Esters and Their Role in Neuroprotection against 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Experimental Parkinson's-Like Disease

A promising approach to neurotherapeutics involves activating the nuclear-factor-E2-related factor 2 (Nrf2)/antioxidant response element signaling, which regulates expression of antioxidant, anti-inflammatory, and cytoprotective genes. Tecfidera, a putative Nrf2 activator, is an oral formulation of dimethylfumarate (DMF) used to treat multiple sclerosis. We compared the effects of DMF and its bioactive metabolite monomethylfumarate (MMF) on Nrf2 signaling and their ability to block 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced experimental Parkinson's disease (PD). We show that in vitro DMF and MMF activate the Nrf2 pathway via S-alkylation of the Nrf2 inhibitor Keap1 and by causing nuclear exit of the Nrf2 repressor Bach1. Nrf2 activation by DMF but not MMF was associated with depletion of glutathione, decreased cell viability, and inhibition of mitochondrial oxygen consumption and glycolysis rates in a dose-dependent manner, whereas MMF increased these activities in vitro However, both DMF and MMF upregulated mitochondrial biogenesis in vitro in an Nrf2-dependent manner. Despite the in vitro differences, both DMF and MMF exerted similar neuroprotective effects and blocked MPTP neurotoxicity in wild-type but not in Nrf2 null mice. Our data suggest that DMF and MMF exhibit neuroprotective effects against MPTP neurotoxicity because of their distinct Nrf2-mediated antioxidant, anti-inflammatory, and mitochondrial functional/biogenetic effects, but MMF does so without depleting glutathione and inhibiting mitochondrial and glycolytic functions. Given that oxidative damage, neuroinflammation, and mitochondrial dysfunction are all implicated in PD pathogenesis, our results provide preclinical evidence for the development of MMF rather than DMF as a novel PD therapeutic.

SIGNIFICANCE STATEMENT

Almost two centuries since its first description by James Parkinson, Parkinson's disease (PD) remains an incurable disease with limited symptomatic treatment. The current study provides preclinical evidence that a Food and Drug Administration-approved drug, dimethylfumarate (DMF), and its metabolite monomethylfumarate (MMF) can block nigrostriatal dopaminergic neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD. We elucidated mechanisms by which DMF and its active metabolite MMF activates the redox-sensitive transcription factor nuclear-factor-E2-related factor 2 (Nrf2) to upregulate antioxidant, anti-inflammatory, mitochondrial biosynthetic and cytoprotective genes to render neuroprotection via distinct S-alkylating properties and depletion of glutathione. Our data suggest that targeting Nrf2-mediated gene transcription using MMF rather than DMF is a promising approach to block oxidative stress, neuroinflammation, and mitochondrial dysfunction for therapeutic intervention in PD while minimizing side effects.

Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: a case series

BACKGROUND

Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fanconi syndrome.

METHODS

Descriptive case series with two cases of Fanconi syndrome associated with FAE treatment diagnosed at two Dutch university nephrology departments, three cases reported at the Dutch and German national pharmacovigilance databases and six previously reported cases.

RESULTS

All 11 cases involved female patients with psoriasis. The median age at the time of onset was 38 years [interquartile range (IQR) 37-46]. Patients received long-term FAEs treatment with a median treatment duration of 60 months (IQR 28-111). Laboratory tests were typically significant for low serum levels of phosphate and uric acid, while urinalysis showed glycosuria and proteinuria. Eight (73%) patients had developed a hypophosphataemic osteomalacia and three (27%) had pathological bone fractures. All patients discontinued FAEs, while four (36%) patients were treated with supplementation of phosphate and/or vitamin D. Five (45%) patients had persisting symptoms despite FAEs discontinuation.

CONCLUSIONS

FAEs treatment can cause drug-induced Fanconi syndrome, but the association has been reported infrequently. Female patients with psoriasis treated long term with FAEs seem to be particularly at risk. Physicians treating patients with FAEs should be vigilant and monitor for the potential occurrence of Fanconi syndrome. Measurement of the urinary albumin:total protein ratio is a suggested screening tool for tubular proteinuria in Fanconi syndrome.

Fumaric acid esters in the management of psoriasis

Fumaric acid esters (FAE) are small molecules with immunomodulating, anti-inflammatory, and anti-oxidative effects. FAE were introduced as a systemic psoriasis treatment in 1959 and empirically developed further between 1970 and 1990 in Germany, Switzerland, and the Netherlands. The development of FAE as psoriasis treatment did not follow the traditional drug development phases. Nonetheless, in 1994 FAE were approved in Germany for the treatment of severe plaque psoriasis. FAE are currently one of the most commonly used treatments in Germany, and FAE are increasingly being used as an unlicensed treatment in several other European countries. To date, six randomized controlled trials and 29 observational studies have evaluated FAE in a combined total of 3,439 patients. The efficacy and safety profile of FAE is favorable. About 50%–70% of patients achieve at least 75% improvement in psoriasis severity after 16 weeks of treatment. Common adverse events of FAE include gastrointestinal complaints and flushing symptoms, which lead to treatment discontinuation in up to 40% of patients. Lymphocytopenia, eosinophilia, and proteinuria are commonly observed during FAE treatment, but rarely require treatment discontinuation. The long-term safety profile of continuous FAE treatment is favorable without an increased risk for infections, malignancies, or other serious adverse events. There are no known drug-interactions for FAE. The 2009 European evidence-based S3-guidelines on psoriasis treatment recommend FAE and suggest it as a first-line systemic treatment for moderate-to-severe plaque psoriasis. This review is aimed to give an overview of FAE treatment in the management of psoriasis.