Safety and efficacy of ceftriaxone for amyotrophic lateral sclerosis: a multi-stage, randomised, double-blind, placebo-controlled trial

Prognostic clinical and biological markers for amyotrophic lateral sclerosis disease progression: validation and implications for clinical trial design and analysis

BACKGROUND

With increasing recognition of the value of incorporating prognostic markers into amyotrophic lateral sclerosis (ALS) trial design and analysis plans, there is a pressing need to understand which among the prevailing clinical and biochemical markers have real value, and how they can be optimally used.

METHODS

A subset of patients with ALS recruited through the multi-center Phenotype-Genotype-Biomarker study (clinicaltrials.gov: NCT02327845) was identified as "trial-like" based on meeting common trial eligibility criteria. Clinical phenotyping was performed by evaluators trained in relevant assessments. Serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH), urinary p75ECD, plasma microRNA-181, and an array of biochemical and clinical measures were evaluated for their prognostic value. Associations with functional progression were estimated by random-slopes mixed models of ALS functional rating scale-revised (ALSFRS-R) score. Associations with survival were estimated by log-rank test and Cox proportional hazards regression. Potential sample size savings from adjusting for given biomarkers in a hypothetical trial were estimated.

FINDINGS

Baseline serum NfL is a powerful prognostic biomarker, predicting survival and ALSFRS-R rate of decline. Serum NfL <40 pg/mL and >100 pg/mL correspond to future ALSFRS-R slopes of ∼0.5 and ∼1.5 points/month, respectively. Serum NfL also adds value to the best available clinical predictors, encapsulated by the European Network to Cure ALS (ENCALS) predictor score. In models of functional decline, the addition of NfL yields ∼25% sample size saving above those achieved by inclusion of either clinical predictors or ENCALS score alone. The prognostic value of serum pNfH, urinary p75ECD, and plasma miR-181ab is more limited.

INTERPRETATION

Among the multitude of biomarkers considered, only blood NfL adds value to the ENCALS prediction model and should be incorporated into analysis plans for all ongoing and future ALS trials. Defined thresholds of NfL might also be used in trial design, for enrichment or stratified randomisation, to improve trial efficiency.

FUNDING

NIH (U01-NS107027, U54-NS092091). ALSA (16-TACL-242).

Discovery of Novel Inhibitors against ALS-Related SOD1(A4V) Aggregation through the Screening of a Chemical Library Using Differential Scanning Fluorimetry (DSF)

BACKGROUND

Cu/Zn Superoxide Dismutase 1 (SOD1) is a 32 kDa cytosolic dimeric metalloenzyme that neutralizes superoxide anions into oxygen and hydrogen peroxide. Mutations in SOD1 are associated with ALS, a disease causing motor neuron atrophy and subsequent mortality. These mutations exert their harmful effects through a gain of function mechanism, rather than a loss of function. Despite extensive research, the mechanism causing selective motor neuron death still remains unclear. A defining feature of ALS pathogenesis is protein misfolding and aggregation, evidenced by ubiquitinated protein inclusions containing SOD1 in affected motor neurons. This work aims to identify compounds countering SOD1(A4V) misfolding and aggregation, which could potentially aid in ALS treatment.

METHODS

The approach employed was in vitro screening of a library comprising 1280 pharmacologically active compounds (LOPAC®) in the context of drug repurposing. Using differential scanning fluorimetry (DSF), these compounds were tested for their impact on SOD1(A4V) thermal stability.

RESULTS AND CONCLUSIONS

Dimer stability was the parameter chosen as the criterion for screening, since the dissociation of the native SOD1 dimer is the step prior to its in vitro aggregation. The screening revealed one compound raising protein-ligand Tm by 6 °C, eleven inducing a higher second Tm, suggesting a stabilization effect, and fourteen reducing Tm from 10 up to 26 °C, suggesting possible interactions or non-specific binding.

Prognostic Clinical and Biological Markers for Amyotrophic Lateral Sclerosis Disease Progression: Validation and Implications for Clinical Trial Design and Analysis

Background

With increasing recognition of the value of incorporating prognostic markers into amyotrophic lateral sclerosis (ALS) trial design and analysis plans, there is a pressing need to understand which among the prevailing clinical and biochemical markers have real value, and how they can be optimally used.

Methods

A subset of patients with ALS recruited through the multi-center Phenotype-Genotype-Biomarker study (clinicaltrials.gov: NCT02327845) was identified as "trial-like" based on meeting common trial eligibility criteria. Clinical phenotyping was performed by evaluators trained in relevant assessments. Serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH), urinary p75ECD, plasma microRNA-181, and an array of biochemical and clinical measures were evaluated for their prognostic value. Associations with functional progression were estimated by random-slopes mixed models of ALS functional rating scale-revised (ALSFRS-R) score. Associations with survival were estimated by log-rank test and Cox proportional hazards regression. Potential sample size savings from adjusting for given biomarkers in a hypothetical trial were estimated.

Findings

Baseline serum NfL is a powerful prognostic biomarker, predicting survival and ALSFRS-R rate of decline. Serum NfL <40pg/ml and >100pg/ml correspond to future ALSFRS-R slopes of ~0.5 and 1.5 points/month, respectively. Serum NfL also adds value to the best available clinical predictors, encapsulated by the European Network to Cure ALS (ENCALS) predictor score. In models of functional decline, the addition of NfL yields ~25% sample size saving above those achieved by inclusion of either clinical predictors or ENCALS score alone. The prognostic value of serum pNfH, urinary p75ECD, and plasma miR-181ab is more limited.

Interpretation

Among the multitude of biomarkers considered, only blood NfL adds value to the ENCALS prediction model and should be incorporated into analysis plans for all ongoing and future ALS trials. Defined thresholds of NfL might also be used in trial design, for enrichment or stratified randomisation, to improve trial efficiency.

Funding

NIH (U01-NS107027, U54-NS092091). ALSA (16-TACL-242).

Dysfunctional astrocyte glutamate uptake in the hypothalamic paraventricular nucleus contributes to visceral pain and anxiety-like behavior in mice with chronic pancreatitis

Abdominal visceral pain is a predominant symptom in patients with chronic pancreatitis (CP); however, the underlying mechanism of pain in CP remains elusive. We hypothesized that astrocytes in the hypothalamic paraventricular nucleus (PVH) contribute to CP pain pathogenesis. A mouse model of CP was established by repeated intraperitoneal administration of caerulein to induce abdominal visceral pain. Abdominal mechanical stimulation, open field and elevated plus maze tests were performed to assess visceral pain and anxiety-like behavior. Fiber photometry, brain slice Ca2+ imaging, electrophysiology, and immunohistochemistry were used to investigate the underlying mechanisms. Mice with CP displayed long-term abdominal mechanical allodynia and comorbid anxiety, which was accompanied by astrocyte glial fibrillary acidic protein reactivity, elevated Ca2+ signaling, and astroglial glutamate transporter-1 (GLT-1) deficits in the PVH. Specifically, reducing astrocyte Ca2+ signaling in the PVH via chemogenetics significantly rescued GLT-1 deficits and alleviated mechanical allodynia and anxiety in mice with CP. Furthermore, we found that GLT-1 deficits directly contributed to the hyperexcitability of VGLUT2PVH neurons in mice with CP, and that pharmacological activation of GLT-1 alleviated the hyperexcitability of VGLUT2PVH neurons, abdominal visceral pain, and anxiety in these mice. Taken together, our data suggest that dysfunctional astrocyte glutamate uptake in the PVH contributes to visceral pain and anxiety in mice with CP, highlighting GLT-1 as a potential therapeutic target for chronic pain in patients experiencing CP.

Drug repurposing for neurodegenerative diseases

Neurodegenerative diseases (NDDs) are neuronal problems that include the brain and spinal cord and result in loss of sensory and motor dysfunction. Common NDDs include Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Multiple Sclerosis (MS), and Amyotrophic Lateral Sclerosis (ALS) etc. The occurrence of these diseases increases with age and is one of the challenging problems among elderly people. Though, several scientific research has demonstrated the key pathologies associated with NDDs still the underlying mechanisms and molecular details are not well understood and need to be explored and this poses a lack of effective treatments for NDDs. Several lines of evidence have shown that NDDs have a high prevalence and affect more than a billion individuals globally but still, researchers need to work forward in identifying the best therapeutic target for NDDs. Thus, several researchers are working in the directions to find potential therapeutic targets to alter the disease pathology and treat the diseases. Several steps have been taken to identify the early detection of the disease and drug repurposing for effective treatment of NDDs. Moreover, it is logical that current medications are being evaluated for their efficacy in treating such disorders; therefore, drug repurposing would be an efficient, safe, and cost-effective way in finding out better medication. In the current manuscript we discussed the utilization of drugs that have been repurposed for the treatment of AD, PD, HD, MS, and ALS.

Drug repurposing for regenerative medicine and cosmetics: Scientific, technological and economic issues

Regenerative medicine and cosmetics are currently two outstanding fields for drug discovery. Although many pharmaceutical products for regenerative medicine and cosmetics have received approval by official agencies, several challenges are still needed to overcome, especially financial and time issues. As a result, drug repositioning, which is the usage of previously approved drugs for new treatment, stands out as a promising approach to tackle these problems. Recently, increasing scientific evidence is collected to demonstrate the applicability of this novel method in the field of regenerative medicine and cosmetics. Experts in drug development have also taken advantage of novel technologies to discover new candidates for repositioning purposes following computational approach, one of two main approaches of drug repositioning. Therefore, numerous repurposed candidates have obtained approval to enter the market and have witnessed financial success such as minoxidil and fingolimod. The benefits of drug repositioning are undeniable for regenerative medicine and cosmetics. However, some aspects still need to be carefully considered regarding this method including actual effectiveness during clinical trials, patent regulations, data integration and analysis, publicly unavailable databases as well as environmental concerns and more effort are required to overcome these obstacles.

Neuronal Circuit Dysfunction in Amyotrophic Lateral Sclerosis

The primary neural circuit affected in Amyotrophic Lateral Sclerosis (ALS) patients is the corticospinal motor circuit, originating in upper motor neurons (UMNs) in the cerebral motor cortex which descend to synapse with the lower motor neurons (LMNs) in the spinal cord to ultimately innervate the skeletal muscle. Perturbation of these neural circuits and consequent loss of both UMNs and LMNs, leading to muscle wastage and impaired movement, is the key pathophysiology observed. Despite decades of research, we are still lacking in ALS disease-modifying treatments. In this review, we document the current research from patient studies, rodent models, and human stem cell models in understanding the mechanisms of corticomotor circuit dysfunction and its implication in ALS. We summarize the current knowledge about cortical UMN dysfunction and degeneration, altered excitability in LMNs, neuromuscular junction degeneration, and the non-cell autonomous role of glial cells in motor circuit dysfunction in relation to ALS. We further highlight the advances in human stem cell technology to model the complex neural circuitry and how these can aid in future studies to better understand the mechanisms of neural circuit dysfunction underpinning ALS.

How do we get from hyperexcitability to excitotoxicity in amyotrophic lateral sclerosis?

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease that, at present, has no effective cure. Evidence of increased circulating glutamate and hyperexcitability of the motor cortex in patients with amyotrophic lateral sclerosis have provided an empirical support base for the 'dying forward' excitotoxicity hypothesis. The hypothesis postulates that increased activation of upper motor neurons spreads pathology to lower motor neurons in the spinal cord in the form of excessive glutamate release, which triggers excitotoxic processes. Many clinical trials have focused on therapies that target excitotoxicity via dampening neuronal activation, but not all are effective. As such, there is a growing tension between the rising tide of evidence for the 'dying forward' excitotoxicity hypothesis and the failure of therapies that target neuronal activation. One possible solution to these contradictory outcomes is that our interpretation of the current evidence requires revision in the context of appreciating the complexity of the nervous system and the limitations of the neurobiological assays we use to study it. In this review we provide an evaluation of evidence relevant to the 'dying forward' excitotoxicity hypothesis and by doing so, identify key gaps in our knowledge that need to be addressed. We hope to provide a road map from hyperexcitability to excitotoxicity so that we can better develop therapies for patients suffering from amyotrophic lateral sclerosis. We conclude that studies of upper motor neuron activity and their synaptic output will play a decisive role in the future of amyotrophic lateral sclerosis therapy.

Amyotrophic lateral sclerosis: exploring pathophysiology in the context of treatment

Amyotrophic lateral sclerosis (ALS) is a complex, neurodegenerative disorder in which alterations in structural, physiological, and metabolic parameters act synergistically. Over the last decade there has been a considerable focus on developing drugs to slow the progression of the disease. Despite this, only four disease-modifying therapies are approved in North America. Although additional research is required for a thorough understanding of ALS, we have accumulated a large amount of knowledge that could be better integrated into future clinical trials to accelerate drug development and provide patients with improved treatment options. It is likely that future, successful ALS treatments will take a multi-pronged therapeutic approach, targeting different pathways, akin to personalized medicine in oncology. In this review, we discuss the link between ALS pathophysiology and treatments, looking at the therapeutic failures as learning opportunities that can help us refine and optimize drug development.

Astroglial activation: Current concepts and future directions

Astrocytes are abundantly and ubiquitously expressed cell types with diverse functions throughout the central nervous system. Astrocytes show remarkable plasticity and exhibit morphological, molecular, and functional remodeling in response to injury, disease, or infection of the central nervous system, as evident in neurodegenerative diseases. Astroglial mediated inflammation plays a prominent role in the pathogenesis of neurodegenerative diseases. This review focus on the role of astrocytes as essential players in neuroinflammation and discuss their morphological and functional heterogeneity in the normal central nervous system and explore the spatial and temporal variations in astroglial phenotypes observed under different disease conditions. This review discusses the intimate relationship of astrocytes to pathological hallmarks of neurodegenerative diseases. Finally, this review considers the putative therapeutic strategies that can be deployed to modulate the astroglial functions in neurodegenerative diseases. HIGHLIGHTS: Astroglia mediated neuroinflammation plays a key role in the pathogenesis of neurodegenerative diseases. Activated astrocytes exhibit diverse phenotypes in a region-specific manner in brain and interact with β-amyloid, tau, and α-synuclein species as well as with microglia and neuronal circuits. Activated astrocytes are likely to influence the trajectory of disease progression of neurodegenerative diseases, as determined by the stage of disease, individual susceptibility, and state of astroglial priming. Modulation of astroglial activation may be a therapeutic strategy at various stages in the trajectory of neurodegenerative diseases to modify the disease course.

The Conventional and Breakthrough Tool for the Study of L-Glutamate Transporters

In our recent report, we clarified the direct interaction between the excitatory amino acid transporter (EAAT) 1/2 and polyunsaturated fatty acids (PUFAs) by applying electrophysiological and molecular biological techniques to Xenopus oocytes. Xenopus oocytes have a long history of use in the scientific field, but they are still attractive experimental systems for neuropharmacological studies. We will therefore summarize the pharmacological significance, advantages (especially in the study of EAAT2), and experimental techniques that can be applied to Xenopus oocytes; our new findings concerning L-glutamate (L-Glu) transporters and PUFAs; and the significant outcomes of our data. The data obtained from electrophysiological and molecular biological studies of Xenopus oocytes have provided us with further important questions, such as whether or not some PUFAs can modulate EAATs as allosteric modulators and to what extent docosahexaenoic acid (DHA) affects neurotransmission and thereby affects brain functions. Xenopus oocytes have great advantages in the studies about the interactions between molecules and functional proteins, especially in the case when the expression levels of the proteins are small in cell culture systems without transfections. These are also proper to study the mechanisms underlying the interactions. Based on the data collected in Xenopus oocyte experiments, we can proceed to the next step, i.e., the physiological roles of the compounds and their significances. In the case of EAAT2, the effects on the neurotransmission should be examined by electrophysiological approach using acute brain slices. For new drug development, pharmacokinetics pharmacodynamics (PKPD) data and blood brain barrier (BBB) penetration data are also necessary. In order not to miss the promising candidate compounds at the primary stages of drug development, we should reconsider using Xenopus oocytes in the early phase of drug development.

Harmonized standard operating procedures for administering the ALS functional rating scale-revised

The ALS Functional Rating Scale-Revised is the most commonly used primary outcome measure in current ALS clinical trials. While rigorous training and certification is generally recognized as critical to reliable performance, differences have existed between training in the two groups responsible for most training in ALS outcome measures. We present a harmonized standard operating procedure which is intended to further reduce response variability by the use of identical training in North America and Europe.

Effects of Beta Lactams on Behavioral Outcomes of Substance Use Disorders: A Meta-Analysis of Preclinical Studies

INTRODUCTION

Preclinical studies demonstrated that beta-lactams have neuroprotective effects in conditions involving glutamate neuroexcitotoxicity, including substance use disorders (SUDs). This meta-analysis aims to analyze the existing evidences on the effects of beta-lactams as glutamate transporter 1 (GLT-1) upregulators in animal models of SUDs, identification of gaps in the literature, and setting the stage for potential translation into clinical phases.

METHODS

Meta-analysis was conducted on preclinical studies retrieved systematically from MEDLINE and ScienceDirect databases. Abused substances were identified by refereeing to the National Institute on Drug Abuse (NIDA). The results were quantitatively described with a focus on the behavioral outcomes. Treatment effect sizes were described using standardized mean difference, and they were pooled using random effect model. I2-statistic was used to assess heterogeneity, and Funnel plot and Egger's test were used for assessment of publication bias.

RESULTS

Literature search yielded a total of 71 studies that were eligible to be included in the analysis. Through these studies, the effects of beta-lactams were evaluated in animal models of nicotine, cannabis, amphetamines, synthetic cathinone, opioids, ethanol, and cocaine use disorders as well as steroids-related aggressive behaviors. Meta-analysis showed that treatments with beta-lactams consistently reduced the pooled undesired effects of the abused substances in several paradigms, including drug-self administration, conditioned place preference, drug seeking behaviors, hyperlocomotion, withdrawal syndromes, tolerance to analgesic effects, hyperalgesia, and hyperthermia.

CONCLUSION

This meta-analysis revealed that enhancing GLT-1 expression in the brain through beta-lactams seemed to be a promising treatment approach in the context of substance use disorders, as indicated by results in animal models.

Brain-inhabiting bacteria and neurodegenerative diseases: the "brain microbiome" theory

Controversies surrounding the validity of the toxic proteinopathy theory of Alzheimer's disease have led the scientific community to seek alternative theories in the pathogenesis of neurodegenerative disorders (ND). Recent studies have provided evidence of a microbiome in the central nervous system. Some have hypothesized that brain-inhabiting organisms induce chronic neuroinflammation, leading to the development of a spectrum of NDs. Bacteria such as Chlamydia pneumoniae, Helicobacter pylori, and Cutibacterium acnes have been found to inhabit the brains of ND patients. Furthermore, several fungi, including Candida and Malassezia species, have been identified in the central nervous system of these patients. However, there remains several limitations to the brain microbiome hypothesis. Varying results across the literature, concerns regarding sample contamination, and the presence of exogenous deoxyribonucleic acids have led to doubts about the hypothesis. These results provide valuable insight into the pathogenesis of NDs. Herein, we provide a review of the evidence for and against the brain microbiome theory and describe the difficulties facing the hypothesis. Additionally, we define possible mechanisms of bacterial invasion of the brain and organism-related neurodegeneration in NDs and the potential therapeutic premises of this theory.

Molecular mechanisms of ischemia and glutamate excitotoxicity

Excitotoxicity is classically defined as the neuronal damage caused by the excessive release of glutamate, and subsequent activation of excitatory plasma membrane receptors. In the mammalian brain, this phenomenon is mainly driven by excessive activation of glutamate receptors (GRs). Excitotoxicity is common to several chronic disorders of the Central Nervous System (CNS) and is considered the primary mechanism of neuronal loss of function and cell death in acute CNS diseases (e.g. ischemic stroke). Multiple mechanisms and pathways lead to excitotoxic cell damage including pro-death signaling cascade events downstream of glutamate receptors, calcium (Ca2+) overload, oxidative stress, mitochondrial impairment, excessive glutamate in the synaptic cleft as well as altered energy metabolism. Here, we review the current knowledge on the molecular mechanisms that underlie excitotoxicity, emphasizing the role of Nicotinamide Adenine Dinucleotide (NAD) metabolism. We also discuss novel and promising therapeutic strategies to treat excitotoxicity, highlighting recent clinical trials. Finally, we will shed light on the ongoing search for stroke biomarkers, an exciting and promising field of research, which may improve stroke diagnosis, prognosis and allow better treatment options.

Astrocytes: Dissecting Their Diverse Roles in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are fatal neurodegenerative disorders often co-occurring in the same patient, a feature that suggests a common origin of the two diseases. Consistently, pathological inclusions of the same proteins as well as mutations in the same genes can be identified in both ALS/FTD. Although many studies have described several disrupted pathways within neurons, glial cells are also regarded as crucial pathogenetic contributors in ALS/FTD. Here, we focus our attention on astrocytes, a heterogenous population of glial cells that perform several functions for optimal central nervous system homeostasis. Firstly, we discuss how post-mortem material from ALS/FTD patients supports astrocyte dysfunction around three pillars: neuroinflammation, abnormal protein aggregation, and atrophy/degeneration. Furthermore, we summarize current attempts at monitoring astrocyte functions in living patients using either novel imaging strategies or soluble biomarkers. We then address how astrocyte pathology is recapitulated in animal and cellular models of ALS/FTD and how we used these models both to understand the molecular mechanisms driving glial dysfunction and as platforms for pre-clinical testing of therapeutics. Finally, we present the current clinical trials for ALS/FTD, restricting our discussion to treatments that modulate astrocyte functions, directly or indirectly.

Wearable device and smartphone data quantify ALS progression and may provide novel outcome measures

Amyotrophic lateral sclerosis (ALS) therapeutic development has largely relied on staff-administered functional rating scales to determine treatment efficacy. We sought to determine if mobile applications (apps) and wearable devices can be used to quantify ALS disease progression through active (surveys) and passive (sensors) data collection. Forty ambulatory adults with ALS were followed for 6-months. The Beiwe app was used to administer the self-entry ALS functional rating scale-revised (ALSFRS-RSE) and the Rasch Overall ALS Disability Scale (ROADS) surveys every 2-4 weeks. Each participant used a wrist-worn activity monitor (ActiGraph Insight Watch) or an ankle-worn activity monitor (Modus StepWatch) continuously. Wearable device wear and app survey compliance were adequate. ALSFRS-R highly correlated with ALSFRS-RSE. Several wearable data daily physical activity measures demonstrated statistically significant change over time and associations with ALSFRS-RSE and ROADS. Active and passive digital data collection hold promise for novel ALS trial outcome measure development.

Glutamatergic neurotransmission: A potential pharmacotherapeutic target for the treatment of cognitive disorders

In the mammalian brain, glutamate is regarded to be the primary excitatory neurotransmitter due to its widespread distribution and wide range of metabolic functions. Glutamate plays key roles in regulating neurogenesis, synaptogenesis, neurite outgrowth, and neuron survival in the brain. Ionotropic and metabotropic glutamate receptors, neurotransmitters, neurotensin, neurosteroids, and others co-ordinately formulate a complex glutamatergic network in the brain that maintains optimal excitatory neurotransmission. Cognitive activities are potentially synchronized by the glutamatergic activities in the brain via restoring synaptic plasticity. Dysfunctional glutamate receptors and other glutamatergic components are responsible for the aberrant glutamatergic activity in the brain that cause cognitive impairments, loss of synaptic plasticity, and neuronal damage. Thus, controlling the brain's glutamatergic transmission and modifying glutamate receptor function could be a potential therapeutic strategy for cognitive disorders. Certain drugs that regulate glutamate receptor activities have shown therapeutic promise in improving cognitive functions in preclinical and clinical studies. However, several issues regarding precise functional information of glutamatergic activity are yet to be comprehensively understood. The present article discusses the scope of developing glutamatergic systems as prospective pharmacotherapeutic targets to treat cognitive disorders. Special attention has been given to recent developments, challenges, and future prospects.

A Medicinal Chemistry Perspective on Excitatory Amino Acid Transporter 2 Dysfunction in Neurodegenerative Diseases

The excitatory amino acid transporter 2 (EAAT2) plays a key role in the clearance and recycling of glutamate - the major excitatory neurotransmitter in the mammalian brain. EAAT2 loss/dysfunction triggers a cascade of neurodegenerative events, comprising glutamatergic excitotoxicity and neuronal death. Nevertheless, our current knowledge regarding EAAT2 in neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD), is restricted to post-mortem analysis of brain tissue and experimental models. Thus, detecting EAAT2 in the living human brain might be crucial to improve diagnosis/therapy for ALS and AD. This perspective article describes the role of EAAT2 in physio/pathological processes and provides a structure-activity relationship of EAAT2-binders, bringing two perspectives: therapy (activators) and diagnosis (molecular imaging tools).

Identification of potential pathways and biomarkers linked to progression in ALS

OBJECTIVE

To identify potential diagnostic and prognostic biomarkers for clinical management and clinical trials in amyotrophic lateral sclerosis.

METHODS

We analysed proteomics data of ALS patient-induced pluripotent stem cell-derived motor neurons available through the AnswerALS consortium. After stratifying patients using clinical ALSFRS-R and ALS-CBS scales, we identified differentially expressed proteins indicative of ALS disease severity and progression rate as candidate ALS-related and prognostic biomarkers. Pathway analysis for identified proteins was performed using STITCH. Protein sets were correlated with the effects of drugs using the Connectivity Map tool to identify compounds likely to affect similar pathways. RNAi screening was performed in a Drosophila TDP-43 ALS model to validate pathological relevance. A statistical classification machine learning model was constructed using ridge regression that uses proteomics data to differentiate ALS patients from controls.

RESULTS

We identified 76, 21, 71 and 1 candidate ALS-related biomarkers and 22, 41, 27 and 64 candidate prognostic biomarkers from patients stratified by ALSFRS-R baseline, ALSFRS-R progression slope, ALS-CBS baseline and ALS-CBS progression slope, respectively. Nineteen proteins enhanced or suppressed pathogenic eye phenotypes in the ALS fly model. Nutraceuticals, dopamine pathway modulators, statins, anti-inflammatories and antimicrobials were predicted starting points for drug repurposing using the connectivity map tool. Ten diagnostic biomarker proteins were predicted by machine learning to identify ALS patients with high accuracy and sensitivity.

INTERPRETATION

This study showcases the powerful approach of iPSC-motor neuron proteomics combined with machine learning and biological confirmation in the prediction of novel mechanisms and diagnostic and predictive biomarkers in ALS.

Amyotrophic Lateral Sclerosis Clinical Trials and Interpretation of Functional End Points and Fluid Biomarkers: A Review

Importance

Clinical trial activity in amyotrophic lateral sclerosis (ALS) is dramatically increasing; as a result, trial modifications have been introduced to improve efficiency, outcome measures have been reassessed, and considerable discussion about the level of data necessary to advance a drug to approval has occurred. This review discusses what recent pivotal studies can teach the community about these topics.

Observations

By restricting inclusion and exclusion criteria, recent trials have enrolled populations distinct from previous studies. This has led to efficacy signals being observed in studies that are smaller and shorter than was thought feasible previously. However, such trials raise questions about generalizability of results. Small trials with equivocal clinical results also raise questions about the data necessary to lead to regulatory approval. The ALS Functional Rating Scale-Revised remains the most commonly used primary outcome measure; this review discusses innovations in its use. Blood neurofilament levels can predict prognosis in ALS and may be a sensitive indicator of biologic effect; current knowledge does not yet support its use as a primary outcome.

Conclusions and Relevance

It is now possible to use specific inclusion criteria to recruit a homogeneous patient population progressing at a specific rate; this will likely impact trials in the future. Generalizability of results on limited populations remains a concern. Although clinical outcomes remain the most appropriate primary outcome measures, fluid markers reflecting biologically important processes will assume more importance as more is learned about the association between such markers and clinical end points. The benefit of use of analytic strategies, such as responder analyses, is still uncertain.

A bioinformatic inquiry of the EAAT2 interactome in postmortem and neuropsychiatric datasets

Altered expression and localization of the glutamate transporter EAAT2 is found in schizophrenia and other neuropsychiatric (major depression, MDD) and neurological disorders (amyotrophic lateral sclerosis, ALS). However, the EAAT2 interactome, the network of proteins that physically or functionally interact with EAAT2 to support its activity, has yet to be characterized in severe mental illness. We compiled a list of "core" EAAT2 interacting proteins. Using Kaleidoscope, an R-shiny application, we data mined publically available postmortem transcriptome datasets to determine whether components of the EAAT2 interactome are differentially expressed in schizophrenia and, using Reactome, identify which interactome-associated biological pathways are altered. Overall, these "look up" studies highlight region-specific, primarily frontal cortex (dorsolateral prefrontal cortex and anterior cingulate cortex), changes in the EAAT2 interactome and implicate altered metabolism pathways in schizophrenia. Pathway analyses also suggest that perturbation of components of the EAAT2 interactome in animal models of antipsychotic administration impact metabolism. Similar changes in metabolism pathways are seen in ALS, in addition to altered expression of many components of the EAAT2 interactome. However, although EAAT2 expression is altered in a postmortem MDD dataset, few other components of the EAAT2 interactome are changed. Thus, "look up" studies suggest region- and disease-relevant biological pathways related to the EAAT2 interactome that implicate glutamate reuptake perturbations in schizophrenia, while providing a useful tool to exploit "omics" datasets.

Therapeutic drug repositioning with special emphasis on neurodegenerative diseases: Threats and issues

Drug repositioning or repurposing is the process of discovering leading-edge indications for authorized or declined/abandoned molecules for use in different diseases. This approach revitalizes the traditional drug discovery method by revealing new therapeutic applications for existing drugs. There are numerous studies available that highlight the triumph of several drugs as repurposed therapeutics. For example, sildenafil to aspirin, thalidomide to adalimumab, and so on. Millions of people worldwide are affected by neurodegenerative diseases. According to a 2021 report, the Alzheimer's disease Association estimates that 6.2 million Americans are detected with Alzheimer's disease. By 2030, approximately 1.2 million people in the United States possibly acquire Parkinson's disease. Drugs that act on a single molecular target benefit people suffering from neurodegenerative diseases. Current pharmacological approaches, on the other hand, are constrained in their capacity to unquestionably alter the course of the disease and provide patients with inadequate and momentary benefits. Drug repositioning-based approaches appear to be very pertinent, expense- and time-reducing strategies for the enhancement of medicinal opportunities for such diseases in the current era. Kinase inhibitors, for example, which were developed for various oncology indications, demonstrated significant neuroprotective effects in neurodegenerative diseases. This review expounds on the classical and recent examples of drug repositioning at various stages of drug development, with a special focus on neurodegenerative disorders and the aspects of threats and issues viz. the regulatory, scientific, and economic aspects.

Identifying patterns in amyotrophic lateral sclerosis progression from sparse longitudinal data

The clinical presentation of amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, varies widely across patients, making it challenging to determine if potential therapeutics slow progression. We sought to determine whether there were common patterns of disease progression that could aid in the design and analysis of clinical trials. We developed an approach based on a mixture of Gaussian processes to identify clusters of patients sharing similar disease progression patterns, modeling their average trajectories and the variability in each cluster. We show that ALS progression is frequently nonlinear, with periods of stable disease preceded or followed by rapid decline. We also show that our approach can be extended to Alzheimer's and Parkinson's diseases. Our results advance the characterization of disease progression of ALS and provide a flexible modeling approach that can be applied to other progressive diseases.

Herbal medicine for amyotrophic lateral sclerosis: A systematic review and meta-analysis

Background: The effect of herbal medicine (HM) on amyotrophic lateral sclerosis (ALS) is controversial. Clinical trials investigating HMs continue; however, the use of HM is still questioned. We aimed to systematically review the literature pertaining to the effects and safety of HM in ALS.

Methods: Randomised controlled trials (RCTs) that investigated the efficacy of HMs in ALS patients compared to any types of controls were identified. Nine databases and six registers were searched from their inception dates to 25 March 2022. Per the PRISMA guidelines, trials were identified and extracted. The risk of bias was evaluated using the Cochrane’s tool. Certainty of evidence was assessed as per the GRADE criteria. Forest plots were constructed to assess the effect size and corresponding 95% CIs using fixed-effect models, and random-effect models were employed when required. The primary outcome was the activity limitation measured by validated tools, such as the revised ALS Functional Rating Scale.

Results: Twenty studies (N = 1,218) were eligible. Of these, only five studies were double-blinded, and two were placebo-controlled. Fourteen HMs (fifty-one single botanicals) were involved; Astragalus mongholicus Bunge, Atractylodes macrocephala Koidz., and Glycyrrhiza glabra L. were commonly used in nine, eight, and six trials, respectively. For delaying activity limitation, Jiweiling injection (MD, 2.84; 95% CI, 1.21 to 4.46; p = 0.0006) and Shenmai injection (SMD, 1.07; 0.69 to 1.45; p < 0.00001) were significantly more efficacious than Riluzole, but the evidence was low quality. For ameliorating motor neuron loss, Jiweiling injection [right abductor pollicis brevis (APB): MD, 32.42; 7.91 to 56.93; p = 0.01 and left APB: MD, 34.44; 12.85 to 56.03; p = 0.002] was favoured, but the evidence was very low quality. Nine studies reported one hundred and twenty-three adverse events, twenty-six of which occurred in the treatment groups and ninety-seven in the control groups.

Conclusion: Very low to low quality of evidence suggests that HMs seem to produce superior treatment responses for ALS without increased risk of adverse events. Additional studies with homogeneous participants, reduced methodological issues, and more efficient outcome measures are required to provide confirmatory evidence.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021277443.

Ceftriaxone as a Novel Therapeutic Agent for Hyperglutamatergic States: Bridging the Gap Between Preclinical Results and Clinical Translation

Dysregulation of glutamate homeostasis is a well-established core feature of neuropsychiatric disorders. Extracellular glutamate concentration is regulated by glutamate transporter 1 (GLT-1). The discovery of a beta-lactam antibiotic, ceftriaxone (CEF), as a safe compound with unique ability to upregulate GLT-1 sparked the interest in testing its efficacy as a novel therapeutic agent in animal models of neuropsychiatric disorders with hyperglutamatergic states. Indeed, more than 100 preclinical studies have shown the efficacy of CEF in attenuating the behavioral manifestations of various hyperglutamatergic brain disorders such as ischemic stroke, amyotrophic lateral sclerosis (ALS), seizure, Huntington’s disease, and various aspects of drug use disorders. However, despite rich and promising preclinical data, only one large-scale clinical trial testing the efficacy of CEF in patients with ALS is reported. Unfortunately, in that study, there was no significant difference in survival between placebo- and CEF-treated patients. In this review, we discussed the translational potential of preclinical efficacy of CEF based on four different parameters: (1) initiation of CEF treatment in relation to induction of the hyperglutamatergic state, (2) onset of response in preclinical models in relation to onset of GLT-1 upregulation, (3) mechanisms of action of CEF on GLT-1 expression and function, and (4) non-GLT-1-mediated mechanisms for CEF. Our detailed review of the literature brings new insights into underlying molecular mechanisms correlating the preclinical efficacy of CEF. We concluded here that CEF may be clinically effective in selected cases in acute and transient hyperglutamatergic states such as early drug withdrawal conditions.

Considerations for Amyotrophic Lateral Sclerosis (ALS) Clinical Trial Design

Thoughtful clinical trial design is critical for efficient therapeutic development, particularly in the field of amyotrophic lateral sclerosis (ALS), where trials often aim to detect modest treatment effects among a population with heterogeneous disease progression. Appropriate outcome measure selection is necessary for trials to provide decisive and informative results. Investigators must consider the outcome measure's reliability, responsiveness to detect change when change has actually occurred, clinical relevance, and psychometric performance. ALS clinical trials can also be performed more efficiently by utilizing statistical enrichment techniques. Innovations in ALS prediction models allow for selection of participants with less heterogeneity in disease progression rates without requiring a lead-in period, or participants can be stratified according to predicted progression. Statistical enrichment can reduce the needed sample size and improve study power, but investigators must find a balance between optimizing statistical efficiency and retaining generalizability of study findings to the broader ALS population. Additional progress is still needed for biomarker development and validation to confirm target engagement in ALS treatment trials. Selection of an appropriate biofluid biomarker depends on the treatment mechanism of interest, and biomarker studies should be incorporated into early phase trials. Inclusion of patients with ALS as advisors and advocates can strengthen clinical trial design and study retention, but more engagement efforts are needed to improve diversity and equity in ALS research studies. Another challenge for ALS therapeutic development is identifying ways to respect patient autonomy and improve access to experimental treatment, something that is strongly desired by many patients with ALS and ALS advocacy organizations. Expanded access programs that run concurrently to well-designed and adequately powered randomized controlled trials may provide an opportunity to broaden access to promising therapeutics without compromising scientific integrity or rushing regulatory approval of therapies without adequate proof of efficacy.

Analysis of the US Safety Data for Edaravone (Radicava®) From the Third Year After Launch

Background

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neuromuscular disease with no curative therapies. Edaravone (Radicava^®) (Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan), approved in the United States (US) for ALS in adults in 2017, was shown in a clinical trial to slow the rate of physical functional decline in ALS and is administered intravenously. The aim of this paper is to summarize the observed safety profile from real-world patient use during the first 3 years of edaravone availability in the US.

Methods

Edaravone usage data were collected, and adverse events (AEs) were identified from a postmarketing safety database from August 8, 2017 through August 7, 2020 (cutoff date).

Results

As of October 3, 2020, 5207 ALS patients had been treated with edaravone. As of August 7, 2020, the most commonly reported AEs included death (not specified), drug ineffective, disease progression, therapeutic response unexpected, fall, asthenia, fatigue, muscular weakness, gait disturbance, and dyspnea. The most commonly reported serious AEs (SAEs) included death (not specified), pneumonia, disease progression, ALS, fall, dyspnea, respiratory failure, device-related infection, hospitalization, and injection-site infection. There were 687 deaths, with 494 reported as death without specifying the cause. Deaths were most commonly attributed to ALS, disease progression, respiratory failure, or pneumonia. Review for administration-site reactions revealed 95 AEs, including 34 site infections, with 22 SAEs (all non-fatal). Five non-fatal SAEs of anaphylaxis were reported.

Conclusion

In the postmarketing reporting to date, no new safety signals were identified beyond those already known from the edaravone clinical trial program.

Drug Repurposing to Target Neuroinflammation and Sensory Neuron-Dependent Pain

Around 20% of the American population have chronic pain and estimates in other Western countries report similar numbers. This represents a major challenge for global health care systems. Additional problems for the treatment of chronic and persistent pain are the comparably low efficacy of existing therapies, the failure to translate effects observed in preclinical pain models to human patients and related setbacks in clinical trials from previous attempts to develop novel analgesics. Drug repurposing offers an alternative approach to identify novel analgesics as it can bypass various steps of classical drug development. In recent years, several approved drugs were attributed analgesic properties. Here, we review available data and discuss recent findings suggesting that the approved drugs minocycline, fingolimod, pioglitazone, nilotinib, telmisartan, and others, which were originally developed for the treatment of different pathologies, can have analgesic, antihyperalgesic, or neuroprotective effects in preclinical and clinical models of inflammatory or neuropathic pain. For our analysis, we subdivide the drugs into substances that can target neuroinflammation or substances that can act on peripheral sensory neurons, and highlight the proposed mechanisms. Finally, we discuss the merits and challenges of drug repurposing for the development of novel analgesics.

Comprehensive Research on Past and Future Therapeutic Strategies Devoted to Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly debilitating fatal neurodegenerative disorder, causing muscle atrophy and weakness, which leads to paralysis and eventual death. ALS has a multifaceted nature affected by many pathological mechanisms, including oxidative stress (also via protein aggregation), mitochondrial dysfunction, glutamate-induced excitotoxicity, apoptosis, neuroinflammation, axonal degeneration, skeletal muscle deterioration and viruses. This complexity is a major obstacle in defeating ALS. At present, riluzole and edaravone are the only drugs that have passed clinical trials for the treatment of ALS, notwithstanding that they showed modest benefits in a limited population of ALS. A dextromethorphan hydrobromide and quinidine sulfate combination was also approved to treat pseudobulbar affect (PBA) in the course of ALS. Globally, there is a struggle to prevent or alleviate the symptoms of this neurodegenerative disease, including implementation of antisense oligonucleotides (ASOs), induced pluripotent stem cells (iPSCs), CRISPR-9/Cas technique, non-invasive brain stimulation (NIBS) or ALS-on-a-chip technology. Additionally, researchers have synthesized and screened new compounds to be effective in ALS beyond the drug repurposing strategy. Despite all these efforts, ALS treatment is largely limited to palliative care, and there is a strong need for new therapeutics to be developed. This review focuses on and discusses which therapeutic strategies have been followed so far and what can be done in the future for the treatment of ALS.

Randomized phase 2 study of perampanel for sporadic amyotrophic lateral sclerosis

OBJECTIVE

To evaluate the efficacy and safety of perampanel in patients with sporadic amyotrophic lateral sclerosis (SALS).

METHODS

This randomized, double-blind, placebo-controlled, multicenter, phase 2 clinical study was conducted at 12 sites. Patients with probable or definite ALS as defined by revised El Escorial criteria were enrolled. Sixty-six patients were randomly assigned (1:1:1) to receive placebo, 4 mg perampanel, or 8 mg perampanel daily for 48 weeks. Adverse events (AEs) were recorded throughout the trial period. The primary efficacy outcome was the change in Amyotrophic Lateral Sclerosis Rating Scale-Revised (ALSFRS-R) score after 48 weeks of treatment.

RESULTS

One patient withdrew before starting the treatment. Of 65 patients included, 18 of 22 patients randomized to placebo (82%), 14 of 22 patients randomized to 4 mg perampanel (64%), and 7 of 21 patients randomized to 8 mg perampanel (33%) completed the trial. There was a significant difference in the change of ALSFRS-R scores [- 8.4 (95% CI - 13.9 to - 2.9); p = 0.015] between the placebo and the perampanel 8 mg group, primarily due to worsening of the bulbar subscore in the perampanel 8 mg group. Serious AEs were more frequent in the perampanel 8 mg group than in the placebo group (p = 0.0483).

CONCLUSIONS

Perampanel was associated with a significant decline in ALSFRS-R score and was linked to worsening of the bulbar subscore in the 8 mg group.

Integrating gene expression and clinical data to identify drug repurposing candidates for hyperlipidemia and hypertension

Discovering novel uses for existing drugs, through drug repurposing, can reduce the time, costs, and risk of failure associated with new drug development. However, prioritizing drug repurposing candidates for downstream studies remains challenging. Here, we present a high-throughput approach to identify and validate drug repurposing candidates. This approach integrates human gene expression, drug perturbation, and clinical data from publicly available resources. We apply this approach to find drug repurposing candidates for two diseases, hyperlipidemia and hypertension. We screen >21,000 compounds and replicate ten approved drugs. We also identify 25 (seven for hyperlipidemia, eighteen for hypertension) drugs approved for other indications with therapeutic effects on clinically relevant biomarkers. For five of these drugs, the therapeutic effects are replicated in the All of Us Research Program database. We anticipate our approach will enable researchers to integrate multiple publicly available datasets to identify high priority drug repurposing opportunities for human diseases.

A chemogenomic approach is required for effective treatment of amyotrophic lateral sclerosis

ALS is a fatal untreatable disease involving degeneration of motor neurons. Μultiple causative genes encoding proteins with versatile functions have been identified indicating that diverse biological pathways lead to ALS. Chemical entities still represent a promising choice to delay ALS progression, attenuate symptoms and/or increase life expectancy, but also gene-based and stem cell-based therapies are in the process of development, and some are tested in clinical trials. Various compounds proved effective in transgenic models overexpressing distinct ALS causative genes unfortunately though, they showed no efficacy in clinical trials. Notably, while animal models provide a uniform genetic background for preclinical testing, ALS patients are not stratified, and the distinct genetic forms of ALS are treated as one group, which could explain the observed discrepancies between treating genetically homogeneous mice and quite heterogeneous patient cohorts. We suggest that chemical entity-genotype correlation should be exploited to guide patient stratification for pharmacotherapy, that is administered drugs should be selected based on the ALS genetic background.

Drugs repurposed: An advanced step towards the treatment of breast cancer and associated challenges

Breast cancer (BC) is mostly observed in women and is responsible for huge mortality in women subjects globally. Due to the continued development of drug resistance and other contributing factors, the scientific community needs to look for new alternatives, and drug repurposing is one of the best opportunities. Here we light upon the drug repurposing with a major focus on breast cancer. BC is a division of cancer known as the leading cause of death of 2.3 million women globally, with 685,000 fatalities. This number is steadily rising, necessitating the development of a treatment that can extend survival time. All available treatments for BC are very costly as well as show side effects. This unfulfilled requirement of the anti-cancer drugs ignited an enthusiasm for drug repositioning, which means finding out the anti-cancer use of already marketed drugs for other complications. With the advancement in proteomics, genomics, and computational approaches, the drug repurposing process hastens. So many drugs are repurposed for the BC, including alkylating agents, antimetabolite, anthracyclines, an aromatase inhibitor, mTOR, and many more. The drug resistance in breast cancer is rising, so reviewing how the challenges in breast cancer can be combated with drug repurposing. This paper provides the updated information on all the repurposed drugs candidates for breast cancer with the molecular mechanism responsible for their anti-tumor activity. Additionally, all the challenges that occur during the repurposing of the drugs are discussed.

Clinical trials in amyotrophic lateral sclerosis: a systematic review and perspective

Amyotrophic lateral sclerosis is a progressive and devastating neurodegenerative disease. Despite decades of clinical trials, effective disease-modifying drugs remain scarce. To understand the challenges of trial design and delivery, we performed a systematic review of Phase II, Phase II/III and Phase III amyotrophic lateral sclerosis clinical drug trials on trial registries and PubMed between 2008 and 2019. We identified 125 trials, investigating 76 drugs and recruiting more than 15 000 people with amyotrophic lateral sclerosis. About 90% of trials used traditional fixed designs. The limitations in understanding of disease biology, outcome measures, resources and barriers to trial participation in a rapidly progressive, disabling and heterogenous disease hindered timely and definitive evaluation of drugs in two-arm trials. Innovative trial designs, especially adaptive platform trials may offer significant efficiency gains to this end. We propose a flexible and scalable multi-arm, multi-stage trial platform where opportunities to participate in a clinical trial can become the default for people with amyotrophic lateral sclerosis.

Neuroprotective Effects of Ceftriaxone Involve the Reduction of Aβ Burden and Neuroinflammatory Response in a Mouse Model of Alzheimer's Disease

Ceftriaxone (CEF) is a safe and multipotent antimicrobial agent that possesses neuroprotective properties. Earlier, we revealed the restoration of cognitive function in OXYS rats with signs of Alzheimer's disease (AD)-like pathology by CEF along with its modulating the expression of genes related to the system of amyloid beta (Aβ) metabolism in the brain. The aim of this study was to determine the effects of CEF on behavior, Aβ deposition, and associated neuroinflammation using another model of an early AD-like pathology induced by Aβ. Mice were injected bilaterally i.c.v. with Aβ fragment 25-35 to produce the AD model, while the CEF treatment (100 mg/kg/day, i.p., 36 days) started the next day after the surgery. The open field test, T-maze, Barnes test, IntelliCage, and passive avoidance test were used for behavioral phenotyping. Neuronal density, amyloid accumulation, and the expression of neuroinflammatory markers were measured in the frontal cortex and hippocampus. CEF exhibited beneficial effects on some cognitive features impaired by Aβ neurotoxicity including complete restoration of the fear-induced memory and learning in the passive avoidance test and improved place learning in the IntelliCage. CEF significantly attenuated amyloid deposition and neuroinflammatory response. Thus, CEF could be positioned as a potent multipurpose drug as it simultaneously targets proteostasis network and neuroinflammation, as well as glutamate excitotoxicity, oxidative pathways, and neurotrophic function as reported earlier. Together with previous reports on the positive effects of CEF in AD models, the results confirm the potential of CEF as a promising treatment against cognitive decline from the early stages of AD progression.

NRF2 as a therapeutic opportunity to impact in the molecular roadmap of ALS

Amyotrophic Lateral Sclerosis (ALS) is a devastating heterogeneous disease with still no convincing therapy. To identify the most strategically significant hallmarks for therapeutic intervention, we have performed a comprehensive transcriptomics analysis of dysregulated pathways, comparing datasets from ALS patients and healthy donors. We have identified crucial alterations in RNA metabolism, intracellular transport, vascular system, redox homeostasis, proteostasis and inflammatory responses. Interestingly, the transcription factor NRF2 (nuclear factor (erythroid-derived 2)-like 2) has significant effects in modulating these pathways. NRF2 has been classically considered as the master regulator of the antioxidant cellular response, although it is currently considered as a key component of the transduction machinery to maintain coordinated control of protein quality, inflammation, and redox homeostasis. Herein, we will summarize the data from NRF2 activators in ALS pre-clinical models as well as those that are being studied in clinical trials. As we will discuss, NRF2 is a promising target to build a coordinated transcriptional response to motor neuron injury, highlighting its therapeutic potential to combat ALS.

Challenges and Opportunities of Targeting Astrocytes to Halt Neurodegenerative Disorders

Neurodegenerative diseases are a heterogeneous group of disorders whose incidence is likely to duplicate in the next 30 years along with the progressive aging of the western population. Non-cell-specific therapeutics or therapeutics designed to tackle aberrant pathways within neurons failed to slow down or halt neurodegeneration. Yet, in the last few years, our knowledge of the importance of glial cells to maintain the central nervous system homeostasis in health conditions has increased exponentially, along with our awareness of their fundamental and multifaced role in pathological conditions. Among glial cells, astrocytes emerge as promising therapeutic targets in various neurodegenerative disorders. In this review, we present the latest evidence showing the astonishing level of specialization that astrocytes display to fulfill the demands of their neuronal partners as well as their plasticity upon injury. Then, we discuss the controversies that fuel the current debate on these cells. We tackle evidence of a potential beneficial effect of cell therapy, achieved by transplanting astrocytes or their precursors. Afterwards, we introduce the different strategies proposed to modulate astrocyte functions in neurodegeneration, ranging from lifestyle changes to environmental cues. Finally, we discuss the challenges and the recent advancements to develop astrocyte-specific delivery systems.

Progressive arm muscle weakness in ALS follows the same sequence regardless of onset site: use of TOMS, a novel analytic method to track limb strength

Objective: Examine sequence of weakness in arm muscles from longitudinal hand-held dynamometry (HHD) data in ALS for congruence with contiguous spread of neurodegeneration along spinal cord segments. Methods: Longitudinal HHD data from the Ceftriaxone clinical trial were examined using nonlinear mixed models, assuming a logistic trajectory from normal to zero strength. Unobserved baseline normal strength of weak muscles was assumed using strength of the best-preserved muscle. A novel metric called "time from onset to midway strength" (TOMS) was estimated for each muscle group, and TOMS ratios were examined to identify sequence of weakness, overall and by onset site. Results: Shoulder flexion (SF), elbow flexion (EF), elbow extension (EE), wrist extension (WE), and first dorsal interosseous (FDI) were measured on each side. Over a median of 36 weeks, 513 subjects provided 2589 sets of HHD measures. TOMS increased sequentially in the following order: FDI, WE, SF, EF, and EE. TOMS ratios estimates with 95% CIs (adjusted for multiple comparisons) were: WE/FDI 1.32 (1.24-1.41), SF/WE 1.06 (1.01-1.10), EF/SF 1.06 (1.02-1.10), and EE/EF 1.18 (1.12-1.23). Elbow and shoulder flexors weakened sooner than did elbow extensors. The sequence of arm muscle weakness progression was similar regardless of onset site. Conclusion: Nonsegmental progression of arm muscle weakness that is similar for different onset sites favors cortical influence/network spread over contiguous spread of neurodegeneration in the spinal cord. Furthermore, this study confirms the "split elbow" pattern. TOMS and other proposed methods may have value as outcome measures in clinical research.

Drug repurposing strategies of relevance for Parkinson's disease

Parkinson's disease is a highly disabling, progressive neurodegenerative disease that manifests as a mix of motor and non-motor signs. Although we are equipped with some symptomatic treatments, especially for the motor signs of the disease, there are still no established disease-modifying drugs so the disease progresses unchecked. Standard drug discovery programs for disease-modifying therapies have provided key insights into the pathogenesis of Parkinson's disease but, of the many positive candidates identified in pre-clinical studies, none has yet translated into a successful clinically efficacious drug. Given the huge cost of drug discovery programs, it is not surprising that much attention has turned toward repurposing strategies. The trialing of an established therapeutic has the advantage of bypassing the need for preclinical safety testing and formulation optimization, thereby cutting both time and costs involved in getting a treatment to the clinic. Additional reduced failure rates for repurposed drugs are also a potential bonus. Many different strategies for drug repurposing are open to researchers in the Parkinson's disease field. Some of these have already proven effective in identifying suitable drugs for clinical trials, lending support to such approaches. In this review, we present a summary of the different strategies for drug repurposing, from large-scale epidemiological correlation analysis through to single-gene transcriptional approaches. We provide examples of past or ongoing studies adopting each strategy, where these exist. For strategies that have yet to be applied to Parkinson's disease, their utility is illustrated using examples taken from other disorders.

Hand-held dynamometry for assessment of muscle strength in patients with inflammatory myopathies

OBJECTIVES

Muscle weakness in idiopathic inflammatory myopathies (IIMs) is conventionally assessed using manual muscle testing (MMT). However, more objective tools must be developed to accurately and reliably quantify muscle strength in myositis patients. Hand-held dynamometry (HHD) is a quantitative, portable device with reported reliability in neuromuscular disorders. Our aim was to assess the reliability, validity and responsiveness of HHD in myositis.

METHODS

Myositis patients [DM, necrotizing myopathy (NM), PM and anti-synthetase syndrome] evaluated at the University of Pittsburgh myositis centre were prospectively enrolled. Each patient was assessed at 0, 3 and 6 months for validated outcome measures of myositis disease activity and physical function. At each visit, muscle strength was assessed using both MMT and HHD (Micro FET2, Hoggan Health Industries, Draper, UT, USA). The reliability, validity and responsiveness of the HHD was assessed using standard statistical methods.

RESULTS

Fifty IIM patients (60% female; mean age 51.6 years; 6 PM, 9 NM, 24 DM and 11 anti-synthetase syndrome) were enrolled. HHD showed strong test-retest intrarater reliability (r = 0.96) and interrater reliability (r = 0.98). HHD correlated significantly with the MMT score (r = 0.48, P = 0.0006) and myositis disease activity and functional measures. Longitudinal analysis showed a significant and strong association between the HHD and MMT as well as 2016 ACR/EULAR myositis response criteria (r = 0.8, P < 0.0001) demonstrating responsiveness. The mean effect size and standardized response mean of HHD was large: 0.95 and 1.03, respectively. MMT had a high ceiling effect compared with HHD.

CONCLUSION

HHD demonstrated strong reliability, construct validity and responsiveness in myositis patients. External validation studies are required to confirm these findings.

Chronic optogenetic stimulation of Bergman glia leads to dysfunction of EAAT1 and Purkinje cell death, mimicking the events caused by expression of pathogenic ataxin-1

Bergmann glia (BG) are highly specialized radial astrocytes of the cerebellar cortex, which play a key role in the uptake of synaptic glutamate via the excitatory amino acid transporter EAAT1. Multiple lines of evidence suggest that in cerebellar neurodegenerative diseases reactive BG has a negative impact on neuronal function and survival through compromised EAAT activity. A family of such diseases are those caused by expansion of CAG repeats in genes of the ataxin family, resulting in spinocerebellar ataxias (SCA). We investigated the contribution of BG to the pathogenesis of cerebellar neurodegeneration in a model of SCA1, which was induced by expression of a polyglutamine mutant of ataxin-1 (ATXN1[Q85]) in BG specifically. We compared the outcomes with a novel model where we triggered excitotoxicity by a chronic optogenetic activation of BG with channelrhodopsin-2 (ChR2). In both cases we detected evidence of reduced glutamate uptake manifested by prolongation of excitatory postsynaptic currents in Purkinje cells which is consistent with documented reduction of expression and/or function of EAAT1. In both models we detected astroglyosis and Purkinje cells atrophy. Finally, the same pattern was detected in a knock-in mouse which expresses a polyglutamine mutant ataxin-1 ATXN1[Q154] in a non-cell-selective manner. Our results suggest that ATXN1[Q85] and ChR2-induced insult targeted to BG closely mimics SCA1 pathology, where excessive glutamate signaling appears to be a common feature likely being an important contributor to cerebellar neurodegeneration.

Targeting for Success: Demonstrating Proof-of-Concept with Mechanistic Early Phase Clinical Pharmacology Studies for Disease-Modification in Neurodegenerative Disorders

The clinical failure rate for disease-modifying treatments (DMTs) that slow or stop disease progression has been nearly 100% for the major neurodegenerative disorders (NDDs), with many compounds failing in expensive and time-consuming phase 2 and 3 trials for lack of efficacy. Here, we critically review the use of pharmacological and mechanistic biomarkers in early phase clinical trials of DMTs in NDDs, and propose a roadmap for providing early proof-of-concept to increase R&D productivity in this field of high unmet medical need. A literature search was performed on published early phase clinical trials aimed at the evaluation of NDD DMT compounds using MESH terms in PubMed. Publications were selected that reported an early phase clinical trial with NDD DMT compounds between 2010 and November 2020. Attention was given to the reported use of pharmacodynamic (mechanistic and physiological response) biomarkers. A total of 121 early phase clinical trials were identified, of which 89 trials (74%) incorporated one or multiple pharmacodynamic biomarkers. However, only 65 trials (54%) used mechanistic (target occupancy or activation) biomarkers to demonstrate target engagement in humans. The most important categories of early phase mechanistic and response biomarkers are discussed and a roadmap for incorporation of a robust biomarker strategy for early phase NDD DMT clinical trials is proposed. As our understanding of NDDs is improving, there is a rise in potentially disease-modifying treatments being brought to the clinic. Further increasing the rational use of mechanistic biomarkers in early phase trials for these (targeted) therapies can increase R&D productivity with a quick win/fast fail approach in an area that has seen a nearly 100% failure rate to date.

Improving clinical trial outcomes in amyotrophic lateral sclerosis

Individuals who are diagnosed with amyotrophic lateral sclerosis (ALS) today face the same historically intransigent problem that has existed since the initial description of the disease in the 1860s - a lack of effective therapies. In part, the development of new treatments has been hampered by an imperfect understanding of the biological processes that trigger ALS and promote disease progression. Advances in our understanding of these biological processes, including the causative genetic mutations, and of the influence of environmental factors have deepened our appreciation of disease pathophysiology. The consequent identification of pathogenic targets means that the introduction of effective therapies is becoming a realistic prospect. Progress in precision medicine, including genetically targeted therapies, will undoubtedly change the natural history of ALS. The evolution of clinical trial designs combined with improved methods for patient stratification will facilitate the translation of novel therapies into the clinic. In addition, the refinement of emerging biomarkers of therapeutic benefits is critical to the streamlining of care for individuals. In this Review, we synthesize these developments in ALS and discuss the further developments and refinements needed to accelerate the introduction of effective therapeutic approaches.

Monocyclic beta-lactams for therapeutic uses: a patent overview (2010-2020)

INTRODUCTION

Monocyclic beta-lactams are four-membered cyclic amides with various structural modifications of the nucleus that determine their chemical reactivity and target specificity. Their historical use is based on their antibacterial activity, but they have recently appeared in other areas as well.

AREAS COVERED

This review summarizes the relevant patent development on monocyclic beta-lactams in various therapeutic areas over the last 10 years. The majority of patents describe compounds with antibacterial activity, while there are some recent patents describing the neuroprotective, anti-inflammatory, anti-cancer, anticoagulant and antihyperlipidemic effects of 2-azetidinones.

EXPERT OPINION

Monocyclic beta-lactams can be considered safe and nontoxic drugs, as they have been used in the clinic for almost half of the century. Recently, monocyclic beta-lactams have been increasingly recognized for their non-antibiotic activity, which has led to some promising new clinical candidates in the field of neurodegenerative diseases and coagulation therapy. With regard to their antibacterial activity, there is still room for improvement of their activity and broadening of their spectrum of action, especially in Gram-positive bacteria and on drug-insensitive penicillin-binding proteins, and in increasing their beta-lactamase stability.

Portable fixed dynamometry: towards remote muscle strength measurements in patients with motor neuron disease

Background

We aimed to determine (1) the test–retest reliability of a newly developed portable fixed dynamometer (PFD) as compared to the hand-held dynamometer (HHD) in patients with motor neuron disease (MND) and (2) the PFD’s ability to reduce possible examiner-induced ceiling effects.

Methods

Test–retest reliability of isometric muscle strength of the quadriceps was measured in patients with MND and non-neurological controls using the HHD and PFD. Reliability was estimated by the intraclass correlation coefficient (ICC) and standard error of measurement (SEM) using linear mixed effects models, and the Bland–Altman method of agreement.

Results

In total, 45 patients with MND and 43 healthy controls were enrolled in this study. The ICC of the PFD was excellent and similar in both patients and controls (ICC _Patients 99.5% vs. ICC _Controls 98.6%) with a SEM of 6.2%. A strong examiner-induced ceiling effect in HHD was found when the participant’s strength exceeded that of examiner. Employing the PFD increased the range of muscle strength measurements across individuals nearly twofold from 414 to 783 N.

Conclusions

Portable fixed dynamometry may significantly reduce examiner-induced ceiling effects, optimize the standardization of muscle strength testing, and maximize reliability. Ultimately, PFD may improve the delivery of care due to its potential for unsupervised, home-based assessments and reduce the burden to the patient of participating in clinical trials for MND or other neuromuscular diseases.

Drug repositioning and repurposing for Alzheimer disease

Drug repositioning and repurposing can enhance traditional drug development efforts and could accelerate the identification of new treatments for individuals with Alzheimer disease (AD) dementia and mild cognitive impairment. Transcriptional profiling offers a new and highly efficient approach to the identification of novel candidates for repositioning and repurposing. In the future, novel AD transcriptional signatures from cells isolated at early stages of disease, or from human neurons or microglia that carry mutations that increase the risk of AD, might be used as probes to identify additional candidate drugs. Phase II trials assessing repurposed agents must consider the best target population for a specific candidate therapy as well as the mechanism of action of the treatment. In this Review, we highlight promising compounds to prioritize for clinical trials in individuals with AD, and discuss the value of Delphi consensus methodology and evidence-based reviews to inform this prioritization process. We also describe emerging work, focusing on the potential value of transcript signatures as a cost-effective approach to the identification of novel candidates for repositioning.