Safety and efficacy of dimethyl fumarate in ALS: randomised controlled study

Objective Neuroinflammation is an important pathogenic mechanism in amyotrophic lateral sclerosis (ALS), with regulatory T cells (Tregs) mediating a slower rate of disease progression. Dimethyl fumarate enhances Treg levels and suppresses pro-inflammatory T cells. The present study assessed the safety and efficacy of dimethyl fumarate in ALS. Methods Phase-2, double-blind, placebo-controlled randomised clinical trial recruited participants from May 1, 2018 to September 25, 2019, across six Australian sites. Participants were randomised (2:1 ratio) to dimethyl fumarate (480 mg/day) or matching placebo, completing visits at screening, baseline, weeks 12, 24 and 36. The primary efficacy endpoint was a change in Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) at week 36. Secondary outcome measures included survival, neurophysiological index (NI), respiratory function, urinary neurotrophin-receptor p75 and quality of life. Results A total of 107 participants were randomised to dimethyl fumarate (n = 72) or placebo (n = 35). ALSFRS-R score was not significantly different at week 36 (−1.12 [−3.75 to 1.52, p = 0.41]). Dimethyl fumarate was associated with a reduced NI decline week 36 (differences in the least-squares mean: (0.84 [−0.51 to 2.22, p = 0.22]). There were no significant differences in other secondary outcome measures. Safety profiles were comparable between groups. Interpretation Dimethyl fumarate, in combination with riluzole, was safe and well-tolerated in ALS. There was no significant improvement in the primary endpoint. The trial provides class I evidence for safety and lack of efficacy of dimethyl fumarate in ALS

Phase 2 randomized placebo controlled double blind study to assess the efficacy and safety of tecfidera in patients with amyotrophic lateral sclerosis (TEALS Study)

Background: Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disorder of the human motor system. Neuroinflammation appears to be an important modulator of disease progression in ALS. Specifically, reduction of regulatory T cell (Treg) levels, along with an increase in pro-inflammatory effector T cells, macrophage activation and upregulation of co-stimulatory pathways have all been associated with a rapid disease course in ALS. Autologous infusion of expanded Tregs into sporadic ALS patients, resulted in greater suppressive function, slowing of disease progression and stabilization of respiratory function. Tecfidera (dimethyl fumarate) increases the ratio of anti-inflammatory (Treg) to proinflammatory T-cells in patients with relapsing remitting multiple sclerosis and rebalances the regulatory: inflammatory axis towards a neuroprotective phenotype. Consequently, the aim of this study was to assess the efficacy, safety, and tolerability of Tecfidera in sporadic ALS. Methods: The study is an investigator led Phase 2 multi-center, randomized, placebo controlled, double blind clinical trial assessing the efficacy and safety of Tecfidera in patients with sporadic ALS. The study duration is 40 weeks, with a 36-week study period and end of study visit occurring at 40 weeks or at early termination/withdrawal from study. The TEALS study has been registered with the Australian and New Zealand Clinical Trials registry (ANZCTR) under the trials registration number ACTRN12618000534280 and has been approved by the Human Research Ethics Committee and Research Governance Office at the lead site (Westmead Hospital) with the ethics number HREC/17/WMEAD/353. The participating sites have obtained site specific ethics and governance approvals from the local institution. Results: The primary endpoint is slowing of disease progression as reflected by the differences in the ALS Functional Rating Score-Revised (ALSFRS-R) score at Week 36. The secondary endpoints will include effects in survival, lower motor neuron function, respiratory function, quality of life and safety. Conclusion: This Phase 2 multi-center, randomized, placebo controlled, double blind clinical trial will provide evidence of efficacy and safety of Tecfidera in sporadic ALS

Allogeneic chondrogenically differentiated human bone marrow stromal cells do not induce dendritic cell maturation

Bone marrow stromal cell (BMSC)-mediated endochondral bone formation may be a promising alternative to the current gold standards of autologous bone transplantation, in the development of novel methods for bone repair. Implantation of chondrogenically differentiated BMSCs leads to bone formation in vivo via endochondral ossification. The success of this bone formation in an allogeneic system depends upon the interaction between the implanted constructs and the host immune system. The current study investigated the effect of chondrogenically differentiated human bone marrow stromal cell (hBMSC) pellets on the maturation and function of dendritic cells (DCs) by directly coculturing bone forming chondrogenic hBMSC pellets and immature or lipopolysaccharide (LPS)-matured DCs in vitro. Allogeneic chondrogenic hBMSC pellets did not affect the expression of CD80, CD86, or HLADR on immature or LPS-matured DCs following 24, 48, or 72 hr of coculture. Furthermore, they did not induce or inhibit antigen uptake or migration of the DCs over time. IL-6 was secreted by allogeneic chondrogenic hBMSC pellets in response to LPS-matured DCs. Overall, this study has demonstrated that maturation of immature DCs was not influenced by allogeneic chondrogenic hBMSC pellets. This suggests that allogeneic chondrogenic hBMSC pellets do not stimulate immunogenic responses from DCs in vitro and are not expected to indirectly activate T cells via DCs. For this reason, allogeneic chondrogenic bone marrow stromal cell pellets are promising candidates for future tissue engineering strategies utilising allogeneic cells for bone repair

Controversies and priorities in amyotrophic lateral sclerosis

Two decades after the discovery that 20% of familial amyotrophic lateral sclerosis (ALS) cases were linked to mutations in the superoxide dismutase-1 (SOD1) gene, a substantial proportion of the remainder of cases of familial ALS have now been traced to an expansion of the intronic hexanucleotide repeat sequence in C9orf72. This breakthrough provides an opportunity to re-evaluate longstanding concepts regarding the cause and natural history of ALS, coming soon after the pathological unification of ALS with frontotemporal dementia through a shared pathological signature of cytoplasmic inclusions of the ubiquitinated protein TDP-43. However, with profound clinical, prognostic, neuropathological, and now genetic heterogeneity, the concept of ALS as one disease appears increasingly untenable. This background calls for the development of a more sophisticated taxonomy, and an appreciation of ALS as the breakdown of a wider network rather than a discrete vulnerable population of specialised motor neurons. Identification of C9orf72 repeat expansions in patients without a family history of ALS challenges the traditional division between familial and sporadic disease. By contrast, the 90% of apparently sporadic cases and incomplete penetrance of several genes linked to familial cases suggest that at least some forms of ALS arise from the interplay of multiple genes, poorly understood developmental, environmental, and age-related factors, as well as stochastic events

Functional characterisation of the amyotrophic lateral sclerosis risk locus GPX3/TNIP1

Background Amyotrophic lateral sclerosis (ALS) is a complex, late-onset, neurodegenerative disease with a genetic contribution to disease liability. Genome-wide association studies (GWAS) have identified ten risk loci to date, including the TNIP1/GPX3 locus on chromosome five. Given association analysis data alone cannot determine the most plausible risk gene for this locus, we undertook a comprehensive suite of in silico, in vivo and in vitro studies to address this. Methods The Functional Mapping and Annotation (FUMA) pipeline and five tools (conditional and joint analysis (GCTA-COJO), Stratified Linkage Disequilibrium Score Regression (S-LDSC), Polygenic Priority Scoring (PoPS), Summary-based Mendelian Randomisation (SMR-HEIDI) and transcriptome-wide association study (TWAS) analyses) were used to perform bioinformatic integration of GWAS data (Ncases = 20,806, Ncontrols = 59,804) with ‘omics reference datasets including the blood (eQTLgen consortium N = 31,684) and brain (N = 2581). This was followed up by specific expression studies in ALS case-control cohorts (microarray Ntotal = 942, protein Ntotal = 300) and gene knockdown (KD) studies of human neuronal iPSC cells and zebrafish-morpholinos (MO). Results SMR analyses implicated both TNIP1 and GPX3 (p < 1.15 × 10−6), but there was no simple SNP/expression relationship. Integrating multiple datasets using PoPS supported GPX3 but not TNIP1. In vivo expression analyses from blood in ALS cases identified that lower GPX3 expression correlated with a more progressed disease (ALS functional rating score, p = 5.5 × 10−3, adjusted R2 = 0.042, Beffect = 27.4 ± 13.3 ng/ml/ALSFRS unit) with microarray and protein data suggesting lower expression with risk allele (recessive model p = 0.06, p = 0.02 respectively). Validation in vivo indicated gpx3 KD caused significant motor deficits in zebrafish-MO (mean difference vs. control ± 95% CI, vs. control, swim distance = 112 ± 28 mm, time = 1.29 ± 0.59 s, speed = 32.0 ± 2.53 mm/s, respectively, p for all < 0.0001), which were rescued with gpx3 expression, with no phenotype identified with tnip1 KD or gpx3 overexpression. Conclusions These results support GPX3 as a lead ALS risk gene in this locus, with more data needed to confirm/reject a role for TNIP1. This has implications for understanding disease mechanisms (GPX3 acts in the same pathway as SOD1, a well-established ALS-associated gene) and identifying new therapeutic approaches. Few previous examples of in-depth investigations of risk loci in ALS exist and a similar approach could be applied to investigate future expected GWAS findings

Computing linkage disequilibrium aware genome embeddings using autoencoders

Motivation The completion of the genome has paved the way for genome-wide association studies (GWAS), which explained certain proportions of heritability. GWAS are not optimally suited to detect non-linear effects in disease risk, possibly hidden in non-additive interactions (epistasis). Alternative methods for epistasis detection using, e.g. deep neural networks (DNNs) are currently under active development. However, DNNs are constrained by finite computational resources, which can be rapidly depleted due to increasing complexity with the sheer size of the genome. Besides, the curse of dimensionality complicates the task of capturing meaningful genetic patterns for DNNs; therefore necessitates dimensionality reduction. Results We propose a method to compress single nucleotide polymorphism (SNP) data, while leveraging the linkage disequilibrium (LD) structure and preserving potential epistasis. This method involves clustering correlated SNPs into haplotype blocks and training per-block autoencoders to learn a compressed representation of the block’s genetic content. We provide an adjustable autoencoder design to accommodate diverse blocks and bypass extensive hyperparameter tuning. We applied this method to genotyping data from Project MinE, and achieved 99% average test reconstruction accuracy—i.e. minimal information loss—while compressing the input to nearly 10% of the original size. We demonstrate that haplotype-block based autoencoders outperform linear Principal Component Analysis (PCA) by approximately 3% chromosome-wide accuracy of reconstructed variants. To the extent of our knowledge, our approach is the first to simultaneously leverage haplotype structure and DNNs for dimensionality reduction of genetic data

Saccadic abnormalities in frontotemporal dementia

Objective: To characterize saccadic eye movements, as a marker of decision-making processes, in frontotemporal dementia (FTD).   Methods: Saccadometry was performed on a cross-section of patients with FTD, using a portable saccadometer, and results compared to matched control subjects. We used the Linear Approach to Threshold with Ergodic Rate model to generate measures of decision-making speed and incidence of early saccades. Patterns of cortical atrophy were related to decision-making processes using voxel-based morphometry (VBM) analysis.   Results: A total of 45 subjects (22 FTD: 10 with behavioral variant FTD and 12 with primary progressive aphasia, and 23 controls) were studied. A measure of decision-making speed, was reduced in FTD, resulting in prolonged saccadic latency, but the incidence of early saccades was increased compared to controls. In addition, performance on an antisaccade task was poor in FTD compared to controls. Decision-making speed and the incidence of early saccades were independently correlated with atrophy of the left frontal eye field, and decision-making speed also correlated with atrophy of the left cingulate eye field.   Conclusion: Saccades are abnormal in FTD, reflecting reduced decision-making speed, and these abnormalities related to atrophy of the left frontal eye field. In addition, patients with FTD had an increased incidence of early saccades, which may be due to reduced inhibition of primitive responses

Motor neurone disease: progress and challenges

Major progress has been made over the past decade in the understanding of motor neurone disease (MND), changing the landscape of this complex disease. Through identifying positive prognostic factors, new evidence-based standards of care have been established that improve patient survival, reduce burden of disease for patients and their carers, and enhance quality of life. These factors include early management of respiratory dysfunction with non-invasive ventilation, maintenance of weight and nutritional status, as well as instigation of a multidisciplinary team including neurologists, general practitioners and allied health professionals. Advances in technology have enhanced our understanding of the genetic architecture of MND considerably, with implications for patients, their families and clinicians. Recognition of extra-motor involvement, particularly cognitive dysfunction, has identified a spectrum of disease from MND through to frontotemporal dementia. Although riluzole remains the only disease-modifying medication available in clinical practice in Australia, several new therapies are undergoing clinical trials nationally and globally, representing a shift in treatment paradigms. Successful translation of this clinical research through growth in community funding, awareness and national MND research organisations has laid the foundation for closing the research-practice gap on this debilitating disease. In this review, we highlight these recent developments, which have transformed treatment, augmented novel therapeutic platforms, and established a nexus between research and the MND community. This era of change is of significant relevance to both specialists and general practitioners who remain integral to the care of patients with MND