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.

Mutations in the vesicular trafficking protein annexin A11 are associated with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. We screened 751 familial ALS patient whole-exome sequences and identified six mutations including p.D40G in the ANXA11 gene in 13 individuals. The p.D40G mutation was absent from 70,000 control whole-exome sequences. This mutation segregated with disease in two kindreds and was present in another two unrelated cases (P = 0.0102), and all mutation carriers shared a common founder haplotype. Annexin A11-positive protein aggregates were abundant in spinal cord motor neurons and hippocampal neuronal axons in an ALS patient carrying the p.D40G mutation. Transfected human embryonic kidney cells expressing ANXA11 with the p.D40G mutation and other N-terminal mutations showed altered binding to calcyclin, and the p.R235Q mutant protein formed insoluble aggregates. We conclude that mutations in ANXA11 are associated with ALS and implicate defective intracellular protein trafficking in disease pathogenesis.

No evidence for shared genetic basis of common variants in multiple sclerosis and amyotrophic lateral sclerosis.

Genome-wide association studies have been successful in identifying common variants that influence the susceptibility to complex diseases. From these studies, it has emerged that there is substantial overlap in susceptibility loci between diseases. In line with those findings, we hypothesized that shared genetic pathways may exist between multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). While both diseases may have inflammatory and neurodegenerative features, epidemiological studies have indicated an increased co-occurrence within individuals and families. To this purpose, we combined genome-wide data from 4088 MS patients, 3762 ALS patients and 12 030 healthy control individuals in whom 5 440 446 single-nucleotide polymorphisms (SNPs) were successfully genotyped or imputed. We tested these SNPs for the excess association shared between MS and ALS and also explored whether polygenic models of SNPs below genome-wide significance could explain some of the observed trait variance between diseases. Genome-wide association meta-analysis of SNPs as well as polygenic analyses fails to provide evidence in favor of an overlap in genetic susceptibility between MS and ALS. Hence, our findings do not support a shared genetic background of common risk variants in MS and ALS.

A genome-wide association meta-analysis identifies a novel locus at 17q11.2 associated with sporadic amyotrophic lateral sclerosis.

Identification of mutations at familial loci for amyotrophic lateral sclerosis (ALS) has provided novel insights into the aetiology of this rapidly progressing fatal neurodegenerative disease. However, genome-wide association studies (GWAS) of the more common (∼90%) sporadic form have been less successful with the exception of the replicated locus at 9p21.2. To identify new loci associated with disease susceptibility, we have established the largest association study in ALS to date and undertaken a GWAS meta-analytical study combining 3959 newly genotyped Italian individuals (1982 cases and 1977 controls) collected by SLAGEN (Italian Consortium for the Genetics of ALS) together with samples from Netherlands, USA, UK, Sweden, Belgium, France, Ireland and Italy collected by ALSGEN (the International Consortium on Amyotrophic Lateral Sclerosis Genetics). We analysed a total of 13 225 individuals, 6100 cases and 7125 controls for almost 7 million single-nucleotide polymorphisms (SNPs). We identified a novel locus with genome-wide significance at 17q11.2 (rs34517613 with P = 1.11 × 10(-8); OR 0.82) that was validated when combined with genotype data from a replication cohort (P = 8.62 × 10(-9); OR 0.833) of 4656 individuals. Furthermore, we confirmed the previously reported association at 9p21.2 (rs3849943 with P = 7.69 × 10(-9); OR 1.16). Finally, we estimated the contribution of common variation to heritability of sporadic ALS as ∼12% using a linear mixed model accounting for all SNPs. Our results provide an insight into the genetic structure of sporadic ALS, confirming that common variation contributes to risk and that sufficiently powered studies can identify novel susceptibility loci.

An MND/ALS phenotype associated with C9orf72 repeat expansion: abundant p62-positive, TDP-43-negative inclusions in cerebral cortex, hippocampus and cerebellum but without associated cognitive decline.

The transactive response DNA binding protein (TDP-43) proteinopathies describe a clinico-pathological spectrum of multi-system neurodegeneration that spans motor neuron disease/amyotrophic lateral sclerosis (MND/ALS) and frontotemporal lobar degeneration (FTLD). We have identified four male patients who presented with the clinical features of a pure MND/ALS phenotype (without dementia) but who had distinctive cortical and cerebellar pathology that was different from other TDP-43 proteinopathies. All patients initially presented with weakness of limbs and respiratory muscles and had a family history of MND/ALS. None had clinically identified cognitive decline or dementia during life and they died between 11 and 32 months after symptom onset. Neuropathological investigation revealed lower motor neuron involvement with TDP-43-positive inclusions typical of MND/ALS. In contrast, the cerebral pathology was atypical, with abundant star-shaped p62-immunoreactive neuronal cytoplasmic inclusions in the cerebral cortex, basal ganglia and hippocampus, while TDP-43-positive inclusions were sparse. This pattern was also seen in the cerebellum where p62-positive, TDP-43-negative inclusions were frequent in granular cells. Western blots of cortical lysates, in contrast to those of sporadic MND/ALS and FTLD-TDP, showed high p62 levels and low TDP-43 levels with no high molecular weight smearing. MND/ALS-associated SOD1, FUS and TARDBP gene mutations were excluded; however, further investigations revealed that all four of the cases did show a repeat expansion of C9orf72, the recently reported cause of chromosome 9-linked MND/ALS and FTLD. We conclude that these chromosome 9-linked MND/ALS cases represent a pathological sub-group with abundant p62 pathology in the cerebral cortex, hippocampus and cerebellum but with no significant associated cognitive decline.

Cognitive impairment in patients with multiple system atrophy and progressive supranuclear palsy.

This article reports the severity and profile of neuropsychological impairment on a prevalent cohort of patients with a clinical diagnosis of either multiple system atrophy (n=372) or progressive supranuclear palsy (n=311) from the Neuroprotection and Natural History in Parkinson Plus Syndromes cohort. The Dementia Rating Scale and Frontal Assessment Battery were used to assess global cognition and executive dysfunction. For the Dementia Rating Scale impairment was observed in approximately 57% of the progressive supranuclear palsy group and 20% of the multiple system atrophy group. In the former, impairment in a single cognitive domain was observed in 40%, with the same number showing impairment in multiple domains, while in the latter the figures were 28.6 and 13.5%, respectively. On the Frontal Assessment Battery, impairment was observed in 62.0% of patients with progressive supranuclear palsy and 31.8% of those with multiple system atrophy. Although the progressive supranuclear palsy group performed worse overall, the cognitive profiles of the two groups on the Dementia Rating Scale subscales were identical, with the main impairment of the Initiation and Perseveration subscale. The impaired patients in the two groups were largely indistinguishable, qualitatively and quantitatively. Impairment was associated with greater age and clinical disability in both groups and was evident even in the early stages (22% in multiple system atrophy and 50% in progressive supranuclear palsy). Where a pathological diagnosis was available, the original clinical diagnosis was confirmed in the majority of cases, including those with significant cognitive impairment. The rate of impairment in those with a confirmed pathological diagnosis was comparable to that of the sample as a whole. These results demonstrate, in the largest prospectively recruited cohort of patients with progressive supranuclear palsy and multiple system atrophy studied to date, the existence of a cognitive profile similar to that previously reported in idiopathic Parkinson's disease. The results indicate a high level of cognitive impairment associated with progressive supranuclear palsy, but also point to comparable dysfunction in a substantial proportion of the patients with multiple system atrophy. Significant cognitive impairment appears consistent with a diagnosis of multiple system atrophy, even early in the disease, with important implications for diagnosis, research and management.

Interaction between PON1 and population density in amyotrophic lateral sclerosis.

Paraoxonase polymorphisms have been associated with amyotrophic lateral sclerosis (ALS). Paraoxonases are detoxifying enzymes involved in the metabolism of organophosphates. We tested the hypothesis that genetic variation within paraoxonase genes would interact with the environmental exposure to paraoxonase substrates. We used population density in the location of residence of ALS patients as a surrogate marker for environmental exposure. Paraoxonase genotypes at previously associated single nucleotide polymorphisms rs662, rs854560, rs6954345, and rs11981433 were studied in 98 patients from the South East England ALS population-based register. A case-only analysis was carried out and median population density was used to categorize patients into rural or urban environments. We found a significant interaction with population density for marker rs854560 (L55M) in ALS.

A longitudinal study of diffusion tensor MRI in ALS.

In this study, we investigated whether diffusion tensor MRI (DTI) could detect progressive corticospinal tract degeneration in amyotrophic lateral sclerosis (ALS) and whether changes in diffusion variables reflected clinical deterioration. Twenty-three ALS patients and 25 healthy volunteers underwent whole brain DTI. Patients and a subset (n = 12) of controls returned for a second scan. Clinical measures of disease severity were assessed in the ALS group. Changes in fractional anisotropy (FA) and mean diffusivity (MD) were measured along the corticospinal tract using a region of interest approach. Adequate DTI data were available in 11 ALS patients and 11 controls at two time points. FA and MD differed significantly between ALS patients and controls at both time points, but neither changed significantly over time, while global measures of disease severity in patients increased with time. Although we confirmed that DTI detects corticospinal tract damage in ALS, there were no significant changes in diffusion measures over time. The sensitivity of DTI may be improved by advanced data analysis techniques, although the high dropout rate suggests that use of MRI as a biomarker in ALS may be restricted to earlier stages of disease.

Three soccer playing friends with simultaneous amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is a neurodegenerative disease of largely unknown cause, predominantly affecting upper and lower motor neurons. A recent study in Italy suggested an increased incidence of ALS among professional Italian soccer players. We report a cluster of three amateur league soccer players who were friends from the same part of southern England, and developed ALS simultaneously. This might suggest that keen amateur soccer players are also at risk.

Management of respiration in MND/ALS patients: an evidence based review.

This systematic review comprises an objective appraisal of the evidence in regard to the management of respiration in patients with motor neuron disease (MND/ALS). Studies were identified through computerised searches of 32 databases. Internet searches of websites of drug companies and MND/ALS research web sites, 'snow balling' and hand searches were also employed to locate any unpublished study or other 'grey literature' on respiration and MND/ALS. Since management of MND/ALS involves a number of health professionals and care workers, searches were made across multiple disciplines. No time frame was imposed on the search in order to increase the probability of identifying all relevant studies, although there was a final limit of March 2005. Recommendations for patient and carer-based guidelines for the clinical management of respiration for MND/ALS patients are suggested on the basis of qualitative analyses of the available evidence. However, these recommendations are based on current evidence of best practice, which largely comprises observational research and clinical opinion. There is a clear need for further evidence, in particular randomised and non-randomised controlled trials on the effects of non-invasive ventilation and additional larger scale cohort studies on the issues of initial assessment of respiratory symptoms, and management and timing of interventions.

Survival of patients with ALS following institution of enteral feeding is related to pre-procedure oximetry: a retrospective review of 98 patients in a single centre.

A retrospective review was carried out on the influence of pre-procedure respiratory assessment on survival of patients with amyotrophic lateral sclerosis (ALS) requiring nutritional support with either a gastrostomy or a nasogastric feeding tube. Over a five-year period 98 patients (49 male, 49 female; median age 61 years, range 26-86 years) with ALS were referred for enteral feeding with either radiological inserted gastrostomy (RIG), percutaneous endoscopic gastrostomy (PEG) or nasogastric tube (NG). Case notes review was performed to record patient age, sex, pre-procedure respiratory assessment, method of enteral feeding and survival post-procedure. Kaplan-Meier survival curves were constructed for each group, with Cox regression analyses performed in order to establish the effect of each variable on outcome. Median survival (with 95% confidence intervals) following RIG, PEG and NG was 6.31 months (4.58-8.04 months), 7.13 months (4.81-9.45 months) and 0.95 months (0.00-2.77 months), respectively. The survival advantage between RIG and PEG was not statistically significant (p = 0.50), but for NG versus RIG and PEG groups combined, there was a significant difference (p = 0.03). For patients with normal overnight oximetry, median survival was 8.54 months (3.88-13.21 months), compared to 4.80 months (1.20-8.39 months) in the abnormal oximetry group (p = 0.03; relative risk 1.97). It is concluded that RIG and PEG are equivalent in terms of post-procedure survival. Abnormal oximetry prior to the procedure is a significant indicator of post-procedure survival.

Integrating preferences into health status assessment for amyotrophic lateral sclerosis: the ALS Utility Index.

We developed a preference-based measure, the Amyotrophic Lateral Sclerosis Utility Index (ALSUI), allowing computation of US population-based utility weights for the wide range of health states observed among ALS patients. A multi-attribute utility approach was used. An ALS Health State Classification System was developed comprising the following attributes with different severity levels: Speech and Swallowing (A1); Eating, Dressing, and Bathing (A2); Leg Function (A3); and Respiratory Function (A4). An internet-based survey was administered to a random sample of the US population to assess preferences for ALS health states based on this system using visual analog scale (VAS) and standard gamble (SG) questions. Using the VAS and SG data from 1374 individuals in the general population, utility functions were computed that corresponded to each severity level within A1, A2, A3, and A4. ALSUI scores for a given patient are computed by inputting his corresponding utility functions into the following multiplicative formula: ALSUI score = 1.06 x (A1 x A2 x A3 x A4) - 0.06 on a scale where 0.0 reflects death and 1.0 reflects healthy. This study provides a useful tool for classifying ALS patients and determining a general public-based utility score for ALS health states.

VEGF is a modifier of amyotrophic lateral sclerosis in mice and humans and protects motoneurons against ischemic death.

Amyotrophic lateral sclerosis (ALS) is an incurable degenerative disorder of motoneurons. We recently reported that reduced expression of Vegfa causes ALS-like motoneuron degeneration in Vegfa(delta/delta) mice. In a meta-analysis of over 900 individuals from Sweden and over 1,000 individuals from Belgium and England, we now report that subjects homozygous with respect to the haplotypes -2,578A/-1,154A/-634G or -2,578A/-1,154G/-634G in the VEGF promoter/leader sequence had a 1.8 times greater risk of ALS (P = 0.00004). These 'at-risk' haplotypes lowered circulating VEGF levels in vivo and reduced VEGF gene transcription, IRES-mediated VEGF expression and translation of a novel large-VEGF isoform (L-VEGF) in vivo. Moreover, SOD1(G93A) mice crossbred with Vegfa(delta/delta) mice died earlier due to more severe motoneuron degeneration. Vegfa(delta/delta) mice were unusually susceptible to persistent paralysis after spinal cord ischemia, and treatment with Vegfa protected mice against ischemic motoneuron death. These findings indicate that VEGF is a modifier of motoneuron degeneration in human ALS and unveil a therapeutic potential of Vegfa for stressed motoneurons in mice.

Stem therapy for ALS: hope and reality.

All are agreed that there is pressing need for an effective treatment for Amyotrophic Lateral Sclerosis (ALS; MND). Such treatment may derive from a combination of therapeutic strategies aimed at different aspects of the disorder, and might include drugs directed at the initial, intermediate or terminal cascade of events leading to cell death, as well as the use of stem cells to replace dead motor neurons, or to protect those that remain. The attraction of cell implantation or transplantation is that it might help to overcome the inability of the CNS to replace lost neurons. It is also clear that neural implantation will yield little benefit if the donor cells fail to integrate functionally into the recipient CNS circuitry. In this respect, ALS poses an especially difficult problem. The recent breakthroughs in stem cell research might nevertheless provide possibilities for neural implantation and cell replacement therapy for patients with ALS. The potential impact of these new approaches to neurodegenerative diseases has been emphasised by the many experiments using human foetal cell grafts in patients affected by Parkinson's and Huntington's disease. Clinical benefits in Parkinson's disease seem to be associated with integration of the donor cells into the recipient brain. Despite promising results, however, significant constraints have hampered the use of foetal cells for neural implantation and transplantation. Besides ethical concerns, the viability, purity, and final destiny of the foetal tissue have not been completely defined. Foetal cells are, in addition, post-mitotic and cannot be expanded or stored for long periods, necessitating close synchronisation of tissue donation and neurosurgery.