Clinical trials in ALS: a review of the role of clinical and neurophysiological measurements

Review of disease-modifying drug trials in amyotrophic lateral sclerosis

We analysed clinical trials of pharmacological interventions on patients with amyotrophic lateral sclerosis (ALS), and compared study quality and design features. The systematic review included articles published in PubMed and trials registered in ClinicalTrials.gov. Included studies were randomised double-blind placebo-controlled clinical trials assessing a disease-modifying pharmacological intervention. Studies were excluded if primary end points were safety or dose finding. A total of 28 735 articles and 721 current trials were identified. 76 published articles and 23 ongoing trials met inclusion criteria; they referred to distinct populations comprising 22 817 participants with ALS. Most articles and all current trials had parallel group design; few articles had cross-over design. A run-in observation period was included in about 20% of published studies and ongoing trials. Primary end points included functional assessment, survival, muscle strength, respiratory function, biomarkers and composite measures. Most recent trials had only functional assessment and survival. Risk of bias was high in 23 articles, moderate in 35, low in 18. A disease modification effect was observed for 10 interventions in phase II studies, two of which were confirmed in phase III. Three confirmatory phase III studies are currently underway. The present review provides cues for the design of future trials. Functional decline and survival, as single or composite measures, stand as the reference end points. Post hoc analyses should not be performed, particularly in studies using composite end points. There is a general agreement on diagnostic criteria; but eligibility criteria must be improved. Run-in observations may be used for censoring patients but are discouraged for refining participants' eligibility. The ALS Functional Rating Scale-Revised needs improvement for use as an ordinal measure of functional decline.

Lower and upper motor neuron involvement and their impact on disease prognosis in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a fatal neurodegenerative disease characterized by progressive muscle wasting, breathing and swallowing difficulties resulting in patient’s death in two to five years after disease onset. In amyotrophic lateral sclerosis, both upper and lower motor neurons of the corticospinal tracts are involved in the process of neurodegeneration, accounting for great clinical heterogeneity of the disease. Clinical phenotype has great impact on the pattern and rate of amyotrophic lateral sclerosis progression and overall survival prognosis. Creating more homogenous patient groups in order to study the effects of drug agents on specific manifestations of the disease is a challenging issue in amyotrophic lateral sclerosis clinical trials. Since amyotrophic lateral sclerosis has low incidence rates, conduction of multicenter trials requires certain standardized approaches to disease diagnosis and staging. This review focuses on the current approaches in amyotrophic lateral sclerosis classification and staging system based on clinical examination and additional instrumental methods, highlighting the role of upper and lower motor neuron involvement in different phenotypes of the disease. We demonstrate that both clinical and instrumental findings can be useful in evaluating severity of upper motor neuron and lower motor neuron involvement and predicting the following course of the disease. Addressing disease heterogeneity in amyotrophic lateral sclerosis clinical trials could lead to study designs that will assess drug efficacy in specific patient groups, based on the disease pathophysiology and spatiotemporal pattern. Although clinical evaluation can be a sufficient screening method for dividing amyotrophic lateral sclerosis patients into clinical subgroups, we provide proof that instrumental studies could provide valuable insights in the disease pathology.

Verapamil and riluzole cocktail liposomes overcome pharmacoresistance by inhibiting P-glycoprotein in brain endothelial and astrocyte cells: A potent approach to treat amyotrophic lateral sclerosis

Riluzole is currently one of two approved medications for the treatment of amyotrophic lateral sclerosis (ALS). However, brain disposition of riluzole, as a substrate of P-glycoprotein (P-gp), is limited by the efflux transporters at the blood-brain barrier (BBB). We propose to develop a liposomal co-delivery system that could effectively transport riluzole to brain cells by reducing efflux pumps with a P-gp inhibitor, verapamil. Riluzole and verapamil cocktail liposomes were prepared by lipid film hydration. The average particle size of cocktail liposomes was 194.3 ± 6.0 nm and their polydispersity index (PDI) was 0.272 ± 0.017. The encapsulation efficiencies of verapamil and riluzole in the cocktail liposomes were 86.0 ± 1.4% and 85.6 ± 1.1%, respectively. The drug release from cocktail liposomes after 8 h in PBS at 37 °C was 78.4 ± 6.2% of riluzole and 76.7 ± 3.8% of verapamil. The average particle size of liposomes did not show significant changes at 4 °C after three months. Verapamil cocktail liposomes inhibited P-gp levels measured by western blotting in dose and time-dependent manners in brain endothelial bEND.3 cells. Increased drug efflux transporters were detected in bEND.3 and astrocytes C8D1A cells, promoted by tumor necrosis factor (TNF-α) or hydrogen peroxide (H₂O₂). Restored accumulations of riluzole and fluorescent dye rhodamine 123 were observed in bEND.3 cells after treatments with cocktail liposomes. It indicated that inhibitory potential of co-delivery liposome system towards P-gp could mediate the transport of both P-gp substrates. Verapamil and riluzole co-loaded liposomes may be used to overcome pharmacoresistance of riluzole for improving ALS therapy.

Markers for upper limb dysfunction in Amyotrophic Lateral Sclerosis using analysis of typing activity

OBJECTIVE

Assistive devices based on keyboard access support communication and control tools for patients with Amyotrophic Lateral Sclerosis (ALS). The aim of this work was to explore movement activity in the use of keyboards and identify markers for upper limb (UL) dysfunction.

METHODS

We present a longitudinal study including 19 ALS patients, followed for 2-20 months. Typing activity was recorded with an accelerometer placed on the posterior part of patients' index finger. Participants performed the same 10-word typing task (2-6 assessments). Time and acceleration during keystroke were the main outcomes of this study. Patients were compared with 20 healthy subjects and 6 patients with other neuromuscular disorders.

RESULTS

During disease progression, mean time in holding down a key increased and was longer than in control subjects. Acceleration at key press and key release decreased with progression of UL dysfunction. Delay between tapping and pressing down each key increased with UL dysfunction.

CONCLUSIONS

Delay in pressing and releasing keys are markers of UL dysfunction in ALS. The decrease in the acceleration of movements related to keystroke can contribute to monitor disease progression.

SIGNIFICANCE

Typing activity can be explored to access remotely and continuously to ALS progression by patients who use assistive communication devices.

Biological markers of mesenchymal stromal cells as predictors of response to autologous stem cell transplantation in patients with amyotrophic lateral sclerosis: an investigator-initiated trial and in vivo study

Bone marrow mesenchymal stromal cells (MSCs) can modify disease progression in amyotrophic lateral sclerosis (ALS) model. However, there are currently no accurate biological markers for predicting the efficacy of autologous MSC transplants in ALS patients. This open-label, single-arm, investigator-initiated clinical study was designed to identify markers of MSCs that could be used as potential predictors of response to autologous MSC therapy in patients with ALS. We enrolled 37 patients with ALS who received autologous MSCs via intrathecal injection in two monthly doses. After a 6-month follow-up period, the patients were categorized as responders and non-responders based on their scores on the revised ALS Functional Rating Scale (ALSFRS-R). Biological markers including β-fibroblast growth factor-2, stromal cell-derived factor-1α, vascular endothelial growth factor (VEGF), insulin-like growth factor-1, brain-derived neurotrophic factor, angiogenin (ANG), interleukin (IL)-4, IL-10, and transforming growth factor-β (TGF-β) were measured in the MSC cultures and their levels were compared between the responders and nonresponders. To confirm the markers' predictive ability, MSCs isolated from one patient in each group were transplanted into the cisterna magna of mutant SOD1(G93A) transgenic mice to measure their lifespans, locomotor activity, and motor neuron numbers. The levels of VEGF, ANG, and TGF-β were significantly higher in responders than in nonresponders. In the mouse model, the recipients of responder MSCs had a significantly slower onset of symptoms and a significantly longer lifespan than the recipients of nonresponders or controls. Our data suggest that VEGF, ANG, and TGF-β levels in MSCs could be used as potential biological markers to predict the effectiveness of autologous MSC therapy and to identify those patients who could optimally benefit from MSC treatment.

Recombinant human erythropoietin in amyotrophic lateral sclerosis: a pilot study of safety and feasibility

Background and Purpose

It has been shown that erythropoietin is neuroprotective in animal models of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). The aim of this study was to determine the safety and feasibility of repetitive high-dose recombinant human erythropoietin (rhEPO) therapy in ALS patients.

Methods

Two consecutive studies were conducted. We first recruited 26 subjects for an initial single-arm safety study. After a lead-in period of 3 months to assess the disease progression, rhEPO was infused intravenously (35,000 IU) once per month for 3 months, and the subjects were followed for an additional 3 months. The ALS Functional Rating Scale-Revised (ALSFRS-R) was used for clinical assessment. After confirming the safety of rhEPO, 60 subjects were recruited for the second controlled study (rhEPO and control groups), which involved a total of 6 infusions at a rate of 1/month.

Results

There were no serious adverse events in the first study. The mean rate of decline in the ALSFRS-R score was lower during the treatment period than during the lead-in period (mean±SD: 2.6±1.8 and 3.7±2.6, respectively; p=0.02). However, the rate of decline during the subsequent 3 months returned to that observed in the lead-in period. In the second study, the mean rate of decline in ALSFRS-R score was significantly lower in the rhEPO group than in the control group (during months 0-3, 1.8±1.7 vs. 3.1±2.3, p=0.03; during months 4-6, 2.1±2.2 vs. 3.5±2.3, p=0.02).

Conclusions

Intravenous high-dose rhEPO is both safe and feasible for the treatment of ALS. Further investigation using different intervals and doses should be considered.

Roles of vascular endothelial growth factor in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal devastating neurodegenerative disorder, involving progressive degeneration of motor neurons in spinal cord, brainstem, and motor cortex. Riluzole is the only drug approved in ALS but it only confers a modest improvement in survival. In spite of a high number of clinical trials no other drug has proved effectiveness. Recent studies support that vascular endothelial growth factor (VEGF), originally described as a key angiogenic factor, also plays a key role in the nervous system, including neurogenesis, neuronal survival, neuronal migration, and axon guidance. VEGF has been used in exploratory clinical studies with promising results in ALS and other neurological disorders. Although VEGF is a very promising compound, translating the basic science breakthroughs into clinical practice is the major challenge ahead. VEGF-B, presenting a single safety profile, protects motor neurons from degeneration in ALS animal models and, therefore, it will be particularly interesting to test its effects in ALS patients. In the present paper the authors make a brief description of the molecular properties of VEGF and its receptors and review its different features and therapeutic potential in the nervous system/neurodegenerative disease, particularly in ALS.

Biomarkers for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common form of motor neuron disease. ALS is a fatal neurodegenerative disease and clinical diagnosis typically takes many months to complete. Early disease diagnosis through the use of biomarkers may aid in correct clinical management of patients and possibly delay time to ventilator and morbidity. This review explores the progress of biomarker discovery efforts for ALS and the many challenges that remain. Included are different technologies utilized in biomarker discovery efforts (proteomic, genomic and metabolomic) and putative biomarkers uncovered using these techniques. These studies have discovered genetic mutations leading to familial forms of ALS, and specific protein alterations that occur in biological fluids (cerebrospinal fluid and blood) and/or tissues of ALS subjects. More recent high-throughput technologies have revealed panels of proteomic or metabolic biomarkers that can discriminate between ALS and control groups. The identification of disease-specific biomarkers will provide opportunities to develop early diagnostic measures as well as surrogate markers to monitor disease progression and test drug efficacy in clinical trials.

Differential motor neuron impairment and axonal regeneration in sporadic and familiar amyotrophic lateral sclerosis with SOD-1 mutations: lessons from neurophysiology

Amyotrophic Lateral Sclerosis (ALS) is a degenerative disorder of the motor system. About 10% of cases are familial and 20% of these families have point mutations in the Cu/Zn superoxide dismutase 1 (SOD-1) gene. SOD-1 catalyses the superoxide radical (O⁻²) into hydrogen peroxide and molecular oxygen. The clinical neurophysiology in ALS plays a fundamental role in differential diagnosis between the familial and sporadic forms and in the assessment of its severity and progression. Sixty ALS patients (34 males; 26 females) were enrolled in the study and examined basally (T0) and every 4 months (T1, T2, and T3). Fifteen of these patients are SOD-1 symptomatic mutation carriers (nine males, six females). We used Macro-EMG and Motor Unit Number Estimation (MUNE) in order to evaluate the neuronal loss and the re-innervation process at the onset of disease and during follow-up period. Results and Discussion: SOD-1 mutation carriers have a higher number of motor units at the moment of diagnosis when compared with the sporadic form, despite a more dramatic drop in later stages. Moreover, in familiar SOD-1 ALS there is not a specific time interval in which the axonal regeneration can balance the neuronal damage. Taken together, these results strengthen the idea of a different pathogenetic mechanism at the base of sALS and fALS.

Peripheral nerve and muscle ultrasound in amyotrophic lateral sclerosis

INTRODUCTION

High-resolution ultrasound has been used to evaluate several neuromuscular conditions, but it has only been used on a limited basis in amyotrophic lateral sclerosis (ALS) patients. It has not been used to assess their peripheral nerves. This study was designed to use neuromuscular ultrasound to investigate nerve cross-sectional area and muscle thickness in ALS.

METHODS

Twenty individuals with ALS and 20 matched controls underwent neuromuscular ultrasound to measure the cross-sectional area of their median and sural nerves and the thickness of their biceps/brachialis muscle complex.

RESULTS

The cross-sectional area of the median nerve in the mid-arm was smaller in the ALS group than in controls (10.5 mm(2) vs. 12.7 mm(2) , P = 0.0023), but no difference was seen in the sural nerve (4.5 mm(2) vs. 5.0 mm(2) , P = 0.1927). The ALS group also had thinner biceps/brachialis than controls (2.1 cm vs. 2.9 cm, P = 0.0007).

CONCLUSIONS

Neuromuscular ultrasound demonstrates nerve and muscle atrophy in ALS and should be further explored as a disease biomarker.

Latent cluster analysis of ALS phenotypes identifies prognostically differing groups

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a degenerative disease predominantly affecting motor neurons and manifesting as several different phenotypes. Whether these phenotypes correspond to different underlying disease processes is unknown. We used latent cluster analysis to identify groupings of clinical variables in an objective and unbiased way to improve phenotyping for clinical and research purposes.

METHODS

Latent class cluster analysis was applied to a large database consisting of 1467 records of people with ALS, using discrete variables which can be readily determined at the first clinic appointment. The model was tested for clinical relevance by survival analysis of the phenotypic groupings using the Kaplan-Meier method.

RESULTS

The best model generated five distinct phenotypic classes that strongly predicted survival (p<0.0001). Eight variables were used for the latent class analysis, but a good estimate of the classification could be obtained using just two variables: site of first symptoms (bulbar or limb) and time from symptom onset to diagnosis (p<0.00001).

CONCLUSION

The five phenotypic classes identified using latent cluster analysis can predict prognosis. They could be used to stratify patients recruited into clinical trials and generating more homogeneous disease groups for genetic, proteomic and risk factor research.

Long-term motor cortex stimulation for amyotrophic lateral sclerosis

BACKGROUND

Motor cortex stimulation has been proposed for treatment of amyotrophic lateral sclerosis (ALS) and preliminary studies have reported a slight reduction of disease progression using both invasive and noninvasive repetitive stimulation of the motor cortex.

OBJECTIVE

The aim of this proof of principle study was to investigate the effects of motor cortex stimulation performed for a prolonged period (about 2 years) on ALS progression.

METHODS

Two patients were included in the study; the first patient was treated with monthly cycles of repetitive transcranial magnetic stimulation (rTMS) and the second one was treated with chronic epidural motor cortex stimulation. The rate of progression of the disease before and during treatment was compared.

RESULTS

The treatments were well tolerated by the patients. Both patients deteriorated during treatment; however, the patient treated with rTMS showed a slight reduction in deterioration rate.

CONCLUSIONS

Although we cannot be sure whether the effects observed in the patient treated with rTMS can be attributed to this form of stimulation, our study set the groundwork for possible future studies investigating the effects of rTMS, for a prolonged period, on a larger group of ALS patients.

The costs of amyotrophic lateral sclerosis, according to type of care

Our objective was to estimate the economic burden of patients with amyotrophic lateral sclerosis (ALS) and to examine the effect of treatment in a multidisciplinary ALS treatment centre versus general care on costs and to describe differences in costs according to clinical characteristics. In a cross-sectional study 208 patients with ALS and their caregivers were interviewed and were asked to fill in a cost diary for six months. Patients were divided in groups according to type of treatment they received and according to clinical characteristics (site of onset, severity). The direct healthcare and non-healthcare costs were calculated according to Dutch guidelines for cost analysis in healthcare research, standardized for the year 2003. Ninety-eight patients were included when they had filled in the cost diary for at least three months and were affected for three years or less. Mean monthly costs were 1336 euros for the group receiving multidisciplinary care and 1271 euros for those receiving general care. This study shows that the costs of multidisciplinary ALS care were practically identical to the costs of general care. Earlier study showed that patients receiving multidisciplinary care had a better quality of life; therefore, the present study encourages the formation of multidisciplinary teams of professionals specialized in ALS care to further improve standards of care and QoL of patients suffering from ALS.

Amyotrophic lateral sclerosis – The tools of the trait

The aim of this review is to analyze how our knowledge on the etiology, pathology, and treatment of amyotrophic lateral sclerosis (ALS) has profited from the application of biotechnology tools for the identification of disease markers, the development of animal disease models, and the design of innovative therapeutics. In humans, ALS-specific clinical, genetic or protein biomarkers, or panels of biomarkers stemming from genomics and proteomics analyses can be critical for early diagnosis, monitoring of disease progression, drug validation in clinical trials, and identification of therapeutic targets for subsequent drug development. At the same time, animal models representing a number of human superoxide dismutase 1 mutations, intermediate-filament disorganization or axonal-transport defects have been invaluable in unraveling aspects of the pathophysiology of the disease; in each case, these only represent a small proportion of all ALS patients. Preclinical and clinical trials, although at present heavily concentrating on pharmacological approaches, are embracing the emerging alternative strategies of stem-cell and gene therapy. In combination with a further subcategorization of patients and the development of corresponding model systems for functional analyses, they will significantly influence the already changing face of ALS therapy.

Respiratory systems abnormalities and clinical milestones for patients with amyotrophic lateral sclerosis with emphasis upon survival

Respiratory system complications and abnormalities are common in patients with amyotrophic lateral sclerosis (ALS) and respiratory failure remains the most common cause of death. Extensive epidemiological longitudinal data have documented the extent, magnitude, and clinical course of these abnormalities, but few studies have provided objective information that can have prognostic significance for individual patients. In this study, the reported data represent results from a retrospective review of the medical records of 153 patients with ALS cared for at a single institution (The Penn State Milton S. Hershey Medical Center) over a 50-month period. Medical information in relation to respiratory system abnormalities and complications including pulmonary function measurements was extracted for data analyses. The intent of this review of longitudinal data from a relatively large cohort of patients with ALS was to identify clinically relevant easily-identifiable objective information and clinical milestones that could have potential prognostic significance when applied to individual patients. Demographic data including gender, survival outcome, respiratory symptoms, age of disease onset, and age at death were similar to previously published epidemiological studies: mean age at ALS disease onset was 58.9+/-12.7 years, and mean age at death was 66.7+/-10.8 years. For 151 patients with available data, the incidence of study defined respiratory complications included infectious pneumonia 13 (9%), venothromboembolism 9 (6%), and tracheostomy and mechanical ventilation 6 (4%). For 139 patients with serial measurements of forced vital capacity (FVC), median values for calculated rate of decline in FVC was 97 ml/30 days (2.4% predicted/30 days); 25% of patients had FVC rates of decline less than 52 ml/30 days (1.4% predicted/30 days) and 25% had rates of decline greater than 170 ml/30 days (4.4% predicted/30 days). Stratifying patients into two distinct clinical subgroups based upon rates of decline in FVC less than or greater than the median value of 97 ml/30 days identified an apparent two-fold increase in survival duration for ALS patients with slower rates of pulmonary physiology deterioration when referenced to either date of dyspnea onset or time from bi-level positive airway pressure (BiPAP) initiation (2.0+/-1.4 vs. 1.0+/-0.8 years; 1.9+/-1.5 vs. 1.0+/-0.9 years, respectively). We concluded that the correlation between clinically defined milestones, most importantly onset of dyspnea, and the calculated rate of decline in FVC represent obtainable and objective measurements that predict the natural course of respiratory muscle dysfunction in patients with ALS and provide important prognostic information in relation to individual patient survival duration.

Amyotrophic Lateral Sclerosis: New Developments in Diagnostic Markers

There is an intensive search for diagnostic markers in amyotrophic lateral sclerosis (ALS). Protein analysis (proteomics) of the cerebrospinal fluid (CSF) appears particularly promising using mass spectrometry and 2-D gel electrophoresis to detect low and high molecular weight proteins, respectively. It is open whether protein changes specific for ALS will be found. This also holds true for inflammatory proteins such as the cytokine monocyte chemoattractant protein-1 which has been detected in CSF in ALS and for other cytokines such as interleukin-1beta. Increases of the protein Nogo A and B in muscle tissue and decreases of the growth factor vascular endothelial growth factor in blood may also be useful for monitoring the course of ALS. Clinical neurophysiology provides markers for upper and lower motor neuron damage. A very sensitive method to detect early upper motor neuron involvement is the transcranial magnetic stimulation modification 'triple stimulation technique' which can show significant changes in patients without clinical upper motor neuron signs. The loss of lower motor neurons can be closely monitored by MUNE techniques (motor unit number estimate). In modern imaging, the MRI technique DTI (diffusion tensor imaging) has the greatest diagnostic potential for ALS. It can separate between normal and ALS in group comparisons and may be improved to be diagnostic in individual patients. Voxel-based morphometry can reliably demonstrate regional cortical atrophy in motor areas and beyond although it is not appropriate for use in individual patients.

Motor unit number estimates correlate with strength in polio survivors

Motor unit number estimation (MUNE) has been proposed as an outcome measure in clinical trials for the motor neuron diseases. One major criticism of MUNE is that it may not represent a clinically meaningful endpoint. We prospectively studied a cohort of polio survivors over a period of 15 years with respect to MUNE and strength. We identified a significant association between thenar MUNE and arm strength, extensor digitorum brevis MUNE and leg strength, and the summated MUNE and global strength of the polio survivors. These findings confirm the clinical relevance of MUNE as an outcome measure in the motor neuron diseases and provide further validation for its use in clinical trial research.