The ALSFRS-R Summit: a global call to action on the use of the ALSFRS-R in ALS clinical trials.

The Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS) was developed more than 25 years ago as an instrument to monitor functional change over time in patients with ALS. It has since been revised and extended to meet the needs of high data quality in ALS trials (ALSFRS-R), however a full re-validation of the scale was not completed. Despite this, the scale has remained a primary outcome measure in clinical trials. We convened a group of clinical trialists to discuss and explore opportunities to improve the scale and propose alternative measures. In this meeting report, we present a call to action on the use of the ALSFRS-Revised scale in clinical trials, focusing on the need for (1) harmonization of the ALSFRS-R administration globally, (2) alignment on a set of recommendations for clinical trial design and statistical analysis plans (SAPs), and (3) use of additional outcome measures.

Healthcare resource utilization at different stages of amyotrophic lateral sclerosis: Results from a real-world survey.

People with amyotrophic lateral sclerosis (pALS) require complex, multi-disciplinary care, resulting in extensive healthcare resource utilization (HCRU). To investigate the relationship between HCRU and ALS progression, the study objectives were (i) to characterize HCRU in pALS and (ii) to establish whether this varied according to disease stage, as defined using three different methodologies: neurologist-defined early/mid/late stage, the King's clinical staging system for ALS, and the Milan Torino Staging system for ALS (MiToS). Real-world data were drawn from the Adelphi ALS Disease-Specific Programme™, a point-in-time survey of neurologists in France, Germany, Italy, Spain, the UK, and the USA conducted July 2020-March 2021. The analysis included survey responses from 142 physicians with respect to 880 pALS. With advancing ALS stage, significant differences were observed in the number of healthcare professional consultations and X-rays per person (both p < 0.05 for all staging systems), and the proportion of pALS with emergency room admissions, intensive care unit admissions, and assisted ventilation (all p < 0.05 for all staging systems). Across stages, >55% of pALS received care from a general neurologist and a general/primary care practitioner. With increasing stage, there was a significant difference in the proportion receiving care from a physical therapist, pulmonologist/respiratory care practitioner, respiratory therapist, speech/language therapist, and palliative care team, and in the proportion receiving care only from professional caregivers (all p < 0.05 for all staging systems). This study confirmed the substantial HCRU required to support pALS through all stages of ALS and highlighted an increasing need for healthcare resources as the disease progresses.

Primary lateral sclerosis natural history study - planning, designing, and early enrollment.

Introduction/Aims. Primary lateral sclerosis (PLS) is exceedingly rare and has been an enigmatic disease. Recent progress has drastically changed this perception, with early biomarkers being investigated and potential medications for PLS emerging at the preclinical stage. The aim of this paper is to describe a study of PLS natural history and discuss the limitations and proposed solutions to the study of a rare and slowly progressive disease. Methods. The PLS Natural History Study is a 30-site, 24-month, prospective study that is supported by multiple funding sources. The study aims to enroll 50 early PLS (disease duration ≤4 years) and 50 definite PLS (disease duration 4 to 15 years) participants using modified PLS Diagnostic Criteria. Smartphone-based assessments including semi-quantitative and quantitative measures and patient-reported outcomes are utilized. In-person quantitative measures are also completed during site visits. The change in the PLS Functional Rating Scale score is the primary outcome. The study utilizes the NeuroBANK® patient-centric data capture and management platform. The biostatistical analysis plan has been developed. Results. In one year, 28 participants have been recruited. Enrollment has been much slower than anticipated due to the COVID-19 pandemic, the rarity of PLS, and potential study competition for internal resources from ALS clinical trials. Discussion. We discuss the need for more innovative methods to enroll and study individuals with such rare diseases and propose a number of mechanisms by which more efficient enrollment could be facilitated.

Clinically meaningful change: evaluation of the Rasch-built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) and the ALSFRS-R.

OBJECTIVE: To investigate clinically meaningful change for ROADS and ALSFRS-R using a patient-defined approach. METHODS: Data were reviewed from participants assessed at the Emory ALS Center from 2019-2022 with two assessments using both ROADS and ALSFRS-R and a completed patient-reported global impression of change scale at the second visit. Minimal important difference (MID), or the smallest amount of change that is clinically relevant, was assessed based on patient reported impression of change for ROADS and ALSFRS-R. Minimal detectable change (MDC), the smallest amount of change exceeding the threshold for measurement error, was assessed for ROADS and ALSFRS-R using standard deviations for participants self-rated as "unchanged". RESULTS: Data were included from 162 participants. For ROADS (total possible normed score = 146), MID = 5.81 and MDC = 2.83 points. For ALSFRS-R (total possible sum-score = 48), MID = 3.24 and MDC = 1.59 points. Clinically meaningful decline during the assessment period was observed in 98/162 (60.49%) participants on ROADS and 75/162 (46.30) participants on ALSFRS-R (OR = 1.63, 95% CI [1.0009, 2.66]). CONCLUSIONS: Changes that are on average less than 5.81 points (3.98%) on the normed ROADS score or less than 3.24 points (6.75%) on the ALSFRS-R sum-score may not be clinically meaningful according to a patient-defined approach. Understanding the clinical and statistical limitations of these scales is crucial when designing and interpreting ALS research studies.

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.

Longitudinal comparison of the self-entry Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-RSE) and Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) as outcome measures in people with amyotrophic lateral sclerosis.

INTRODUCTION/AIMS: Improved functional outcome measures in amyotrophic lateral sclerosis (ALS) would aid ALS trial design and help hasten drug discovery. We evaluate the longitudinal performance of the Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) compared to the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised for Self-Entry (ALSFRS-RSE) as patient reported outcomes of functional status in people with ALS. METHODS: Participants completed the ROADS and the ALSFRS-RSE questionnaires at baseline, 3-, 6-, and 12- mo using Research Electronic Data Capture as part of a prospective, longitudinal, remote, online survey study of fatigue in ALS from 9/2020 to 12/2021. The scales were compared cross-sectionally (at baseline) and longitudinally. Correlation coefficients, coefficients of variation, and descriptive statistics were assessed. RESULTS: A total of 182 adults with ALS consented to the study. This volunteer sample was comprised of predominantly White, non-Hispanic, non-smoking participants. Consented participant survey completion was approximately 90% at baseline and greater than 40% at 12 mo. The ALSFRS-RSE and the ROADS had high, significant agreement at 3 and 6 mo by Cohen's kappa ≥71% (p < 0.001); the number of functional increases or plateaus on the two scales were not significantly different; and the coefficient of variation of functional decline was similar at the 6-month mark, though higher for the ROADS at 3 mo and lower at 12 mo. DISCUSSION: Although the ROADS performed similarly to the ALSFRS-RSE in an observational cohort, it has psychometric advantages, such as Rasch-modeling and unidimensionality. It merits further investigation as a patient reported outcome of overall disability and efficacy outcome measure in ALS trials.

Effect of sodium phenylbutyrate/taurursodiol on tracheostomy/ventilation-free survival and hospitalisation in amyotrophic lateral sclerosis: long-term results from the CENTAUR trial.

BACKGROUND: Coformulated sodium phenylbutyrate/taurursodiol (PB/TURSO) was shown to prolong survival and slow functional decline in amyotrophic lateral sclerosis (ALS). OBJECTIVE: Determine whether PB/TURSO prolonged tracheostomy/ventilation-free survival and/or reduced first hospitalisation in participants with ALS in the CENTAUR trial. METHODS: Adults with El Escorial Definite ALS ≤18 months from symptom onset were randomised to PB/ TURSO or placebo for 6 months. Those completing randomised treatment could enrol in an open-label extension (OLE) phase and receive PB/TURSO for ≤30 months. Times to the following individual or combined key events were compared in the originally randomised treatment groups over a period spanning trial start through July 2020 (longest postrandomisation follow-up, 35 months): death, tracheostomy, permanent assisted ventilation (PAV) and first hospitalisation. RESULTS: Risk of any key event was 47% lower in those originally randomised to PB/TURSO (n=87) versus placebo (n=48, 71% of whom received delayed-start PB/TURSO in the OLE phase) (HR=0.53; 95% CI 0.35 to 0.81; p=0.003). Risks of death or tracheostomy/PAV (HR=0.51; 95% CI 0.32 to 0.84; p=0.007) and first hospitalisation (HR=0.56; 95% CI 0.34 to 0.95; p=0.03) were also decreased in those originally randomised to PB/TURSO. CONCLUSIONS: Early PB/TURSO prolonged tracheostomy/PAV-free survival and delayed first hospitalisation in ALS. TRIAL REGISTRATION NUMBER: NCT03127514; NCT03488524.

Gut microbiome differences between amyotrophic lateral sclerosis patients and spouse controls.

Objective: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that is incurable and ultimately fatal. Few therapeutic options are available to patients. In this study, we explored differences in microbiome composition associated with ALS. Methods: We compared the gut microbiome and inflammatory marker profiles of ALS patients (n = 10) to those of their spouses (n = 10). Gut microbiome profiles were determined by 16S rRNA gene sequencing. Results: The gut microbial communities of the ALS patients were more diverse and were deficient in Prevotella spp. compared with those of their spouses. In contrast, healthy couples (n = 10 couples of the opposite sex) recruited from the same geographic region as the patient population did not exhibit these differences. Stool and plasma inflammatory markers were similar between ALS patients and their spouses. Predictive analysis of microbial enzymes revealed that ALS patients had decreased activity in several metabolic pathways, including carbon metabolism, butyrate metabolism, and systems involving histidine kinase and response regulators. Conclusions: ALS patients exhibit differences in their gut microbial communities compared with spouse controls. Our findings suggest that modifying the gut microbiome, such as via amelioration of Prevotella spp. deficiency, and/or altering butyrate metabolism may have translational value for ALS treatment.

Validation of the Italian version of the Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) administered to patients and their caregivers.

Introduction: The Amyotrophic Lateral Sclerosis (ALS) functional rating scale - revised (ALSFRS-R) is the most widely used tool for the clinical monitoring in ALS patients. Despite his usefulness as a multidimensional scale, the combined score derived from different domains is not linearly related to symptoms severity. The Rasch-Built Overall ALS Disability Scale (ROADS) has recently been developed to overcome some of these limitations. Objectives: To validate the Italian version of the ROADS scale and assess the reliability of its administration to patients versus their respective caregivers and the correlation to the corresponding ALSFRS-R. Methods: In the Turin ALS Center, the ROADS Scale questionnaire was administered together with ALSFRS-R to 55 ALS patients and their caregivers during regular follow-up assessments. Correlation analysis was performed using Spearman's rho, Bland-Altman difference plots, Cronbach's alpha coefficient and Intraclass correlation coefficient (ICC), one-way random effects were used for proper comparison. Results: Their correlation coefficient between patients and caregivers ROADS was found to be very high (ICC 0.95, p < 0.001). Stratifying for age, sex, site of onset, type of caregiver, disease duration, and progression rate, ICC values that did not change significantly among the considered categories. We also found a high correlation between ROADS and ALSFRS-R total score (patients' correlation coefficient: 0.88). Conclusions: The Italian version of the ROADS scale is a valid and reliable tool to monitor disease burden, showing a high level of agreement between the responses given by patients and caregivers.

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.

Development and validation of a machine-learning ALS survival model lacking vital capacity (VC-Free) for use in clinical trials during the COVID-19 pandemic.

Introduction: Vital capacity (VC) is routinely used for ALS clinical trial eligibility determinations, often to exclude patients unlikely to survive trial duration. However, spirometry has been limited by the COVID-19 pandemic. We developed a machine-learning survival model without the use of baseline VC and asked whether it could stratify clinical trial participants and a wider ALS clinic population. Methods. A gradient boosting machine survival model lacking baseline VC (VC-Free) was trained using the PRO-ACT ALS database and compared to a multivariable model that included VC (VCI) and a univariable baseline %VC model (UNI). Discrimination, calibration-in-the-large and calibration slope were quantified. Models were validated using 10-fold internal cross validation, the VITALITY-ALS clinical trial placebo arm and data from the Emory University tertiary care clinic. Simulations were performed using each model to estimate survival of patients predicted to have a > 50% one year survival probability. Results. The VC-Free model suffered a minor performance decline compared to the VCI model yet retained strong discrimination for stratifying ALS patients. Both models outperformed the UNI model. The proportion of excluded vs. included patients who died through one year was on average 27% vs. 6% (VCI), 31% vs. 7% (VC-Free), and 13% vs. 10% (UNI). Conclusions. The VC-Free model offers an alternative to the use of VC for eligibility determinations during the COVID-19 pandemic. The observation that the VC-Free model outperforms the use of VC in a broad ALS patient population suggests the use of prognostic strata in future, post-pandemic ALS clinical trial eligibility screening determinations.

Chinese validation of the Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale.

BACKGROUND AND PURPOSE: The Rasch-Built Overall Amyotrophic Lateral Sclerosis Disability Scale (ROADS) was developed using Rasch methodology. This scale has been demonstrated as a reliable outcome measure of amyotrophic lateral sclerosis (ALS) trials. To date, there are no similar interval-weighted scales to assess disability in ALS patients. The current study aimed to validate a Chinese version of the ROADS via Rasch methodology. METHODS: The Chinese version of the ROADS was obtained through a standardized forward-backward translation and cultural adaptation. ALS patients were recruited from the Department of Neurology of Peking University Third Hospital in Beijing, China to complete the ROADS and the revised ALS Functional Rating Scale (ALSFRS-R). Overall, 254 participants with ALS finished the Chinese scale. Rasch analysis was performed on the ROADS for validation and the ALSFRS-R for comparison. RESULTS: The Chinese version of the ROADS was modified according to the statistical results. A final 28-question scale was constructed that fulfilled all the requirements of the Rasch model with proper validity and reliability. Furthermore, the ROADS showed improved item targeting compared to the ALSFRS-R. Conversely, the ALSFRS-R did not fit the Rasch model expectations due to misfit values and disordered thresholds for all 12 items. CONCLUSIONS: The Chinese adaptation of the ROADS is a linearly weighted scale that specifically captures overall disability in ALS patients. This scale indicates a wider range of item difficulties and better responsiveness than the ALSFRS-R. The ROADS could be used as a valuable tool for use in ALS trials and in the clinic in Chinese settings.

Long-term survival of participants in the CENTAUR trial of sodium phenylbutyrate-taurursodiol in amyotrophic lateral sclerosis.

An orally administered, fixed-dose coformulation of sodium phenylbutyrate-taurursodiol (PB-TURSO) significantly slowed functional decline in a randomized, placebo-controlled, phase 2 trial in ALS (CENTAUR). Herein we report results of a long-term survival analysis of participants in CENTAUR. In CENTAUR, adults with ALS were randomized 2:1 to PB-TURSO or placebo. Participants completing the 6-month (24-week) randomized phase were eligible to receive PB-TURSO in the open-label extension. An all-cause mortality analysis (35-month maximum follow-up post-randomization) incorporated all randomized participants. Participants and site investigators were blinded to treatment assignments through the duration of follow-up of this analysis. Vital status was obtained for 135 of 137 participants originally randomized in CENTAUR. Median overall survival was 25.0 months among participants originally randomized to PB-TURSO and 18.5 months among those originally randomized to placebo (hazard ratio, 0.56; 95% confidence interval, 0.34-0.92; P = .023). Initiation of PB-TURSO treatment at baseline resulted in a 6.5-month longer median survival as compared with placebo. Combined with results from CENTAUR, these results suggest that PB-TURSO has both functional and survival benefits in ALS.

Comparison of Phenotypic Characteristics and Prognosis Between Black and White Patients in a Tertiary ALS Clinic.

OBJECTIVE: To compare characteristics between Black and White patients with amyotrophic lateral sclerosis (ALS) in order to identify disparities and phenotypic variability. METHODS: We performed database review for patients seen between 1997 and 2020 at the Emory ALS Center in Atlanta, Georgia. Patients with ALS were included for analyses if race was self-reported as Black or White and symptom onset was prior to January 1, 2017. Variables examined include race, age at onset, diagnostic delay, site of onset, median income, C9orf72 mutation status, feeding tube and tracheostomy status, vital capacity, Amyotrophic Lateral Sclerosis Functional Rating Scale-revised(ALSFRS-R) score, and survival time. RESULTS: A total of 2,363 patient records were queried, and 1,298 were included in analysis; 203 self-identified as Black and 1,095 as White. Black patients had younger age at symptom onset, lower frequency of C9orf72 mutations, lower median income, longer diagnostic delay, and lower baseline ALSFRS-R and vital capacity compared to White patients. Black patients had a longer median survival than White patients; however, race was not an independent predictor of survival time when controlling for age at symptom onset, bulbar onset, and C9orf72 positivity. CONCLUSIONS: Black patients with ALS had longer median survival compared to White patients, but race was not independently associated with survival after controlling for age, site of onset, and C9orf72 status, factors known to predict prognosis. Black patients with ALS had longer diagnostic delay and lower baseline ventilatory and functional status at first clinic visit compared to White patients, which could be suggestive of barriers to tertiary care. Further studies are needed to identify the underlying causes of ALS racial differences.

Trial of Sodium Phenylbutyrate-Taurursodiol for Amyotrophic Lateral Sclerosis.

BACKGROUND: Sodium phenylbutyrate and taurursodiol have been found to reduce neuronal death in experimental models. The efficacy and safety of a combination of the two compounds in persons with amyotrophic lateral sclerosis (ALS) are not known. METHODS: In this multicenter, randomized, double-blind trial, we enrolled participants with definite ALS who had had an onset of symptoms within the previous 18 months. Participants were randomly assigned in a 2:1 ratio to receive sodium phenylbutyrate-taurursodiol (3 g of sodium phenylbutyrate and 1 g of taurursodiol, administered once a day for 3 weeks and then twice a day) or placebo. The primary outcome was the rate of decline in the total score on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R; range, 0 to 48, with higher scores indicating better function) through 24 weeks. Secondary outcomes were the rates of decline in isometric muscle strength, plasma phosphorylated axonal neurofilament H subunit levels, and the slow vital capacity; the time to death, tracheostomy, or permanent ventilation; and the time to death, tracheostomy, permanent ventilation, or hospitalization. RESULTS: A total of 177 persons with ALS were screened for eligibility, and 137 were randomly assigned to receive sodium phenylbutyrate-taurursodiol (89 participants) or placebo (48 participants). In a modified intention-to-treat analysis, the mean rate of change in the ALSFRS-R score was -1.24 points per month with the active drug and -1.66 points per month with placebo (difference, 0.42 points per month; 95% confidence interval, 0.03 to 0.81; P = 0.03). Secondary outcomes did not differ significantly between the two groups. Adverse events with the active drug were mainly gastrointestinal. CONCLUSIONS: Sodium phenylbutyrate-taurursodiol resulted in slower functional decline than placebo as measured by the ALSFRS-R score over a period of 24 weeks. Secondary outcomes were not significantly different between the two groups. Longer and larger trials are necessary to evaluate the efficacy and safety of sodium phenylbutyrate-taurursodiol in persons with ALS. (Funded by Amylyx Pharmaceuticals and others; CENTAUR ClinicalTrials.gov number, NCT03127514.).

The NEALS primary lateral sclerosis registry.

BACKGROUND AND OBJECTIVE: Primary lateral sclerosis (PLS) is a neurodegenerative disease characterized by progressive upper motor neuron dysfunction. Because PLS patients represent only 1 to 4% of patients with adult motor neuron diseases, there is limited information about the disease's natural history. The objective of this study was to establish a large multicenter retrospective longitudinal registry of PLS patients seen at Northeast ALS Consortium (NEALS) sites to better characterize the natural progression of PLS. Methods: Clinical characteristics, electrophysiological findings, laboratory values, disease-related symptoms, and medications for symptom management were collected from PLS patients seen between 2000 and 2015. Results: The NEALS registry included data from 250 PLS patients. Median follow-up time was 3 years. The mean rate of functional decline measured by ALSFRS-R total score was -1.6 points/year (SE:0.24, n = 124); the mean annual decline in vital capacity was -3%/year (SE:0.55, n = 126). During the observational period, 18 patients died, 17 patients had a feeding tube placed and 7 required permanent assistive ventilation. Conclusions: The NEALS PLS Registry represents the largest available aggregation of longitudinal clinical data from PLS patients and provides a description of expected natural disease progression. Data from the registry will be available to the PLS community and can be leveraged to plan future clinical trials in this rare disease.