Noninvasive ventilation use by patients enrolled in VITALITY-ALS.

Objectives: To evaluate the prescribing practices of noninvasive ventilation (NIV) and patient compliance during VITALITY-ALS. Methods: VITALITY-ALS enrolled patients with a slow vital capacity (SVC) ≥70% of predicted who were not using NIV at screening. Physicians prescribed NIV without restriction following randomization. Reason(s) for NIV prescription, dates prescribed and initiated, and compliance were recorded. Compliance was recorded as prescribed but never initiated, used ≥2 h/24 h, used ≥4 h/24 h, or used ≥22 h/24 h. In addition to other outcome measures, SVC and the revised ALS functional rating scale (ALSFRS-R) were performed at all visits. Patients were followed up to 56 weeks. Results: 565 patients were randomized and dosed with placebo or tirasemtiv in VITALITY-ALS; 195 (34.5%) were prescribed NIV: of these, 78.5% used it for ≥2 h/24 h, 71.3% for ≥4 h/24 h, and 11.8% for ≥22 h/24 h. The three most common reasons NIV was prescribed were decline in vital capacity, respiratory symptoms, and sleep-related symptoms. During the trial, 179/565 (31.7%) patients had a decline of SVC below 50%; of these patients, 122/179 (68.2%) were prescribed NIV. Reasons for prescribing NIV were different for patients from North America compared with Europe. Conclusions: Despite allowing for NIV initiation at any point following randomization in VITALITY-ALS, only slightly more than two out of three patients whose SVC fell below 50% were prescribed NIV; this was similar in Europe and in North America. Underutilization of NIV could influence survival outcomes in patients with ALS including those involved in clinical trials.

Improved stratification of ALS clinical trials using predicted survival.

INTRODUCTION: In small trials, randomization can fail, leading to differences in patient characteristics across treatment arms, a risk that can be reduced by stratifying using key confounders. In ALS trials, riluzole use (RU) and bulbar onset (BO) have been used for stratification. We hypothesized that randomization could be improved by using a multifactorial prognostic score of predicted survival as a single stratifier. METHODS: We defined a randomization failure as a significant difference between treatment arms on a characteristic. We compared randomization failure rates when stratifying for RU and BO ("traditional stratification") to failure rates when stratifying for predicted survival using a predictive algorithm. We simulated virtual trials using the PRO-ACT database without application of a treatment effect to assess balance between cohorts. We performed 100 randomizations using each stratification method - traditional and algorithmic. We applied these stratification schemes to a randomization simulation with a treatment effect using survival as the endpoint and evaluated sample size and power. RESULTS: Stratification by predicted survival met with fewer failures than traditional stratification. Stratifying predicted survival into tertiles performed best. Stratification by predicted survival was validated with an external dataset, the placebo arm from the BENEFIT-ALS trial. Importantly, we demonstrated a substantial decrease in sample size required to reach statistical power. CONCLUSIONS: Stratifying randomization based on predicted survival using a machine learning algorithm is more likely to maintain balance between trial arms than traditional stratification methods. The methodology described here can translate to smaller, more efficient clinical trials for numerous neurological diseases.

VITALITY-ALS, a phase III trial of tirasemtiv, a selective fast skeletal muscle troponin activator, as a potential treatment for patients with amyotrophic lateral sclerosis: study design and baseline characteristics.

OBJECTIVE: To assess the efficacy of tirasemtiv, a fast skeletal muscle troponin activator, vs. placebo on respiratory function and other functional measures in patients with amyotrophic lateral sclerosis (ALS). This study was designed to confirm and extend results from a large phase IIb trial and maximize tolerability with a slower dose escalation. METHODS: VITALITY-ALS (NCT02496767) was a multinational, double-blind, randomized, placebo-controlled, parallel-group study in ALS patients. Participants who tolerated two weeks of open-label tirasemtiv (125 mg twice a day) were randomized 3:2:2:2 to placebo or one of three target total daily dose levels of tirasemtiv (250, 375, or 500 mg). Participants randomized to tirasemtiv escalated their dose every two weeks to their target dose level or maximum tolerated dose. The primary outcome measure was change in slow vital capacity from baseline to 24 weeks. Secondary endpoints assessed the effect of tirasemtiv on muscle strength and certain respiratory milestones of disease progression. A four-week randomized withdrawal phase followed 48 weeks of treatment to evaluate the possibility of sustained benefit or rebound decline. RESULTS: Data collection will be complete in the fourth quarter of 2017. CONCLUSIONS: VITALITY-ALS was a phase III trial designed to evaluate the efficacy, safety, and tolerability of tirasemtiv in ALS.

Profile of medical care costs in patients with amyotrophic lateral sclerosis in the Medicare programme and under commercial insurance.

OBJECTIVE: To determine amyotrophic lateral sclerosis (ALS)-associated costs incurred by patients covered by Medicare and/or commercial insurance before, during and after diagnosis and provide cost details. METHODS: Costs were calculated from the Medicare Standard Analytical File 5% sample claims data from Parts A and B from 2009, 2010 and 2011 for ALS Medicare patients aged ≥70 years (monthly costs) and ≥65 years (costs associated with disability milestones). Commercial insurance patients aged 18-63 years were selected based on the data provided in the Coordination of Benefits field from Truven MarketScan® in 2008-2010. RESULTS: Monthly costs increased nine months before diagnosis, peaked during the index month (Medicare: $10,398; commercial: $9354) and decreased but remained high post-index. Costs generally shifted from outpatient to inpatient and private nursing after diagnosis; prescriptions and durable medical equipment costs were much higher for commercial patients post-diagnosis. Patients appeared to progress to disability milestones more rapidly as their disease progressed in severity (14.4 months to non-invasive ventilation [NIV] vs. 16.6 months to hospice), and their costs increased accordingly (NIV: $58,973 vs. hospice: $76,179). CONCLUSIONS: For newly diagnosed ALS patients in the U.S., medical costs are substantial and increase rapidly and substantially with each disability milestone.

Longitudinal modeling to predict vital capacity in amyotrophic lateral sclerosis.

OBJECTIVES: Death in amyotrophic lateral sclerosis (ALS) patients is related to respiratory failure, which is assessed in clinical settings by measuring vital capacity. We developed ALS-VC, a modeling tool for longitudinal prediction of vital capacity in ALS patients. METHODS: A gradient boosting machine (GBM) model was trained using the PRO-ACT (Pooled Resource Open-access ALS Clinical Trials) database of over 10,000 ALS patient records. We hypothesized that a reliable vital capacity predictive model could be developed using PRO-ACT. RESULTS: The model was used to compare FVC predictions with a 30-day run-in period to predictions made from just baseline. The internal root mean square deviations (RMSD) of the run-in and baseline models were 0.534 and 0.539, respectively, across the 7L FVC range captured in PRO-ACT. The RMSDs of the run-in and baseline models using an unrelated, contemporary external validation dataset (0.553 and 0.538, respectively) were comparable to the internal validation. The model was shown to have similar accuracy for predicting SVC (RMSD = 0.562). The most important features for both run-in and baseline models were "Baseline forced vital capacity" and "Days since baseline." CONCLUSIONS: We developed ALS-VC, a GBM model trained with the PRO-ACT ALS dataset that provides vital capacity predictions generalizable to external datasets. The ALS-VC model could be helpful in advising and counseling patients, and, in clinical trials, it could be used to generate virtual control arms against which observed outcomes could be compared, or used to stratify patients into slowly, average, and rapidly progressing subgroups.

A randomized, placebo-controlled, double-blind phase IIb trial evaluating the safety and efficacy of tirasemtiv in patients with amyotrophic lateral sclerosis.

Our objectives were to evaluate the safety and tolerability of tirasemtiv over 12 weeks and its effect on the revised ALS Functional Rating Scale (ALSFRS-R) and other secondary functional measures. This randomized, double-blind, placebo-controlled trial enrolled adults with ALS and slow vital capacity (SVC) > 50% from 73 centers in eight countries. Patients who tolerated open-label tirasemtiv 125 mg b.i.d. for one week were randomized to double-blind treatment either to placebo or tirasemtiv, escalating to a maximum tolerated dose up to 250 mg b.i.d. The primary endpoint was the change from baseline in ALSFRS-R; secondary endpoints included SVC, maximum voluntary ventilation, sniff nasal inspiratory pressure, isometric muscle strength, and sub-maximum handgrip fatigue. Of 711 patients enrolled, 596 were randomized and received at least one dose of double-blind treatment. The primary endpoint showed no treatment effect (tirasemtiv: -2.98 ± 0.28, placebo: -2.40 ± 0.25, p = 0.114); however, SVC and muscle strength declined significantly more slowly on tirasemtiv (95% CI p = 0.0006, p = 0.0158, respectively). Dropouts and serious adverse events occurred more frequently in the tirasemtiv group. In conclusion, this was a negative study with respect to the primary endpoint; however, the effects on SVC and muscle strength suggest a potentially important effect of tirasemtiv warranting further evaluation over a longer period in ALS.

Arbaclofen placarbil in GERD: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: It has been shown that arbaclofen placarbil (AP) inhibits reflux in gastroesophageal reflux disease (GERD) following single oral dosing. This study evaluated the efficacy and safety of AP over 4 weeks in subjects with symptomatic GERD. METHODS: One hundred fifty-six subjects with heartburn and/or regurgitation ≥3 days/week and either no history of taking proton pump inhibitors (PPIs naive, n=58) or at least partial symptom response to PPI therapy (PPI responsive, n=98) were enrolled in this randomized, double-blind, placebo-controlled trial. All GERD therapies including PPIs were discontinued 2 weeks before randomization to AP 20, 40, or 60 mg daily, 30 mg twice daily, or placebo for 4 weeks. Randomization was stratified by prior PPI use. RESULTS: In the primary analysis, change from baseline in weekly heartburn events between AP and placebo for the entire study group was not statistically significant. However, a significant interaction was observed between prior PPI use and response to AP treatment. In pre-planned secondary analyses of the PPI-responsive subgroup, percent reductions from baseline in weekly heartburn events were greater for each AP dose vs. placebo (P<0.05) and the percentage of subjects who reported complete resolution of heartburn during week 4 was higher in each AP treatment group (21, 28, 30, and 50% for AP 20, 40, 60 mg daily, and 30 mg twice daily, respectively) compared with placebo (6%) (P<0.05 for 30 mg twice daily). Corresponding analyses of the PPI-naive subgroup showed no significant differences. AP was well tolerated; withdrawals due to adverse events were infrequent. CONCLUSIONS: AP was not superior to placebo in reducing the number of weekly heartburn events over 4 weeks in the primary analysis of the entire study population. Exploratory subgroup analyses suggest that response to PPI treatment before the study was associated with a response to AP treatment.