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Background: Aerobic exercise has shown inconsistent cognitive effects in older adults with Alzheimer's disease (AD) dementia.Objective: To examine the immediate and longitudinal effects of 6-month cycling on cognition in older adults with AD dementia.Methods: This randomized controlled trial randomized 96 participants (64 to cycling and 32 to stretching for six months) and followed them for another six months. The intervention was supervised, moderate-intensity cycling for 20-50 minutes, 3 times a week for six months. The control was light-intensity stretching. Cognition was assessed at baseline, 3, 6, 9, and 12 months using the AD Assessment Scale-Cognition (ADAS-Cog). Discrete cognitive domains were measured using the AD Uniform Data Set battery.Results: The participants were 77.4±6.8 years old with 15.6±2.9 years of education, and 55% were male. The 6-month change in ADAS-Cog was 1.0±4.6 (cycling) and 0.1±4.1 (stretching), which were both significantly less than the natural 3.2±6.3-point increase observed naturally with disease progression. The 12-month change was 2.4±5.2 (cycling) and 2.2±5.7 (control). ADAS-Cog did not differ between groups at 6 (p = 0.386) and 12 months (p = 0.856). There were no differences in the 12-month rate of change in ADAS-Cog (0.192 versus 0.197, p = 0.967), memory (-0.012 versus -0.019, p = 0.373), executive function (-0.020 versus -0.012, p = 0.383), attention (-0.035 versus -0.033, p = 0.908), or language (-0.028 versus -0.026, p = 0.756).Conclusion: Exercise may reduce decline in global cognition in older adults with mild-to-moderate AD dementia. Aerobic exercise did not show superior cognitive effects to stretching in our pilot trial, possibly due to the lack of power. [ABSTRACT FROM AUTHOR]

Estimating causal effects from randomized controlled trials is often complicated due to participant noncompliance to randomized treatment. Although there are a variety of methods to estimate causal effects in the presence of noncompliance, they generally make the assumption that noncompliance is measured without error. This is frequently an untenable assumption, particularly when noncompliance is based on participant self-report. To overcome this issue, we treat compliance as an unobserved variable and show how to estimate the probability of compliance given a biomarker of treatment and the other observed data. We present inverse probability weighted estimators, regression-based estimators, and a doubly-robust augmented estimator that rely on the estimated probability of compliance rather than an indicator of compliance. We investigate the finite-sample properties of the estimators and their efficiency and robustness under correctly specified or misspecified models, and we apply the estimators to a recently completed trial of very low nicotine content cigarettes. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we evaluated the classification accuracy of biomarkers of nicotine exposure for identifying noncompliance in randomized controlled trials (RCTs) of very low nicotine content (VLNC) cigarettes. Methods: We combined data from 2 studies to evaluate the classification accuracy of biomarkers of nicotine exposure for identifying noncompliance in RCTs of VLNC cigarettes. Using a novel approach that did not require knowledge of each participant's compliance status, we modeled the distributions of total nicotine equivalents (TNE), total cotinine, and anatabine in compliant and noncompliant participants using a mixture model. Estimates of the classification accuracy were derived from the estimated densities. Results: TNE and total cotinine had near-perfect classification accuracy, but TNE had better classification accuracy than total cotinine (p = .03) and anatabine (p = .014). The classification accuracy of TNE and total cotinine decreased as self-reported study cigarettes increased; anatabine was similar, but the results were more statistically variable. Conclusions: TNE and total cotinine are better classifiers of compliance than anatabine. These results will be useful in determining biomarker thresholds for identifying noncompliance and will aid in the interpretation of future RCTs of VLNC cigarettes. [ABSTRACT FROM AUTHOR]

Objectives: In this study, we evaluated the classification accuracy of biomarkers of nicotine exposure for identifying noncompliance in randomized controlled trials (RCTs) of very low nicotine content (VLNC) cigarettes. Methods: We combined data from 2 studies to evaluate the classification accuracy of biomarkers of nicotine exposure for identifying noncompliance in RCTs of VLNC cigarettes. Using a novel approach that did not require knowledge of each participant's compliance status, we modeled the distributions of total nicotine equivalents (TNE), total cotinine, and anatabine in compliant and noncompliant participants using a mixture model. Estimates of the classification accuracy were derived from the estimated densities. Results: TNE and total cotinine had near-perfect classification accuracy, but TNE had better classification accuracy than total cotinine (p = .03) and anatabine (p = .014). The classification accuracy of TNE and total cotinine decreased as self-reported study cigarettes increased; anatabine was similar, but the results were more statistically variable. Conclusions: TNE and total cotinine are better classifiers of compliance than anatabine. These results will be useful in determining biomarker thresholds for identifying noncompliance and will aid in the interpretation of future RCTs of VLNC cigarettes. [ABSTRACT FROM AUTHOR]

Background: Ensovibep (MP0420) is a designed ankyrin repeat protein, a novel class of engineered proteins, under investigation as a treatment of SARS-CoV-2 infection.Objective: To investigate if ensovibep, in addition to remdesivir and other standard care, improves clinical outcomes among patients hospitalized with COVID-19 compared with standard care alone.Design: Double-blind, randomized, placebo-controlled, clinical trial. (ClinicalTrials.gov: NCT04501978).Setting: Multinational, multicenter trial.Participants: Adults hospitalized with COVID-19.Intervention: Intravenous ensovibep, 600 mg, or placebo.Measurements: Ensovibep was assessed for early futility on the basis of pulmonary ordinal scores at day 5. The primary outcome was time to sustained recovery through day 90, defined as 14 consecutive days at home or place of usual residence after hospital discharge. A composite safety outcome that included death, serious adverse events, end-organ disease, and serious infections was assessed through day 90.Results: An independent data and safety monitoring board recommended that enrollment be halted for early futility after 485 patients were randomly assigned and received an infusion of ensovibep (n = 247) or placebo (n = 238). The odds ratio (OR) for a more favorable pulmonary outcome in the ensovibep (vs. placebo) group at day 5 was 0.93 (95% CI, 0.67 to 1.30; P = 0.68; OR > 1 would favor ensovibep). The 90-day cumulative incidence of sustained recovery was 82% for ensovibep and 80% for placebo (subhazard ratio [sHR], 1.06 [CI, 0.88 to 1.28]; sHR > 1 would favor ensovibep). The primary composite safety outcome at day 90 occurred in 78 ensovibep participants (32%) and 70 placebo participants (29%) (HR, 1.07 [CI, 0.77 to 1.47]; HR < 1 would favor ensovibep).Limitation: The trial was prematurely stopped because of futility, limiting power for the primary outcome.Conclusion: Compared with placebo, ensovibep did not improve clinical outcomes for hospitalized participants with COVID-19 receiving standard care, including remdesivir; no safety concerns were identified.Primary Funding Source: National Institutes of Health. [ABSTRACT FROM AUTHOR]

Background: Developing non-pharmacological interventions with strong potential to prevent or delay the onset of Alzheimer's disease (AD) in high-risk populations is critical. Aerobic exercise and cognitive training are two promising interventions. Aerobic exercise increases aerobic fitness, which in turn improves brain structure and function, while cognitive training improves selective brain function intensively. Hence, combined aerobic exercise and cognitive training may have a synergistic effect on cognition by complementary strengthening of different neural functions. Few studies have tested the effects of such a combined intervention, and the findings have been discrepant, largely due to varying doses and formats of the interventions.Methods/design: The purpose of this single-blinded, 2 × 2 factorial phase II randomized controlled trial is to test the efficacy and synergistic effects of a 6-month combined cycling and speed of processing training intervention on cognition and relevant mechanisms (aerobic fitness, cortical thickness, and functional connectivity in the default mode network) in older adults with amnestic mild cognitive impairment. This trial will randomize 128 participants equally to four arms: cycling and speed of processing, cycling only, speed of processing only, or attention control for 6 months, and then follow them for another 12 months. Cognition and aerobic fitness will be assessed at baseline and at 3, 6, 12, and 18 months; cortical thickness and functional connectivity at baseline and at 6, 12, and 18 months; Alzheimer's disease (AD) conversion at 6, 12, and 18 months. The specific aims are to (1) determine the efficacy and synergistic effects of the combined intervention on cognition over 6 months, (2) examine the underlying mechanisms of the combined intervention, and (3) calculate the long-term effect sizes of the combined intervention on cognition and AD conversion. The analysis will use intention-to-treat and linear mixed-effects modeling.Discussion: This trial will be among the first to test the synergistic effects on cognition and mechanisms (relevant to Alzheimer's-associated neurodegeneration) of a uniquely conceptualized and rigorously designed aerobic exercise and cognitive training intervention in older adults with mild cognitive impairment. It will advance Alzheimer's prevention research by providing precise effect-size estimates of the combined intervention.Trial Registration: ClinicalTrials.gov, NCT03313895 . Registered on 18 October 2017. [ABSTRACT FROM AUTHOR]