The HOPE4MCI study: A randomized double-blind assessment of AGB101 for the treatment of MCI due to AD.

INTRODUCTION: In addition to the accumulation of amyloid plaques and neurofibrillary tangles, the presence of excess neural activity is a pathological hallmark of Alzheimer's disease (AD) and a prognostic indicator for progression of AD pathology and clinical/cognitive worsening in mild cognitive impairment due to Alzheimer's disease (MCI due to AD). The HOPE4MCI clinical study tested the efficacy of a therapeutic with demonstrated ability to normalize heightened neural activity in the hippocampus in a randomized controlled trial of 78 weeks duration in patients with MCI due to AD. METHODS: One hundred and sixty-four participants were randomized to placebo (n = 83) or AGB101 (n = 81), an extended-release formulation of low dose (220 mg) levetiracetam. The primary endpoint was the change in Clinical Dementia Rating Scale Sum of Boxes score (CDR-SB) comparing follow up at 18 months to baseline. The goal of the primary efficacy analysis was to estimate the difference between the AGB101 and placebo arms in the mean change of the primary endpoint. RESULTS: The mean change in CDR-SB was estimated to be 1.12 (95% confidence interval [CI]: 0.66, 1.69) for the AGB101 arm and 1.22 (95% CI: 0.75, 1.78) for the placebo arm. The estimated difference between arms is -0.10 (95% CI: -0.85, 0.58), which was not statistically significant. In a prespecified analysis, the difference was -0.45 (95% CI: -1.43, 0.53) for ApoE-4 noncarriers and -0.10 (95% CI: -0.92, 0.72) for apolipoprotein E (ApoE)-4 carriers. DISCUSSION: The possibility that ApoE-4 carriers and noncarriers will respond differently to therapeutic intervention is consistent with recently reported findings from biologics and the present results show further testing of AGB101 in patients with MCI due to AD who are noncarriers of the ApoeE-4 allele is warranted. Conclusions from the HOPE4MCI study are limited primarily due to the small sample size and results can only be regarded as a guide to future research.

The Bio-Hermes Study: Biomarker database developed to investigate blood-based and digital biomarkers in community-based, diverse populations clinically screened for Alzheimer's disease.

INTRODUCTION: Alzheimer's disease (AD) trial participants are often screened for eligibility by brain amyloid positron emission tomography/cerebrospinal fluid (PET/CSF), which is inefficient as many are not amyloid positive. Use of blood-based biomarkers may reduce screen failures. METHODS: We recruited 755 non-Hispanic White, 115 Hispanic, 112 non-Hispanic Black, and 19 other minority participants across groups of cognitively normal (n = 417), mild cognitive impairment (n = 312), or mild AD (n = 272) participants. Plasma amyloid beta (Aß)40, Aß42, Aß42/Aß40, total tau, phosphorylated tau (p-tau)181, and p-tau217 were measured; amyloid PET/CSF (n = 956) determined amyloid positivity. Clinical, blood biomarker, and ethnicity/race differences associated with amyloid status were evaluated. RESULTS: Greater impairment, older age, and carrying an apolipoprotein E (apoE) ε4 allele were associated with greater amyloid burden. Areas under the receiver operating characteristic curve for amyloid status of plasma Aß42/Aß40, p-tau181, and p-tau217 with amyloid positivity were ≥ 0.7117 for all ethnoracial groups (p-tau217, ≥0.8128). Age and apoE ε4 adjustments and imputation of biomarker values outside limit of quantitation provided small improvement in predictive power. DISCUSSION: Blood-based biomarkers are highly associated with amyloid PET/CSF results in diverse populations enrolled at clinical trial sites. HIGHLIGHTS: Amyloid beta (Aß)42/Aß40, phosphorylated tau (p-tau)181, and p-tau 217 blood-based biomarkers predicted brain amyloid positivity. P-tau 217 was the strongest predictor of brain amyloid positivity. Biomarkers from diverse ethnic, racial, and clinical cohorts predicted brain amyloid positivity. Community-based populations have similar Alzheimer's disease (AD) biomarker levels as other populations. A prescreen process with blood-based assays may reduce the number of AD trial screen failures.

CERAD (Consortium to Establish a Registry for Alzheimer's Disease) Neuropsychology Assessment Battery: 35 Years and Counting.

BACKGROUND: In 1986, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) was mandated to develop a brief neuropsychological assessment battery (CERAD-NAB) for AD, for uniform neuropsychological assessment, and information aggregation. Initially used across the National Institutes of Aging-funded Alzheimer's Disease Research Centers, it has become widely adopted wherever information is desired on cognitive status and change therein, particularly in older populations. OBJECTIVE: Our purpose is to provide information on the multiple uses of the CERAD-NAB since its inception, and possible further developments. METHODS: Since searching on "CERAD neuropsychological assessment battery" or similar terms missed important information, "CERAD" alone was entered into PubMed and SCOPUS, and CERAD-NAB use identified from the resulting studies. Use was sorted into major categories, e.g., psychometric information, norms, dementia/differential dementia diagnosis, epidemiology, intervention evaluation, genetics, etc., also translations, country of use, and alternative data gathering approaches. RESULTS: CERAD-NAB is available in ∼20 languages. In addition to its initial purpose assessing AD severity, CERAD-NAB can identify mild cognitive impairment, facilitate differential dementia diagnosis, determine cognitive effects of naturally occurring and experimental interventions (e.g., air pollution, selenium in soil, exercise), has helped to clarify cognition/brain physiology-neuroanatomy, and assess cognitive status in dementia-risk conditions. Surveys of primary and tertiary care patients, and of population-based samples in multiple countries have provided information on prevalent and incident dementia, and cross-sectional and longitudinal norms for ages 35-100 years. CONCLUSION: CERAD-NAB has fulfilled its original mandate, while its uses have expanded, keeping up with advances in the area of dementia.

Challenges and progress in research, diagnostics, and therapeutics in Alzheimer's disease and related dementias.

The health, well-being, and financial security of Americans are greatly impacted by Alzheimer's disease. The forecast paints an upward trajectory with the number of Americans suffering from Alzheimer's disease and related dementia. To discuss the Alzheimer's crisis, The Senate Committee on Finance, Subcommittee on Health Care, held a hearing titled, "The Alzheimer's Crisis: Examining, Testing, and Treatment Pipelines and Fiscal Implications," on December 16, 2020. Here, we summarize and expand on the discussion of the panel and its review of recent progress, ongoing challenges associated with Alzheimer's disease, and potential initiatives that promise to speed progress in developing treatments and improving care.

Value-Generating Exploratory Trials in Neurodegenerative Dementias.

Drug development for Alzheimer disease and other neurodegenerative dementias, including frontotemporal dementia, has experienced a long history of phase 2 and phase 3 clinical trials that failed to show efficacy of investigational drugs. Despite differences in clinical and behavioral characteristics, these disorders have shared pathologies and face common challenges in designing early-phase trials that are predictive of late-stage success. Here, we discuss exploratory clinical trials in neurodegenerative dementias. These are generally phase 1b or phase 2a trials that are designed to assess pharmacologic effects and rely on biomarker outcomes, with shorter treatment durations and fewer patients than traditional phase 2 studies. Exploratory trials can establish go/no-go decision points, support proof of concept and dose selection, and terminate drugs that fail to show target engagement with suitable exposure and acceptable safety profiles. Early failure saves valuable resources including opportunity costs. This is especially important for programs in academia and small biotechnology companies but may be applied to high-risk projects in large pharmaceutical companies to achieve proof of concept more rapidly at lower costs than traditional approaches. Exploratory studies in a staged clinical development program may provide promising data to warrant the substantial resources needed to advance compounds through late-stage development. To optimize the design and application of exploratory trials, the Alzheimer's Drug Discovery Foundation and the Association for Frontotemporal Degeneration convened an advisory panel to provide recommendations on outcome measures and statistical considerations for these types of studies and study designs that can improve efficiency in clinical development.

A simulation study comparing slope model with mixed-model repeated measure to assess cognitive data in clinical trials of Alzheimer's disease.

INTRODUCTION: In clinical trials of Alzheimer's disease, a mixed-model repeated measure approach often serves as the primary analysis when evaluating disease progression; a slope model may be secondary. METHODS: Longitudinal change from baseline (14-item version of Alzheimer's Disease Assessment Scale-Cognitive Subscale) was simulated for treatment/placebo from multivariate normal distributions with the variance-covariance matrix estimated from solanezumab trial data. Type I error, power, and bias were based on 18-month treatment contrast. Sample sizes included 500 and 1000 patients/arm. RESULTS: The slope model was more powerful in most scenarios. Mixed-model repeated measure was relatively unbiased in parameter estimation. The slope model yielded unbiased estimates whenever the underlying trajectory was not detectably different from linear. Both methods led to similar type I error. DISCUSSION: In clinical trials of Alzheimer's disease, mixed-model repeated measure analysis with relaxed assumptions on disease progression seems to be preferred. The slope model might be more powerful if the trajectory has little departure from linearity.

Drug discovery and development: Role of basic biological research.

This article provides a brief overview of the processes of drug discovery and development. Our aim is to help scientists whose research may be relevant to drug discovery and/or development to frame their research report in a way that appropriately places their findings within the drug discovery and development process and thereby support effective translation of preclinical research to humans. One overall theme of our article is that the process is sufficiently long, complex, and expensive so that many biological targets must be considered for every new medicine eventually approved for clinical use and new research tools may be needed to investigate each new target. Studies that contribute to solving any of the many scientific and operational issues involved in the development process can improve the efficiency of the process. An awareness of these issues allows the early implementation of measures to increase the opportunity for success. As editors of the journal, we encourage submission of research reports that provide data relevant to the issues presented.

Randomized controlled trials in mild cognitive impairment: Sources of variability.

OBJECTIVE: To examine the variability in performance among placebo groups in randomized controlled trials for mild cognitive impairment (MCI). METHODS: Placebo group data were obtained from 2 National Institute on Aging (NIA) MCI randomized controlled trials, the Alzheimer's Disease Cooperative Study (ADCS) MCI trial and the Alzheimer's Disease Neuroimaging Initiative (ADNI), which is a simulated clinical trial, in addition to industry-sponsored clinical trials involving rivastigmine, galantamine, rofecoxib, and donepezil. The data were collated for common measurement instruments. The performance of the placebo participants from these studies was tracked on the Alzheimer's Disease Assessment Scale-cognitive subscale, Mini-Mental State Examination, and Clinical Dementia Rating-sum of boxes, and for progression on these measures to prespecified clinical study endpoints. APOE status, where available, was also analyzed for its effects. RESULTS: The progression to clinical endpoints varied a great deal among the trials. The expected performances were seen for the participants in the 2 NIA trials, ADCS and ADNI, with generally worsening of performance over time; however, the industry-sponsored trials largely showed stable or improved performance in their placebo participants. APOE4 carrier status influenced results in an expected fashion on the study outcomes, including rates of progression and cognitive subscales. CONCLUSIONS: In spite of apparently similar criteria for MCI being adopted by the 7 studies, the implementation of the criteria varied a great deal. Several explanations including instruments used to characterize participants and variability among study populations contributed to the findings.

Proof-of-Concept Study to Assess the Nociceptin Receptor Antagonist LY2940094 as a New Treatment for Alcohol Dependence.

BACKGROUND: This was a proof-of-concept study to evaluate the efficacy of LY2940094, a nociceptin/orphanin FQ peptide receptor antagonist, in reducing alcohol consumption in actively alcohol-drinking patients with alcohol dependence. METHODS: Eighty-eight patients, 21 to 66 years of age, diagnosed with alcohol dependence, reporting 3 to 6 heavy drinking days per week, were randomized (1:1) to 8 weeks of treatment with once-daily oral placebo (N = 44) or 40 mg/d of LY2940094 (N = 44). The primary efficacy analysis was the change from baseline in number of drinks per day (NDD) utilizing mixed-model repeated measures comparing LY2940094 and placebo in Month 2 of the 8-week double-blind treatment period. The probability that the difference relative to placebo in NDD was ≤0 at endpoint was calculated, and a probability ≥80% was considered to be evidence that LY2940094 was associated with the reduction in NDD. RESULTS: After 8 weeks of treatment, reduction in mean NDD did not differ between LY2940094 versus placebo (-1.4 vs. -1.5, respectively, 44% probability of greater reduction relative to placebo), but there was a greater reduction in the mean percentage of heavy drinking days in a month with LY2940094 versus placebo (-24.5 vs. -15.7%, respectively, 93% probability of a greater reduction relative to placebo), and an increase in the mean percentage of abstinent days in a month compared to placebo (9.1 vs. 1.9%, respectively, 91% probability of a greater increase relative to placebo). Patients who were treated with LY2940094 showed decreased plasma levels of gamma-glutamyl transferase with probabilities ≥98% for greater reduction compared with placebo at Weeks 1, 4, 6, and 8. Treatment-emergent adverse events in ≥5% of patients treated with LY2940094 included insomnia, vomiting, and anxiety. There were no serious adverse events or significant changes in laboratory assessments or vital signs with LY2940094. CONCLUSIONS: Although not reducing the NDD, LY2940094, compared to placebo, did reduce heavy drinking days and increased abstinence days in patients with alcohol dependence.

A Selective Nociceptin Receptor Antagonist to Treat Depression: Evidence from Preclinical and Clinical Studies.

Nociceptin/Orphanin FQ (N/OFQ) is an endogenous ligand of the N/OFQ peptide (NOP) receptor, which is a G protein-coupled receptor in brain regions associated with mood disorders. We used a novel, potent, and selective orally bioavailable antagonist, LY2940094, to test the hypothesis that blockade of NOP receptors would induce antidepressant effects. In this study we demonstrate that targeting NOP receptors with LY2940094 translates to antidepressant-like effects in rodent models and, importantly, to antidepressant efficacy in patients with major depressive disorder (MDD). The proof-of-concept study (POC) was an 8-week, double-blind, placebo-controlled trial that evaluated LY2940094 as a novel oral medication for the treatment of patients with MDD. Once daily oral dosing of LY2940094 at 40 mg for 8 weeks vs placebo provided some evidence for an antidepressant effect based on the change from baseline to week 8 in the GRID-Hamilton Depression Rating Scale-17 item total score, although the predefined POC efficacy criterion (probability of LY2940094 being better than placebo⩾88%) was not met (82.9%). LY2940094 also had an early effect on the processing of emotional stimuli at Week 1 as shown by an increased recognition of positive relative to negative facial expressions in an emotional test battery. LY2940094 was safe and well tolerated. Overall, these are the first human data providing evidence that the blockade of NOP receptor signaling represents a promising strategy for the treatment of MDD.

Erratum: A Selective Nociceptin Receptor Antagonist to Treat Depression: Evidence from Preclinical and Clinical Studies.

[This corrects the article DOI: 10.1038/npp.2015.348.].

Cognitive Impairment Precedes and Predicts Functional Impairment in Mild Alzheimer's Disease.

BACKGROUND: The temporal relationship of cognitive deficit and functional impairment in Alzheimer's disease (AD) is not well characterized. Recent analyses suggest cognitive decline predicts subsequent functional decline throughout AD progression. OBJECTIVE: To better understand the relationship between cognitive and functional decline in mild AD using autoregressive cross-lagged (ARCL) panel analyses in several clinical trials. METHODS: Data included placebo patients with mild AD pooled from two multicenter, double-blind, Phase 3 solanezumab (EXPEDITION/2) or semagacestat (IDENTITY/2) studies, and from AD patients participating in the Alzheimer's Disease Neuroimaging Initiative (ADNI). Cognitive and functional outcomes were assessed using AD Assessment Scale-Cognitive subscale (ADAS-Cog), AD Cooperative Study-Activities of Daily Living instrumental subscale (ADCS-iADL), or Functional Activities Questionnaire (FAQ), respectively. ARCL panel analyses evaluated relationships between cognitive and functional impairment over time. RESULTS: In EXPEDITION, ARCL panel analyses demonstrated cognitive scores significantly predicted future functional impairment at 5 of 6 time points, while functional scores predicted subsequent cognitive scores in only 1 of 6 time points. Data from IDENTITY and ADNI programs yielded consistent results whereby cognition predicted subsequent function, but not vice-versa. CONCLUSIONS: Analyses from three databases indicated cognitive decline precedes and predicts subsequent functional decline in mild AD dementia, consistent with previously proposed hypotheses, and corroborate recent publications using similar methodologies. Cognitive impairment may be used as a predictor of future functional impairment in mild AD dementia and can be considered a critical target for prevention strategies to limit future functional decline in the dementia process.

Peripheral and central effects of γ-secretase inhibition by semagacestat in Alzheimer's disease.

INTRODUCTION: The negative efficacy study examining the γ-secretase inhibitor semagacestat in mild to moderate Alzheimer's disease (AD) included a number of biomarkers of the disease as well as safety outcomes. We analyzed these data to explore relationships between drug exposure and pharmacodynamic effects and to examine the correlations among outcome measures. METHODS: The study was a multicenter, randomized, placebo-controlled trial of two dose regimens of semagacestat and a placebo administered for 18 months to individuals with mild to moderate AD. Changes in measures of central and peripheral drug activity were compared between the three treatment groups using one-way analysis of variance. The relationship between changes in each of the outcome measures and measures of drug exposure and peripheral pharmacodynamic effect were assessed using Spearman's correlation coefficient. RESULTS: Assignment to the active treatment arms was associated with reduction in plasma amyloid-ß (Aß) peptides, increase in ventricular volume, decrease in cerebrospinal fluid phosphorylated tau (p-tau) and several other laboratory measures and adverse event categories. Within the active arms, exposure to drug, as indicated by area under the concentration curve (AUC) of blood concentration, was associated with reduction in plasma Aß peptides and a subset of laboratory changes and adverse event rates. Ventricular volume increase, right hippocampal volume loss and gastrointestinal symptoms were related to change in plasma Aß peptide but not AUC, supporting a link to inhibition of γ-secretase cleavage of the amyloid precursor protein. Cognitive decline correlated with ventricular expansion and reduction in p-tau. CONCLUSION: These findings may inform future studies of drugs targeting secretases involved in Aß generation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00594568. Registered 11 January 2008.

Cognitive and functional decline and their relationship in patients with mild Alzheimer's dementia.

BACKGROUND: In patients with Alzheimer's disease (AD), the relationship between cognitive and functional progression is not fully understood; however, functional decline has been postulated to follow cognitive decline. OBJECTIVE: To assess the relationship between cognitive and functional treatment effects in mild AD dementia patients. METHODS: Data of patients with mild AD were pooled from two multicenter, double-blind, Phase 3 studies. Patients were randomized to infusions of 400-mg solanezumab (n = 654), or placebo (n = 660) every 4 weeks for 18 months. Cognitive and functional outcome measures were assessed using the AD Assessment Scale-Cognitive subscale (ADAS-Cog) and the AD Cooperative Study-Activities of Daily Living (ADCS-ADL), respectively. Analyses included comparisons among normalized scales, correlations between outcome measures, and path analyses to model the relationship of treatment effect on cognition and function. RESULTS: Normalized ADAS-Cog and ADCS-ADL scales showed cognitive impairment was more evident than functional impairment in mild AD. The correlation between cognition and function increased over time. Path analyses demonstrated that 87% of the treatment effect on function was driven by the treatment effect on cognition, with the remaining 13% due to direct treatment effect. CONCLUSION: Findings from this study are consistent with the hypothesis that functional impairment is primarily driven by and follows cognitive decline in mild AD dementia. The cognitive treatment effect appeared to explain the majority of the functional treatment effect. It is possible that a cognitive treatment effect may be considered as a leading indicator for functional outcomes in an 18-month clinical trial for milder stages of AD.

2014 Report on the Milestones for the US National Plan to Address Alzheimer's Disease.

With increasing numbers of people with Alzheimer's and other dementias across the globe, many countries have developed national plans to deal with the resulting challenges. In the United States, the National Alzheimer's Project Act, signed into law in 2011, required the creation of such a plan with annual updates thereafter. Pursuant to this, the US Department of Health and Human Services (HHS) released the National Plan to Address Alzheimer's Disease in 2012, including an ambitious research goal of preventing and effectively treating Alzheimer's disease by 2025. To guide investments, activities, and the measurement of progress toward achieving this 2025 goal, in its first annual plan update (2013) HHS also incorporated into the plan a set of short, medium and long-term milestones. HHS further committed to updating these milestones on an ongoing basis to account for progress and setbacks, and emerging opportunities and obstacles. To assist HHS as it updates these milestones, the Alzheimer's Association convened a National Plan Milestone Workgroup consisting of scientific experts representing all areas of Alzheimer's and dementia research. The workgroup evaluated each milestone and made recommendations to ensure that they collectively constitute an adequate work plan for reaching the goal of preventing and effectively treating Alzheimer's by 2025. This report presents these Workgroup recommendations.

Phase 3 trials of solanezumab for mild-to-moderate Alzheimer's disease.

BACKGROUND: Alzheimer's disease is characterized by amyloid-beta plaques, neurofibrillary tangles, gliosis, and neuronal loss. Solanezumab, a humanized monoclonal antibody, preferentially binds soluble forms of amyloid and in preclinical studies promoted its clearance from the brain. METHODS: In two phase 3, double-blind trials (EXPEDITION 1 and EXPEDITION 2), we randomly assigned 1012 and 1040 patients, respectively, with mild-to-moderate Alzheimer's disease to receive placebo or solanezumab (administered intravenously at a dose of 400 mg) every 4 weeks for 18 months. The primary outcomes were the changes from baseline to week 80 in scores on the 11-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog11; range, 0 to 70, with higher scores indicating greater cognitive impairment) and the Alzheimer's Disease Cooperative Study-Activities of Daily Living scale (ADCS-ADL; range, 0 to 78, with lower scores indicating worse functioning). After analysis of data from EXPEDITION 1, the primary outcome for EXPEDITION 2 was revised to the change in scores on the 14-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog14; range, 0 to 90, with higher scores indicating greater impairment), in patients with mild Alzheimer's disease. RESULTS: Neither study showed significant improvement in the primary outcomes. The modeled difference between groups (solanezumab group minus placebo group) in the change from baseline was -0.8 points for the ADAS-cog11 score (95% confidence interval [CI], -2.1 to 0.5; P=0.24) and -0.4 points for the ADCS-ADL score (95% CI, -2.3 to 1.4; P=0.64) in EXPEDITION 1 and -1.3 points (95% CI, -2.5 to 0.3; P=0.06) and 1.6 points (95% CI, -0.2 to 3.3; P=0.08), respectively, in EXPEDITION 2. Between-group differences in the changes in the ADAS-cog14 score were -1.7 points in patients with mild Alzheimer's disease (95% CI, -3.5 to 0.1; P=0.06) and -1.5 in patients with moderate Alzheimer's disease (95% CI, -4.1 to 1.1; P=0.26). In the combined safety data set, the incidence of amyloid-related imaging abnormalities with edema or hemorrhage was 0.9% with solanezumab and 0.4% with placebo for edema (P=0.27) and 4.9% and 5.6%, respectively, for hemorrhage (P=0.49). CONCLUSIONS: Solanezumab, a humanized monoclonal antibody that binds amyloid, failed to improve cognition or functional ability. (Funded by Eli Lilly; EXPEDITION 1 and 2 ClinicalTrials.gov numbers, NCT00905372 and NCT00904683.).