Alzheimer's disease drug development in an evolving therapeutic landscape.

Unlabelled: The Alzheimer's disease (AD) research field has entered a new era, where our fundamental understanding of the pathophysiology of AD and advances in biomarkers have not only allowed for earlier, timely, and accurate detection and diagnosis of the disease, but that amyloid removal has been shown to be associated with signals of slowing cognitive and functional decline. Although recent FDA-approved amyloid plaque-lowering monoclonal antibody therapies have shifted the trajectory of AD, additional treatment options will be key to further slowing clinical decline or stopping disease progression. Thus, new and emerging therapies for AD have created an evolving therapeutic landscape.

Plasma pTau217 ratio predicts continuous regional brain tau accumulation in amyloid-positive early Alzheimer's disease.

Background: This study examines whether phosphorylated plasma Tau217 ratio (pTau217R) can predict tau accumulation in different brain regions, as measured by positron emission tomography (PET) standardized uptake value ratio (SUVR), for staging Alzheimer's disease (AD).

Methods: Plasma pTau217R was measured using immunoprecipitation-mass spectrometry. Models for predicting tau PET SUVR, developed with 144 early AD individuals using [F]MK6240, were validated in two validation sets, VS1 (98 early AD) and VS2 (47 preclinical/early AD with a different tracer, flortaucipir (Tauvid)), all amyloid-beta positive (Aβ+).

Harmonizing tau positron emission tomography in Alzheimer's disease: The CenTauR scale and the joint propagation model.

Introduction: Tau-positron emission tomography (PET) outcome data of patients with Alzheimer's disease (AD) cannot currently be meaningfully compared or combined when different tracers are used due to differences in tracer properties, instrumentation, and methods of analysis.

Methods: Using head-to-head data from five cohorts with tau PET radiotracers designed to target tau deposition in AD, we tested a joint propagation model (JPM) to harmonize quantification (units termed "CenTauR" [CTR]). JPM is a statistical model that simultaneously models the relationships between head-to-head and anchor point data.

Plasma pTau217 predicts continuous brain amyloid levels in preclinical and early Alzheimer's disease.

Background: This study investigated the potential of phosphorylated plasma Tau217 ratio (pTau217R) and plasma amyloid beta (Aβ) 42/Aβ40 in predicting brain amyloid levels measured by positron emission tomography (PET) Centiloid (CL) for Alzheimer's disease (AD) staging and screening.

Methods: Quantification of plasma pTau217R and Aβ42/Aβ40 employed immunoprecipitation-mass spectrometry. CL prediction models were developed on a cohort of 904 cognitively unimpaired, preclinical and early AD subjects and validated on two independent cohorts.

Lewy body dementia: Overcoming barriers and identifying solutions.

Despite its high prevalence among dementias, Lewy body dementia (LBD) remains poorly understood with a limited, albeit growing, evidence base. The public-health burden that LBD imposes is worsened by overlapping pathologies, which contribute to misdiagnosis, and lack of treatments. For this report, we gathered and analyzed public-domain information on advocacy, funding, research outputs, and the therapeutic pipeline to identify gaps in each of these key elements.

Alzheimer's Targeted Treatments: Focus on Amyloid and Inflammation.

Alzheimer's disease (AD) is the major cause of dementia that is now threatening the lives of billions of elderly people on the globe, and recent progress in the elucidation of the pathomechanism of AD is now opening venue to tackle the disease by developing and implementing "disease-modifying therapies" that directly act on the pathophysiology and slow down the progression of neurodegeneration. A recent example is the success of clinical trials of anti-amyloid b antibody drugs, whereas other therapeutic targets, e.g.

Lewy Body Dementia Association's Industry Advisory Council: proceedings of the second annual meeting.

In 2019, the Lewy Body Dementia Association formed an Industry Advisory Council to bring together a collaborative group of stakeholders with the goal of accelerating clinical research into Lewy body dementia treatments. At the second annual meeting of the Industry Advisory Council, held virtually on June 18, 2020, the key members presented ongoing and planned efforts toward the council's goals. The meeting also featured a discussion about the effects of the COVID-19 pandemic on Lewy body dementia clinical research, lessons learned from that experience, and how those lessons can be applied to the design and conduct of future clinical trials.

New directions in clinical trials for frontotemporal lobar degeneration: Methods and outcome measures.

Introduction: Frontotemporal lobar degeneration (FTLD) is the most common form of dementia for those under 60 years of age. Increasing numbers of therapeutics targeting FTLD syndromes are being developed.

Methods: In March 2018, the Association for Frontotemporal Degeneration convened the Frontotemporal Degeneration Study Group meeting in Washington, DC, to discuss advances in the clinical science of FTLD.

Secondary prevention of Alzheimer's dementia: neuroimaging contributions.

Background: In Alzheimer's disease (AD), pathological changes may arise up to 20 years before the onset of dementia. This pre-dementia window provides a unique opportunity for secondary prevention. However, exposing non-demented subjects to putative therapies requires reliable biomarkers for subject selection, stratification, and monitoring of treatment.

Severity dependent distribution of impairments in PSP and CBS: Interactive visualizations.

Background: Progressive supranuclear palsy (PSP) -Richardson's Syndrome and Corticobasal Syndrome (CBS) are the two classic clinical syndromes associated with underlying four repeat (4R) tau pathology. The PSP Rating Scale is a commonly used assessment in PSP clinical trials; there is an increasing interest in designing combined 4R tauopathy clinical trials involving both CBS and PSP.

Objectives: To determine contributions of each domain of the PSP Rating Scale to overall severity and characterize the probable sequence of clinical progression of PSP as compared to CBS.

Topographic staging of tau positron emission tomography images.

Introduction: It has been proposed that the signal distribution on tau positron emission tomography (PET) images could be used to define pathologic stages similar to those seen in neuropathology.

Methods: Three topographic staging schemes for tau PET, two sampling the temporal and occipital subregions only and one sampling cortical gray matter across the major brain lobes, were evaluated on flortaucipir F 18 PET images in a test-retest scenario and from Alzheimer's Disease Neuroimaging Initiative 2.

Results: All three schemes estimated stages that were significantly associated with amyloid status and when dichotomized to tau positive or negative were 90% to 94% concordant in the populations identified.

Development and validation of an algorithm for identifying urinary retention in a cohort of patients with epilepsy in a large US administrative claims database.

Purpose: The aim of this study was to develop and validate an insurance claims-based algorithm for identifying urinary retention (UR) in epilepsy patients receiving antiepileptic drugs to facilitate safety monitoring.

Methods: Data from the HealthCore Integrated Research Database(SM) in 2008-2011 (retrospective) and 2012-2013 (prospective) were used to identify epilepsy patients with UR. During the retrospective phase, three algorithms identified potential UR: (i) UR diagnosis code with a catheterization procedure code; (ii) UR diagnosis code alone; or (iii) diagnosis with UR-related symptoms.

Lipoprotein-associated phospholipase A2 and risk of dementia in the Cardiovascular Health Study.

Objective: To evaluate associations between Lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity with risk of dementia and its subtypes.

Methods: Analysis were completed on 3320 participants of the Cardiovascular Health Study (CHS), a population-based longitudinal study of community-dwelling adults age ≥65 years followed for an average of 5.4 years.

Incidence of type 2 diabetes among patients exposed to the combination of pravastatin and paroxetine.

Purpose: This study evaluated the effects of concomitant pravastatin and paroxetine use on the incidence of Type 2 Diabetes Mellitus (T2DM).

Methods: A new-user retrospective cohort design was employed using data selected from US health insurance claims databases (OptumInsight and MarketScan) between July 1, 2002, and December 31, 2009. Patients included were of age ≥18; newly prescribed pravastatin or paroxetine; and enrolled in the database for ≥180 days prior to the index date (i.

Plasma lipoprotein-associated phospholipase A2 activity in Alzheimer's disease, amnestic mild cognitive impairment, and cognitively healthy elderly subjects: a cross-sectional study.

Introduction: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a circulating enzyme with pro-inflammatory and oxidative activities associated with cardiovascular disease and ischemic stroke. While high plasma Lp-PLA2 activity was reported as a risk factor for dementia in the Rotterdam study, no association between Lp-PLA2 mass and dementia or Alzheimer's disease (AD) was detected in the Framingham study. The objectives of the current study were to explore the relationship of plasma Lp-PLA2 activity with cognitive diagnoses (AD, amnestic mild cognitive impairment (aMCI), and cognitively healthy subjects), cardiovascular markers, cerebrospinal fluid (CSF) markers of AD, and apolipoprotein E (APOE) genotype.

The epidemiology of Alzheimer's disease: laying the foundation for drug design, conduct, and analysis of clinical trials.

Epidemiological studies increasingly inform Alzheimer's disease (AD) public health impact, prevention strategies, drug targets, therapeutic interventions, and clinical trial design. For this reason, the Alzheimer's Association Research Roundtable convened an international group of AD experts with experience in conducting both observational and clinical trials for a meeting on October 19 and 20, 2010, in Washington, DC, to discuss the role of epidemiologic studies in AD research and therapeutic advances. Topics included wellness markers and risk factors, with a focus on special populations such as those at elevated risk, super agers, and underserved populations.

Incidence of new-onset seizures in mild to moderate Alzheimer disease.

Objective: To estimate the incidence rate and predictors of seizures in patients with mild to moderate Alzheimer disease (AD).

Design: Cohort study of patients with mild to moderate AD in clinical trials. Risk factors for potential seizures were evaluated by stratified descriptive statistics and univariable and multivariable Cox proportional hazards regressions.

Risk of cancer in patients exposed to gabapentin in two electronic medical record systems.

Purpose: High doses of gabapentin were associated with pancreatic acinar cell tumors in male Wistar rats, but there is little published epidemiological data regarding gabapentin and carcinogenicity. We explored the association between gabapentin and cancer in a US medical care program and followed up nominally significant associations in a UK primary care database.

Methods: In the US Kaiser Permanente Northern California (KPNC) health system, we performed nested case-control analyses of gabapentin and 55 cancer sites and all cancers combined using conditional logistic regression.

Background incidence of liver chemistry abnormalities in pediatric clinical trials for conditions with and without underlying liver disease.

Background: The FDA provides guidance regarding pre-marketing liver chemistry subject stopping criteria. This study was undertaken to determine the background rates of liver chemistry abnormalities in pediatric clinical trials for conditions with and without underlying liver disease (LD).

Methods: The study included 5410 subjects aged 0-18years in 24 trials for conditions without LD.

Modeling Alzheimer's disease progression using the disease system analysis approach.

A novel mechanistic model based on a disease system analysis paradigm was developed to explore the role of homeostatic mechanisms involved in Alzheimer's disease (AD) progression. We used longitudinal AD Assessment Scale-cognitive subscale (ADAS-cog) scores from 926 subjects with AD on stable acetylcholinesterase inhibitor therapy randomized to placebo treatment in two 54-week clinical trials. Alternative mechanistic models were evaluated by assuming that the rate of change of ADAS-cog over time was jointly regulated by a process characterizing the deterioration of ADAS-cog and by a process associated with a compensatory regulatory response.

Risk factors for antiepileptic drug regimen change in patients with newly diagnosed epilepsy.

This study aimed to investigate the evolution of treatment within patients with newly diagnosed epilepsy identified from a large US commercial health care database. Postdiagnosis, patient follow-up was divided into observation units defined by consecutive antiepileptic drug (AED) prescriptions. Consecutive prescriptions were compared to assess whether a change in AED regimen had occurred.

Genetic deficiency of plasma lipoprotein-associated phospholipase A2 (PLA2G7 V297F null mutation) and risk of Alzheimer's disease in Japan.

High plasma lipoprotein phospholipase A2 activity (Lp-PLA2) is reported to be a risk factor for dementia. A loss of function polymorphism in the Lp-PLA2 gene - PLA2G7 V279F - is found almost exclusively in Asians. In 1,952 subjects with late-onset AD and 2,079 non-demented controls recruited from Japan, the PLA2G7 null allele was not associated with risk or age at onset of AD: logistic regression OR 0.

Effects of simvastatin on cholesterol metabolism and Alzheimer disease biomarkers.

Preclinical and epidemiologic studies suggest a protective effect of statins on Alzheimer disease (AD). Experimental evidence indicates that some statins can cross the blood-brain barrier, alter brain cholesterol metabolism, and may ultimately decrease the production of amyloid-beta (Abeta) peptide. Despite these promising leads, clinical trials have yielded inconsistent results regarding the benefits of statin treatment in AD.

Caffeine protects against combined paraquat and maneb-induced dopaminergic neuron degeneration.

Environmental exposures suspected of contributing to the pathophysiology of Parkinson's disease (PD) include potentially neurotoxic pesticides, which have been linked to an increased risk of PD. Conversely, possible protective factors such as the adenosine antagonist caffeine have been linked to a reduced risk of the disease. Here we assessed whether caffeine alters dopaminergic neuron loss induced by exposure to environmentally relevant pesticides (paraquat and maneb) over 8weeks.