Publications by authors named "Lynn Kramer"

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+).

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Abstract: Plasma pTau181, a marker of amyloid and tau burden, was evaluated as a prognostic predictor of clinical decline and Alzheimer's disease (AD) progression of amyloid-positive (Aβ+) patients with mild cognitive impairment (MCI). The training cohort for constructing the Bayesian prediction models comprised 135 Aβ+ MCI clinical trial placebo subjects. Performance was evaluated in two validation cohorts.

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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.

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Article Synopsis
  • Alzheimer disease (AD) is a significant global health issue, and Lecanemab, an FDA-approved treatment for early AD, targets toxic Aβ protofibrils to improve patient outcomes.* -
  • The Clarity AD study was an 18-month, double-blind trial that evaluated Lecanemab's safety and efficacy, involving nearly 2,000 participants with early AD.* -
  • Results indicated that Lecanemab was generally well-tolerated, with some adverse events like infusion reactions and amyloid-related imaging abnormalities, and a total of 24 deaths observed, with a few linked to the treatment.*
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Background: Models for forecasting individual clinical progression trajectories in early Alzheimer's disease (AD) are needed for optimizing clinical studies and patient monitoring.

Methods: Prediction models were constructed using a clinical trial training cohort (TC; n = 934) via a gradient boosting algorithm and then evaluated in two validation cohorts (VC 1, n = 235; VC 2, n = 421). Model inputs included baseline clinical features (cognitive function assessments, APOE ε4 status, and demographics) and brain magnetic resonance imaging (MRI) measures.

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  • The study assessed eligibility rates for participation in Alzheimer's disease (AD) clinical trials among different racial and ethnic groups across the U.S.
  • Out of 10,804 screened participants, there was a significant underrepresentation of Hispanic and Black participants, with higher chances of ineligibility based on amyloid biomarker criteria compared to their non-Hispanic White counterparts.
  • The findings suggest that varying eligibility criteria may contribute to the underrepresentation of certain minored groups in early AD trials, which could impact treatment outcomes and research efficacy.
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  • Bayesian clinical trial designs are becoming more prevalent, endorsed by the FDA, and they enhance drug development efficiency and clinical trial accuracy, especially with incomplete data.
  • The study focuses on the bayesian approach used in the lecanemab trial 201, aimed at identifying the effective dose for treating early Alzheimer's disease while showcasing the benefits of adaptive design and treatment-dependent handling of missing data.
  • In the lecanemab 201 trial, 854 participants were randomly assigned to various treatment doses or a placebo, with the main outcome being the Alzheimer's Disease Composite Clinical Score after 12 months of treatment.
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  • Lecanemab is a monoclonal antibody designed to target specific forms of amyloid in the brain, an element related to Alzheimer's disease, and its ARIA profiles vary among different anti-amyloid treatments.
  • The phase 2 Study 201 was designed to evaluate ARIA occurrences using both core and open-label methods, employing statistical models to analyze the data.
  • Results showed a low incidence of ARIA-E (less than 10%) during treatment, primarily mild-to-moderate and often asymptomatic, with correlations to serum concentrations and higher risk in ApoE4 carriers.*
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  • Lecanemab, a monoclonal antibody targeting soluble Aβ protofibrils, showed significant brain amyloid reduction and slowed decline in early Alzheimer's Disease (AD) during a clinical study involving 856 patients.
  • In a double-blind, placebo-controlled trial and subsequent open-label extension, patients receiving lecanemab demonstrated dose-dependent improvements in brain amyloid levels and cognitive function, whereas those on placebo did not.
  • The study findings suggest that reducing amyloid plaques correlates with clinical benefits, indicating lecanemab's potential as an effective treatment for early AD.
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  • Lecanemab is an experimental antibody designed to target specific forms of amyloid-beta associated with Alzheimer's disease, showing promising results in a phase 2 study involving 856 participants over 18 months.
  • The study employed various statistical methods to analyze the efficacy of lecanemab, all indicating a significant slowing of clinical decline in early Alzheimer's compared to placebo.
  • Sensitivity analyses confirmed the robustness of these findings, demonstrating a consistent treatment effect on cognitive decline across multiple assessment tools at both 12 and 18 months.
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  • The study investigates lecanemab, a monoclonal antibody targeting amyloid-beta, in treating early Alzheimer's disease over 18 months.
  • It involved 1,795 participants divided equally between lecanemab and placebo, focusing on cognitive impairment and amyloid levels.
  • Results showed lecanemab users had a smaller increase in cognitive impairment scores compared to the placebo group, indicating potential benefits in early Alzheimer’s treatment.
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Introduction: The lack of ideal measurement of treatment efficacy is a well acknowledged problem in the epilepsy community, both in clinical care and clinical trials. Whilst still the current gold-standard, self-reported seizure frequency significantly underestimates the true number of seizures and does not account for any other at least equally important outcome parameters, such as neurodevelopment and cognition. With the rise of disease modifying treatments, the need for more reliable endpoints in practice and clinical trials becomes more pressing.

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  • - The study aimed to assess how quickly patients experienced a pre-randomization seizure count (T-PSC) while using adjunctive perampanel for treatment-resistant primary generalized tonic-clonic seizures in generalized-onset epilepsy.
  • - Conducted as a double-blind, multicenter trial with participants aged 12 and older, it compared the effects of perampanel (up to 8 mg/day) against a placebo over 17 weeks, analyzing seizure frequency changes.
  • - Results showed that perampanel significantly increased the time to exceed pre-randomization seizure counts (43 days on placebo vs. over 120 days on perampanel), suggesting T-PSC could be a useful measure in clinical trials for evaluating treatment effectiveness
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  • Alzheimer's disease (AD) begins with a long asymptomatic stage characterized by the accumulation of amyloid beta (Aβ) before clinical symptoms arise; the AHEAD 3-45 Study tests if the drug lecanemab can intervene in this stage to slow decline.
  • Launched in July 2020, the study includes two trials, A3 and A45, targeting cognitively unimpaired individuals aged 55-80, with different dosing based on their Aβ levels noted in PET scans.
  • The study employs innovative recruitment methods to enrich the sample for those with elevated brain amyloid, using various registries and advanced plasma screening techniques to identify suitable participants.
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  • - Lecanemab (BAN2401) is an antibody designed to target forms of amyloid beta linked to Alzheimer's, tested in a double-blind trial comparing it with a placebo in early-stage disease.
  • - The trial aimed to find an effective dose (ED90) that reduces clinical decline by at least 25% compared to placebo, using various assessment scales and brain imaging techniques over 12 and 18 months.
  • - Although the initial 12-month results did not meet the effectiveness threshold, by 18 months, lecanemab showed promising reductions in amyloid levels and clinical decline, while being well-tolerated by participants with a low incidence of adverse effects.
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BACE1 (beta-site amyloid precursor protein cleaving enzyme 1) was initially cloned and characterized in 1999. It is required for the generation of all monomeric forms of amyloid-β (Aβ), including Aβ, which aggregates into bioactive conformational species and likely initiates toxicity in Alzheimer's disease (AD). BACE1 concentrations and rates of activity are increased in AD brains and body fluids, thereby supporting the hypothesis that BACE1 plays a critical role in AD pathophysiology.

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Objective: To determine whether a novel endpoint of time to prerandomization monthly seizure count could be used to differentiate efficacious and nonefficacious therapies in clinical trials of new add-on antiepileptic drugs (AEDs).

Methods: This analysis used data from 3 randomized, double-blind, placebo-controlled phase III trials of perampanel as an add-on therapy in patients with epilepsy who were experiencing refractory partial seizures: studies 304 (ClinicalTrials.gov identifier NCT00699972), 305 (NCT00699582), and 306 (NCT00700310).

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Objective: To better understand the relationship between efficacy and perampanel dose, integrated actual (last) dose data from three phase III trials and an extension study (blinded Conversion Period; open-label Maintenance Period) were analyzed.

Methods: Seizure frequency data were analyzed in patients who were randomized to and completed the 13-week Maintenance Period of the phase III studies on perampanel 8 mg, and who received an actual (last) dose of 12 mg during (1) the extension 16-week blinded Conversion Period or (2) weeks 1-13 of the extension Maintenance Period. Due to a treatment-by-region interaction (p = 0.

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The two major histopathologic hallmarks of Alzheimer's disease (AD) are amyloid beta protein (Aβ) plaques and neurofibrillary tangles (NFT). Aβ pathology is a common feature in the aged nonhuman primate brain, whereas NFT are found almost exclusively in humans. Few studies have examined AD-related pathology in great apes, which are the closest phylogenetic relatives of humans.

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Purpose: Three phase III studies (304 [ClinicalTrials.gov identifier: NCT00699972], 305 [NCT00699582], 306 [NCT00700310]) evaluated perampanel, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, as adjunctive therapy for refractory partial seizures. We report post hoc analyses of pooled study data by randomized dose.

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Fatal abomasal impaction, often combined with omasal impaction, was diagnosed in 11 bongo (Tragelaphus eurycerus) from five different zoologic collections in the United States between 1981 and 2009. Nine of 11 cases occurred in young females (10 mo-7 yr old) and typical clinical signs prior to diagnosis or death included partial or complete anorexia, dehydration, and scant fecal production. Although the clinical histories in several of the earlier cases are incomplete, clinical signs were known to begin shortly after an anesthetic event in five of 11 bongo (45%).

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Unlabelled: A consensus meeting was convened by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) to provide recommendations for interpreting clinical importance of treatment outcomes in clinical trials of the efficacy and effectiveness of chronic pain treatments. A group of 40 participants from universities, governmental agencies, a patient self-help organization, and the pharmaceutical industry considered methodologic issues and research results relevant to determining the clinical importance of changes in the specific outcome measures previously recommended by IMMPACT for 4 core chronic pain outcome domains: (1) Pain intensity, assessed by a 0 to 10 numerical rating scale; (2) physical functioning, assessed by the Multidimensional Pain Inventory and Brief Pain Inventory interference scales; (3) emotional functioning, assessed by the Beck Depression Inventory and Profile of Mood States; and (4) participant ratings of overall improvement, assessed by the Patient Global Impression of Change scale. It is recommended that 2 or more different methods be used to evaluate the clinical importance of improvement or worsening for chronic pain clinical trial outcome measures.

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