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1.
Cerebellum ; 22(4): 531-533, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35881322

RESUMO

Prior to 1982, ovarian and certain other cancers were known to have a rare complication of progressive cerebellar ataxia, a disorder characterized pathologically by severe-often total-obliteration of cerebellar Purkinje cells. However, the cause of cerebellar injury in these patients was unknown. In that year, we began studies in which sera from individuals with this disorder were reacted with frozen sections of human cerebellum. These studies revealed that patients with ovarian cancer and cerebellar degeneration had high titers of antibodies directed against cytoplasmic antigens of Purkinje cells and deep cerebellar nuclei-a previously undescribed pattern of antibody response which was subsequently found not to be present in ovarian cancer patients who remained neurologically normal. This antibody, now known as "anti-Yo" or "anti-PCA1" provides a marker for rapidly progressive cerebellar ataxia and is heavily associated with gynecological and breast malignancies. Although the role of anti-Yo antibody in cerebellar injury has not been established in living animals, in vitro studies have demonstrated that anti-Yo antibody causes Purkinje cell death in the absence of T lymphocytes. In this commentary, we describe our studies leading to initial discovery of anti-Yo antibody, discuss the relationship of this discovery to current knowledge of paraneoplastic neurological disease, and outline some important questions which remain to be resolved before we fully understand the pathogenesis and optimal treatment of this disorder.


Assuntos
Ataxia Cerebelar , Doenças Cerebelares , Neoplasias Ovarianas , Degeneração Paraneoplásica Cerebelar , Degenerações Espinocerebelares , Animais , Feminino , Humanos , Doenças Cerebelares/patologia , Cerebelo/patologia , Autoanticorpos , Células de Purkinje/metabolismo , Degenerações Espinocerebelares/patologia , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia
2.
N Engl J Med ; 370(4): 322-33, 2014 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-24450891

RESUMO

BACKGROUND: Bapineuzumab, a humanized anti-amyloid-beta monoclonal antibody, is in clinical development for the treatment of Alzheimer's disease. METHODS: We conducted two double-blind, randomized, placebo-controlled, phase 3 trials involving patients with mild-to-moderate Alzheimer's disease--one involving 1121 carriers of the apolipoprotein E (APOE) ε4 allele and the other involving 1331 noncarriers. Bapineuzumab or placebo, with doses varying by study, was administered by intravenous infusion every 13 weeks for 78 weeks. The primary outcome measures were scores on the 11-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog11, with scores ranging from 0 to 70 and higher scores indicating greater impairment) and the Disability Assessment for Dementia (DAD, with scores ranging from 0 to 100 and higher scores indicating less impairment). A total of 1090 carriers and 1114 noncarriers were included in the efficacy analysis. Secondary outcome measures included findings on positron-emission tomographic amyloid imaging with the use of Pittsburgh compound B (PIB-PET) and cerebrospinal fluid phosphorylated tau (phospho-tau) concentrations. RESULTS: There were no significant between-group differences in the primary outcomes. At week 78, the between-group differences in the change from baseline in the ADAS-cog11 and DAD scores (bapineuzumab group minus placebo group) were -0.2 (P=0.80) and -1.2 (P=0.34), respectively, in the carrier study; the corresponding differences in the noncarrier study were -0.3 (P=0.64) and 2.8 (P=0.07) with the 0.5-mg-per-kilogram dose of bapineuzumab and 0.4 (P=0.62) and 0.9 (P=0.55) with the 1.0-mg-per-kilogram dose. The major safety finding was amyloid-related imaging abnormalities with edema among patients receiving bapineuzumab, which increased with bapineuzumab dose and APOE ε4 allele number and which led to discontinuation of the 2.0-mg-per-kilogram dose. Between-group differences were observed with respect to PIB-PET and cerebrospinal fluid phospho-tau concentrations in APOE ε4 allele carriers but not in noncarriers. CONCLUSIONS: Bapineuzumab did not improve clinical outcomes in patients with Alzheimer's disease, despite treatment differences in biomarkers observed in APOE ε4 carriers. (Funded by Janssen Alzheimer Immunotherapy and Pfizer; Bapineuzumab 301 and 302 ClinicalTrials.gov numbers, NCT00575055 and NCT00574132, and EudraCT number, 2009-012748-17.).


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/análise , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Anticorpos Monoclonais Humanizados/efeitos adversos , Apolipoproteínas E/genética , Biomarcadores/análise , Biomarcadores/líquido cefalorraquidiano , Encéfalo/patologia , Cognição/efeitos dos fármacos , Método Duplo-Cego , Edema/induzido quimicamente , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fosforilação , Tomografia por Emissão de Pósitrons , Índice de Gravidade de Doença , Falha de Tratamento , Proteínas tau/líquido cefalorraquidiano
3.
J Neurol Neurosurg Psychiatry ; 87(1): 106-12, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25669746

RESUMO

BACKGROUND: Amyloid-related imaging abnormalities due to haemosiderin deposition (ARIA-H) occur in patients with mild to moderate dementia due to Alzheimer's disease (AD) and have been reported with increased incidence in clinical trials of amyloid-lowering therapies under development for AD. OBJECTIVE: Our objective was to explore the relationship between the incidences of ARIA-H during treatment with placebo and different doses of bapineuzumab, a humanised monoclonal antibody directed against amyloid ß. METHODS: Two neuroradiologists independently reviewed 2572 GRE/T2* MRI sequences from 262 participants in two phase two clinical trials of bapineuzumab and an open-label extension study. Readers were blinded to the participant's therapy, APOE ε4 genotype and medical history. RESULTS: Several risk factors for small ARIA-H <10 mm (microhaemorrhages) were identified: APOE ε4, bapineuzumab treatment, pre-existing small ARIA-H and use of antithrombotics. The HR (95%CI) for incident ARIA-H <10 mm associated with the number of APOE ε4 alleles was 11.9 (3.3 to 42.5) for 2 versus no alleles and 3.5 (1.0 to 12.0) for 1 versus no allele. The HR for bapineuzumab therapy was 3.5 (1.0 to 12.0); for the presence of baseline ARIA-H <10 mm, it was 3.5 (1.6 to 7.8), and for the use of antithrombotic agents it was 2.2 (1.0 to 4.8). The incidence rate for ARIA-H <10 mm was elevated only in the initial 6 months of active treatment and declined after this interval to a rate similar to that observed in the group treated with placebo. CONCLUSIONS: ARIA-H represents a spectrum of MRI findings due to haemosiderin deposition that appears to be related to impaired vascular integrity. The increased risk for ARIA-H associated with APOE ε4 allele frequency, pre-existing ARIA-H, treatment with bapineuzumab and use of antithrombotic agents provides additional support for this hypothesis of loss of integrity of cerebral vessels due to amyloid burden. TRIAL REGISTRATION: NCT00112073 and NCT00606476.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Anticorpos Monoclonais Humanizados/uso terapêutico , Hemossiderina/análise , Nootrópicos/uso terapêutico , Placa Amiloide/patologia , Idoso , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides/antagonistas & inibidores , Anticorpos Monoclonais Humanizados/administração & dosagem , Apolipoproteína E4/sangue , Ensaios Clínicos Fase II como Assunto , Estudos de Coortes , Relação Dose-Resposta a Droga , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Neuroimagem , Nootrópicos/administração & dosagem , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia , Substância Branca/patologia
4.
Pharm Stat ; 15(2): 109-22, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26643012

RESUMO

In clinical trials, continuous monitoring of event incidence rate plays a critical role in making timely decisions affecting trial outcome. For example, continuous monitoring of adverse events protects the safety of trial participants, while continuous monitoring of efficacy events helps identify early signals of efficacy or futility. Because the endpoint of interest is often the event incidence associated with a given length of treatment duration (e.g., incidence proportion of an adverse event with 2 years of dosing), assessing the event proportion before reaching the intended treatment duration becomes challenging, especially when the event onset profile evolves over time with accumulated exposure. In particular, in the earlier part of the study, ignoring censored subjects may result in significant bias in estimating the cumulative event incidence rate. Such a problem is addressed using a predictive approach in the Bayesian framework. In the proposed approach, experts' prior knowledge about both the frequency and timing of the event occurrence is combined with observed data. More specifically, during any interim look, each event-free subject will be counted with a probability that is derived using prior knowledge. The proposed approach is particularly useful in early stage studies for signal detection based on limited information. But it can also be used as a tool for safety monitoring (e.g., data monitoring committee) during later stage trials. Application of the approach is illustrated using a case study where the incidence rate of an adverse event is continuously monitored during an Alzheimer's disease clinical trial. The performance of the proposed approach is also assessed and compared with other Bayesian and frequentist methods via simulation.


Assuntos
Teorema de Bayes , Monitoramento de Medicamentos/métodos , Modelos Estatísticos , Doença de Alzheimer/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Monitoramento de Medicamentos/estatística & dados numéricos , Previsões , Humanos
5.
Alzheimers Dement ; 12(5): 623-30, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27017906

RESUMO

Given the complex neuropathology Alzheimer's disease (AD), combination therapy may be necessary for effective treatment. However, scientific, pragmatic, regulatory, and business challenges need to be addressed before combination therapy for AD can become a reality. Leaders from academia and industry, along with a former member of the Food and Drug Administration and the Alzheimer's Association, have explored these challenges and here propose a strategy to facilitate proof-of-concept combination therapy trials in the near future. First, a more integrated understanding of the complex pathophysiology and progression of AD is needed to identify the appropriate pathways and the disease stage to target. Once drug candidates are identified, novel clinical trial designs and selection of appropriate outcome assessments will be needed to enable definition and evaluation of the appropriate dose and dosing regimen and determination of efficacy. Success in addressing this urgent problem will only be achieved through collaboration among multiple stakeholders.


Assuntos
Doença de Alzheimer/fisiopatologia , Avaliação de Medicamentos , Quimioterapia Combinada , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/administração & dosagem , Humanos
6.
Pain Pract ; 14(4): 332-42, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23692321

RESUMO

The results of 3 proof-of-concept studies to evaluate carisbamate's efficacy and safety in treating neuropathic pain are presented. In studies 1 (postherpetic neuralgia, n = 91) and 2 (diabetic neuropathy, n = 137), patients received carisbamate 400 mg/day or placebo for 4 weeks and then crossed over to the other treatment for 4 weeks. In study 3 (diabetic neuropathy, higher carisbamate doses), patients (n = 386) were randomized (1:1:1:1) to receive either carisbamate 800 mg/day, 1200 mg/day, pregabalin 300 mg/day or placebo for 15 weeks. Primary efficacy end point was the mean of the last 7 average daily pain scores obtained on days the study drug was taken, for all 3 studies. Least square mean (95% CI) differences between carisbamate and placebo groups on the primary end point were as follows: study 1: -0.512 (-1.32, 0.29) carisbamate 400 mg/day; study 2: -0.307 (-0.94, 0.33) carisbamate 400 mg/day; and study 3: -0.51 (-1.10, 0.08), carisbamate 800 mg/day; -0.55 (-1.13, 0.04), carisbamate 1200 mg/day; and -0.43 (-1.01, 0.15), pregabalin 300 mg/day. Neither carisbamate (all 3 studies) nor pregabalin (study 3) significantly differed from placebo, although multiple secondary end points showed significant improvement in efficacy with carisbamate in studies 1 and 2. Dizziness was the only treatment-emergent adverse event occurring at ≥10% difference in carisbamate groups versus placebo (study 1: 12% vs. 1%; study 3: 14% vs. 4%; study 2: 1% vs. 2%). Carisbamate, although well tolerated, did not demonstrate efficacy in neuropathic pain across these studies, nor did the active comparator pregabalin (study 3).


Assuntos
Carbamatos/uso terapêutico , Neuropatias Diabéticas/tratamento farmacológico , Neuralgia Pós-Herpética/tratamento farmacológico , Neurotransmissores/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Índice de Gravidade de Doença , Resultado do Tratamento , Adulto Jovem
7.
Neurol Clin Pract ; 14(2): e200265, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38585443

RESUMO

Background and Objectives: Preclinical Alzheimer disease (AD) trials simultaneously test candidate treatments and the implications of disclosing biomarker information to cognitively unimpaired individuals. Methods: The EARLY trial was a randomized, double-blind, placebo-controlled, phase 2b/3 study conducted in 143 centers across 14 countries from November 2015 to December 2018 after being stopped prematurely because of treatment-related hepatotoxicity. Participants age 60-85 years deemed cognitively unimpaired were disclosed an elevated or not elevated brain amyloid result by a certified clinician. Among 3,686 participants, 2,066 underwent amyloid imaging, 1,394 underwent CSF biomarker assessment, and 226 underwent both. Among biomarker-tested participants with at least one change score on an outcome of interest, 680 with elevated and 2,698 with not elevated amyloid were included in this analysis. We compared the Geriatric Depression Scale (GDS), the State-Trait Anxiety Scale (STAI), and the Columbia Suicide Severity Rating Scale (CSSRS) before disclosure between amyloid groups. After disclosure, we assessed for differences in the Impact of Events Scale (IES, collected 24-72 hours after disclosure), a measure of intrusive thoughts. Additional scales included the Concerns for AD scale. Results: Among 3378 included participants, the mean (SD) age was 69.0 (5.3); most were female (60%) and White race (84%). No differences were observed before disclosure between participants with elevated and not elevated amyloid for the GDS, STAI, or CSSRS. Participants with elevated amyloid demonstrated higher Concerns for AD scores compared with participants with not elevated amyloid before disclosure. Participants with elevated amyloid demonstrated higher IES scores (9.6 [10.8] vs 5.1 [8.0]) after disclosure and increased Concerns about AD. Patterns of reactions (elevated vs not elevated) were similar for biomarker modalities, although scores were lower among those undergoing CSF compared with PET testing. Although score differences were apparent comparing geographical regions, patterns of group differences were similar. Discussion: Although sample bias must be considered, these results suggest that amyloid disclosure resulted in increased perceived risk and mild distress in those learning an elevated result. Although this study did not assess psychological safety, observed associations intrusive thoughts and distress could be important considerations in the future clinical practice.

8.
Alzheimers Dement ; 9(2): 123-131.e1, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23411394

RESUMO

Current research including the basic biology of Alzheimer's disease (AD) provides a foundation to explore whether our current state of knowledge is sufficient to initiate prevention studies and allow us to believe prevention of AD is possible. Current research and recently revised criteria for the diagnosis of AD by the National Institutes on Aging and the Alzheimer's Association suggest a continuum of disease from preclinical asymptomatic to symptomatic Alzheimer's dementia. In light of these revised criteria, the possibility of secondary prevention and even primary prevention is under discussion. The Alzheimer's Association Research Roundtable convened a meeting to discuss the rationale and feasibility of conducting secondary prevention trials in AD.


Assuntos
Doença de Alzheimer/prevenção & controle , Ensaios Clínicos como Assunto , Prevenção Secundária/métodos , Humanos
9.
Alzheimers Dement ; 9(4): 438-44, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23809364

RESUMO

An international task force of investigators from academia, industry, nonprofit foundations, and regulatory agencies met in Monte Carlo, Monaco, on October 31, 2012, to review lessons learned from the recent bapineuzumab and solanezumab trials, and to incorporate insights gained from these trials into future clinical studies. Although there is broad consensus that Alzheimer's disease (AD) should be treated during its earliest stages, the concept of secondary prevention has evolved to be described more accurately as treatment of preclinical, presymptomatic, or early AD. There continues to be a strong emphasis on biomarkers and a need for new biomarkers; however, there has also been a realization, based on completed trials, that the most reliable indicator of clinical efficacy across the entire spectrum of disease from asymptomatic to AD dementia is likely a measure of cognition. The task force made many recommendations that should improve the likelihood of success in future trials, including larger phase 2 or combined phase 2/phase 3 studies, clear evidence of target engagement in the central nervous system, evidence of downstream effects on biomarkers before initiating phase 3 studies, consideration of adaptive and targeted trial designs, and use of sensitive measures of cognition as the most robust indicator of treatment benefit.


Assuntos
Doença de Alzheimer/prevenção & controle , Anticorpos Monoclonais Humanizados/uso terapêutico , Ensaios Clínicos Fase III como Assunto/métodos , Estudos Multicêntricos como Assunto/métodos , Nootrópicos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/análise , Apolipoproteínas E/análise , Apolipoproteínas E/genética , Atrofia/etiologia , Biomarcadores , Encéfalo/patologia , Química Encefálica , Edema Encefálico/etiologia , Ensaios Clínicos Fase II como Assunto/estatística & dados numéricos , Disfunção Cognitiva/tratamento farmacológico , Progressão da Doença , Determinação de Ponto Final/métodos , Humanos , Neuroimagem , Seleção de Pacientes , Falha de Tratamento
11.
J Prev Alzheimers Dis ; 9(2): 255-261, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35542998

RESUMO

BACKGROUND: Cognitive composites commonly serve as primary outcomes in Alzheimer's disease (AD) secondary prevention trials. OBJECTIVE: To evaluate the association between amyloid (Aß) burden level (+/-) and performance on three separate composite endpoints: Preclinical Alzheimer's Cognitive Composite (PACC), PACC+Semantic Fluency (PACC5), and Repeatable Battery for Neuropsychological Status (RBANS). DESIGN: Screening data from the randomized, double-blind, placebo-controlled, phase 2b/3 atabecestat EARLY study in preclinical AD participants were used in this analysis. SETTING: The EARLY study was conducted at 143 centers across 14 countries. PARTICIPANTS: 3,569 cognitively unimpaired older adults (Clinical Dementia Rating of 0; aged 60-85 years) screened for inclusion in the EARLY study with Aß status and at least PACC or RBANS at screening were included. Participants were categorized as those with non-pathological Aß levels (Aß-, n=2,824) and those with pathological Aß levels (Aß+, n=745) based on florbetapir uptake or levels of cerebrospinal fluid Aß1-42. MEASUREMENTS: Analysis of Covariance models controlling for age, sex, and education were used to examine the difference in PACC, PACC5, and RBANS between Aß groups. Nonparametric bootstrap was used to compare sensitivity of composites to differentiate between Aß status. RESULTS: Of 3,569 participants, 2,116 were women (59%); 3,006 were Caucasian (84%); mean (SD) age was 68.98 (5.28) years. Aß+ participants performed worse versus Aß- participants on all cognitive composites though the magnitude of the Aß effect was generally small. The Aß+/- effect size for the PACC (Cohen's d=-0.15) was significantly greater than the RBANS (d=-0.097) while the PACC5 effect size (d=-0.139) was numerically larger than the RBANS. When examining subscores from the composites, memory tests (i.e., Free and Cued Selective Reminding Test, Figure Recall) and speed of processing (i.e., Digit-Symbol/Coding on the PACC/RBANS) exhibited the largest Aß+/- effect sizes. CONCLUSIONS: Cross-sectional relationships between Aß and cognition among clinically unimpaired older adults are detectable on multi-domain cognitive composites but are relatively small in magnitude. The Aß+/- group effect was statistically larger for PACC and marginally larger for PACC5 versus RBANS. However, interpretation of composite sensitivity to Aß status cross-sectionally cannot be generalized to sensitivity to change over time.


Assuntos
Doença de Alzheimer , Tiazinas , Idoso , Doença de Alzheimer/tratamento farmacológico , Amiloide , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Cognição , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Piridinas , Ensaios Clínicos Controlados Aleatórios como Assunto , Tiazinas/uso terapêutico
12.
Epilepsy Behav ; 22(2): 324-30, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21849260

RESUMO

Adverse cognitive effects are an important concern for drugs that influence the central nervous system. Carisbamate is a novel drug in development for treatment of seizures and neuropathic pain. Information on its cognitive effects is limited. Three controlled, multiple-dose, crossover studies with treatment durations of 5-9 days were designed to examine the cognitive effects of carisbamate on healthy volunteers. In one study, apparent dose-dependent effects on response, vigilance, and recognition speed were observed (1000 mg and 1500 mg/day). Carisbamate did not differ from placebo for most variables in the other two studies, but increased reaction time and reduced Sternberg memory were seen at higher dosages. Carisbamate did not produce clinically significant adverse effects on cognitive performance at doses <1000 mg/day. Effects were mild to modest at the higher doses tested.


Assuntos
Anticonvulsivantes/efeitos adversos , Carbamatos/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Nível de Alerta/efeitos dos fármacos , Comportamento de Escolha/efeitos dos fármacos , Transtornos Cognitivos/diagnóstico , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Memória/efeitos dos fármacos , Testes Neuropsicológicos , Estimulação Luminosa , Tempo de Reação/efeitos dos fármacos , Fatores de Tempo
13.
Alzheimers Dement ; 7(4): 367-85, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21784348

RESUMO

Amyloid imaging related abnormalities (ARIA) have now been reported in clinical trials with multiple therapeutic avenues to lower amyloid-ß burden in Alzheimer's disease (AD). In response to concerns raised by the Food and Drug Administration, the Alzheimer's Association Research Roundtable convened a working group to review the publicly available trial data, attempts at developing animal models, and the literature on the natural history and pathology of related conditions. The spectrum of ARIA includes signal hyperintensities on fluid attenuation inversion recoverysequences thought to represent "vasogenic edema" and/or sulcal effusion (ARIA-E), as well as signal hypointensities on GRE/T2* thought to represent hemosiderin deposits (ARIA-H), including microhemorrhage and superficial siderosis. The etiology of ARIA remains unclear but the prevailing data support vascular amyloid as a common pathophysiological mechanism leading to increased vascular permeability. The workgroup proposes recommendations for the detection and monitoring of ARIA in ongoing AD clinical trials, as well as directions for future research.


Assuntos
Doença de Alzheimer , Amiloide/metabolismo , Ensaios Clínicos como Assunto/métodos , Imageamento por Ressonância Magnética , Sociedades Médicas/organização & administração , Doença de Alzheimer/complicações , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Amiloide/imunologia , Animais , Edema Encefálico/etiologia , Edema Encefálico/metabolismo , Edema Encefálico/patologia , Hemorragia Cerebral/etiologia , Hemorragia Cerebral/metabolismo , Hemorragia Cerebral/patologia , Ensaios Clínicos como Assunto/normas , Modelos Animais de Doenças , Humanos
14.
JAMA Neurol ; 78(3): 293-301, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33464300

RESUMO

Importance: Atabecestat, a nonselective oral ß-secretase inhibitor, was evaluated in the EARLY trial for slowing cognitive decline in participants with preclinical Alzheimer disease. Preliminary analyses suggested dose-related cognitive worsening and neuropsychiatric adverse events (AEs). Objective: To report efficacy, safety, and biomarker findings in the EARLY trial, both on and off atabecestat treatment, with focus on potential recovery of effects on cognition and behavior. Design, Setting, and Participants: Randomized, double-blind, placebo-controlled, phase 2b/3 study conducted from November 2015 to December 2018 after being stopped prematurely. The study was conducted at 143 centers across 14 countries. Participants were permitted to be followed off-treatment by the original protocol, collecting safety and efficacy data. From 4464 screened participants, 557 amyloid-positive, cognitively normal (Clinical Dementia Rating of 0; aged 60-85 years) participants (approximately 34% of originally planned 1650) were randomized before the trial sponsor stopped enrollment. Interventions: Participants were randomized (1:1:1) to atabecestat, 5 mg (n = 189), 25 mg (n = 183), or placebo (n = 185). Main Outcomes and Measures: Primary outcome: change from baseline in Preclinical Alzheimer Cognitive Composite score. Secondary outcomes: change from baseline in the Cognitive Function Index and the Repeatable Battery for the Assessment of Neuropsychological Status total scale score. Safety was monitored throughout the study. Results: Of 557 participants, 341 were women (61.2%); mean (SD) age was 70.4 (5.56) years. In May 2018, study medication was stopped early owing to hepatic-related AEs; participants were followed up off-treatment for 6 months. Atabecestat, 25 mg, showed significant cognitive worsening vs placebo for Preclinical Alzheimer Cognitive Composite at month 6 (least-square mean difference, -1.09; 95% CI, -1.66 to -0.53; P < .001) and month 12 (least-square mean, -1.62; 95% CI, -2.49 to -0.76; P < .001), and at month 3 for Repeatable Battery for the Assessment of Neuropsychological Status (least-square mean, -3.70; 95% CI, -5.76 to -1.63; P < .001). Cognitive Function Index participant report showed nonsignificant worsening at month 12. Systemic and neuropsychiatric-related treatment-emergent AEs were greater in atabecestat groups vs placebo. After stopping treatment, follow-up cognitive testing and AE assessment provided evidence of reversibility of drug-induced cognitive worsening and AEs in atabecestat groups. Conclusions and Relevance: Atabecestat treatment was associated with dose-related cognitive worsening as early as 3 months and presence of neuropsychiatric treatment-emergent AEs, with evidence of reversibility after 6 months off treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02569398.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Tiazinas/administração & dosagem , Tiazinas/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/enzimologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Biomarcadores/metabolismo , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Transtornos Mentais/induzido quimicamente , Pessoa de Meia-Idade , Resultado do Tratamento
15.
Alzheimers Dement (N Y) ; 6(1): e12069, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32885024

RESUMO

Alzheimer's disease (AD) is a continuum consisting of a preclinical stage that occurs decades before symptoms appear. As researchers make advances in investigating the continuum, the importance of developing drugs for secondary prevention is garnering increased discussion. For efficacious drug development for secondary prevention it is important to define what are the earliest biological stages of AD. The Alzheimer's Association Research Roundtable convened November 27 to 28, 2018 to focus on pre-clinical AD. This review will address the biological approach to defining pre-clinical AD, detection, identification of at-risk individuals, and lessons learned from trials such as A4 and TOMMORROW.

16.
Alzheimers Res Ther ; 12(1): 58, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32410694

RESUMO

BACKGROUND: Atabecestat, a potent brain-penetrable inhibitor of BACE1 activity that reduces CSF amyloid beta (Aß), was developed for oral treatment for Alzheimer's disease (AD). The long-term safety and effect of atabecestat on cognitive performance in participants with predementia AD in two phase 2 studies were assessed. METHODS: In the placebo-controlled double-blind parent ALZ2002 study, participants aged 50 to 85 years were randomized (1:1:1) to placebo or atabecestat 10 or 50 mg once daily (later reduced to 5 and 25 mg) for 6 months. Participants entered ALZ2004, a 12-month treatment extension with placebo or atabecestat 10 or 25 mg, followed by an open-label phase. Safety, changes in CSF biomarker levels, brain volume, and effects on cognitive performance were assessed. RESULTS: Of 114 participants randomized in ALZ2002, 99 (87%) completed, 90 entered the ALZ2004 double-blind phase, and 77 progressed to the open-label phase. CSF Aß fragments and sAPPß were reduced dose-proportionately. Decreases in whole brain and hippocampal volumes were greater in participants with mild cognitive impairment (MCI) due to AD than in preclinical AD, but were not affected by treatment. In ALZ2004, change from baseline in RBANS trended toward worse scores for atabecestat versus placebo. Elevated liver enzyme adverse events reported in 12 participants on atabecestat resulted in dosage modification and increased frequency of safety monitoring. Treatment discontinuation normalized ALT or AST in all except one with pretreatment elevation, which remained mildly elevated. No case met ALT/AST > 3× ULN and total bilirubin > 2× ULN (Hy's law). CONCLUSION: Atabecestat was associated with trend toward declines in cognition, and elevation of liver enzymes. TRIAL REGISTRATION: ALZ2002: ClinicalTrials.gov, NCT02260674, registered October 9, 2014; ALZ2004: ClinicalTrials.gov, NCT02406027, registered April 1, 2015.


Assuntos
Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides , Ácido Aspártico Endopeptidases , Método Duplo-Cego , Humanos , Piridinas , Tiazinas , Resultado do Tratamento
17.
Acta Neurol Scand ; 119(1): 22-31, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18518863

RESUMO

OBJECTIVE: To analyze mortality data from patients with Alzheimer's disease (AD), Alzheimer's plus cerebrovascular disease (AD + CVD) or vascular dementia (VaD). METHODS: (1) Meta-analysis of mortality data from double-blind, placebo-controlled, randomized trials; and (2) recontact study to collect additional longer term mortality data from previous galantamine trial participants. RESULTS (META-ANALYSIS): Across 12 trials (< or =6 months duration), there was no increased risk of mortality associated with the use of galantamine (n = 4116) compared with that of placebo (n = 2386) (OR galantamine/placebo: 0.67, 95% CI 0.41-1.10). RESULTS (RECONTACT STUDY): Median survival was 79 months for patients with AD (n = 478) and 59 months for patients with AD + CVD (n = 180) or VaD (n = 145). Prolonged galantamine treatment (> vs < or =6 months) was not associated with decreased survival time (75 vs 61 months respectively; P = 0.02). Cox regression analyses were consistent with the Kaplan-Meier analyses. CONCLUSIONS: We found no short-term or longer term evidence of increased risk of mortality associated with the use of galantamine in patients with AD, AD + CVD or VaD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/mortalidade , Inibidores da Colinesterase/toxicidade , Galantamina/toxicidade , Idade de Início , Idoso , Feminino , Seguimentos , Humanos , Institucionalização/estatística & dados numéricos , Masculino , National Institute of Neurological Disorders and Stroke (USA) , Inventário de Personalidade , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sobrevida , Sobreviventes , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
18.
Clin Pharmacol Drug Dev ; 8(3): 326-335, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29920980

RESUMO

This study was designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending subcutaneous doses of bapineuzumab in patients with mild to moderate Alzheimer disease. Forty patients were randomized across 5 cohorts (5 mg, 10 mg, 20 mg, 40 mg, 80 mg; 8 patients each [bapineuzumab 6; placebo 2]). The incidence of treatment-emergent adverse events (TEAEs) was higher in pooled bapineuzumab cohorts (83%) than in the pooled placebo group (27.7%). Most common TEAEs in the bapineuzumab group were gastrointestinal disorders and musculoskeletal and connective tissue disorders (bapineuzumab 17% each; placebo 0%). Serious TEAEs were observed in 7% of bapineuzumab-treated patients without any deaths or adverse event-related discontinuation. The median times to reach peak measurable concentration (Cmax ) of bapineuzumab were 14 days for 5-, 10-, and 20-mg cohorts, 11 days for 40-mg, and 7 days for 80-mg cohorts. The apparent volume of distribution of bapineuzumab was 134.29 to 204.68 mL/kg. The total body clearance was consistent at 10 to 80 mg. The average terminal half-life ranged from 26 to 46 days (5- to 80-mg groups). Exposure to bapineuzumab increased dose-proportionally from 10 to 80 mg. There was a positive correlation between Cmax and area under the concentration-time curve to the last measurable concentration (AUClast ) of plasma amyloid-ß, and between the Cmax and AUClast of serum bapineuzumab.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Anticorpos Monoclonais Humanizados , Nootrópicos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/sangue , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/sangue , Anticorpos Monoclonais Humanizados/uso terapêutico , Cognição/efeitos dos fármacos , Estudos de Coortes , Relação Dose-Resposta a Droga , Método Duplo-Cego , Meia-Vida , Humanos , Injeções Subcutâneas , Pessoa de Meia-Idade , Nootrópicos/efeitos adversos , Nootrópicos/sangue , Nootrópicos/uso terapêutico , Índice de Gravidade de Doença , Resultado do Tratamento
19.
J Prev Alzheimers Dis ; 6(4): 256-266, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31686098

RESUMO

BACKGROUND: The CHARIOT PRO Main study is a prospective, non-interventional study evaluating cognitive trajectories in participants at the preclinical stage of Alzheimer's disease (AD) classified by risk levels for developing mild cognitive impairment due to AD (MCI-AD). OBJECTIVES: The study aimed to characterize factors and markers influencing cognitive and functional progression among individuals at-risk for developing MCI-AD, and examine data for more precise predictors of cognitive change, particularly in relation to APOE ε4 subgroup. DESIGN: This single-site study was conducted at the Imperial College London (ICL) in the United Kingdom. Participants 60 to 85 years of age were classified as high, medium (amnestic or non-amnestic) or low risk for developing MCI-AD based on RBANS z-scores. A series of clinical outcome assessments (COAs) on factors influencing baseline cognitive changes were collected in each of the instrument categories of cognition, lifestyle exposure, mood, and sleep. Data collection was planned to occur every 6 months for 48 months, however the median follow-up time was 18.1 months due to early termination of study by the sponsor. RESULTS: 987 participants were screened, among them 690 participants were actively followed-up post baseline, of whom 165 (23.9%) were APOE ε4 carriers; with at least one copy of the allele. The mean age was 68.73 years, 94.6% were white, 57.4% were female, and 34.8% had a Family History of Dementia with a somewhat larger percentage in the APOE ε4 carrier group (42.4%) compared to the non-carrier group (32.4%). Over half of the participants were married and 53% had a Bachelor's or higher degree. Most frequently, safety events typical for this population consisted of upper respiratory tract infection (10.4%), falls (5.2%), hypertension (3.5%) and back pain (3.0%). Conclusion (clinical relevance): AD-related measures collected during the CHARIOT PRO Main study will allow identification and evaluation of AD risk factors and markers associated with cognitive performance from the pre-clinical stage. Evaluating the psycho-biological characteristics of these pre-symptomatic individuals in relation to their natural neurocognitive trajectories will enhance current understanding on determinants of the initial signs of cognitive changes linked to AD.


Assuntos
Doença de Alzheimer/epidemiologia , Cognição , Disfunção Cognitiva/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Ansiedade/psicologia , Apolipoproteína E4/genética , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Estudos de Coortes , Depressão/psicologia , Eficiência , Feminino , Voluntários Saudáveis , Humanos , Estudos Longitudinais , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estudos Prospectivos , Fatores de Risco , Sono , Reino Unido/epidemiologia , Trabalho
20.
Curr Alzheimer Res ; 15(13): 1231-1243, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30129411

RESUMO

BACKGROUND: Bapineuzumab is a humanized anti-amyloid-beta (Aß) monoclonal antibody directed at lowering the cerebral Aß deposit in Alzheimer's disease (AD). OBJECTIVE: This phase 2, open-label extension (OLE) study evaluated long-term safety and efficacy of bapineuzumab in patients with the mild-to-moderate AD. METHODS: Patients (58-78 years) who completed either of two randomized, placebo-controlled, doubleblind studies (subcutaneous [SC] single-dose-escalation, or intravenous (IV) multiple-ascending-dose)) entered the OLE. Three groups were assessed: bapineuzumab or placebo SC, and bapineuzumab (IV) in OLE (bapi SC/bapi IV); bapineuzumab (IV) in Study 201 and OLE (bapi/bapi); and placebo in Study 201 and bapineuzumab IV in OLE (placebo/bapi). RESULTS: Of 194 patients enrolled, 158 withdrew from OLE; primarily due to withdrawal by subject (n=85) and AE (n=30). Mean (SD) bapineuzumab exposure was 2.9 (1.90) years. There were no significant differences for efficacy endpoints (AD Assessment Scale-cognitive subscale [ADAS-Cog], Disability Assessment for Dementia [DAD] and MMSE scores) between the bapi/bapi and placebo/bapi groups. Most patients (94.8%, 184/194) reported ≥1 treatment-emergent adverse events (TEAEs) in OLE. Amyloid-related imaging abnormalities with effusion or edema (ARIA-E) occurred in 22 (11.3%) patients. The most common TEAEs (>20% patients) were fall, agitation and urinary tract infection with similar incidences between bapi/bapi and placebo/bapi groups. CONCLUSION: No significant difference was seen in cognitive and functional decline between early and delayed treatment groups. No new safety concerns emerged. ARIA-E incidence was higher in patients first exposed to bapineuzumab in OLE versus previously exposed. No clear pattern of etiology contributed to death events.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Anticorpos Monoclonais Humanizados/uso terapêutico , Fatores Imunológicos/uso terapêutico , Resultado do Tratamento , Idoso , Doença de Alzheimer/diagnóstico por imagem , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Avaliação da Deficiência , Método Duplo-Cego , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estados Unidos
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