Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Biom J ; 65(8): e2200370, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37609878

RESUMO

Decentralized clinical trials (DCTs), that is, studies integrating elements of telemedicine and mobile/local healthcare providers allowing for home-based assessments, are an important concept to make studies more resilient and more patient-centric by taking into consideration participant's views and shifting trial activities to better meet the needs of trial participants. There are however, not only advantages but also challenges associated with DCTs. An area to be addressed by appropriate statistical methodology is the integration of data resulting from a possible mix of home and clinic assessments at different visits for the same variable, especially in adjusting for sources of possible systematic differences. One source of systematic bias may be how a participant perceives their disease and treatment in their home versus in a clinical setting. In this paper, we will discuss these issues with a focus on Neuroscience when participants have the choice between home and clinic assessments to illustrate how to identify systematic biases and describe appropriate approaches to maintain clinical trial scientific rigor. We will describe the benefits and challenges of DCTs in Neuroscience and then describe the relevance of home versus clinic assessments using the estimand framework. We outline several options to enable home assessments in a study. Results of simulations will be presented to help deciding between design and analysis options in a simple scenario where there might be differences in response between clinic and home assessments.


Assuntos
Viés , Ensaios Clínicos como Assunto , Humanos
2.
Transpl Int ; 33(3): 310-320, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31729770

RESUMO

Ganciclovir (GCV) inhibits spermatogenesis in preclinical studies but long-term effects on fertility in renal transplant patients are unknown. In a prospective, multicenter, open-label, nonrandomized study, male patients were assigned to Cohort A [valganciclovir (VGCV), a prodrug of GCV] (n = 38) or B (no VGCV) (n = 21) by cytomegalovirus prophylaxis requirement. Changes in semen parameters and DNA fragmentation were assessed via a mixed-effects linear regression model accounting for baseline differences. Sperm concentration increased post-transplant, but between baseline and treatment end (mean 164 days Cohort A, 211 days Cohort B), the model-based change was lower in Cohort A (difference: 43.82 × 106 /ml; P = 0.0038). Post-treatment, sperm concentration increased in Cohort A so that by end of follow-up (6 months post-treatment) changes were comparable between cohorts (difference: 2.09 × 106 /ml; P = 0.92). Most patients' sperm concentration improved by end of follow-up; none with normal baseline concentrations (≥20 × 106 /ml) were abnormal at end of follow-up. Changes in seminal volume, sperm motility/morphology, DNA fragmentation, and hormone levels were comparable between cohorts at end of follow-up. Improvement in semen parameters after renal transplant was delayed in men receiving VCGV, but 6 months post-treatment parameters were comparable between cohorts.


Assuntos
Infecções por Citomegalovirus , Transplante de Rim , Antivirais/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Ganciclovir/uso terapêutico , Humanos , Masculino , Estudos Prospectivos , Motilidade dos Espermatozoides , Espermatogênese , Valganciclovir/uso terapêutico
3.
Am Heart J ; 215: 178-186, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31349109

RESUMO

Cardiovascular outcome trials (CVOTs) have been employed in multiple therapeutic areas to explore whether a noncardiovascular drug increases the risk for cardiovascular events. These studies are now a central part of drug development programs for antihyperglycemic drugs. These programs are expected to demonstrate that new antihyperglycemic drugs for patients with Type 2 diabetes do not have unacceptable cardiovascular risk. The hazard ratio, which is usually provided as evidence that patients receiving the investigational treatment are not at statistically significantly greater cardiovascular risk than patients on the control treatment, can be difficult to interpret for various reasons. Therefore, an alternative approach known as the Restricted Mean Survival Time (RMST) or τ-year mean survival time is presented, and its ability to overcome interpretation challenges with the hazard ratio discussed. The RMST approach is applied to five completed CVOTs and is compared with the corresponding hazard ratios. Additionally, detailed considerations are given on how to design a non-inferiority CVOT using the RMST approach. The RMST methodology is shown to be a practical alternative to the hazard ratio methodology for designing a non-inferiority CVOT.


Assuntos
Doenças Cardiovasculares/mortalidade , Diabetes Mellitus Tipo 2/tratamento farmacológico , Desenvolvimento de Medicamentos , Hipoglicemiantes/uso terapêutico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/mortalidade , Saúde Global , Humanos , Taxa de Sobrevida/tendências
4.
Int J Clin Pharmacol Ther ; 57(10): 506-519, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31397274

RESUMO

OBJECTIVE: Mycophenolate mofetil (MMF) is widely used as an immunosuppressant for the prophylaxis of acute organ rejection in recipients of solid organ transplants. MATERIALS AND METHODS: We have compared, in healthy subjects, the pharmacokinetics of mycophenolic acid when MMF was administered in the form of the innovator product CellCept (F. Hoffmann-La Roche Ltd.) or one of three commercially available generics, Renodapt (Biocon Ltd.), Mycept (Panacea Biotec), or Cellmune (Cipla Ltd.). The study was powered to detect a 20% difference in mean formulation performance measures, but not to formally evaluate bioequivalence. Geometric mean ratios of maximum concentrations (Cmax) and areas under plasma concentration-time curves were calculated. RESULTS: Comparing generics against each other, the differences in point estimates of the geometric mean ratios of Cmax of two of the comparisons were either borderline within (Renodapt/Cellmune) or clearly outside (Mycept/Cellmune) a region of 80 - 125% around the reference mean, indicating that bioequivalence between these generics may be difficult to show. CONCLUSION: Physicians in the field of transplantation should be aware of the potential risk of altering the therapeutic outcome when switching from one preparation of MMF to another. ClinicalTrials.gov identifier: NCT02981290.


Assuntos
Medicamentos Genéricos/farmacocinética , Imunossupressores/farmacocinética , Ácido Micofenólico/farmacocinética , Equivalência Terapêutica , Estudos Cross-Over , Rejeição de Enxerto , Humanos
5.
J Biopharm Stat ; 26(2): 191-201, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25372950

RESUMO

When performing a pivotal clinical trial, it may be of interest to assess the probability of success (PoS) of that trial. Initially evaluated when the trial is designed, PoS can be updated as the trial progresses and new information about the drug effect becomes available. Such information can be external to the trial, such as results from trials conducted in parallel, or internal, such as continuing after an interim analysis. We develop a framework to update PoS based on such internal and external information for a time-to-event endpoint and illustrate it using a realistic development program for a new molecule.


Assuntos
Ensaios Clínicos Fase III como Assunto/estatística & dados numéricos , Determinação de Ponto Final/estatística & dados numéricos , Modelos Estatísticos , Projetos de Pesquisa/estatística & dados numéricos , Resultado do Tratamento , Interpretação Estatística de Dados , Humanos , Funções Verossimilhança
6.
Pharm Stat ; 15(5): 438-46, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27442271

RESUMO

Bayesian predictive power, the expectation of the power function with respect to a prior distribution for the true underlying effect size, is routinely used in drug development to quantify the probability of success of a clinical trial. Choosing the prior is crucial for the properties and interpretability of Bayesian predictive power. We review recommendations on the choice of prior for Bayesian predictive power and explore its features as a function of the prior. The density of power values induced by a given prior is derived analytically and its shape characterized. We find that for a typical clinical trial scenario, this density has a u-shape very similar, but not equal, to a ß-distribution. Alternative priors are discussed, and practical recommendations to assess the sensitivity of Bayesian predictive power to its input parameters are provided. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Teorema de Bayes , Comportamento de Escolha , Descoberta de Drogas/estatística & dados numéricos , Descoberta de Drogas/métodos , Previsões , Humanos , Probabilidade
7.
N Engl J Med ; 367(22): 2089-99, 2012 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-23126252

RESUMO

BACKGROUND: In observational analyses, higher levels of high-density lipoprotein (HDL) cholesterol have been associated with a lower risk of coronary heart disease events. However, whether raising HDL cholesterol levels therapeutically reduces cardiovascular risk remains uncertain. Inhibition of cholesteryl ester transfer protein (CETP) raises HDL cholesterol levels and might therefore improve cardiovascular outcomes. METHODS: We randomly assigned 15,871 patients who had had a recent acute coronary syndrome to receive the CETP inhibitor dalcetrapib, at a dose of 600 mg daily, or placebo, in addition to the best available evidence-based care. The primary efficacy end point was a composite of death from coronary heart disease, nonfatal myocardial infarction, ischemic stroke, unstable angina, or cardiac arrest with resuscitation. RESULTS: At the time of randomization, the mean HDL cholesterol level was 42 mg per deciliter (1.1 mmol per liter), and the mean low-density lipoprotein (LDL) cholesterol level was 76 mg per deciliter (2.0 mmol per liter). Over the course of the trial, HDL cholesterol levels increased from baseline by 4 to 11% in the placebo group and by 31 to 40% in the dalcetrapib group. Dalcetrapib had a minimal effect on LDL cholesterol levels. Patients were followed for a median of 31 months. At a prespecified interim analysis that included 1135 primary end-point events (71% of the projected total number), the independent data and safety monitoring board recommended termination of the trial for futility. As compared with placebo, dalcetrapib did not alter the risk of the primary end point (cumulative event rate, 8.0% and 8.3%, respectively; hazard ratio with dalcetrapib, 1.04; 95% confidence interval, 0.93 to 1.16; P=0.52) and did not have a significant effect on any component of the primary end point or total mortality. The median C-reactive protein level was 0.2 mg per liter higher and the mean systolic blood pressure was 0.6 mm Hg higher with dalcetrapib as compared with placebo (P<0.001 for both comparisons). CONCLUSIONS: In patients who had had a recent acute coronary syndrome, dalcetrapib increased HDL cholesterol levels but did not reduce the risk of recurrent cardiovascular events. (Funded by F. Hoffmann-La Roche; dal-OUTCOMES ClinicalTrials.gov number, NCT00658515.).


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticolesterolemiantes/uso terapêutico , Proteínas de Transferência de Ésteres de Colesterol/antagonistas & inibidores , HDL-Colesterol/sangue , Compostos de Sulfidrila/uso terapêutico , Idoso , Amidas , Anticolesterolemiantes/efeitos adversos , Apolipoproteínas/sangue , Biomarcadores/sangue , Pressão Sanguínea/efeitos dos fármacos , Proteína C-Reativa/análise , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/prevenção & controle , LDL-Colesterol/sangue , Ésteres , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Prevenção Secundária , Compostos de Sulfidrila/efeitos adversos , Triglicerídeos/sangue
8.
Anticancer Drugs ; 26(5): 565-72, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25643050

RESUMO

The aim of this study was to evaluate the effect of coadministration of acid-reducing agents on the pharmacokinetic exposure of orally administered epidermal growth factor receptor inhibitor erlotinib, a drug that displays pH-dependent solubility. Two studies were conducted, the first with the proton pump inhibitor omeprazole and the second with the H2-receptor antagonist ranitidine. Twenty-four healthy male and female volunteers were enrolled in each study. Erlotinib was administered as a single oral 150 mg dose on day 1. After the washout a subsequent study period evaluated 150 mg erlotinib administered with the acid-reducing agent. Omeprazole (40 mg once daily) was given on days 11-14, concomitantly with erlotinib on day 15, and for two additional days (days 16-17). In the ranitidine study, on day 13, participants were randomized to either concomitant dosing (treatment B) or staggered administration (treatment C) of erlotinib and ranitidine and crossed over to the other treatment starting on day 27. For treatment B, ranitidine (300 mg once daily) was administered in the morning for 5 days, 2 h before erlotinib. For treatment C, ranitidine was administered as a divided dose (150 mg twice daily) for 5 days, with erlotinib given 10 h after the previous evening dose and 2 h before the next ranitidine morning dose. Plasma samples were obtained for determination of the concentrations of erlotinib and its metabolite OSI-420, following each erlotinib dose. All participants were monitored for safety and tolerability. The geometric mean ratios of AUC0-∞ and Cmax for erlotinib and AUC0-last and Cmax for OSI-420 were substantially decreased when erlotinib was dosed with omeprazole. The estimated mean ratio (90% confidence interval) for erlotinib was 0.54 (0.49-0.59) for AUC0-∞ and 0.39 (0.32-0.48) for Cmax. For OSI-420, the estimated mean ratio was 0.42 (0.37-0.48) for AUC0-last and 0.31 (0.24-0.41) for Cmax. AUC0-∞ and Cmax for erlotinib were substantially decreased by 33 and 54%, respectively, upon coadministration with ranitidine, but the decrease was only 15 and 17% when ranitidine and erlotinib were given staggered. Similar results were observed for the metabolite OSI-420. Erlotinib was generally well-tolerated alone or in combination with omeprazole or ranitidine. Erlotinib pharmacokinetic exposure was substantially reduced upon coadministration with omeprazole and ranitidine, but not when administered with a staggered dosing approach to ranitidine. Therefore, it is recommended that the concomitant use of erlotinib with proton pump inhibitors be avoided. If treatment with an H2-receptor antagonist such as ranitidine is required, erlotinib must be administered 10 h after the H2-receptor antagonist dosing and at least 2 h before the next dose of the H2-receptor antagonist.


Assuntos
Antineoplásicos/farmacocinética , Ácido Gástrico/química , Antagonistas dos Receptores H2 da Histamina/farmacocinética , Omeprazol/farmacocinética , Inibidores da Bomba de Prótons/farmacocinética , Quinazolinas/farmacocinética , Ranitidina/farmacocinética , Adolescente , Adulto , Idoso , Estudos Cross-Over , Esquema de Medicação , Interações Medicamentosas , Cloridrato de Erlotinib , Feminino , Ácido Gástrico/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
J Cardiovasc Pharmacol ; 65(6): 611-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25714598

RESUMO

Inclacumab, a novel monoclonal antibody against P-selectin in development for the treatment and prevention of atherosclerotic cardiovascular diseases, was administered in an ascending single-dose study as intravenous infusion to evaluate safety, pharmacokinetics, and pharmacodynamics. Fifty-six healthy subjects were enrolled in this randomized, double-blind placebo-controlled study. Each dose level (0.03-20 mg/kg) was investigated in separate groups of 8 subjects (6 on inclacumab, 2 on placebo). Platelet-leukocyte aggregates, free/total soluble P-selectin concentration ratio, drug concentrations, bleeding time, platelet aggregation, antibody formation, and routine laboratory parameters were measured frequently until 32 weeks. Pharmacokinetic profiles were indicative of target-mediated drug disposition. Platelet-leukocyte aggregate inhibition and soluble P-selectin occupancy showed dose dependency and were strongly correlated to inclacumab plasma concentrations, with IC50 of 740 and 4600 ng/mL, respectively. Inclacumab was well tolerated by the majority of subjects and did neither affect bleeding time nor platelet aggregation. These findings allowed the investigation of the potential beneficial therapeutic use of inclacumab in patient study.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Fármacos Cardiovasculares/administração & dosagem , Selectina-P/antagonistas & inibidores , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/farmacocinética , Tempo de Sangramento , Fármacos Cardiovasculares/efeitos adversos , Fármacos Cardiovasculares/sangue , Fármacos Cardiovasculares/farmacocinética , Método Duplo-Cego , Inglaterra , Feminino , Voluntários Saudáveis , Hemorragia/induzido quimicamente , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Selectina-P/imunologia , Agregação Plaquetária/efeitos dos fármacos , Valor Preditivo dos Testes , Medição de Risco , Adulto Jovem
10.
Cardiovasc Drugs Ther ; 29(1): 7-14, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25749868

RESUMO

PURPOSE: Cholesterol efflux from macrophages to HDL, measured in vitro, is augmented by treatment with agents which raise HDL cholesterol. In vitro, cholesterol depletion by statins is known to trigger a positive feedback on the cholesterol synthetic pathway via sterol regulatory element-binding protein (SREBP) transcription and changes in expression of SREBP regulated genes including microRNA33 (miR33) which is co-transcribed with SREBP and down-regulates ABCA1 and ABCG1 expression. METHODS: We investigated whether miR33 up-regulation, associated with SREBP increased transcription by statins, reduces macrophage ATP-binding cassette (ABC) transporter expression, thereby decreasing HDL-mediated cholesterol efflux at the tissue level. RESULTS: In human macrophage THP-1 cells cholesterol-loaded with acetylated LDL, incubation with 1 µM atorvastatin increased miR33 by 33 % (P < 0.05), and decreased ABCA1 messenger RNA (mRNA) and ABCG1 mRNA by 47 % (P < 0.05) and 27 % (NS), respectively. In J774A.1 mouse macrophage, labelled with 3H-cholesterol, ABCA1 mRNA and ABCA1-mediated cholesterol efflux were decreased by 1 µM statin: simvastatin > pitavastatin > atorvastatin > rosuvastatin > pravastatin. HDL incubated with rhCETP and dalcetrapib increased ABCA1-mediated cholesterol efflux. However, incremental simvastatin concentrations decreased cholesterol efflux to HDL treated with rhCETP and dalcetrapib. When HDL was incubated with rhCETP, addition of dalcetrapib augmented ABCA1-mediated cholesterol efflux from J774A.1 macrophages. However, simvastatin ≥1 µM virtually eliminated any HDL-ABCA1-mediated cholesterol efflux and any augmentation of that process by dalcetrapib. CONCLUSIONS: In vitro, statins increase miR33 expression, and decrease ABCA1 expression and cholesterol efflux from peripheral tissues; this may counteract the potential benefit of agents that raise HDL and apolipoprotein A-I in statin-treated patients.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/metabolismo , Colesterol/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lipoproteínas HDL/metabolismo , MicroRNAs/metabolismo , Sinvastatina/farmacologia , Transportador 1 de Cassete de Ligação de ATP/genética , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Linhagem Celular , Humanos , Camundongos , RNA Mensageiro/metabolismo , Receptores de LDL/genética
11.
Lancet ; 378(9802): 1547-59, 2011 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-21908036

RESUMO

BACKGROUND: Dalcetrapib modulates cholesteryl ester transfer protein (CETP) activity to raise high-density lipoprotein cholesterol (HDL-C). After the failure of torcetrapib it was unknown if HDL produced by interaction with CETP had pro-atherogenic or pro-inflammatory properties. dal-PLAQUE is the first multicentre study using novel non-invasive multimodality imaging to assess structural and inflammatory indices of atherosclerosis as primary endpoints. METHODS: In this phase 2b, double-blind, multicentre trial, patients (aged 18-75 years) with, or with high risk of, coronary heart disease were randomly assigned (1:1) to dalcetrapib 600 mg/day or placebo for 24 months. Randomisation was done with a computer-generated randomisation code and was stratified by centre. Patients and investigators were masked to treatment. Coprimary endpoints were MRI-assessed indices (total vessel area, wall area, wall thickness, and normalised wall index [average carotid]) after 24 months and (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT assessment of arterial inflammation within an index vessel (right carotid, left carotid, or ascending thoracic aorta) after 6 months, with no-harm boundaries established before unblinding of the trial. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00655473. FINDINGS: 189 patients were screened and 130 randomly assigned to placebo (66 patients) or dalcetrapib (64 patients). For the coprimary MRI and PET/CT endpoints, CIs were below the no-harm boundary or the adverse change was numerically lower in the dalcetrapib group than in the placebo group. MRI-derived change in total vessel area was reduced in patients given dalcetrapib compared with those given placebo after 24 months; absolute change from baseline relative to placebo was -4·01 mm(2) (90% CI -7·23 to -0·80; nominal p=0·04). The PET/CT measure of index vessel most-diseased-segment target-to-background ratio (TBR) was not different between groups, but carotid artery analysis showed a 7% reduction in most-diseased-segment TBR in the dalcetrapib group compared with the placebo group (-7·3 [90% CI -13·5 to -0·8]; nominal p=0·07). Dalcetrapib did not increase office blood pressure and the frequency of adverse events was similar between groups. INTERPRETATION: Dalcetrapib showed no evidence of a pathological effect related to the arterial wall over 24 months. Moreover, this trial suggests possible beneficial vascular effects of dalcetrapib, including the reduction in total vessel enlargement over 24 months, but long-term safety and clinical outcomes efficacy of dalcetrapib need to be analysed. FUNDING: F Hoffmann-La Roche Ltd.


Assuntos
Anticolesterolemiantes/administração & dosagem , Doença da Artéria Coronariana/prevenção & controle , Estenose Coronária/prevenção & controle , Diagnóstico por Imagem/métodos , Hipercolesterolemia/tratamento farmacológico , Compostos de Sulfidrila/administração & dosagem , Adolescente , Adulto , Idoso , Amidas , Intervalos de Confiança , Doença da Artéria Coronariana/diagnóstico , Estenose Coronária/diagnóstico , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ésteres , Feminino , Seguimentos , Humanos , Hipercolesterolemia/diagnóstico , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons/métodos , Valores de Referência , Medição de Risco , Resultado do Tratamento , Adulto Jovem
12.
Pharm Stat ; 10(5): 433-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21932300

RESUMO

Superiority claims for improved efficacy are the backbone of clinical development of new therapies. However, not every new therapy in development allows for such a claim. Some therapies per se do not try to improve efficacy further but concentrate on important aspects in safety or convenience. Such improvements can be equally important to patients, and development strategies should be available for such compounds. A three-arm design with placebo, active control and experimental treatment may be viewed as the golden standard for such compounds; however, it may be difficult if not impossible to add a placebo arm in certain diseases. In such situations, non-inferiority designs are the only development option left. This paper will highlight some of the key issues with such designs in practice and will report experience from two studies from different therapeutic areas intended for regulatory submission.


Assuntos
Ensaios Clínicos como Assunto/métodos , Aprovação de Drogas/estatística & dados numéricos , Estudos de Avaliação como Assunto , Modelos Estatísticos , Anemia/complicações , Anemia/diagnóstico , Anemia/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Neoplasias Colorretais/tratamento farmacológico , Intervalos de Confiança , Grupos Controle , Diálise/efeitos adversos , Progressão da Doença , Intervalo Livre de Doença , Aprovação de Drogas/métodos , Drogas em Investigação/efeitos adversos , Drogas em Investigação/metabolismo , Humanos , Nefropatias/complicações , Nefropatias/tratamento farmacológico , Satisfação do Paciente , Placebos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Medição de Risco/estatística & dados numéricos , Resultado do Tratamento
13.
Transl Vis Sci Technol ; 10(12): 8, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34614163

RESUMO

Inflammation and endothelial activation play a pivotal role in development and progression of diabetic retinopathy (DR), a vision-threatening complication of diabetes mellitus (DM) and the leading cause of blindness in the working age population. Easily accessible and validated biomarkers for DR early diagnosis and progression are required for use in clinical trials: here, we reviewed the available literature to understand the association of circulating levels of selected markers of inflammation and endothelial activation with the presence of nonproliferative and proliferative DR (NPDR and PDR) and investigate the relationship between their systemic and ocular levels. We additionally provide data synthesis and perform statistical analysis for interpretation of the collected evidence. CRP, IL-1ß, IL-6, TNFα, sICAM1, and sVCAM1 circulating levels were increased in subjects with DM compared to healthy individuals. Moreover, TNFα and sVCAM1 showed increasing systemic levels with DR presence and severity; circulating CRP increased with the transition from no DR to NPDR, whereas IL-6 was increased in PDR compared to NDPR stages. The relationship between ocular and systemic concentrations of these proteins remained unclear due to the low number of studies with matched sampling. In conclusion, the available data supports the use of systemic biomarkers of inflammation and endothelial activation to identify DM status and DR severity. These systemic biomarkers are likely reflecting an overall state of inflammation and vascular activation in different tissues of the body, including the eyes. Prospective, longitudinal datasets are required to validate these biomarkers as predictors of early DR presence, of DR progression, or for disease monitoring.


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Biomarcadores , Retinopatia Diabética/diagnóstico , Humanos , Inflamação , Estudos Prospectivos
14.
Biol Psychiatry Glob Open Sci ; 1(1): 70-77, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36324430

RESUMO

Background: Reduced activation of dopamine D1 receptor signaling may be implicated in reward functioning as a potential driver of negative symptoms in schizophrenia. Phosphodiesterase 10A (PDE10A), an enzyme that is highly expressed in the striatum, modulates both dopamine D2- and D1-dependent signaling. Methods: We assessed whether augmentation of D1 signaling by the PDE10 inhibitor RG7203 enhances imaging and behavioral markers of reward functions in patients with schizophrenia and negative symptoms. In a 3-period, double-blind, crossover study, we investigated the effects of RG7203 (5 mg and 15 mg doses) and placebo as adjunctive treatment to stable background antipsychotic treatment in patients with chronic schizophrenia with moderate levels of negative symptoms. Effects on reward functioning and reward-based effortful behavior were evaluated using the monetary incentive delay task during functional magnetic resonance imaging and the effort-cost-benefit and working memory reinforcement learning tasks. Results: Patients (N = 33; 30 male, mean age ± SD 36.6 ± 7.0 years; Positive and Negative Syndrome Scale negative symptom factor score 23.0 ± 3.5 at screening) were assessed at three study centers in the United States; 24 patients completed the study. RG7203 at 5 mg significantly increased reward expectation-related activity in the monetary incentive delay task, but in the context of significantly decreased overall activity across all task conditions. Conclusions: In contrast to our expectations, RG7203 significantly worsened reward-based effortful behavior and indices of reward learning. The results do not support the utility of RG7203 as adjunctive treatment for negative symptoms in patients with schizophrenia.

15.
Br J Clin Pharmacol ; 70(6): 825-33, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21175438

RESUMO

AIMS: Dalcetrapib, which targets cholesteryl ester transfer protein activity, is in development for prevention of cardiovascular events. Because dalcetrapib will likely be prescribed with other lipid-modifying therapies such as ezetimibe, a study was performed to investigate potential pharmacokinetic interactions between dalcetrapib and ezetimibe. Lipids changes and tolerability were secondary endpoints. METHODS: Co-administration of dalcetrapib 900 mg (higher than the phase III dose) with ezetimibe was investigated in a three period, three treatment crossover study in healthy males: 7 days of dalcetrapib, 7 days of dalcetrapib plus ezetimibe, 7 days of ezetimibe alone. A full pharmacokinetic profile was performed on day 7 of each treatment. RESULTS: Co-administration of dalcetrapib with ezetimibe was associated with minimal changes in dalcetrapib exposure compared with dalcetrapib alone. Least squares mean ratio (LSMR) (90% confidence interval) was 93.6 (87.1, 100.7) for AUC(0,24 h) and 99.0 (85.2, 115.0) for C(max) . Ezetimibe exposure was reduced with co-administration of ezetimibe with dalcetrapib compared with ezetimibe alone: LSMR 80.3 (74.6, 86.4) for AUC(0,24 h) and 88.9 (80.9, 99.9) for C(max) for total ezetimibe. High-density lipoprotein cholesterol increases associated with co-administration of dalcetrapib with ezetimibe (+29.8%) were comparable with those with dalcetrapib alone (+25.6%), while the reduction in low-density lipoprotein cholesterol with co-administration (-35.9%) was greater than with ezetimibe alone (-20.9%). Dalcetrapib was generally well tolerated when administered alone and when co-administered with ezetimibe. CONCLUSION: Co-administration of dalcetrapib with ezetimibe was not associated with clinically significant changes in pharmacokinetic parameters or tolerability and did not diminish the lipid effects of either drug.


Assuntos
Anticolesterolemiantes/farmacologia , Azetidinas/farmacologia , Compostos de Sulfidrila/farmacologia , Adolescente , Adulto , Idoso , Amidas , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/efeitos adversos , Anticolesterolemiantes/sangue , Azetidinas/administração & dosagem , Azetidinas/efeitos adversos , Azetidinas/sangue , Estudos Cross-Over , Esquema de Medicação , Interações Medicamentosas , Ésteres , Ezetimiba , Humanos , Hipertensão/induzido quimicamente , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Compostos de Sulfidrila/administração & dosagem , Compostos de Sulfidrila/efeitos adversos , Compostos de Sulfidrila/sangue , Adulto Jovem
16.
Eur J Clin Pharmacol ; 66(8): 775-83, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20521033

RESUMO

PURPOSE: Evaluate dalcetrapib's potential to prolong QT intervals in healthy subjects. METHODS: This was a single-center, randomized, active and placebo-controlled, six-sequence, three-period cross-over study. Participants [18-65 years; body mass index (BMI) 18-30 kg/m(2)] were randomized to daily doses of dalcetrapib 600 mg (therapeutic) or 3,900 mg (supratherapeutic) or to dalcetrapib-matched placebo for 7 days. On Day 8, subjects received single-dose moxifloxacin 400 mg (active control) or placebo, following the placebo or dalcetrapib, respectively. Electrocardiographic parameters were recorded on Days -1, 1, 7, and 8. The primary endpoint was the difference to placebo of time-matched change from baseline in the study-specific corrected QT interval (QTcS) at seven time-points within 24 h after dalcetrapib 3,900 mg on Day 7. An upper 95% confidence interval (CI) <10 ms confirmed the absence of a significant effect. Pharmacokinetic and lipid-related parameters were measured. RESULTS: Subjects (n = 49) were predominantly male (71%), and all were white, with a mean age of 45 years and mean BMI of 25 kg/m(2). For the primary analysis, the upper 95% CI for dalcetrapib 3,900 mg was <10 ms at all time-points. Similar findings were obtained for dalcetrapib 600 mg. Following the administration of moxifloxacin, the QTcS increased by >5 ms. At Day 7, exposure for dalcetrapib 3,900 mg was approximately eightfold higher than that for dalcetrapib 600 mg [mean area under the plasma concentration-time curve between time 0 and 24 h 68,500 vs. 8,280 ng*h/mL; mean peak concentration 6,810 vs. 861 ng/mL]. Cholesteryl ester transfer protein activity was inhibited by 30%, and high-density lipoprotein cholesterol increased by 26% for dalcetrapib 600 mg. Dalcetrapib was well tolerated. CONCLUSIONS: Dalcetrapib is not associated with QT interval prolongation, even at doses markedly greater than intended therapeutically.


Assuntos
Anticolesterolemiantes/farmacologia , Compostos de Sulfidrila/farmacologia , Administração Oral , Adulto , Amidas , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/efeitos adversos , Anticolesterolemiantes/farmacocinética , Área Sob a Curva , Arritmias Cardíacas/induzido quimicamente , Compostos Aza/efeitos adversos , Compostos Aza/farmacocinética , Compostos Aza/farmacologia , Proteínas de Transferência de Ésteres de Colesterol/sangue , HDL-Colesterol/sangue , Intervalos de Confiança , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Eletrocardiografia Ambulatorial/efeitos dos fármacos , Ésteres , Fluoroquinolonas , Coração/efeitos dos fármacos , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Moxifloxacina , Quinolinas/efeitos adversos , Quinolinas/farmacocinética , Quinolinas/farmacologia , Compostos de Sulfidrila/administração & dosagem , Compostos de Sulfidrila/efeitos adversos , Compostos de Sulfidrila/farmacocinética , Adulto Jovem
17.
Clin Pharmacol Ther ; 106(5): 968-980, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30993670

RESUMO

Traditionally, in dose-escalating first-in-human (FiH) studies, a dose cap with a 10-fold safety margin to the no observed effect level in animals is implemented if convulsive events are observed in animals. However, the convulsive risk seen in animals does not generally translate to humans. Several lines of evidence are summarized indicating that in a dose-escalating setting, electroencephalographic epileptiform abnormalities occur at lower doses than clinical convulsive events. Therefore, we propose to consider the occurrence of epileptiform abnormalities in toxicology studies as premonitory signals for convulsions in dose-escalating FiH studies. Compared with the traditional dose-cap approach, this may allow the exploration of higher doses in FiH and, subsequently, phase II studies without compromising human safety. Similarly, the presence or absence of electroencephalographic epileptiform abnormalities may also aid the assessment of proconvulsive risk in situations of increased perpetrator burden as potentially present in pharmacokinetic and/or pharmacodynamic drug-drug interactions.


Assuntos
Ensaios Clínicos como Assunto/métodos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Eletroencefalografia , Convulsões/induzido quimicamente , Animais , Nível de Efeito Adverso não Observado , Especificidade da Espécie
18.
N Engl J Med ; 352(26): 2696-704, 2005 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-15987918

RESUMO

BACKGROUND: Intravenous bolus fluorouracil plus leucovorin is the standard adjuvant treatment for colon cancer. The oral fluoropyrimidine capecitabine is an established alternative to bolus fluorouracil plus leucovorin as first-line treatment for metastatic colorectal cancer. We evaluated capecitabine in the adjuvant setting. METHODS: We randomly assigned a total of 1987 patients with resected stage III colon cancer to receive either oral capecitabine (1004 patients) or bolus fluorouracil plus leucovorin (Mayo Clinic regimen; 983 patients) over a period of 24 weeks. The primary efficacy end point was at least equivalence in disease-free survival; the primary safety end point was the incidence of grade 3 or 4 toxic effects due to fluoropyrimidines. RESULTS: Disease-free survival in the capecitabine group was at least equivalent to that in the fluorouracil-plus-leucovorin group (in the intention-to-treat analysis, P<0.001 for the comparison of the upper limit of the hazard ratio with the noninferiority margin of 1.20). Capecitabine improved relapse-free survival (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99; P=0.04) and was associated with significantly fewer adverse events than fluorouracil plus leucovorin (P<0.001). CONCLUSIONS: Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Capecitabina , Quimioterapia Adjuvante , Neoplasias do Colo/mortalidade , Neoplasias do Colo/cirurgia , Desoxicitidina/efeitos adversos , Intervalo Livre de Doença , Feminino , Fluoruracila/análogos & derivados , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Análise de Sobrevida
19.
J Clin Pharmacol ; 58(12): 1618-1628, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30052269

RESUMO

Alectinib is approved and recommended as the preferred first-line treatment for patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer. The effect of hepatic impairment on the pharmacokinetics (PK) of alectinib was assessed with physiologically based PK modeling prospectively and in a clinical study. An open-label study (NCT02621047) investigated a single 300-mg dose of alectinib in moderate (n = 8) and severe (n = 8) hepatic impairment (Child-Pugh B/C), and healthy subjects (n = 12) matched for age, sex, and body weight. Physiologically based PK modeling was conducted prospectively to inform the clinical study design and support the use of a lower dose and extended PK sampling in the study. PK parameters were calculated for alectinib, its major similarly active metabolite, M4, and the combined exposure of alectinib and M4. Unbound concentrations were assessed at 6 and 12 hours postdose. Administration of alectinib to subjects with hepatic impairment increased the area under the plasma concentration-time curve from time 0 to infinity of the combined exposure of alectinib and M4 to 136% (90% confidence interval [CI], 94.7-196) and 176% (90%CI 98.4-315), for moderate and severe hepatic impairment, respectively, relative to matched healthy subjects. Unbound concentrations for alectinib and M4 did not appear substantially different between hepatic-impaired and healthy subjects. Moderate hepatic impairment had only a modest, not clinically significant effect on alectinib exposure, while the higher exposure observed in severe hepatic impairment supports a dose adjustment in this population.


Assuntos
Carbazóis/farmacocinética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Hepatopatias/metabolismo , Fígado/metabolismo , Piperidinas/farmacocinética , Adulto , Área Sob a Curva , Carbazóis/metabolismo , Estudos de Casos e Controles , Feminino , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Piperidinas/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética
20.
Cancer Chemother Pharmacol ; 79(3): 559-568, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28243683

RESUMO

PURPOSE: Alectinib, a central nervous system (CNS)-active ALK inhibitor, has demonstrated efficacy and safety in ALK+ non-small-cell lung cancer that has progressed following crizotinib treatment. Other ALK inhibitors have shown concentration-dependent QTc prolongation and treatment-related bradycardia. Therefore, this analysis evaluated alectinib safety in terms of electrophysiologic parameters. METHODS: Intensive triplicate centrally read electrocardiogram (ECG) and matched pharmacokinetic data were collected across two alectinib single-arm trials. Analysis of QTcF included central tendency analysis [mean changes from baseline with one-sided upper 95% confidence intervals (CIs)], categorical analyses, and relationship between change in QTcF and alectinib plasma concentrations. Alectinib effects on other ECG parameters (heart rate, PR interval and QRS duration) were also evaluated. RESULTS: Alectinib did not cause a clinically relevant change in QTcF. The maximum mean QTcF change from baseline was 5.3 ms observed pre-dose at week 2. The upper one-sided 95% CI was <10 ms at all time points. There was no relevant relationship between change in QTcF and alectinib plasma concentrations. Alectinib treatment resulted in a generally asymptomatic exposure-dependent decrease in mean heart rate of ~11 to 13 beats per minute at week 2. No clinically relevant effects were seen on other ECG parameters. Approximately 5% of patients reported cardiac adverse events of bradycardia or sinus bradycardia; however, these were all grade 1-2. CONCLUSIONS: Alectinib does not prolong the QTc interval or cause changes in cardiac function to a clinically relevant extent, with the exception of a decrease in heart rate which was generally asymptomatic.


Assuntos
Carbazóis/efeitos adversos , Eletrocardiografia/efeitos dos fármacos , Piperidinas/efeitos adversos , Receptores Proteína Tirosina Quinases/antagonistas & inibidores , Algoritmos , Quinase do Linfoma Anaplásico , Bradicardia/induzido quimicamente , Bradicardia/fisiopatologia , Carbazóis/farmacocinética , Carbazóis/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Relação Dose-Resposta a Droga , Testes de Função Cardíaca , Frequência Cardíaca/efeitos dos fármacos , Humanos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/fisiopatologia , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/tratamento farmacológico , Monitorização Fisiológica , Piperidinas/farmacocinética , Piperidinas/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA