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1.
Pharm Stat ; 22(6): 1062-1075, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37553959

RESUMO

The power of randomized controlled clinical trials to demonstrate the efficacy of a drug compared with a control group depends not just on how efficacious the drug is, but also on the variation in patients' outcomes. Adjusting for prognostic covariates during trial analysis can reduce this variation. For this reason, the primary statistical analysis of a clinical trial is often based on regression models that besides terms for treatment and some further terms (e.g., stratification factors used in the randomization scheme of the trial) also includes a baseline (pre-treatment) assessment of the primary outcome. We suggest to include a "super-covariate"-that is, a patient-specific prediction of the control group outcome-as a further covariate (but not as an offset). We train a prognostic model or ensembles of such models on the individual patient (or aggregate) data of other studies in similar patients, but not the new trial under analysis. This has the potential to use historical data to increase the power of clinical trials and avoids the concern of type I error inflation with Bayesian approaches, but in contrast to them has a greater benefit for larger sample sizes. It is important for prognostic models behind "super-covariates" to generalize well across different patient populations in order to similarly reduce unexplained variability whether the trial(s) to develop the model are identical to the new trial or not. In an example in neovascular age-related macular degeneration we saw efficiency gains from the use of a "super-covariate".


Assuntos
Projetos de Pesquisa , Humanos , Grupos Controle , Teorema de Bayes , Ensaios Clínicos Controlados Aleatórios como Assunto , Tamanho da Amostra , Simulação por Computador
2.
Pharm Stat ; 21(2): 439-459, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34907654

RESUMO

There are several steps to confirming the safety and efficacy of a new medicine. A sequence of trials, each with its own objectives, is usually required. Quantitative risk metrics can be useful for informing decisions about whether a medicine should transition from one stage of development to the next. To obtain an estimate of the probability of regulatory approval, pharmaceutical companies may start with industry-wide success rates and then apply to these subjective adjustments to reflect program-specific information. However, this approach lacks transparency and fails to make full use of data from previous clinical trials. We describe a quantitative Bayesian approach for calculating the probability of success (PoS) at the end of phase II which incorporates internal clinical data from one or more phase IIb studies, industry-wide success rates, and expert opinion or external data if needed. Using an example, we illustrate how PoS can be calculated accounting for differences between the phase II data and future phase III trials, and discuss how the methods can be extended to accommodate accelerated drug development pathways.


Assuntos
Desenvolvimento de Medicamentos , Projetos de Pesquisa , Teorema de Bayes , Desenvolvimento de Medicamentos/métodos , Humanos , Probabilidade
3.
Pharm Stat ; 21(5): 1005-1021, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35373454

RESUMO

Pharmaceutical companies regularly need to make decisions about drug development programs based on the limited knowledge from early stage clinical trials. In this situation, eliciting the judgements of experts is an attractive approach for synthesising evidence on the unknown quantities of interest. When calculating the probability of success for a drug development program, multiple quantities of interest-such as the effect of a drug on different endpoints-should not be treated as unrelated. We discuss two approaches for establishing a multivariate distribution for several related quantities within the SHeffield ELicitation Framework (SHELF). The first approach elicits experts' judgements about a quantity of interest conditional on knowledge about another one. For the second approach, we first elicit marginal distributions for each quantity of interest. Then, for each pair of quantities, we elicit the concordance probability that both lie on the same side of their respective elicited medians. This allows us to specify a copula to obtain the joint distribution of the quantities of interest. We show how these approaches were used in an elicitation workshop that was performed to assess the probability of success of the registrational program of an asthma drug. The judgements of the experts, which were obtained prior to completion of the pivotal studies, were well aligned with the final trial results.


Assuntos
Asma , Desenvolvimento de Medicamentos , Asma/tratamento farmacológico , Humanos , Preparações Farmacêuticas , Probabilidade
4.
Blood Press ; 30(2): 82-89, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33403886

RESUMO

PURPOSE: Available data of event-based clinical outcomes trials show that little evidence supports the guidelines recommendations to lower blood pressure (BP) to <130/80 mmHg in middle-aged and elderly people with type 2 diabetes mellitus and hypertension. We addressed this issue by post-hoc analysing the risk of cardiovascular (CV) events in mostly elderly high-risk hypertensive patients with type 2 diabetes mellitus participating in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial. MATERIAL AND METHODS: Patients (n = 5250) were divided into 4 groups according to the proportion of on-treatment visits before the occurrence of an event (<25% to ≥ 75%) in which BP was reduced to <140/90 or <130/80 mmHg. RESULTS: After adjustment for baseline demographic differences between groups, a reduction in the proportion of visits in which BP achieved <140/90 mmHg accompanied a progressive increase in the risk of CV mortality and morbidity as well as of cause-specific events such as stroke, myocardial infarction and heart failure. A progressive reduction in the proportion of visits in which BP was reduced <130/80 mmHg did not have any effect on CV risks. CONCLUSION: In mostly elderly high-risk hypertensive patients with type 2 diabetes mellitus participating in the VALUE trial, achieving more frequently BP <140/90 mmHg showed a marked protective effect on overall and all cause-specific cardiovascular outcomes. This was not the case for a more frequent achievement of the more intensive BP target, i.e. <130/80 mmHg.


Assuntos
Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 2 , Hipertensão , Idoso , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Humanos , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
5.
Blood Press ; 30(2): 90-97, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33403890

RESUMO

PURPOSE: Event-based clinical outcome trials have shown limited evidence to support guidelines recommendations to lower blood pressure (BP) to <130/80 mmHg in middle-aged and elderly hypertensive patients with diabetes mellitus or with general high cardiovascular (CV) risk. We addressed this issue by post-hoc analysing the risk of CV events in patients who participated in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial and compared the hypertensive patients with type 2 diabetes mellitus with all high-risk hypertensive patients. MATERIALS AND METHODS: Patients were divided into 4 groups according to the proportion of on-treatment visits before the occurrence of an event (<25% to ≥75%) in which BP was reduced to <140/90 or <130/80 mmHg. Patients with diabetes mellitus (n = 5250) were compared with the entire VALUE population with high CV risk (n = 15,245). RESULTS: After adjustments for baseline differences between groups, a reduction in the proportion of visits in which BP was reduced to <140/90 mmHg, but not to <130/80 mmHg, was accompanied by a progressive increase in the risk of CV morbidity and mortality as well as stroke, myocardial infarction and heart failure in both diabetes mellitus and in all high-risk patients. Target BP <130/80 mmHg reduced stroke risk in the main population but not in the diabetes mellitus patients. Patients with diabetes mellitus had higher event rates for the primary cardiac endpoint and all-cause mortality driven by a higher rate of heart failure. CONCLUSION: In the high-risk hypertensive patients of the VALUE trial achieving more frequently BP <140/90 mmHg, but not <130/80 mmHg, showed principally the same protective effect on overall and cause-specific cardiovascular outcomes in patients with diabetes mellitus and in the general high-risk hypertensive population.


Assuntos
Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Diabetes Mellitus Tipo 2 , Hipertensão , Idoso , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Humanos , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
6.
Stat Med ; 37(6): 867-882, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29152777

RESUMO

Information from historical trials is important for the design, interim monitoring, analysis, and interpretation of clinical trials. Meta-analytic models can be used to synthesize the evidence from historical data, which are often only available in aggregate form. We consider evidence synthesis methods for trials with recurrent event endpoints, which are common in many therapeutic areas. Such endpoints are typically analyzed by negative binomial regression. However, the individual patient data necessary to fit such a model are usually unavailable for historical trials reported in the medical literature. We describe approaches for back-calculating model parameter estimates and their standard errors from available summary statistics with various techniques, including approximate Bayesian computation. We propose to use a quadratic approximation to the log-likelihood for each historical trial based on 2 independent terms for the log mean rate and the log of the dispersion parameter. A Bayesian hierarchical meta-analysis model then provides the posterior predictive distribution for these parameters. Simulations show this approach with back-calculated parameter estimates results in very similar inference as using parameter estimates from individual patient data as an input. We illustrate how to design and analyze a new randomized placebo-controlled exacerbation trial in severe eosinophilic asthma using data from 11 historical trials.


Assuntos
Teorema de Bayes , Ensaios Clínicos como Assunto/métodos , Metanálise como Assunto , Análise de Regressão , Asma , Simulação por Computador , Análise de Dados , Interpretação Estatística de Dados , Humanos , Funções Verossimilhança , Placebos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa
7.
Eur Respir J ; 50(2)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28838980

RESUMO

Dose-related efficacy and safety of fevipiprant (QAW039), an oral DP2 (CRTh2) receptor antagonist, was assessed in patients with allergic asthma uncontrolled by low-dose inhaled corticosteroids (ICS).Adult patients were randomised to 12 weeks' treatment with once-daily (1, 3, 10, 30, 50, 75, 150, 300 or 450 mg q.d) or twice-daily (2, 25, 75 or 150 mg b.i.d) fevipiprant (n=782), montelukast 10 mg q.d (n=139) or placebo (n=137). All patients received inhaled budesonide 200 µg b.i.dFevipiprant produced a statistically significant improvement in the primary end-point of change in pre-dose forced expiratory volume in 1 s at week 12 (p=0.0035) with a maximum model-averaged difference to placebo of 0.112 L. The most favourable pairwise comparisons to placebo were for the fevipiprant 150 mg q.d and 75 mg b.i.d groups, with no clinically meaningful differences between q.d and b.i.d Montelukast also demonstrated a significant improvement in this end-point. No impact on other efficacy end-points was observed. Adverse events were generally mild/moderate in severity, and were evenly distributed across doses and treatments.Fevipiprant appears to be efficacious and well-tolerated in this patient population, with an optimum total daily dose of 150 mg. Further investigations into the clinical role of fevipiprant in suitably designed phase III clinical trials are warranted.


Assuntos
Manuseio das Vias Aéreas/métodos , Asma/terapia , Ácidos Indolacéticos , Piridinas , Acetatos/administração & dosagem , Acetatos/efeitos adversos , Adulto , Antiasmáticos/administração & dosagem , Antiasmáticos/efeitos adversos , Asma/diagnóstico , Budesonida/administração & dosagem , Budesonida/efeitos adversos , Ciclopropanos , Relação Dose-Resposta a Droga , Vias de Administração de Medicamentos , Monitoramento de Medicamentos/métodos , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Glucocorticoides/administração & dosagem , Glucocorticoides/efeitos adversos , Humanos , Ácidos Indolacéticos/administração & dosagem , Ácidos Indolacéticos/efeitos adversos , Masculino , Pessoa de Meia-Idade , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Quinolinas/administração & dosagem , Quinolinas/efeitos adversos , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Índice de Gravidade de Doença , Sulfetos , Resultado do Tratamento
8.
Diabetes Obes Metab ; 19(6): 791-799, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28093841

RESUMO

AIMS: To examine the effect of valsartan on kidney outcomes in patients with impaired glucose tolerance (IGT). METHODS: In a double-blind randomized trial, 9306 patients with IGT were assigned to valsartan (160 mg daily) or placebo. The co-primary endpoints were the development of diabetes and two composite cardiovascular outcomes. Prespecified renal endpoints included: the composite of renal death, end-stage renal disease (ESRD) or doubling of serum creatinine; estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m2 ; hospitalization for renal failure; and progression from normoalbuminuria to microalbuminuria, microalbuminuria to macroalbuminuria, and normoalbuminuria to macroalbuminuria. The median follow-up was 6.2 years. RESULTS: Valsartan reduced the incidence of diabetes but not cardiovascular events. In the valsartan group, 25/4631 patients (0.5%), vs 26/4675 (0.6%) patients in the placebo group, developed ESRD or experienced doubling of serum creatinine (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.55-1.66; P = .87). Few patients in either group developed an eGFR of ≤30 mL/min/1.73 m2 or had a renal hospitalization. Fewer patients on valsartan (237/4084 [5.8%]) than on placebo (342/4092 [8.4%]) developed microalbuminuria (HR 0.68, 95% CI 0.57-0.80; P < .0001), and fewer valsartan-treated patients developed macroalbuminuria. Overall, urinary albumin-to-creatinine ratio (UACR) was 11% lower with valsartan (95% CI 8-13; P < .0001) and 9% lower (95% CI 6-11; P < .0001) after adjusting for both glucose and blood pressure. CONCLUSIONS: The effect of valsartan on UACR was not wholly explained by change in blood pressure or glucose. Valsartan reduced the incidence of microalbuminuria in IGT without increasing the incidence of hyperkalaemia or renal dysfunction compared with placebo.


Assuntos
Albuminúria/prevenção & controle , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Intolerância à Glucose/tratamento farmacológico , Falência Renal Crônica/etiologia , Valsartana/administração & dosagem , Idoso , Albuminúria/epidemiologia , Albuminúria/urina , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Creatinina/urina , Método Duplo-Cego , Feminino , Seguimentos , Intolerância à Glucose/complicações , Intolerância à Glucose/urina , Humanos , Incidência , Falência Renal Crônica/epidemiologia , Masculino , Pessoa de Meia-Idade
9.
Stat Med ; 36(5): 723-737, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-27859465

RESUMO

Meta-analyses of clinical trials often treat the number of patients experiencing a medical event as binomially distributed when individual patient data for fitting standard time-to-event models are unavailable. Assuming identical drop-out time distributions across arms, random censorship, and low proportions of patients with an event, a binomial approach results in a valid test of the null hypothesis of no treatment effect with minimal loss in efficiency compared with time-to-event methods. To deal with differences in follow-up-at the cost of assuming specific distributions for event and drop-out times-we propose a hierarchical multivariate meta-analysis model using the aggregate data likelihood based on the number of cases, fatal cases, and discontinuations in each group, as well as the planned trial duration and groups sizes. Such a model also enables exchangeability assumptions about parameters of survival distributions, for which they are more appropriate than for the expected proportion of patients with an event across trials of substantially different length. Borrowing information from other trials within a meta-analysis or from historical data is particularly useful for rare events data. Prior information or exchangeability assumptions also avoid the parameter identifiability problems that arise when using more flexible event and drop-out time distributions than the exponential one. We discuss the derivation of robust historical priors and illustrate the discussed methods using an example. We also compare the proposed approach against other aggregate data meta-analysis methods in a simulation study. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Metanálise como Assunto , Doenças Cardiovasculares/induzido quimicamente , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/uso terapêutico , Funções Verossimilhança , Modelos Estatísticos , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Rosiglitazona , Estatística como Assunto , Tiazolidinedionas/efeitos adversos , Tiazolidinedionas/uso terapêutico , Fatores de Tempo
10.
Eur Heart J ; 37(12): 955-64, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26590384

RESUMO

AIMS: Recent hypertension guidelines recommend that also in high cardiovascular (CV) risk, hypertensive patients blood pressure (BP) is lowered to <140/90 mmHg as no evidence is available supporting the lower target of <130/80 mmHg recommended in previous guidelines. Whether this represents the optimal treatment strategy is debated, however. METHODS AND RESULTS: The high CV risk hypertensive patients of the Valsartan Antihypertensive Long-term use Evaluation (VALUE) trial were divided into subgroups according to (i) the percentage of on-treatment visits in which BP was reduced to <140/90 or <130/80 mmHg or (ii) the mean systolic or diastolic BP (SBP/DBP) values achieved during the entire treatment period or up to the occurrence of an event. A progressive increase from <25 to ≥75% of the visits in which BP was <140/90 mmHg was accompanied by a significant, progressive marked decrease in the covariate adjusted risk of CV morbidity and mortality, cause specific CV events (myocardial infarction, heart failure, and stroke), and all-cause mortality. Except for a persistent progressive decrease in stroke, no significant trend to a risk decrease occurred for a similar progressive increment of the proportion of visits with BP <130/80 mmHg. Increasing the proportion of visits with a BP <140/90 mmHg (but not <130/80 mmHg) was accompanied by a decreased risk of events also when differences in baseline risk were adjusted using a propensity score. Finally, compared with patients remaining at a mean on-treatment SBP ≥140 or DBP ≥90 mmHg, the risk of all events was markedly reduced when on-treatment mean SBP was lowered to a mean SBP of 130-139 mmHg or a mean DBP of 80-89 mmHg, whereas at on-treatment mean SBP <130 mmHg or DBP <80 mmHg, an additional risk reduction was found for stroke but for any other type of event, the risk of which remained similar or only slightly greater than that seen at the higher BP target. CONCLUSIONS: In the high CV risk, hypertensives of the VALUE trial reducing BP consistently to <140/90 mmHg had marked beneficial effects both when data were calculated as proportion of visits at BP target or as on-treatment mean BP. Reducing BP to <130/80 mmHg led only to some possible further benefit on stroke, whereas the risk of other outcomes remained substantially similar to or slightly greater than that seen at the higher target. Thus, aggressive BP reductions when CV risk is high may not offer substantial advantages, except perhaps in patients or conditions in which stroke risk is particularly common.


Assuntos
Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Valsartana/uso terapêutico , Idoso , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Feminino , Humanos , Hipertensão/mortalidade , Hipertensão/fisiopatologia , Masculino , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/prevenção & controle , Fatores de Risco , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/prevenção & controle , Resultado do Tratamento
11.
Blood Press ; 25(4): 235-40, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26808585

RESUMO

Diabetic and new-onset diabetic patients with hypertension have higher cardiac morbidity than patients without diabetes. We aimed to investigate whether baseline predictors of cardiac morbidity, the major constituent of the primary endpoint in the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial, were different in patients with diabetes and new-onset diabetes compared to patients without diabetes. In total, 15,245 high-risk hypertensive patients in the VALUE trial were followed for an average of 4.2 years. At baseline, 5250 patients were diabetic by the 1999 World Health Organization criteria, 1298 patients developed new-onset diabetes and 8697 patients stayed non-diabetic during follow-up. Cardiac morbidity was defined as a composite of myocardial infarction and heart failure requiring hospitalization, and baseline predictors were identified by univariate and multivariate stepwise Cox regression analyses. History of coronary heart disease (CHD) and age were the most important predictors of cardiac morbidity in both diabetic and non-diabetic patients. History of CHD, history of stroke and age were the only significant predictors of cardiac morbidity in patients with new-onset diabetes. Predictors of cardiac morbidity, in particular history of CHD and age, were essentially the same in high-risk hypertensive patients with diabetes, new-onset diabetes and without diabetes who participated in the VALUE trial.


Assuntos
Anti-Hipertensivos/uso terapêutico , Complicações do Diabetes/complicações , Insuficiência Cardíaca/etiologia , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Infarto do Miocárdio/etiologia , Valsartana/uso terapêutico , Anlodipino/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Complicações do Diabetes/fisiopatologia , Feminino , Insuficiência Cardíaca/fisiopatologia , Hospitalização , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Infarto do Miocárdio/fisiopatologia , Fatores de Risco
12.
Blood Press ; 25(2): 83-92, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26511535

RESUMO

Previous studies have debated the notion that low blood pressure (BP) during treatment, particularly diastolic (DBP), is associated with increased risk of cardiovascular disease. We evaluated the impact of low BP on cardiovascular outcomes in a high-risk population of 15,244 hypertensive patients, almost half of whom had a history of coronary artery disease (CAD). In the prospective Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial, patients were randomized to valsartan or amlodipine regimens and followed for 4.2 years (mean) with no difference in the primary cardiovascular endpoint. A Cox proportional hazards model was used to evaluate the relationship between average on-treatment BP and clinical outcomes. The relationship between BP and cardiovascular events was adjusted for age, gender and body mass index, and baseline qualifying risk factors and diseases (smoking, high total cholesterol, diabetes mellitus, proteinuria, CAD, previous stroke and left ventricular hypertrophy). DBP ≥ 90 mmHg, compared with < 90 mmHg, was associated with increased incidence of the primary cardiovascular endpoint (all cardiac events); however, DBP < 70 mmHg, compared with ≥ 70 mmHg, was not associated with increased incidence after covariate adjustment (no J-shaped curve). Similar results were observed for death, myocardial infarction (MI), heart failure and stroke, considered separately. Nadir for MI was at DBP of 76 mmHg and for stroke 60 mmHg. The ratio of MI to stroke increased with lower DBP. In CAD patients the MI to stroke ratio was more pronounced than in patients without CAD but there was no significant J-curve in either group. Systolic BP ≥ 150 but not < 130 mmHg, compared with 130-149 mmHg, similarly was associated with increased risk for primary outcome. In conclusion, patients in BP strata ≥ 150/90 mmHg, but not patients in BP strata < 130/70 mmHg, were at increased risk for adverse outcomes in this hypertensive, high-risk population. Although benefit in preventing MI in relation to preventing stroke levels off for the lowest BPs, these data provide no support for a J-curve in the treatment of high-risk hypertensive patients . The increase in the ratio of MI to stroke with lower DBP indicates target organ heterogeneity in that the optimal on-treatment DBP for cerebroprotection is below that for cardioprotection.


Assuntos
Anlodipino/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Doença da Artéria Coronariana/diagnóstico , Hipertensão/diagnóstico , Infarto do Miocárdio/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Valsartana/uso terapêutico , Idoso , Determinação da Pressão Arterial , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/tratamento farmacológico , Doença da Artéria Coronariana/fisiopatologia , Diástole , Método Duplo-Cego , Feminino , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/etiologia , Infarto do Miocárdio/fisiopatologia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/fisiopatologia , Sístole , Resultado do Tratamento
13.
Pharm Stat ; 14(6): 433-47, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26337856

RESUMO

The analysis of clinical trials aiming to show symptomatic benefits is often complicated by the ethical requirement for rescue medication when the disease state of patients worsens. In type 2 diabetes trials, patients receive glucose-lowering rescue medications continuously for the remaining trial duration, if one of several markers of glycemic control exceeds pre-specified thresholds. This may mask differences in glycemic values between treatment groups, because it will occur more frequently in less effective treatment groups. Traditionally, the last pre-rescue medication value was carried forward and analyzed as the end-of-trial value. The deficits of such simplistic single imputation approaches are increasingly recognized by regulatory authorities and trialists. We discuss alternative approaches and evaluate them through a simulation study. When the estimand of interest is the effect attributable to the treatments initially assigned at randomization, then our recommendation for estimation and hypothesis testing is to treat data after meeting rescue criteria as deterministically 'missing' at random, because initiation of rescue medication is determined by observed in-trial values. An appropriate imputation of values after meeting rescue criteria is then possible either directly through multiple imputation or implicitly with a repeated measures model. Crucially, one needs to jointly impute or model all markers of glycemic control that can lead to the initiation of rescue medication. An alternative for hypothesis testing only are rank tests with outcomes from patients 'requiring rescue medication' ranked worst, and non-rescued patients ranked according to final visit values. However, an appropriate ranking of not observed values may be controversial.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Glicemia/efeitos dos fármacos , Interpretação Estatística de Dados , Humanos , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto/ética
14.
Cardiovasc Diabetol ; 13: 94, 2014 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-24884602

RESUMO

BACKGROUND: We aimed to assess the safety and tolerability of different doses of canakinumab versus placebo in patients with type 2 diabetes mellitus (T2DM). METHODS: Data were pooled from three studies in 1026 T2DM patients with different routes of administration, treatment regimens and follow-up duration. Canakinumab groups were categorised as low (0.03 mg/kg i.v. once; N = 20), intermediate (0.1 and 0.3 mg/kg i.v. once, 5 and 15 mg s.c. monthly; N = 247), medium (1.5 mg/kg i.v. once, 50 mg s.c. monthly and 150 mg s.c. once; N = 268), and high doses (10 mg/kg i.v. once and 150 mg s.c. monthly; N = 137) and compared with placebo (N = 354). Incidences of adverse events (AEs), serious AEs (SAEs), discontinuations due to AEs, deaths, AEs of special interest related to interleukin-1ß inhibition and T2DM disease, and laboratory abnormalities related to haematology and biochemistry parameters were reported. Safety was also analysed by age (<65, ≥65) and gender. RESULTS: Average exposure across all groups was ≈ 6 months (maximum ~17 months). No dose response in AEs was observed but a trend towards more patients having at least one AE across canakinumab groups relative to placebo (P = 0.0152) was observed. SAEs were few and the incidence rate for most canakinumab groups was lower than that of placebo group except for the high-dose group (0.94% versus 0.58% per month in placebo). A total of five patients discontinued treatment due to AEs across treatment groups. No death was reported in any of the three studies. A small, non-significant increase in the incidence rate of infection AEs was observed on canakinumab groups relative to placebo. Canakinumab was associated with mostly mild decreases in WBC, neutrophils and platelet counts. Additionally, mild increases in SGPT, SGOT and bilirubin were reported. Overall, despite small differences, no clinically relevant findings were observed with respect to laboratory values and vital signs. CONCLUSIONS: This pooled analysis demonstrated that canakinumab was safe and well tolerated over a treatment period up to 1.4 years at the four pooled doses evaluated, in agreement with safety findings reported in the individual studies.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Interleucina-1beta/antagonistas & inibidores , Idoso , Anticorpos Monoclonais Humanizados , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/diagnóstico , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Feminino , Seguimentos , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/diagnóstico , Humanos , Interleucina-1beta/metabolismo , Masculino , Pessoa de Meia-Idade
15.
J Stroke Cerebrovasc Dis ; 23(10): 2814-2818, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25304725

RESUMO

BACKGROUND: Risk factors for first stroke are well established, but less is known about risk factors for recurrent stroke. In the present analysis, we aimed to assess the effect of heart rate and other possible predictors of stroke in a hypertensive population with previous stroke or transient ischemic attack (TIA). METHODS: The Valsartan Antihypertensive Long-Term Use Evaluation trial was a multicentre, double-masked, randomized controlled, parallel group trial comparing the effects of an angiotensin receptor blocker (valsartan) and a calcium channel blocker (amlodipine) in patients with hypertension and high cardiovascular risk. We used Cox proportional hazard models to investigate the effect of baseline variables on the risk of stroke. Quadratic terms of the continuous variables were entered in the models to test for linearity. RESULTS: Of 15,245 patients included in the trial, 3014 had a previous stroke or TIA at baseline and were included in the present analysis. Stroke recurrence occurred in 239 patients (7.9%) during a median of 4.5 years of follow-up. Resting heart rate (per 10 beats per minute; hazard ratio [HR], 2.78; 95% confidence interval [CI], 1.18-6.58) and diabetes mellitus at baseline (HR, 1.47; 95% CI, 1.03-2.10) were significantly associated with an increased risk of stroke recurrence in the multivariable analysis. CONCLUSIONS: In high-risk, hypertensive patients with previous stroke or TIA, resting heart rate was the strongest predictor of recurrent stroke.


Assuntos
Frequência Cardíaca , Hipertensão/complicações , Ataque Isquêmico Transitório/etiologia , Acidente Vascular Cerebral/etiologia , Idoso , Anlodipino/uso terapêutico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Ataque Isquêmico Transitório/diagnóstico , Ataque Isquêmico Transitório/fisiopatologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Recidiva , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Tetrazóis/uso terapêutico , Fatores de Tempo , Resultado do Tratamento , Valina/análogos & derivados , Valina/uso terapêutico , Valsartana
16.
N Engl J Med ; 362(16): 1463-76, 2010 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-20228402

RESUMO

BACKGROUND: The ability of short-acting insulin secretagogues to reduce the risk of diabetes or cardiovascular events in people with impaired glucose tolerance is unknown. METHODS: In a double-blind, randomized clinical trial, we assigned 9306 participants with impaired glucose tolerance and either cardiovascular disease or cardiovascular risk factors to receive nateglinide (up to 60 mg three times daily) or placebo, in a 2-by-2 factorial design with valsartan or placebo, in addition to participation in a lifestyle modification program. We followed the participants for a median of 5.0 years for incident diabetes (and a median of 6.5 years for vital status). We evaluated the effect of nateglinide on the occurrence of three coprimary outcomes: the development of diabetes; a core cardiovascular outcome that was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure; and an extended cardiovascular outcome that was a composite of the individual components of the core composite cardiovascular outcome, hospitalization for unstable angina, or arterial revascularization. RESULTS: After adjustment for multiple testing, nateglinide, as compared with placebo, did not significantly reduce the cumulative incidence of diabetes (36% and 34%, respectively; hazard ratio, 1.07; 95% confidence interval [CI], 1.00 to 1.15; P=0.05), the core composite cardiovascular outcome (7.9% and 8.3%, respectively; hazard ratio, 0.94, 95% CI, 0.82 to 1.09; P=0.43), or the extended composite cardiovascular outcome (14.2% and 15.2%, respectively; hazard ratio, 0.93, 95% CI, 0.83 to 1.03; P=0.16). Nateglinide did, however, increase the risk of hypoglycemia. CONCLUSIONS: Among persons with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors, assignment to nateglinide for 5 years did not reduce the incidence of diabetes or the coprimary composite cardiovascular outcomes. (ClinicalTrials.gov number, NCT00097786.)


Assuntos
Doenças Cardiovasculares/prevenção & controle , Cicloexanos/uso terapêutico , Diabetes Mellitus Tipo 2/prevenção & controle , Intolerância à Glucose/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Fenilalanina/análogos & derivados , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Glicemia/análise , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Cicloexanos/efeitos adversos , Diabetes Mellitus Tipo 2/epidemiologia , Método Duplo-Cego , Quimioterapia Combinada , Exercício Físico , Feminino , Seguimentos , Intolerância à Glucose/dietoterapia , Intolerância à Glucose/terapia , Humanos , Hipoglicemiantes/efeitos adversos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Nateglinida , Fenilalanina/efeitos adversos , Fenilalanina/uso terapêutico , Modelos de Riscos Proporcionais , Fatores de Risco , Tetrazóis/uso terapêutico , Falha de Tratamento , Valina/análogos & derivados , Valina/uso terapêutico , Valsartana
17.
N Engl J Med ; 362(16): 1477-90, 2010 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-20228403

RESUMO

BACKGROUND: It is not known whether drugs that block the renin-angiotensin system reduce the risk of diabetes and cardiovascular events in patients with impaired glucose tolerance. METHODS: In this double-blind, randomized clinical trial with a 2-by-2 factorial design, we assigned 9306 patients with impaired glucose tolerance and established cardiovascular disease or cardiovascular risk factors to receive valsartan (up to 160 mg daily) or placebo (and nateglinide or placebo) in addition to lifestyle modification. We then followed the patients for a median of 5.0 years for the development of diabetes (6.5 years for vital status). We studied the effects of valsartan on the occurrence of three coprimary outcomes: the development of diabetes; an extended composite outcome of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, hospitalization for heart failure, arterial revascularization, or hospitalization for unstable angina; and a core composite outcome that excluded unstable angina and revascularization. RESULTS: The cumulative incidence of diabetes was 33.1% in the valsartan group, as compared with 36.8% in the placebo group (hazard ratio in the valsartan group, 0.86; 95% confidence interval [CI], 0.80 to 0.92; P<0.001). Valsartan, as compared with placebo, did not significantly reduce the incidence of either the extended cardiovascular outcome (14.5% vs. 14.8%; hazard ratio, 0.96; 95% CI, 0.86 to 1.07; P=0.43) or the core cardiovascular outcome (8.1% vs. 8.1%; hazard ratio, 0.99; 95% CI, 0.86 to 1.14; P=0.85). CONCLUSIONS: Among patients with impaired glucose tolerance and cardiovascular disease or risk factors, the use of valsartan for 5 years, along with lifestyle modification, led to a relative reduction of 14% in the incidence of diabetes but did not reduce the rate of cardiovascular events. (ClinicalTrials.gov number, NCT00097786.)


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/prevenção & controle , Intolerância à Glucose/tratamento farmacológico , Tetrazóis/uso terapêutico , Valina/análogos & derivados , Bloqueadores do Receptor Tipo 1 de Angiotensina II/efeitos adversos , Glicemia/análise , Glicemia/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/mortalidade , Cicloexanos/uso terapêutico , Diabetes Mellitus Tipo 2/epidemiologia , Método Duplo-Cego , Quimioterapia Combinada , Exercício Físico , Feminino , Seguimentos , Intolerância à Glucose/dietoterapia , Intolerância à Glucose/terapia , Humanos , Hipoglicemiantes/uso terapêutico , Incidência , Masculino , Pessoa de Meia-Idade , Nateglinida , Fenilalanina/análogos & derivados , Fenilalanina/uso terapêutico , Modelos de Riscos Proporcionais , Fatores de Risco , Tetrazóis/efeitos adversos , Valina/efeitos adversos , Valina/uso terapêutico , Valsartana
19.
J Allergy Clin Immunol Pract ; 11(5): 1463-1474.e3, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36716998

RESUMO

BACKGROUND: The differential diagnosis of asthma and chronic obstructive pulmonary disease (COPD) poses a challenge in clinical practice and its misdiagnosis results in inappropriate treatment, increased exacerbations, and potentially death. OBJECTIVE: To investigate the diagnostic accuracy of the Asthma/COPD Differentiation Classification (AC/DC) tool compared with primary care physicians and pulmonologists in asthma, COPD, and asthma-COPD overlap. METHODS: The AC/DC machine learning-based diagnostic tool was developed using 12 parameters from electronic health records of more than 400,000 patients aged 35 years and older. An expert panel of three pulmonologists and four general practitioners from five countries evaluated 119 patient cases from a prospective observational study and provided a confirmed diagnosis (n = 116) of asthma (n = 53), COPD (n = 43), asthma-COPD overlap (n = 7), or other (n = 13). Cases were then reviewed by 180 primary care physicians and 180 pulmonologists from nine countries and by the AC/DC tool, and diagnostic accuracies were compared with reference to the expert panel diagnoses. RESULTS: Average diagnostic accuracy of the AC/DC tool was superior to that of primary care physicians (median difference, 24%; 95% posterior credible interval: 17% to 29%; P < .0001) and was noninferior and superior (median difference, 12%; 95% posterior credible interval: 6% to 17%; P < .0001 for noninferiority and P = .0006 for superiority) to that of pulmonologists. Average diagnostic accuracies were 73%, 50%, and 61% by AC/DC tool, primary care physicians, and pulmonologists versus expert panel diagnosis, respectively. CONCLUSION: The AC/DC tool demonstrated superior diagnostic accuracy compared with primary care physicians and pulmonologists in the diagnosis of asthma and COPD in patients aged 35 years and greater and has the potential to support physicians in the diagnosis of these conditions in clinical practice.


Assuntos
Asma , Clínicos Gerais , Médicos de Atenção Primária , Doença Pulmonar Obstrutiva Crônica , Humanos , Pneumologistas , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Asma/tratamento farmacológico
20.
Clin Pharmacol Ther ; 111(5): 1050-1060, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34762298

RESUMO

The point at which clinical development programs transition from early phase to pivotal trials is a critical milestone. Substantial uncertainty about the outcome of pivotal trials may remain even after seeing positive early phase data, and companies may need to make difficult prioritization decisions for their portfolio. The probability of success (PoS) of a program, a single number expressed as a percentage reflecting the multitude of risks that may influence the final program outcome, is a key decision-making tool. Despite its importance, companies often rely on crude industry benchmarks that may be "adjusted" by experts based on undocumented criteria and which are typically misaligned with the definition of success used to drive commercial forecasts, leading to overly optimistic expected net present value calculations. We developed a new framework to assess the PoS of a program before pivotal trials begin. Our definition of success encompasses the successful outcome of pivotal trials, regulatory approval and meeting the requirements for market access as outlined in the target product profile. The proposed approach is organized in four steps and uses an innovative Bayesian approach to synthesize all relevant evidence. The new PoS framework is systematic and transparent. It will help organizations to make more informed decisions. In this paper, we outline the rationale and elaborate on the structure of the proposed framework, provide examples, and discuss the benefits and challenges associated with its adoption.


Assuntos
Teorema de Bayes , Humanos , Probabilidade , Incerteza
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