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1.
Biom J ; 61(5): 1232-1241, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30589102

RESUMO

Data Monitoring Committees (DMCs) are an integral part of clinical drug development. Their use has evolved along with changing study designs and regulatory expectations, which has associated statistical and ethical implications. Although there is guidance from the different regulatory agencies, there are opportunities to bring more consistency to address practical issues of establishing and operating a DMC. Challenging issues include defining the scope of DMC decisions, the regulatory requirements and expectations, the perceived independence of DMCs, the specific focus primarily on safety, etc. Wider use of adaptive clinical trial designs in recent years introduce additional challenges in terms of trial governance and the complexity of DMC activities. A panel comprised of clinical and statistical experts from across academia, industry, and regulatory agencies shared their experience and thoughts on the importance of these aspects and offered perspectives on the future of the DMCs. This paper documents the thinking from the panel session at the CEN-ISBS conference held in Vienna, Austria, 2017.


Assuntos
Comitês de Monitoramento de Dados de Ensaios Clínicos/economia , Comitês de Monitoramento de Dados de Ensaios Clínicos/legislação & jurisprudência , Controle Social Formal , Comitês de Monitoramento de Dados de Ensaios Clínicos/organização & administração , Guias como Assunto , Humanos
2.
Pharm Stat ; 17(4): 317-328, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29635777

RESUMO

All clinical trials are designed for success of their primary objectives. Hence, evaluating the probability of success (PoS) should be a key focus at the design stage both to support funding approval from sponsor governance boards and to inform trial design itself. Use of assurance-that is, expected success probability averaged over a prior probability distribution for the treatment effect-to quantify PoS of a planned study has grown across the industry in recent years, and has now become routine within the authors' company. In this paper, we illustrate some of the benefits of systematically adopting assurance as a quantitative framework to support decision making in drug development through several case-studies where evaluation of assurance has proved impactful in terms of trial design and in supporting governance-board reviews of project proposals. In addition, we describe specific features of how the assurance framework has been implemented within our company, highlighting the critical role that prior elicitation plays in this process, and illustrating how the overall assurance calculation may be decomposed into a sequence of conditional PoS estimates which can provide greater insight into how and when different development options are able to discharge risk.


Assuntos
Tomada de Decisões , Desenvolvimento de Medicamentos/estatística & dados numéricos , Indústria Farmacêutica/estatística & dados numéricos , Animais , Estudos de Casos e Controles , Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Desenvolvimento de Medicamentos/métodos , Indústria Farmacêutica/métodos , Humanos
3.
Am Heart J ; 169(5): 622-630.e6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25965709

RESUMO

BACKGROUND: p38 mitogen-activated protein kinase (MAPK) mediates cytokine production and amplification of the inflammatory cascade. Through inhibition of p38 MAPK, losmapimod appears to attenuate the inflammatory response in the vascular wall and thus may help stabilize plaques. STUDY DESIGN: The LATITUDE-TIMI 60 trial is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study planned to be conducted in a 3-stage design. Overall, the trial is designed to include 25,500 patients hospitalized with non-ST-elevation or ST-elevation myocardial infarction (MI) randomized to oral losmapimod (7.5 mg twice daily) versus matching placebo. Part A consists of a leading cohort (n = 3,500) that will provide an initial assessment of safety and exploratory efficacy before progressing to part B. Part B (n = ~22,000) of the study is event driven and will provide the primary assessment of efficacy. An independent safety review will be conducted after 3,500 patients in part B1 to determine whether a more focused schedule of clinic visits and laboratory assessments can be implemented (part B2). All patients are to be treated with study drug until week 12 and followed up until week 24. The primary end point is the composite of cardiovascular death, MI, or severe recurrent ischemia requiring urgent coronary revascularization. The key secondary end point is the composite of cardiovascular death or MI. The trial is designed to provide ≥90% power for the primary end point. CONCLUSIONS: The LATITUDE-TIMI 60 trial will determine the efficacy and safety of short-term p38 MAPK inhibition with losmapimod in acute MI. The trial design adopts a stepwise approach to decision making and collection of data.


Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Ciclopropanos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Projetos de Pesquisa
4.
5.
Pharm Stat ; 7(4): 236-44, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17583558

RESUMO

We consider the problem of sample size calculation for non-inferiority based on the hazard ratio in time-to-event trials where overall study duration is fixed and subject enrollment is staggered with variable follow-up. An adaptation of previously developed formulae for the superiority framework is presented that specifically allows for effect reversal under the non-inferiority setting, and its consequent effect on variance. Empirical performance is assessed through a small simulation study, and an example based on an ongoing trial is presented. The formulae are straightforward to program and may prove a useful tool in planning trials of this type.


Assuntos
Ensaios Clínicos como Assunto/métodos , Ensaios Clínicos como Assunto/estatística & dados numéricos , Tamanho da Amostra , Ensaios Clínicos como Assunto/normas , Seguimentos , Humanos , Projetos de Pesquisa/normas , Fatores de Tempo
6.
Eur J Heart Fail ; 18(5): 482-9, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27071916

RESUMO

Composite endpoints are commonly used as the primary measure of efficacy in heart failure clinical trials to assess the overall treatment effect and to increase the efficiency of trials. Clinical trials still must enrol large numbers of patients to accrue a sufficient number of outcome events and have adequate power to draw conclusions about the efficacy and safety of new treatments for heart failure. Additionally, the societal and health system perspectives on heart failure have raised interest in ascertaining the effects of therapy on outcomes such as repeat hospitalization and the patient's burden of disease. Thus, novel methods for using composite endpoints in clinical trials (e.g. clinical status composite endpoints, recurrent event analyses) are being applied in current and planned trials. Endpoints that measure functional status or reflect the patient experience are important but used cautiously because heart failure treatments may improve function yet have adverse effects on mortality. This paper discusses the use of traditional and new composite endpoints, identifies qualities of robust composites, and outlines opportunities for future research.


Assuntos
Insuficiência Cardíaca/terapia , Hospitalização , Mortalidade , Atividades Cotidianas , Causas de Morte , Ensaios Clínicos como Assunto , Humanos , Avaliação de Resultados em Cuidados de Saúde , Qualidade de Vida , Resultado do Tratamento
7.
Contemp Clin Trials ; 43: 155-63, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26044462

RESUMO

Blinding is a corner-stone for the robustness of many clinical trials. Achieving a robust level of trial blinding involves close partnership across a number of trial disciplines, and numerous challenges can arise. This paper provides a wide-ranging overview of issues to consider in managing blinding, including clinical and statistical considerations, supply planning and inventory management strategy, and the management and disclosure of unplanned unblinding events that arise during trial conduct.


Assuntos
Método Duplo-Cego , Drogas em Investigação , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Humanos , Segurança do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Projetos de Pesquisa
8.
J Heart Lung Transplant ; 21(4): 460-6, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11927223

RESUMO

BACKGROUND: Cytomegalovirus (CMV) is a major cause of serious morbidity following solid organ transplantation via both direct and indirect mechanisms. The aim of this study was to investigate the efficacy and safety of valacyclovir prophylaxis in heart transplant recipients. METHODS: Twenty-seven CMV seropositive adults due to receive a heart transplant were included in a single-center, randomized, double-blind study. Patients were randomized to receive either oral valacyclovir 2000 mg or oral acyclovir 200 mg four times daily starting within 3 days of heart transplant and continuing for 90 days. The primary outcome measure was time to development of CMV antigenemia assessed for 6 months after surgery. Other measures were time to asymptomatic CMV infection, symptomatic CMV infections, and end-organ CMV disease. Patients were monitored for other herpes infections, other opportunistic infections, and acute graft rejection. Safety was assessed by evaluating changes in hematology and clinical chemistry parameters and by the occurrence of adverse events. RESULTS: The median time to CMV antigenemia was 19 days for the acyclovir group compared with 119 days for the valacyclovir group (hazard ratio 0.42; 95% CI, 0.18-0.99; p = 0.049). Similar delays of approximately 100 days were found for CMV infection, symptomatic CMV infection, and CMV disease. There was also a trend for delayed acute rejection, and fewer opportunistic or other herpesvirus infections occurred in the valacyclovir group. Valacyclovir was well tolerated in the study population. CONCLUSION: Oral valacyclovir is a safe and effective mode of prophylaxis of CMV after heart transplantation.


Assuntos
Aciclovir/análogos & derivados , Aciclovir/uso terapêutico , Antivirais/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/prevenção & controle , Transplante de Coração , Valina/análogos & derivados , Valina/uso terapêutico , Adulto , Infecções por Citomegalovirus/complicações , Relação Dose-Resposta a Droga , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Rejeição de Enxerto/complicações , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/prevenção & controle , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Reino Unido/epidemiologia , Valaciclovir
10.
Blood ; 99(8): 3050-6, 2002 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11929799

RESUMO

Oral valacyclovir for cytomegalovirus (CMV) prophylaxis in bone marrow transplantation (BMT) was investigated in a randomized, double-blind, acyclovir-controlled, multicenter clinical trial in recipients of allogeneic BMT who were CMV seropositive (or donor positive) before transplantation and were aged 13 years or older. Patients were randomized before BMT. All initially received intravenous acyclovir (500 mg/m(2)) 3 times daily until day 28 after transplantation or after discharge, then oral valacyclovir (2 g) or acyclovir (800 mg) 4 times daily until week 18 after transplantation. Evidence of CMV infection, CMV disease, and death were documented for 22 weeks. Primary end points were time to CMV infection (detection of CMV in blood, broncho-alveolar lavage) or CMV disease and survival. Preemptive CMV therapy was permitted. Seven hundred twenty-seven patients were evaluable for efficacy. After the administration of intravenous acyclovir, valacyclovir was significantly more effective than oral acyclovir in reducing the incidence of CMV infection. CMV infection or disease developed in 102 (28%) valacyclovir patients, compared with 143 (40%) acyclovir patients (HR, 0.59; 95% CI, 0.46-0.76; P <.0001). Survival did not differ between treatments (76% and 75% in the valacyclovir and acyclovir groups, respectively). The safety of oral valacyclovir was similar to that of high-dose oral acyclovir. Valacyclovir was more effective than acyclovir in preventing CMV reactivation in BMT recipients and showed a similar safety profile. CMV disease incidence was low, and no differences were observed between oral valacyclovir and acyclovir. Survival was similar in each group. Valacyclovir prophylaxis provides a clinically valuable intervention but must be part of an overall strategy for CMV prevention in BMT.


Assuntos
Aciclovir/análogos & derivados , Aciclovir/administração & dosagem , Antivirais/administração & dosagem , Transplante de Medula Óssea/efeitos adversos , Infecções por Citomegalovirus/prevenção & controle , Valina/análogos & derivados , Valina/administração & dosagem , Aciclovir/toxicidade , Adolescente , Adulto , Antivirais/toxicidade , Transplante de Medula Óssea/mortalidade , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/crescimento & desenvolvimento , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/etiologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pró-Fármacos/administração & dosagem , Pró-Fármacos/toxicidade , Análise de Sobrevida , Equivalência Terapêutica , Transplante Homólogo/efeitos adversos , Transplante Homólogo/mortalidade , Valaciclovir , Valina/toxicidade , Ativação Viral/efeitos dos fármacos
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