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1.
Biom J ; 61(5): 1232-1241, 2019 09.
Article in English | MEDLINE | ID: mdl-30589102

ABSTRACT

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.


Subject(s)
Clinical Trials Data Monitoring Committees/economics , Clinical Trials Data Monitoring Committees/legislation & jurisprudence , Social Control, Formal , Clinical Trials Data Monitoring Committees/organization & administration , Guidelines as Topic , Humans
2.
Pharm Stat ; 17(4): 317-328, 2018 07.
Article in English | MEDLINE | ID: mdl-29635777

ABSTRACT

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.


Subject(s)
Decision Making , Drug Development/statistics & numerical data , Drug Industry/statistics & numerical data , Animals , Case-Control Studies , Clinical Trials as Topic/methods , Clinical Trials as Topic/statistics & numerical data , Drug Development/methods , Drug Industry/methods , Humans
4.
Stat Med ; 35(12): 2109-10, 2016 05 30.
Article in English | MEDLINE | ID: mdl-27118630
5.
Eur J Heart Fail ; 18(5): 482-9, 2016 05.
Article in English | MEDLINE | ID: mdl-27071916

ABSTRACT

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.


Subject(s)
Heart Failure/therapy , Hospitalization , Mortality , Activities of Daily Living , Cause of Death , Clinical Trials as Topic , Humans , Outcome Assessment, Health Care , Quality of Life , Treatment Outcome
6.
Contemp Clin Trials ; 43: 155-63, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26044462

ABSTRACT

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.


Subject(s)
Double-Blind Method , Drugs, Investigational , Randomized Controlled Trials as Topic/methods , Humans , Patient Safety , Randomized Controlled Trials as Topic/standards , Research Design
7.
Am Heart J ; 169(5): 622-630.e6, 2015 May.
Article in English | MEDLINE | ID: mdl-25965709

ABSTRACT

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.


Subject(s)
Acute Coronary Syndrome/drug therapy , Cyclopropanes/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyridines/therapeutic use , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Adult , Double-Blind Method , Female , Humans , Male , Middle Aged , Placebos , Research Design
8.
Pharm Stat ; 7(4): 236-44, 2008.
Article in English | MEDLINE | ID: mdl-17583558

ABSTRACT

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.


Subject(s)
Clinical Trials as Topic/methods , Clinical Trials as Topic/statistics & numerical data , Sample Size , Clinical Trials as Topic/standards , Follow-Up Studies , Humans , Research Design/standards , Time Factors
9.
J Heart Lung Transplant ; 21(4): 460-6, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11927223

ABSTRACT

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.


Subject(s)
Acyclovir/analogs & derivatives , Acyclovir/therapeutic use , Antiviral Agents/therapeutic use , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/prevention & control , Heart Transplantation , Valine/analogs & derivatives , Valine/therapeutic use , Adult , Cytomegalovirus Infections/complications , Dose-Response Relationship, Drug , Double-Blind Method , Endpoint Determination , Female , Graft Rejection/complications , Graft Rejection/drug therapy , Graft Rejection/prevention & control , Humans , Incidence , Male , Middle Aged , Severity of Illness Index , Time Factors , Treatment Outcome , United Kingdom/epidemiology , Valacyclovir
10.
Blood ; 99(8): 3050-6, 2002 Apr 15.
Article in English | MEDLINE | ID: mdl-11929799

ABSTRACT

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.


Subject(s)
Acyclovir/analogs & derivatives , Acyclovir/administration & dosage , Antiviral Agents/administration & dosage , Bone Marrow Transplantation/adverse effects , Cytomegalovirus Infections/prevention & control , Valine/analogs & derivatives , Valine/administration & dosage , Acyclovir/toxicity , Adolescent , Adult , Antiviral Agents/toxicity , Bone Marrow Transplantation/mortality , Cytomegalovirus/drug effects , Cytomegalovirus/growth & development , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/etiology , Double-Blind Method , Female , Humans , Male , Middle Aged , Prodrugs/administration & dosage , Prodrugs/toxicity , Survival Analysis , Therapeutic Equivalency , Transplantation, Homologous/adverse effects , Transplantation, Homologous/mortality , Valacyclovir , Valine/toxicity , Virus Activation/drug effects
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