251 research outputs found

    Monitoring overall survival in pivotal trials in indolent cancers

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    Indolent cancers are characterized by long overall survival (OS) times. Therefore, powering a clinical trial to provide definitive assessment of the effects of an experimental intervention on OS in a reasonable timeframe is generally infeasible. Instead, the primary outcome in many pivotal trials is an intermediate clinical response such as progression-free survival (PFS). In several recently reported pivotal trials of interventions for indolent cancers that yielded promising results on an intermediate outcome, however, more mature data or post-approval trials showed concerning OS trends. These problematic results have prompted a keen interest in quantitative approaches for monitoring OS that can support regulatory decision-making related to the risk of an unacceptably large detrimental effect on OS. For example, the US Food and Drug Administration, the American Association for Cancer Research, and the American Statistical Association recently organized a one-day multi-stakeholder workshop entitled 'Overall Survival in Oncology Clinical Trials'. In this paper, we propose OS monitoring guidelines tailored for the setting of indolent cancers. Our pragmatic approach is modeled, in part, on the monitoring guidelines the FDA has used in cardiovascular safety trials conducted in Type 2 Diabetes Mellitus. We illustrate proposals through application to several examples informed by actual case studies.Comment: 13 pages, 5 table

    Through the looking glass: understanding non-inferiority

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    Non-inferiority trials test whether a new product is not unacceptably worse than a product already in use. This paper introduces concepts related to non-inferiority, and discusses the regulatory views of both the European Medicines Agency and the United States Food and Drug Administration

    What constitutes a "clinical trial"?: A survey of oncology professionals

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    <p>Abstract</p> <p>Background</p> <p>What constitutes a "clinical trial" is inconsistently defined in the medical literature. With an initiative by Cancer Care Ontario (CCO) to report institutional clinical trials activity across the province of Ontario, Canada, we sought to investigate the variability in the interpretation of the term by local oncology professionals.</p> <p>Methods</p> <p>A survey amongst the physicians and nurses at the Juravinski Cancer Centre at Hamilton Health Sciences, Ontario was conducted. The survey included 12 summaries of local clinical research studies, and respondents were asked which they believed represented a clinical trial. Subsequently, they were asked which of the same 12 studies they believed should be labeled as clinical trials when considering separate definitions provided by CCO and by the Ontario Cancer Research Network (OCRN).</p> <p>Results</p> <p>A total of 66 (54%) of 123 surveys were completed; 32/46 (70%) by physicians, 21/59 (36%) by primary care nurses, and 13/18 (72%) by clinical trial nurses. Without a standardized definition, all studies, 12/12, were considered to be clinical trials by at least 50% of respondents. When provided with the CCO definition only 6/12 studies were considered to be clinical trials by the majority of respondents, while with the OCRN definition it was 9/12 studies. Studies evaluating natural health products, non-traditional medical interventions, and non-randomized studies with standard interventions consistently ranked the lowest, regardless of the definition used.</p> <p>Conclusion</p> <p>Oncology professionals appear to have a broadly inclusive baseline definition of what constitutes a clinical trial. Establishing rigor and consistency in the definition of a clinical trial is important for any program, institutional or jurisdictional based comparisons of clinical trials activity, especially when used as a quality indicator of patient care.</p

    Statistical design of personalized medicine interventions: The Clarification of Optimal Anticoagulation through Genetics (COAG) trial

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    <p>Abstract</p> <p>Background</p> <p>There is currently much interest in pharmacogenetics: determining variation in genes that regulate drug effects, with a particular emphasis on improving drug safety and efficacy. The ability to determine such variation motivates the application of personalized drug therapies that utilize a patient's genetic makeup to determine a safe and effective drug at the correct dose. To ascertain whether a genotype-guided drug therapy improves patient care, a personalized medicine intervention may be evaluated within the framework of a randomized controlled trial. The statistical design of this type of personalized medicine intervention requires special considerations: the distribution of relevant allelic variants in the study population; and whether the pharmacogenetic intervention is equally effective across subpopulations defined by allelic variants.</p> <p>Methods</p> <p>The statistical design of the Clarification of Optimal Anticoagulation through Genetics (COAG) trial serves as an illustrative example of a personalized medicine intervention that uses each subject's genotype information. The COAG trial is a multicenter, double blind, randomized clinical trial that will compare two approaches to initiation of warfarin therapy: genotype-guided dosing, the initiation of warfarin therapy based on algorithms using clinical information and genotypes for polymorphisms in <it>CYP2C9 </it>and <it>VKORC1</it>; and clinical-guided dosing, the initiation of warfarin therapy based on algorithms using only clinical information.</p> <p>Results</p> <p>We determine an absolute minimum detectable difference of 5.49% based on an assumed 60% population prevalence of zero or multiple genetic variants in either <it>CYP2C9 </it>or <it>VKORC1 </it>and an assumed 15% relative effectiveness of genotype-guided warfarin initiation for those with zero or multiple genetic variants. Thus we calculate a sample size of 1238 to achieve a power level of 80% for the primary outcome. We show that reasonable departures from these assumptions may decrease statistical power to 65%.</p> <p>Conclusions</p> <p>In a personalized medicine intervention, the minimum detectable difference used in sample size calculations is not a known quantity, but rather an unknown quantity that depends on the genetic makeup of the subjects enrolled. Given the possible sensitivity of sample size and power calculations to these key assumptions, we recommend that they be monitored during the conduct of a personalized medicine intervention.</p> <p>Trial Registration</p> <p>clinicaltrials.gov: NCT00839657</p

    The Effectiveness of Alcohol Screening and Brief Intervention in Emergency Departments: A Multicentre Pragmatic Cluster Randomized Controlled Trial

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    BACKGROUND: Alcohol misuse is common in people attending emergency departments (EDs) and there is some evidence of efficacy of alcohol screening and brief interventions (SBI). This study investigated the effectiveness of SBI approaches of different intensities delivered by ED staff in nine typical EDs in England: the SIPS ED trial. METHODS AND FINDINGS: Pragmatic multicentre cluster randomized controlled trial of SBI for hazardous and harmful drinkers presenting to ED. Nine EDs were randomized to three conditions: a patient information leaflet (PIL), 5 minutes of brief advice (BA), and referral to an alcohol health worker who provided 20 minutes of brief lifestyle counseling (BLC). The primary outcome measure was the Alcohol Use Disorders Identification Test (AUDIT) status at 6 months. Of 5899 patients aged 18 or more presenting to EDs, 3737 (63¡3%) were eligible to participate and 1497 (40¡1%) screened positive for hazardous or harmful drinking, of whom 1204 (80¡4%) gave consent to participate in the trial. Follow up rates were 72% (n?=?863) at six, and 67% (n?=?810) at 12 months. There was no evidence of any differences between intervention conditions for AUDIT status or any other outcome measures at months 6 or 12 in an intention to treat analysis. At month 6, compared to the PIL group, the odds ratio of being AUDIT negative for brief advice was 1¡103 (95% CI 0¡328 to 3¡715). The odds ratio comparing BLC to PIL was 1¡247 (95% CI 0¡315 to 4¡939). A per protocol analysis confirmed these findings. CONCLUSIONS: SBI is difficult to implement in typical EDs. The results do not support widespread implementation of alcohol SBI in ED beyond screening followed by simple clinical feedback and alcohol information, which is likely to be easier and less expensive to implement than more complex interventions

    Epimacular Brachytherapy for Previously Treated Neovascular Age-Related Macular Degeneration (MERLOT) A Phase 3 Randomized Controlled Trial Presented in part at: Retina Day, American Academy of Ophthalmology Annual Meeting, November 2015, Las Vegas, Nevada.

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    PurposeTo assess the safety and efficacy of epimacular brachytherapy (EMB) for patients with chronic, active, neovascular age-related macular degeneration (AMD).DesignPhase 3 randomized controlled trial.ParticipantsPatients (n = 363) with neovascular AMD already receiving intravitreal ranibizumab injections.InterventionEither pars plana vitrectomy with 24-gray EMB and ongoing pro re nata (PRN) ranibizumab (n = 224) or ongoing PRN ranibizumab monotherapy (n = 119).Main Outcome MeasuresThe coprimary outcomes, at 12 months, were the number of PRN ranibizumab injections and Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (VA). Secondary outcomes included the proportion of participants losing fewer than 15 ETDRS letters, angiographic total lesion size, choroidal neovascularization (CNV) size, and optical coherence tomography (OCT) foveal thickness. A predefined subgroup analysis tested the influence of baseline ocular characteristics on the response to EMB.ResultsThe mean number of PRN ranibizumab injections was 4.8 in the EMB arm and 4.1 in the ranibizumab monotherapy arm (P = 0.068). The mean VA change was −4.8 letters in the EMB arm and −0.9 letters in the ranibizumab arm (95% confidence interval of difference between groups, −6.6 to −1.8 letters). The proportion of participants losing fewer than 15 letters was 84% in the EMB arm and 92% in the ranibizumab arm (P = 0.007). In the EMB arm, the mean total lesion size increased by 1.2 mm2 versus 0.4 mm2 in the ranibizumab arm (P = 0.27). The CNV size decreased by 0.5 mm2 in the EMB arm and by 1.3 mm2 in the ranibizumab arm (P = 0.27). The OCT foveal thickness decreased by 1.0 μm in the EMB arm and by 15.7 μm in the ranibizumab arm (P = 0.43). Most subgroups favored ranibizumab monotherapy, some significantly so. One participant showed retinal vascular abnormality attributed to radiation, but otherwise safety was acceptable.ConclusionsThese results do not support the use of EMB for chronic, active, neovascular AMD. Safety is acceptable out to 12 months, but radiation retinopathy can occur later, so further follow-up is planned

    A randomised controlled trial and cost-effectiveness evaluation of "booster" interventions to sustain increases in physical activity in middle-aged adults in deprived urban neighbourhoods

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    Background: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active. Methods/Design: Study candidates (n = 1500) will initially be given an interactive DVD and receive two telephone follow ups at monthly intervals checking on receipt and use of the DVD. Only those that have increased their physical activity after three months (n = 600) will be randomised into the study. These participants will receive either a "mini booster" (n = 200), "full booster" (n = 200) or no booster (n = 200). The "mini booster" consists of two telephone calls one month apart to discuss physical activity and maintenance strategies. The "full booster" consists of a face-to-face meeting with the facilitator at the same intervals. The purpose of these booster sessions is to help the individual maintain their increase in physical activity. Differences in physical activity, quality of life and costs associated with the booster interventions, will be measured three and nine months from randomisation. The research will be conducted in 20 of the most deprived neighbourhoods in Sheffield, which have large, ethnically diverse populations, high levels of economic deprivation, low levels of physical activity, poorer health and shorter life expectancy. Participants will be recruited through general practices and community groups, as well as by postal invitation, to ensure the participation of minority ethnic groups and those with lower levels of literacy. Sheffield City Council and Primary Care Trust fund a range of facilities and activities to promote physical activity and variations in access to these between neighbourhoods will make it possible to examine whether the effectiveness of the intervention is modified by access to community facilities. A one-year integrated feasibility study will confirm that recruitment targets are achievable based on a 10% sample.Discussion: The choice of study population, study interventions, brief intervention preceding the study, and outcome measure are discussed

    Experiences of the Data Monitoring Committee for the RECOVERY trial, a large-scale adaptive platform randomised trial of treatments for patients hospitalised with COVID-19

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    Abstract: Aim: To inform the oversight of future clinical trials during a pandemic, we summarise the experiences of the Data Monitoring Committee (DMC) for the Randomised Evaluation of COVID therapy trial (RECOVERY), a large-scale randomised adaptive platform clinical trial of treatments for hospitalised patients with COVID-19. Methods and findings: During the first 24 months of the trial (March 2020 to February 2022), the DMC oversaw accumulating data for 14 treatments in adults (plus 10 in children) involving > 45,000 randomised patients. Five trial aspects key for the DMC in performing its role were: a large committee of members, including some with extensive DMC experience and others who had broad clinical expertise; clear strategic planning, communication, and responsiveness by the trial principal investigators; data collection and analysis systems able to cope with phases of very rapid recruitment and link to electronic health records; an ability to work constructively with regulators (and other DMCs) to address emerging concerns without the need to release unblinded mortality results; and the use of videoconferencing systems that enabled national and international members to meet at short notice and from home during the pandemic when physical meetings were impossible. Challenges included that the first four treatments introduced were effectively ‘competing’ for patients (increasing pressure to make rapid decisions on each one); balancing the global health imperative to report on findings with the need to maintain confidentiality until the results were sufficiently certain to appropriately inform treatment decisions; and reliably assessing safety, especially for newer agents introduced after the initial wave and in the small numbers of pregnant women and children included. We present a series of case vignettes to illustrate some of the issues and the DMC decision-making related to hydroxychloroquine, dexamethasone, casirivimab + imdevimab, and tocilizumab. Conclusions: RECOVERY’s streamlined adaptive platform design, linked to hospital-level and population-level health data, enabled the rapid and reliable assessment of multiple treatments for hospitalised patients with COVID-19. The later introduction of factorial assessments increased the trial’s efficiency, without compromising the DMC’s ability to assess safety and efficacy. Requests for the release of unblinded primary outcome data to regulators at points when data were not mature required significant efforts in communication with the regulators by the DMC to avoid inappropriate early trial termination
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