Maintaining confidentiality of interim data to enhance trial integrity and credibility

Considerations for open-label randomized clinical trials: Design, conduct, and analysis

Randomization and blinding are regarded as the most important tools to help reduce bias in clinical trial designs. Randomization is used to help guarantee that treatment arms differ systematically only by treatment assignment at baseline, and blinding is used to ensure that differences in endpoint evaluation and clinical decision-making during the trial arise only from the treatment received and not, for example, the expectation or desires of the people involved. However, given that there are times when it is not feasible or ethical to conduct fully blinded trials, we discuss what can be done to improve a trial, including conducting the trial as if it were a fully blinded trial and maintaining confidentiality of ongoing study results. In this article, we review how best to design, conduct, and analyze open-label trials to ensure the highest level of study integrity and the reliability of the study conclusions.

Training the Next Generation of Data Monitoring Committee Members: An Initiative of the Heart Failure Collaboratory

Clinical trials are vital for assessing therapeutic interventions. The associated data monitoring committees (DMCs) safeguard patient interests and enhance trial integrity, thus promoting timely, reliable evaluations of those interventions. We face an urgent need to recruit and train new DMC members. The Heart Failure Collaboratory (HFC), a multidisciplinary public-private consortium of academics, trialists, patients, industry representatives, and government agencies, is working to improve the clinical trial ecosystem. The HFC aims to improve clinical trial efficiency and quality by standardizing concepts, and to help meet the demand for experienced individuals on DMCs by creating a standardized approach to training new members. This paper discusses the HFC's training workshop, and an apprenticeship model for new DMC members. It describes opportunities and challenges DMCs face, along with common myths and best practices learned through previous experiences, with an emphasis on data confidentiality and need for quality independent statistical reporting groups.

Propensity score-incorporated adaptive design approaches when incorporating real-world data

The propensity score-integrated composite likelihood (PSCL) method is one method that can be utilized to design and analyze an application when real-world data (RWD) are leveraged to augment a prospectively designed clinical study. In the PSCL, strata are formed based on propensity scores (PS) such that similar subjects in terms of the baseline covariates from both the current study and RWD sources are placed in the same stratum, and then composite likelihood method is applied to down-weight the information from the RWD. While PSCL was originally proposed for a fixed design, it can be extended to be applied under an adaptive design framework with the purpose to either potentially claim an early success or to re-estimate the sample size. In this paper, a general strategy is proposed due to the feature of PSCL. For the possibility of claiming early success, Fisher's combination test is utilized. When the purpose is to re-estimate the sample size, the proposed procedure is based on the test proposed by Cui, Hung, and Wang. The implementation of these two procedures is demonstrated via an example.

5-year follow-up results of a JCOG1104 (OPAS-1) phase III non-inferiority trial to compare 4 courses and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer

BACKGROUND

Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is the standard treatment for pathological stage II gastric cancer. The phase III trial (JCOG1104) investigating the non-inferiority of four courses of S-1 to eight courses was terminated due to futility at the first interim analysis. To confirm the primary results, we reported the results after a 5-years follow-up in JCOG1104.

METHODS

Patients histologically diagnosed with stage II gastric cancer after radical gastrectomy were randomly assigned to receive S-1 for eight or four courses. In detail, 80 mg/m2/day S-1 was administered for 4 weeks followed by a 2-week rest as a single course.

RESULTS

Between February 16, 2012, and March 19, 2017, 590 patients were enrolled and randomly assigned to 8-course (295 patients) and 4-course (295 patients) regimens. After a 5-years follow-up, the relapse-free survival at 3 years was 92.2% for the 8-course arm and 90.1% for the 4-course arm, and that at 5 years was 87.7% for the 8-course arm and 85.6% for the 4-course arm (hazard ratio 1.265, 95% CI 0.846-1.892). The overall survival at 3 years was 94.9% for the 8-course arm, 93.2% for the 4-course arm, and that at 5 years was 89.7% for the 8-course arm, and 88.6% for the 4-course arm (HR 1.121, 95% CI 0.719-1.749).

CONCLUSIONS

The survival of the four-course arm was slightly but consistently inferior to that of the eight-course arm. Eight-course S-1 should thus remain the standard adjuvant chemotherapy for pathological stage II gastric cancer.

Safety and efficacy of oil palm phenolic supplementation in improving lipid profile among hyperlipidemic adults: a phase 2, randomized, double-blind, placebo-controlled clinical trial

Introduction: Oil palm phenolic (OPP) is an antioxidant aqueous palm oil by-product and contains a high amount of phenolics. OPP has been proven to have many therapeutical benefits, and one of them is as an antihyperlipidemic agent. The previous phase 1 clinical trial proved OPP was safe to be orally consumed by healthy volunteers and yielded a good lipid profile. Thus, this phase 2 clinical trial was conducted to determine the effectiveness of OPP in improving the lipid profile among hyperlipidemic subjects. Methods: A parallel, placebo-controlled, randomized, double-blinded clinical trial was conducted for 2 months on 50 hyperlipidemic subjects aged 20-50 years old. The subjects were randomly distributed to two treatment arms with 25 participants each: control/placebo (11 males and 14 females) and 250 mg of OPP (10 males and 15 females). The subjects were required to consume one capsule per day for 60 days. Fasting blood sampling for routine blood profile (hematology, liver function, renal function, and lipid) analysis and a medical examination were conducted at baseline, day 30, and day 60. t-test analysis was used to compare the difference between two test groups. Results: The baseline lipid profile between control group (TC, 5.78 ± 0.52 mmol/L; LDL, 3.88 ± 0.51 mmol/L; HDL, 1.30 ± 0.25; TG, 1.30 ± 0.82), and 250 mg OPP (TC, 5.76 ± 0.54 mmol/L; LDL, 3.82 ± 0.59 mmol/L; HDL, 1.37 ± 0.34; TG, 1.25 ± 0.54) is insignificant. No serious adverse events (SAEs) were reported. No abnormality in fasting blood parameters in all groups was found. Compared to the control group among male participants, the 250 mg OPP group showed an improved serum triglyceride level. There were no statistically significant changes in all blood parameters from day 1 to day 60 with the exception of triglyceride level. Conclusion: The absence of SAEs reported and no abnormal findings in biochemistry and hematology results suggested that the 250 mg OPP was safe to be taken by hyperlipidemic patients with a high probability of reducing triglyceride level in hyperlipidemic male patients The outcomes from this phase II trial suggest that by incorporating OPP supplements into the diet may be a promising strategy for individuals with hyperlipidemia to improve their lipid profiles and reduce cardiovascular risk. However, more research is needed to fully understand the mechanisms of action and establish the long-term efficacy and safety of OPP supplementation in larger scale. Limitation: Small samples size hence lack of diversity (25 subjects per groups) and early sharing of treatment-response results. Clinical Trial Registration: clinicaltrials.gov, identifier NCT04573218.

The Data and Safety Monitoring Board: The Toughest Job in Clinical Trials

The DSMB: The Toughest Job in Clinical TrialsIn this review article, the authors discuss methods that DSMBs can use to compare the absolute and relative risks of benefits and adverse effects between trial interventions and illustrate how the DSMB can use this approach to evaluate the balance of these competing risks. Two approaches are discussed - the win ratio and the DOOR probability on one treatment relative to another.

The effects of releasing early results from ongoing clinical trials

Most trials do not release interim summaries on efficacy and toxicity of the experimental treatments being tested, with this information only released to the public after the trial has ended. While early release of clinical trial data to physicians and patients can inform enrollment decision making, it may also affect key operating characteristics of the trial, statistical validity and trial duration. We investigate the public release of early efficacy and toxicity results, during ongoing clinical studies, to better inform patients about their enrollment options. We use simulation models of phase II glioblastoma (GBM) clinical trials in which early efficacy and toxicity estimates are periodically released accordingly to a pre-specified protocol. Patients can use the reported interim efficacy and toxicity information, with the support of physicians, to decide which trial to enroll in. We describe potential effects on various operating characteristics, including the study duration, selection bias and power.

Surgical or Endovascular Management of Middle Cerebral Artery Aneurysms: A Randomized Comparison

OBJECTIVE

There are few randomized data comparing clipping and coiling for middle cerebral artery (MCA) aneurysms. We analyzed results from patients with MCA aneurysms enrolled in the CURES (Collaborative UnRuptured Endovascular vs. Surgery) and ISAT-2 (International Subarachnoid Aneurysm Trial II) randomized trials.

METHODS

Both trials are investigator-led parallel-group 1:1 randomized studies. CURES includes patients with 3-mm to 25-mm unruptured intracranial aneurysms (UIAs), and ISAT-2 includes patients with ruptured aneurysms (RA) for whom uncertainty remains after ISAT. The primary outcome measure of CURES is treatment failure: 1) failure to treat the aneurysm, 2) intracranial hemorrhage during follow-up, or 3) residual aneurysm at 1 year. The primary outcome of ISAT-2 is death or dependency (modified Rankin Scale score >2) at 1 year. One-year angiographic outcomes are systematically recorded.

RESULTS

There were 100 unruptured and 71 ruptured MCA aneurysms. In CURES, 90 patients with UIA have been treated and 10 await treatment. Surgical and endovascular management of unruptured MCA aneurysms led to treatment failure in 3/42 (7%; 95% confidence interval [CI], 0.02-0.19) for clipping and 13/48 (27%; 95% CI, 0.17-0.41) for coiling (P = 0.025). All 71 patients with RA have been treated. In ISAT-2, patients with ruptured MCA aneurysms managed surgically had died or were dependent (modified Rankin Scale score >2) in 7/38 (18%; 95% CI, 0.09-0.33) cases, and 8/33 (24%; 95% CI, 0.13-0.41) for endovascular. One-year imaging results were available in 80 patients with UIA and 62 with RA. Complete aneurysm occlusion was found in 30/40 (75%; 95% CI, 0.60-0.86) patients with UIA allocated clipping, and 14/40 (35%; 95% CI, 0.22-0.50) patients with UIA allocated coiling. Complete aneurysm occlusion was found in 24/34 (71%; 95% CI, 0.54-0.83) patients with RA allocated clipping, and 15/28 (54%; 95% CI, 0.36-0.70) patients with RA allocated coiling.

CONCLUSIONS

Randomized data from 2 trials show that better efficacy may be obtained with surgical management of patients with MCA aneurysms.

Achieving effective informed oversight by DMCs in COVID clinical trials

Best practices of data monitoring committees (DMCs) in randomized clinical trials are well established. Independent oversight provided by DMCs is particularly important in trials conducted in public health emergencies, such as in HIV/AIDS or coronavirus epidemics. Special considerations are needed to enable DMCs to effectively address novel circumstances they face in such settings. In the COVID-19 pandemic, these include the remarkable speed in which data regarding benefits and risks of interventions are accumulated. DMCs must hold frequent virtual meetings, using state-of-the-art communication software that protects against risk for security breaches. Data capture and DMC reports should be focused on the most informative measures about benefits and risks. Because numerous clinical trials are being concurrently conducted in the COVID-19 setting, often addressing closely related scientific questions, structures for DMC oversight should be efficient and adequately informative. When these concurrently conducted trials are evaluating related regimens in related clinical settings, often individually underpowered for safety and having separate DMCs, processes should be implemented enabling these DMCs to share with each other emerging confidential evidence to better assess risks and benefits. Ideally a single DMC would monitor a portfolio of clinical trials or a trial with multiple arms, such as a platform trial.

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For 5 decades, DMCs have monitored RCTs for safety and benefit.

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In 2020, the World Health Organization declared covid-19 disease to be a pandemic.

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Numerous trials have emerged to evaluate potential therapeutics and vaccines.

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Covid-19 trials bring new challenges to the DMC process, due to the epidemic speed.

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Patients are being recruited and outcome data accumulating very rapidly.

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DMCs oversight very important for extreme emergencies such as coronavirus epidemics.

The adaptive designs CONSORT extension (ACE) statement: a checklist with explanation and elaboration guideline for reporting randomised trials that use an adaptive design

Adaptive designs (ADs) allow pre-planned changes to an ongoing trial without compromising the validity of conclusions and it is essential to distinguish pre-planned from unplanned changes that may also occur. The reporting of ADs in randomised trials is inconsistent and needs improving. Incompletely reported AD randomised trials are difficult to reproduce and are hard to interpret and synthesise. This consequently hampers their ability to inform practice as well as future research and contributes to research waste. Better transparency and adequate reporting will enable the potential benefits of ADs to be realised.This extension to the Consolidated Standards Of Reporting Trials (CONSORT) 2010 statement was developed to enhance the reporting of randomised AD clinical trials. We developed an Adaptive designs CONSORT Extension (ACE) guideline through a two-stage Delphi process with input from multidisciplinary key stakeholders in clinical trials research in the public and private sectors from 21 countries, followed by a consensus meeting. Members of the CONSORT Group were involved during the development process.The paper presents the ACE checklists for AD randomised trial reports and abstracts, as well as an explanation with examples to aid the application of the guideline. The ACE checklist comprises seven new items, nine modified items, six unchanged items for which additional explanatory text clarifies further considerations for ADs, and 20 unchanged items not requiring further explanatory text. The ACE abstract checklist has one new item, one modified item, one unchanged item with additional explanatory text for ADs, and 15 unchanged items not requiring further explanatory text.The intention is to enhance transparency and improve reporting of AD randomised trials to improve the interpretability of their results and reproducibility of their methods, results and inference. We also hope indirectly to facilitate the much-needed knowledge transfer of innovative trial designs to maximise their potential benefits. In order to encourage its wide dissemination this article is freely accessible on the BMJ and Trials journal websites."To maximise the benefit to society, you need to not just do research but do it well" Douglas G Altman.

The Adaptive designs CONSORT Extension (ACE) statement: a checklist with explanation and elaboration guideline for reporting randomised trials that use an adaptive design

Adaptive designs (ADs) allow pre-planned changes to an ongoing trial without compromising the validity of conclusions and it is essential to distinguish pre-planned from unplanned changes that may also occur. The reporting of ADs in randomised trials is inconsistent and needs improving. Incompletely reported AD randomised trials are difficult to reproduce and are hard to interpret and synthesise. This consequently hampers their ability to inform practice as well as future research and contributes to research waste. Better transparency and adequate reporting will enable the potential benefits of ADs to be realised.This extension to the Consolidated Standards Of Reporting Trials (CONSORT) 2010 statement was developed to enhance the reporting of randomised AD clinical trials. We developed an Adaptive designs CONSORT Extension (ACE) guideline through a two-stage Delphi process with input from multidisciplinary key stakeholders in clinical trials research in the public and private sectors from 21 countries, followed by a consensus meeting. Members of the CONSORT Group were involved during the development process.The paper presents the ACE checklists for AD randomised trial reports and abstracts, as well as an explanation with examples to aid the application of the guideline. The ACE checklist comprises seven new items, nine modified items, six unchanged items for which additional explanatory text clarifies further considerations for ADs, and 20 unchanged items not requiring further explanatory text. The ACE abstract checklist has one new item, one modified item, one unchanged item with additional explanatory text for ADs, and 15 unchanged items not requiring further explanatory text.The intention is to enhance transparency and improve reporting of AD randomised trials to improve the interpretability of their results and reproducibility of their methods, results and inference. We also hope indirectly to facilitate the much-needed knowledge transfer of innovative trial designs to maximise their potential benefits.

Interim monitoring for non-inferiority trials: minimizing patient exposure to inferior therapies

The goal of a non-inferiority randomized trial is to demonstrate that an experimental treatment is not unacceptably worse than a standard treatment. The experimental treatment is known to have less toxicity or other quality-of-life benefits when compared with the standard treatment, so that a small decrement in efficacy would be acceptable. Interim monitoring of randomized trials is used to stop trials early if the conclusions of the trial become definitive early. In the context of a non-inferiority trial, of special interest is stopping a trial early when the experimental treatment is inferior to the standard treatment. Methods for performing interim monitoring of non-inferiority trials are reviewed for their ability to minimize patient exposure to inferior experimental treatments. Examples of trials from the literature are discussed along with a computer simulation of a simple non-inferiority monitoring rule. Interim monitoring for non-inferiority trials is shown to substantially reduce the exposure of patients to inferior therapies when, in fact, the experimental treatment is inferior to the standard treatment. Interim monitoring rules typically used in superiority trials may be sub-optimal for non-inferiority trials, and may unnecessarily expose patients to inferior therapies. Examples of trials with inferior experimental arms and trials with sub-optimal monitoring rules are given. Appropriate interim monitoring of non-inferiority trials can reduce the exposure of patients to inferior therapies when the experimental treatment is inferior to the standard treatment.

Reporting Interim Results Can Show the Feasibility of Practicing Outcome-Based Neurovascular Care Within Randomized Trials: An Opinion

BACKGROUND

Randomized trials of commonly performed surgical interventions are notoriously difficult to conduct. The trial methodology may nevertheless be the best way to offer outcome-based neurovascular care in the presence of uncertainty. One obstacle to promoting such trials is the conventional prohibition of publication and dissemination of interim results as the trial progresses.

METHODS

We review the scientific and statistical reasons against the publication of interim analyses as well as exceptions that can occur when 1 treatment is unexpectedly shown to be harmful or when the results of other trials have convincingly shown the comparative benefits of a new intervention. We also discuss the promotion of difficult surgical trials.

RESULTS

Reasons to support the conventional ban on publication of interim results include control of statistical errors, prevention of invalid conclusions, and dissemination of false claims of equivalence of rival interventions. In the early phases of a trial, usually 1 treatment cannot be shown superior to the other. We believe, contrary to the received view, that a transparent report of the early progress of certain trials can be justified, even when interim results are inconclusive, to promote the recruitment of participating centers and the practice of a novel way to offer neurovascular care in the presence of uncertainty in the best medical interest of patients.

CONCLUSIONS

In our opinion, the early publication of inconclusive interim results may increase awareness of the feasibility of surgical care trials.

Data Monitoring Committees: Current issues

Maintaining confidentiality of emerging data and ensuring the independence of Data Monitoring Committees are best practices of considerable importance to the ability of these committees to achieve their mission of safeguarding the interests of study participants and enhancing the integrity and credibility of clinical trials. Even with the wide recognition of these principles, there are circumstances where confidentiality issues remain challenging, controversial or inconsistently addressed. First, consider settings where a clinical trial's interim data could provide the evidence regulatory authorities require for decisions about marketing approval, yet where such a trial would be continued post-approval to provide more definitive evidence about principal safety and/or efficacy outcomes. In such settings, data informative about the longer term objectives of the trial should remain confidential until pre-specified criteria for trial completion have been met. Second, for those other than Data Monitoring Committee members, access to safety and efficacy outcomes during trial conduct, even when presented as data pooled across treatment arms, should be on a limited "need to know" basis relating to the ability to carry out ethical or scientific responsibilities in the conduct of the trial. Third, Data Monitoring Committee members should have access to unblinded efficacy and safety data throughout the trial to enable timely and informed judgments about risks and benefits. Fourth, it should be recognized that a mediator potentially could be useful in rare settings where the Data Monitoring Committee would have serious ethical or scientific concerns about the sponsor's dissemination or lack of dissemination of information. Data Monitoring Committee Contract Agreements, Indemnification Agreements and Charters should be developed in a manner to protect Data Monitoring Committee members and their independence, in order to enhance the Data Monitoring Committee's ability to effectively address their mission.

Adaptive designs in clinical trials: why use them, and how to run and report them

Adaptive designs can make clinical trials more flexible by utilising results accumulating in the trial to modify the trial's course in accordance with pre-specified rules. Trials with an adaptive design are often more efficient, informative and ethical than trials with a traditional fixed design since they often make better use of resources such as time and money, and might require fewer participants. Adaptive designs can be applied across all phases of clinical research, from early-phase dose escalation to confirmatory trials. The pace of the uptake of adaptive designs in clinical research, however, has remained well behind that of the statistical literature introducing new methods and highlighting their potential advantages. We speculate that one factor contributing to this is that the full range of adaptations available to trial designs, as well as their goals, advantages and limitations, remains unfamiliar to many parts of the clinical community. Additionally, the term adaptive design has been misleadingly used as an all-encompassing label to refer to certain methods that could be deemed controversial or that have been inadequately implemented.We believe that even if the planning and analysis of a trial is undertaken by an expert statistician, it is essential that the investigators understand the implications of using an adaptive design, for example, what the practical challenges are, what can (and cannot) be inferred from the results of such a trial, and how to report and communicate the results. This tutorial paper provides guidance on key aspects of adaptive designs that are relevant to clinical triallists. We explain the basic rationale behind adaptive designs, clarify ambiguous terminology and summarise the utility and pitfalls of adaptive designs. We discuss practical aspects around funding, ethical approval, treatment supply and communication with stakeholders and trial participants. Our focus, however, is on the interpretation and reporting of results from adaptive design trials, which we consider vital for anyone involved in medical research. We emphasise the general principles of transparency and reproducibility and suggest how best to put them into practice.

Sharing interim trial results by the Data Safety Monitoring Board with those responsible for the trial's conduct and progress: a narrative review

BACKGROUND

Sharing interim data, results or result extrapolations is an important issue that can affect trial integrity. The different ways in which Data Safety Monitoring Boards (DSMBs) share interim results with non-DSMB members and the acceptability of such practices are poorly understood. Our objective was to undertake a narrative review specifically on what kind of interim results, if any, should be shared by the DSMB with non-DSMB members and why.

METHODS

We conducted a narrative review using a systematic search strategy of several databases and major health research stakeholders. Literature was included if there was some discussion within the full text about sharing interim trial results with non-DSMB members.

RESULTS

About 79.6% (129/162) of included citations were based on author's views, 16.7% (27/162) on research guidelines and 3.7% (6/162) on surveys. The largest group of citations, 73/162 (45%), expresses the opinion or argument against sharing interim results with exceptions. Trailing closely, 71/162 (43.8%) of the included citations support the opinion or argument that interim results should not be shared and should remain confidential with the DSMB. Half of the six surveys support sharing in some capacity, while the other three do not. Eleven circumstances were found that potentially warrant interim result sharing by the DSMB; they relate to (1) usual practices by DSMBs, (2) trial completion threatened, (3) patient safety, (4) regulatory approval and (5) other circumstances. Dominant risks for sharing under these conditions are associated with introducing trial bias.

DISCUSSION/CONCLUSION

There was no majority view in the literature. However, the largest group of citations included express the idea that interim results should remain confidential with the DSMB but also acknowledge circumstances when they could be shared with non-DSMB members. Limitations of this review are that (1) the included literature predominately provides personal perspectives, not evidence, and (2) surveys found globally focus on trial monitoring practices lacking detailed information on what specifically to share, with whom and why. More research is needed with the use of a detailed survey of the clinical trial community focused on DSMB sharing interim results, to better understand and guide DSMB interim result sharing practices.

Data monitoring committees: Promoting best practices to address emerging challenges

BACKGROUND AND PURPOSE

Data monitoring committees are responsible for safeguarding the interests of study participants and assuring the integrity and credibility of clinical trials. The independence of data monitoring committees from sponsors and investigators is essential in achieving this mission. Creative approaches are needed to address ongoing and emerging challenges that potentially threaten data monitoring committees' independence and effectiveness.

METHODS

An expert panel of representatives from academia, industry and government sponsors, and regulatory agencies discussed these challenges and proposed best practices and operating principles for effective functioning of contemporary data monitoring committees.

RESULTS AND CONCLUSIONS

Prospective data monitoring committee members need better training. Options could include didactic instruction as well as apprenticeships to provide real-world experience. Data monitoring committee members should be protected against legal liability arising from their service. While avoiding breaches in confidentiality of interim data remains a high priority, data monitoring committees should have access to unblinded efficacy and safety data throughout the trial to enable informed judgments about risks and benefits. Because overly rigid procedures can compromise their independence, data monitoring committees should have the flexibility necessary to best fulfill their responsibilities. Data monitoring committee charters should articulate principles that guide the data monitoring committee process rather than list a rigid set of requirements. Data monitoring committees should develop their recommendations by consensus rather than through voting processes. The format for the meetings of the data monitoring committee should maintain the committee's independence and clearly establish the leadership of the data monitoring committee chair. The independent statistical group at the Statistical Data Analysis Center should have sufficient depth of knowledge about the study at hand and experience with trials in general to ensure that the data monitoring committee has access to timely, reliable, and readily interpretable insights about emerging evidence in the clinical trial. Contracts engaging data monitoring committee members for industry-sponsored trials should have language customized to the unique responsibilities of data monitoring committee members rather than use language appropriate to consultants for product development. Regulatory scientists would benefit from experiencing data monitoring committee service that does not conflict with their regulatory responsibilities.

Randomized controlled trials - a matter of design

Randomized controlled trials (RCTs) are the hallmark of evidence-based medicine and form the basis for translating research data into clinical practice. This review summarizes commonly applied designs and quality indicators of RCTs to provide guidance in interpreting and critically evaluating clinical research data. It further reflects on the principle of equipoise and its practical applicability to clinical science with an emphasis on critical care and neurological research. We performed a review of educational material, review articles, methodological studies, and published clinical trials using the databases MEDLINE, PubMed, and ClinicalTrials.gov. The most relevant recommendations regarding design, conduction, and reporting of RCTs may include the following: 1) clinically relevant end points should be defined a priori, and an unbiased analysis and report of the study results should be warranted, 2) both significant and nonsignificant results should be objectively reported and published, 3) structured study design and performance as indicated in the Consolidated Standards of Reporting Trials statement should be employed as well as registration in a public trial database, 4) potential conflicts of interest and funding sources should be disclaimed in study report or publication, and 5) in the comparison of experimental treatment with standard care, preplanned interim analyses during an ongoing RCT can aid in maintaining clinical equipoise by assessing benefit, harm, or futility, thus allowing decision on continuation or termination of the trial.

Enhancing trial integrity by protecting the independence of data monitoring committees in clinical trials

Data monitoring committees (DMCs) have important roles in safeguarding patient interests and enhancing trial integrity and credibility. To effectively fulfill their responsibilities, DMCs should be independent of study sponsors, study investigators, and caregivers managing study participants. Unfortunately, in real-world settings where DMCs are in place, there are some practices that threaten to diminish the level of independence of these committees. To address this, some important approaches should be considered: A DMC charter should outline the roles and responsibilities of the DMC without appearing to be a legal contract; the meetings of the DMC should be led by its chair, ideally with a meeting format that ensures independence from the investigators and sponsor; the DMC and those having leadership roles in the monitoring process should have adequate training and experience; procedures should be in place to enable the DMC to have access to interim safety and efficacy data that are accurate, current, and comprehensive; these data should be presented to the DMC unblinded by treatment group, while being kept confidential from all others; DMC recommendations should be developed through consensus development rather than by casting votes; creative approaches are needed for the engagement of DMC members to increase the transparency such that they are neither employees of nor consultants to the sponsor of the trial; meaningful conflicts of interest should be identified and addressed; and finally, members of DMCs should have adequate indemnification that provides effective protection.

Protecting the confidentiality of interim data: addressing current challenges

There is compelling evidence supporting the importance of maintaining confidentiality of interim data in clinical trials designed to reliably address the benefit-to-risk profile of interventions. While this is widely recognized, creative approaches are needed to achieve this in challenging settings where interim data are released for regulatory review and action, even though the trial would be continued to address its primary hypothesis. An illustration is the recently emerging setting of cardiovascular safety trials in type 2 diabetes mellitus. At the first stage of such trials, if large relative increases in cardiovascular major morbidity/mortality can be ruled out, data can be released solely for the purpose of allowing regulatory decision making about marketing approval. The trial is then continued in the post-marketing setting to address the primary hypothesis regarding whether smaller relative increases can be ruled out. Active rather than passive approaches are needed to protect the integrity of cardiovascular safety trials. Given the importance to trial integrity of maintaining confidentiality of interim data such as the estimated relative effect on cardiovascular risk, a Data Access Plan should be in place in these trials to ensure such data are not revealed to study participants and their caregivers, investigators involved in trial conduct, the sponsor's management team, and the public, until trial completion. A Performance Standards Document also should be developed to pre-specify targeted and minimally acceptable levels for recruitment rate, best real-world achievable adherence, avoidance of cross-ins, and retention rate. This document should specify creative approaches for achieving these targets, oversight procedures during trial conduct to monitor performance levels, and actions to be taken if emerging data indicate minimally acceptable levels are not being reached. In settings where meaningful breaches in confidentiality have occurred, such oversight allows adverse effects on trial integrity to be detected earlier and more effectively addressed.

Choosing the best embryo by time lapse versus standard morphology

Within the past few years the morphological evaluation of in vitro fertilized embryos has been extended to include continuous surveillance, enabled by the introduction of time-lapse incubators developed specifically for IVF treatment. As a result time-lapse monitoring has been implemented in many clinics worldwide. The proposed benefits compared with culture in a standard incubator and fixed time-point evaluation are uninterrupted culture, a flexible workflow in the laboratory, and improved embryo selection. The latter is based on the reasonable assumption that more frequent observations will provide substantially more information on the relationship between development, timing, and embryo viability. Several retrospective studies have confirmed a relationship between time-lapse parameters and embryo viability evaluated by developmental competence, aneuploidy, and clinical pregnancy. Furthermore a much anticipated randomized study has shown improved pregnancy rates (PRs) after culture in a time-lapse incubator combined with selection using a hierarchical time-lapse selection model. At present this is the only randomized study on possible benefits of time lapse in human embryology. Strict evidence may still seem too weak to introduce time lapse in routine clinical setting. This aim of this review is therefore to perform a balanced discussion of the evidence for time-lapse monitoring.

Rationale, design, and baseline characteristics of a randomized, placebo-controlled cardiovascular outcome trial of empagliflozin (EMPA-REG OUTCOME™)

BACKGROUND

Evidence concerning the importance of glucose lowering in the prevention of cardiovascular (CV) outcomes remains controversial. Given the multi-faceted pathogenesis of atherosclerosis in diabetes, it is likely that any intervention to mitigate this risk must address CV risk factors beyond glycemia alone. The SGLT-2 inhibitor empagliflozin improves glucose control, body weight and blood pressure when used as monotherapy or add-on to other antihyperglycemic agents in patients with type 2 diabetes. The aim of the ongoing EMPA-REG OUTCOME™ trial is to determine the long-term CV safety of empagliflozin, as well as investigating potential benefits on macro-/microvascular outcomes.

METHODS

Patients who were drug-naïve (HbA1c ≥7.0% and ≤9.0%), or on background glucose-lowering therapy (HbA1c ≥7.0% and ≤10.0%), and were at high risk of CV events, were randomized (1:1:1) and treated with empagliflozin 10 mg, empagliflozin 25 mg, or placebo (double blind, double dummy) superimposed upon the standard of care. The primary outcome is time to first occurrence of CV death, non-fatal myocardial infarction, or non-fatal stroke. CV events will be prospectively adjudicated by an independent Clinical Events Committee. The trial will continue until ≥691 confirmed primary outcome events have occurred, providing a power of 90% to yield an upper limit of the adjusted 95% CI for a hazard ratio of <1.3 with a one-sided α of 0.025, assuming equal risks between placebo and empagliflozin (both doses pooled). Hierarchical testing for superiority will follow for the primary outcome and key secondary outcomes (time to first occurrence of CV death, non-fatal myocardial infarction, non-fatal stroke or hospitalization for unstable angina pectoris) where non-inferiority is achieved.

RESULTS

Between Sept 2010 and April 2013, 592 clinical sites randomized and treated 7034 patients (41% from Europe, 20% from North America, and 19% from Asia). At baseline, the mean age was 63 ± 9 years, BMI 30.6 ± 5.3 kg/m2, HbA1c 8.1 ± 0.8%, and eGFR 74 ± 21 ml/min/1.73 m2. The study is expected to report in 2015.

DISCUSSION

EMPA-REG OUTCOME™ will determine the CV safety of empagliflozin in a cohort of patients with type 2 diabetes and high CV risk, with the potential to show cardioprotection.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01131676.

Interim results in clinical trials: do we need to keep all interim randomised clinical trial results confidential?

OBJECTIVES

Guidelines for the conduct of clinical trials emphasize the importance of keeping the interim results from the main endpoints confidential, in order to maintain the integrity of the trial and to safeguard patients' interests. However, is this essential in every situation?

MATERIALS AND METHODS

We review the evidence for these guidelines and consider recent randomised trials that have released interim results, to assess their impact on the success of the trial. However, because the strength of opinion to keep interim results confidential is so strong, there are limited examples of such trials.

RESULTS

In the QUARTZ trial (which is assessing the value of whole brain radiotherapy in patients with brain metastases from non-small cell lung cancer) the decision to release interim results was taken in response to threatened closure due to poor accrual, whereas in the GRIT trial (which compared two obstetric strategies for the delivery of growth retarded pre-term fetuses) the regular release of interim results was pre-planned. Nevertheless there are a number of common factors between these two trials. In particular, the trial treatments were already in wide use, with no reliable randomised evidence on which treatment should be used for which patients, and there was diverse clinical opinion, which meant that accrual was likely to be challenging. In a situation where a quarter to a third of trials do not accrue their required number of patients, the QUARTZ trial continues to accrue patients, and the GRIT trial successfully accrued its target of nearly 600 babies.

CONCLUSIONS

This article therefore argues that there is a need to re-consider whether it is always essential to keep the interim results of randomized clinical trials confidential, and suggests some criteria that may help groups planning or running challenging trials decide whether releasing interim results would be a useful strategy.

Modeling the relationship between progression-free survival and overall survival: the phase II/III trial

The standard phase II trial design has changed dramatically over the past decade. Randomized phase II studies have essentially become the standard phase II design in oncology for a variety of reasons. The use of these designs is motivated by concerns about the use of historical data to determine if a new agent or regimen shows promise of activity. However, randomized phase II designs come with the cost of increased study duration and patient resources. Progression-free survival (PFS) is an important endpoint used in many phase II designs. In many clinical settings, changes in PFS with the introduction of a new treatment may represent true benefit in terms of the gold standard outcome, overall survival (OS). The phase II/III design has been proposed as an approach to shorten the time of discovery of an active regimen. In this article, design considerations for a phase II/III trial are discussed and presented in terms of a model defining the relationship between OS and PFS. The design is also evaluated using 15 phase III trials completed in the Southwest Oncology Group (SWOG) between 1990 and 2005. The model provides a framework to evaluate the validity and properties of using a phase II/III design. In the evaluation of SWOG trials, three of four positive studies would have also proceeded to the final analysis and 10 of 11 negative studies would have stopped at the phase II analysis if a phase II/III design had been used. Through careful consideration and thorough evaluation of design properties, substantial gains could occur using this approach.

Statistical and methodological issues in microbicide trial design

Microbicide trials aim to measure the effect of a microbicide in reducing the risk of acquiring human immunodeficiency virus. Such trials present a number of challenging issues from design and conduct through to analysis and reporting. This begins with the initial identification of the target trial population. Prevention trials need to identify those at risk of human immunodeficiency virus infection. This can be more difficult in the general population compared with treatment trials that can target specific patient groups who have a confirmed diagnosis of the disease of interest. Consequently, microbicide trial participants will inevitably be recruited who are never at risk of HIV infection. In this chapter we outline the main features of microbicide trial design, key issues during conduct and analysis, and discuss the challenges specific to these types of clinical trials.

Data monitoring committees, interim analysis and early termination in paediatric trials

AIM

To evaluate whether paediatric randomized clinical trials (RCTs) adopt recent guidance on Data Monitoring Committees (DMCs), interim analysis and early termination.

METHODS

We reviewed paediatric RCTs that reported on DMCs, interim analysis or early termination, published in eight general medical and paediatric journals (2005-2007). We searched full-text databases for eligible trials and recorded predefined parameters on each item. Reported activities were compared with current scientific guidance.

RESULTS

A total of 110 of 648 paediatric trials (17%) reported on DMC, interim analysis or early stopping. Various approaches for convening a DMC were identified; information on DMC composition and independence was limited. Strict predefined statistical stopping 'rules' were reported in 10 of 23 trials, and interim analyses were more frequently performed on efficacy than on safety outcomes (39/45 vs 27/45). No adjustment for repeated testing was reported in 11 of 33 trials reporting monitoring methods and in 7 of 17 early terminated trials. Validity of results from early stopped trials was threatened by small sample sizes. Incomplete reporting hampered a full analysis.

CONCLUSION

Few paediatric trials report on DMCs' roles, interim analysis or early stopping. Heterogeneous practices and apparent shortcomings jeopardize the validity of trial results. Easily accessible guidelines for the design, conduct and reporting of paediatric DMCs are needed.

Clinical trials: discerning hype from substance

The interest in being able to interpret and report results in clinical trials as being favorable is pervasive throughout health care research. This important source of bias needs to be recognized, and approaches need to be implemented to effectively address it. The prespecified primary analyses of the primary and secondary end points of a clinical trial should be clearly specified when disseminating results in press releases and journal publications. There should be a focus on these analyses when interpreting the results. A substantial risk for biased conclusions is produced by conducting exploratory analyses with an intention to establish that the benefit-to-risk profile of the experimental intervention is favorable, rather than to determine whether it is. In exploratory analyses, P values will be misleading when the actual sampling context is not presented to allow for proper interpretation, and the effect sizes of outcomes having particularly favorable estimates are probably overestimated because of "random high" bias. Performing exploratory analyses should be viewed as generating hypotheses that usually require reassessment in prospectively conducted confirmatory trials. Awareness of these issues will meaningfully improve our ability to be guided by substance, not hype, in making evidence-based decisions about medical care.

Blinded assessment of treatment effects utilizing information about the randomization block length

It is essential for the integrity of double-blind clinical trials that during the study course the individual treatment allocations of the patients as well as the treatment effect remain unknown to any involved person. Recently, methods have been proposed for which it was claimed that they would allow reliable estimation of the treatment effect based on blinded data by using information about the block length of the randomization procedure. If this would hold true, it would be difficult to preserve blindness without taking further measures. The suggested procedures apply to continuous data. We investigate the properties of these methods thoroughly by repeated simulations per scenario. Furthermore, a method for blinded treatment effect estimation in case of binary data is proposed, and blinded tests for treatment group differences are developed both for continuous and binary data. We report results of comprehensive simulation studies that investigate the features of these procedures. It is shown that for sample sizes and treatment effects which are typical in clinical trials, no reliable inference can be made on the treatment group difference which is due to the bias and imprecision of the blinded estimates.