Methodology and design of platform trials: a meta-epidemiological study

Adaptations and Heterogeneity of Treatment Effects in Platform Trials-Protocol for Two Methodological Studies

BACKGROUND

Adaptive platform trials bring opportunities for improved infrastructure and effective advancement in medical care but are methodologically complex. Assessment of heterogeneity of treatment effects (HTE) according to participant characteristics and adaptations, including adaptive stopping, are important methodological features in these trials, which may be approached in multiple ways. We aim to characterise the assessment of HTE and use of adaptations, including their key methodological features, in adaptive platform trials.

METHODS

This protocol outlines two methodological studies, which will be based on a common, systematic literature search and data extraction. We will include adaptive platform trials conducted from 2005 onwards. Screening and data extraction will be performed independently and in duplicate. In Study I, we will assess methods used to evaluate HTE, and in Study II, we will assess adaptations and stopping rules in the included trials.

DISCUSSION

The two proposed methodological studies will provide an overview of important methodological features regarding the assessment of HTE and adaptations used in adaptive platform trials. Better knowledge of available methods to assess these features can improve the conditions for designing adaptive platform trials and identify areas for further development.

Characteristics, design, and statistical methods in platform trials: a systematic review

BACKGROUND AND OBJECTIVE

Platform trials (PTs) are gaining popularity in clinical research due to their innovative and flexible methodologies. The objective was to determine the characteristics, methodological, and statistical practices in PTs.

METHODS

We identified PTs from trial registries and bibliographic databases up to August 2024. Eligible PTs were randomized controlled trials studying multiple interventions within a single population, with flexibility to add or drop arms. Data were extracted on trial status, design, statistical methods, and reporting practices.

RESULTS

We identified 189 PTs. Most focused on infectious diseases (77, including 57 for COVID-19) and oncology (68). PT initiation peaked during the COVID-19 pandemic but has since stabilized at 84 active PTs, with 25 in planning. A complete master protocol was available for 47% (89/189) of PTs. Bayesian designs featured in 58/189 PTs vs. 56/189 frequentist trials, 20/189 trials utilizing both (unclear in 55/189 PTs). Overall, 25/111 trials (23%) were designed without a predetermined target sample size, all of which were Bayesian. Among these, 16 were explicitly reported as "perpetual" trials. The number of interim analyses was predetermined in 18% (10/57) of Bayesian trials vs. 58% (28/48) of frequentist trials. Simulations to evaluate operating characteristics were used in 93% (39/42) of Bayesian trials. Simulation reports were available in 67% (26/39) of cases, and the procedures were detailed for 62% (24/39) of trials. Only two trials shared the simulation code.

CONCLUSION

PTs remain popular and increasingly diverse. Efforts to enhance transparency and reporting, especially in complex Bayesian PTs, are essential to ensure reliability and broader acceptance.

A Decision-Making Grid for Coenrollment in Multiple Clinical Trials

BACKGROUND

Although subject coenrollment into multiple trials is desirable, thoughtful consideration is required to avoid compromising each trial's scientific integrity.

OBJECTIVE

We developed a Decision-Making Grid (GRID) to help investigators determine whether a clinical trial is compatible with a second clinical trial, thus allowing coenrollment, or if it should be considered competing, prohibiting coenrollment.

METHODS

The GRID evaluates 21 elements across four domains: scientific integrity, data interpretation, feasibility/burden, and additional considerations. Optimally, each principal investigator shares their protocol, completes the GRID independently, and then meets to compare their perspectives, seeking a mutually acceptable agreement.

RESULTS

The GRID has facilitated coenrollment decision-making for the RESTORE and PROSpect pediatric critical care clinical trials. In RESTORE , five trials were reviewed; one was approved for coenrollment, and four were deemed competing. In PROSpect , 26 trials have been reviewed; 20 are approved for coenrollment, and six were deemed competing. In both RESTORE and PROSpect , the principal investigators of multiple trials arranged a mutually acceptable sharing agreement.

DISCUSSION

The GRID provides a systematic process to help investigators evaluate the effect of coenrollment in multiple clinical trials.

INCEPT: The Intensive Care Platform Trial-Design and protocol

BACKGROUND

Adult intensive care unit (ICU) patients receive many interventions, but few are supported by high-certainty evidence. Randomised clinical trials (RCTs) are essential for trustworthy comparisons of intervention effects, but conventional RCTs are costly, cumbersome, inflexible, and often turn out inconclusive. Adaptive platform trials may mitigate these issues and have higher probabilities of obtaining conclusive results faster and at lower costs per participant.

METHODS

The Intensive Care Platform Trial (INCEPT) is an investigator-initiated, pragmatic, randomised, embedded, multifactorial, international, adaptive platform trial including adults acutely admitted to ICUs. INCEPT will assess comparable groups of interventions (primarily commonly used interventions with clinical uncertainty and practice variation) nested in domains. Interventions may be either open-label or masked. New domains will continuously be added to the platform. INCEPT assesses multiple core outcomes selected following substantial stakeholder involvement: mortality, days alive without life support/out of hospital/free of delirium, health-related quality of life, cognitive function, and safety outcomes. Each domain will use one of these core outcomes as the primary outcome. INCEPT primarily uses Bayesian statistical methods with neutral, minimally informative or sceptical priors, adjustment for important prognostic baseline variables, and calculation of absolute and relative differences in the intention-to-treat populations. Domains and intervention arms may be stopped for superiority/inferiority, practical equivalence, or futility according to pre-specified adaptation rules evaluated using statistical simulation or at pre-specified maximum sample sizes. Domains may use response-adaptive randomisation, meaning that more participants will be allocated to interventions with higher probabilities of being superior.

CONCLUSIONS

INCEPT provides an efficient, pragmatic, and flexible platform for comparing the effects of many interventions used in adult ICU patients. The adaptive design enables the trial to use accumulating data to improve the treatment of future participants. INCEPT will provide high-certainty, conclusive evidence for many interventions, directly inform clinical practice, and thus improve patient-important outcomes.

Statistical documentation for multi-disease, multi-domain platform trials: our experience with the Staphylococcus aureus Network Adaptive Platform trial

Platform trials have become widely adopted across multiple disease areas over recent years, however, guidelines for operationalising these trials have not kept pace. We outline a series of documents that summarise the statistical components, and implicit processes, of the Staphylococcus aureus Network Adaptive Platform (SNAP) trial to provide an informal template for other researchers and reviewers of platform trials. We briefly summarise the content and role of the core protocol, statistical appendix, domain-specific appendices, simulation report, statistical implementation guides, data safety and monitoring committee (DSMC) reports, and domain-specific statistical analysis plans and final reports, and a transparent governance structure that ensures separate blinded and unblinded statistical teams. In the absence of guidelines or checklists for platform trial statistical documents, we hope to provide useful guidance to others in terms of what has worked so far for the SNAP trial, stimulate discussion, and inform a future consensus.Trial registration NCT05137119 . Registered on 30 November 2021.

Interventions for the management of post-COVID-19 condition (long COVID): protocol for a living systematic review and network meta-analysis

BACKGROUND

Up to 15% of survivors of COVID-19 infection experience long-term health effects, including fatigue, myalgia and impaired cognitive function, termed post-COVID-19 condition or long COVID. Several trials that study the benefits and harms of various interventions to manage long COVID have been published and hundreds more are planned or are ongoing. Trustworthy systematic reviews that clarify the benefits and harms of interventions are critical to promote evidence-based practice.

OBJECTIVE

To create and maintain a living systematic review and network meta-analysis addressing the benefits and harms of pharmacologic and non-pharmacologic interventions for the treatment and management of long COVID.

METHODS

Eligible trials will randomise adults with long COVID to pharmacologic or non-pharmacologic interventions, placebo, sham or usual care. We will identify eligible studies by searching MEDLINE, EMBASE, CINAHL, PsycINFO, AMED and CENTRAL from inception, without language restrictions.Reviewers will work independently and in duplicate to screen search records, collect data from eligible trials, including trial and patient characteristics and outcomes of interest and assess risk of bias. Our outcomes of interest will include patient-reported fatigue, pain, postexertional malaise, changes in education or employment status, cognitive function, mental health, dyspnoea, quality of life, physical function, recovery and serious adverse events.For each outcome, when possible, we will perform a frequentist random-effects network meta-analysis. When there are compelling reasons to suspect that certain interventions are only applicable or effective for a subtype of long COVID, we will perform separate network meta-analyses. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach will guide our assessment of the certainty of evidence.We will update our living review biannually, on the publication of a seminal trial, or when new evidence emerges that may change clinical practice.

CONCLUSION

This living systematic review and network meta-analysis will provide comprehensive, trustworthy and up-to-date summaries of the evidence addressing the benefits and harms of interventions for the treatment and management of long COVID. We will make our findings available publicly and work with guideline-producing organisations to inform their recommendations.

ETHICS AND DISSEMINATION

The study describes the protocol for a systematic review that uses data from published trial reports. Therefore, the study is exempt from ethics review. We intend to deposit all data in a public repository and publish each iteration of the living review online.

The legacy of the COVID-19 pandemic on critical care research: A descriptive interview study

Background

The COVID-19 pandemic challenged both research and clinical teams in critical care to collaborate on research solutions to new clinical problems. Although an effective, nationally coordinated response helped facilitate critical care research, reprioritisation of research efforts towards COVID-19 studies had significant consequences for existing and planned research activity in critical care.

Aims

Our aim was to explore the impact of the COVID-19 pandemic research prioritisation policies and practices on critical care research funded prior to the pandemic, the conduct of pandemic research, and implications for ongoing and future critical care research.

Methods

We undertook a descriptive qualitative study recruiting research-active clinician researchers and research delivery team members working in critical care. We conducted digitally recorded, semi-structured interviews in 2021-2022. Framework Analysis was used to analyse the data.

Results

We interviewed 22 participants comprising principal investigators, senior trial coordinators and research delivery nurses from across the UK. Six themes were identified: Unit, organisational and national factors; Study specific factors; Resources; Individual/clinician factors; Family/patient factors; Contextual factors. These themes explained how a nationally coordinated response during the pandemic affected individuals, studies and wider organisations in managing the research response in critical care, highlighting future implications for critical care research.

Conclusion

Harnessing the collective response seen in the COVID-19 pandemic in critical care could better support integration of research activity into routine critical care activities. Future endeavours should focus on workforce preparations, contingency planning, strategies for study prioritisation and integration of research as part of the continuum of clinical care.

Clinical research framework proposal for ketogenic metabolic therapy in glioblastoma

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults, with a universally lethal prognosis despite maximal standard therapies. Here, we present a consensus treatment protocol based on the metabolic requirements of GBM cells for the two major fermentable fuels: glucose and glutamine. Glucose is a source of carbon and ATP synthesis for tumor growth through glycolysis, while glutamine provides nitrogen, carbon, and ATP synthesis through glutaminolysis. As no tumor can grow without anabolic substrates or energy, the simultaneous targeting of glycolysis and glutaminolysis is expected to reduce the proliferation of most if not all GBM cells. Ketogenic metabolic therapy (KMT) leverages diet-drug combinations that inhibit glycolysis, glutaminolysis, and growth signaling while shifting energy metabolism to therapeutic ketosis. The glucose-ketone index (GKI) is a standardized biomarker for assessing biological compliance, ideally via real-time monitoring. KMT aims to increase substrate competition and normalize the tumor microenvironment through GKI-adjusted ketogenic diets, calorie restriction, and fasting, while also targeting glycolytic and glutaminolytic flux using specific metabolic inhibitors. Non-fermentable fuels, such as ketone bodies, fatty acids, or lactate, are comparatively less efficient in supporting the long-term bioenergetic and biosynthetic demands of cancer cell proliferation. The proposed strategy may be implemented as a synergistic metabolic priming baseline in GBM as well as other tumors driven by glycolysis and glutaminolysis, regardless of their residual mitochondrial function. Suggested best practices are provided to guide future KMT research in metabolic oncology, offering a shared, evidence-driven framework for observational and interventional studies.

Interventions for the management of long covid (post-covid condition): living systematic review

OBJECTIVE

To compare the effectiveness of interventions for the management of long covid (post-covid condition).

DESIGN

Living systematic review.

DATA SOURCES

Medline, Embase, CINAHL, PsycInfo, Allied and Complementary Medicine Database, and Cochrane Central Register of Controlled Trials from inception to December 2023.

ELIGIBILITY CRITERIA

Trials that randomised adults (≥18 years) with long covid to drug or non-drug interventions, placebo or sham, or usual care.

RESULTS

24 trials with 3695 patients were eligible. Four trials (n=708 patients) investigated drug interventions, eight (n=985) physical activity or rehabilitation, three (n=314) behavioural, four (n=794) dietary, four (n=309) medical devices and technologies, and one (n=585) a combination of physical exercise and mental health rehabilitation. Moderate certainty evidence suggested that, compared with usual care, an online programme of cognitive behavioural therapy (CBT) probably reduces fatigue (mean difference -8.4, 95% confidence interval (CI) -13.11 to -3.69; Checklist for Individual Strength fatigue subscale; range 8-56, higher scores indicate greater impairment) and probably improves concentration (mean difference -5.2, -7.97 to -2.43; Checklist for Individual Strength concentration problems subscale; range 4-28; higher scores indicate greater impairment). Moderate certainty evidence suggested that, compared with usual care, an online, supervised, combined physical and mental health rehabilitation programme probably leads to improvement in overall health, with an estimated 161 more patients per 1000 (95% CI 61 more to 292 more) experiencing meaningful improvement or recovery, probably reduces symptoms of depression (mean difference -1.50, -2.41 to -0.59; Hospital Anxiety and Depression Scale depression subscale; range 0-21; higher scores indicate greater impairment), and probably improves quality of life (0.04, 95% CI 0.00 to 0.08; Patient-Reported Outcomes Measurement Information System 29+2 Profile; range -0.022-1; higher scores indicate less impairment). Moderate certainty evidence suggested that intermittent aerobic exercise 3-5 times weekly for 4-6 weeks probably improves physical function compared with continuous exercise (mean difference 3.8, 1.12 to 6.48; SF-36 physical component summary score; range 0-100; higher scores indicate less impairment). No compelling evidence was found to support the effectiveness of other interventions, including, among others, vortioxetine, leronlimab, combined probiotics-prebiotics, coenzyme Q10, amygdala and insula retraining, combined L-arginine and vitamin C, inspiratory muscle training, transcranial direct current stimulation, hyperbaric oxygen, a mobile application providing education on long covid.

CONCLUSION

Moderate certainty evidence suggests that CBT and physical and mental health rehabilitation probably improve symptoms of long covid.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework https://osf.io/9h7zm/.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication.

Biomarker-directed therapy in multiple myeloma

PURPOSE OF REVIEW

Multiple myeloma is currently treated with a one-size-fits-all approach despite significant heterogeneity in patient outcomes and disease molecular constitution. A personalised approach would tailor therapy to unique patient or disease characteristics.

RECENT FINDINGS

Well established prognostic biomarkers such as cytogenetic risk and patient frailty status are being evaluated as potential predictive biomarkers. Specifically, treatment intensity can be augmented in high-risk patients or conversely attenuated in those at lower risk or lower ability to withstand treatment toxicities. Alternatively, targeted therapy can be rationally designed to exploit vulnerable pathways in myeloma cells as identified using predictive biomarkers. The t(11;14) translocation, found in approximately 15-20% of myeloma cases, is a leading biomarker for response to BCL-2 inhibitors such as venetoclax.

SUMMARY

Active research efforts exploring venetoclax combination therapies, as well as new generation BCL-2 inhibitors are underway. Following the development of venetoclax, numerous other cellular pathways are under investigation as candidate predictive biomarkers to rationally inform newer targeted therapies in myeloma.

Characteristics, Progression, and Output of Randomized Platform Trials: A Systematic Review

Importance

Platform trials have become increasingly common, and evidence is needed to determine how this trial design is actually applied in current research practice.

Objective

To determine the characteristics, progression, and output of randomized platform trials.

Evidence Review

In this systematic review of randomized platform trials, Medline, Embase, Scopus, trial registries, gray literature, and preprint servers were searched, and citation tracking was performed in July 2022. Investigators were contacted in February 2023 to confirm data accuracy and to provide updated information on the status of platform trial arms. Randomized platform trials were eligible if they explicitly planned to add or drop arms. Data were extracted in duplicate from protocols, publications, websites, and registry entries. For each platform trial, design features such as the use of a common control arm, use of nonconcurrent control data, statistical framework, adjustment for multiplicity, and use of additional adaptive design features were collected. Progression and output of each platform trial were determined by the recruitment status of individual arms, the number of arms added or dropped, and the availability of results for each intervention arm.

Findings

The search identified 127 randomized platform trials with a total of 823 arms; most trials were conducted in the field of oncology (57 [44.9%]) and COVID-19 (45 [35.4%]). After a more than twofold increase in the initiation of new platform trials at the beginning of the COVID-19 pandemic, the number of platform trials has since declined. Platform trial features were often not reported (not reported: nonconcurrent control, 61 of 127 [48.0%]; multiplicity adjustment for arms, 98 of 127 [77.2%]; statistical framework, 37 of 127 [29.1%]). Adaptive design features were only used by half the studies (63 of 127 [49.6%]). Results were available for 65.2% of closed arms (230 of 353). Premature closure of platform trial arms due to recruitment problems was infrequent (5 of 353 [1.4%]).

Conclusions and Relevance

This systematic review found that platform trials were initiated most frequently during the COVID-19 pandemic and declined thereafter. The reporting of platform features and the availability of results were insufficient. Premature arm closure for poor recruitment was rare.

The Rise of Adaptive Platform Trials in Critical Care

As durable learning research systems, adaptive platform trials represent a transformative new approach to accelerating clinical evaluation and discovery in critical care. This Perspective provides a brief introduction to the concept of adaptive platform trials, describes several established and emerging platforms in critical care, and surveys some opportunities and challenges for their implementation and impact.