Public availability of results of trials assessing cancer drugs in the United States

Preferred study designs to support a comparative therapeutic strategy question in oncology: a vignette study

OBJECTIVES

Some therapeutic strategy questions in oncology could be answered with studies using observational data. Target trial emulation is the application of design principles from randomized controlled trials (RCTs) to the analysis of observational data, to reduce design-induced biases. Our objective was to determine which type of study physicians would preferably plan to answer a comparative effectiveness question lacking evidence in oncology.

METHODS

We launched an online survey among physicians specialized in oncology. We constructed a vignette-based inquiry where vignettes described study scenarios which could be conducted to answer the predefined question. We designed six vignettes described by study design (RCT or observational study with a trial emulation framework), main study characteristics, probability of the study succeeding and anticipated delay before results availability. Participants randomly assessed five pair-wise comparisons of the vignettes and were asked which study they would preferably plan by using a Likert scale ranging from -5 to 5. The main outcome was the evaluation of clinicians' preferences for each pairwise comparison. Mean and median preference scores were calculated.

RESULTS

Two hundred thirteen participants, specialized in many tumor types, assessed at least one comparison with 82% reporting France as their country of affiliation. The interquartile range was -4 to 4 across pairwise comparisons. The median preference score was in disfavor of the monocentric RCT for the five comparisons where it appeared. The median preference score was strongly in favor of the multicentric national emulated trial when compared to the monocentric emulated trial 4 [IQR 2.5-4]. The mean preference score was the highest for the large European observational study 1.14 (SD 3.33), while the mean preference score was the lowest for the monocentric RCT -1.86 (SD 2.93).

CONCLUSION

No study design was strongly preferred, but the monocentric RCT was the least favored study in pair-wise comparisons. The planification of the new research is a compromise between scientific soundness, feasibility, cost, and time before obtaining results. We need to have the right answers to the right questions at the right time.

Building an infrastructure to support the development, conduct, and reporting of informative clinical studies: The Rockefeller University experience

Introduction

Clinical trials are a vital component of translational science, providing crucial information on the efficacy and safety of new interventions and forming the basis for regulatory approval and/or clinical adoption. At the same time, they are complex to design, conduct, monitor, and report successfully. Concerns over the last two decades about the quality of the design and the lack of completion and reporting of clinical trials, characterized as a lack of "informativeness," highlighted by the experience during the COVID-19 pandemic, have led to several initiatives to address the serious shortcomings of the United States clinical research enterprise.

Methods and Results

Against this background, we detail the policies, procedures, and programs that we have developed in The Rockefeller University Center for Clinical and Translational Science (CCTS), supported by a Clinical and Translational Science Award (CTSA) program grant since 2006, to support the development, conduct, and reporting of informative clinical studies.

Conclusions

We have focused on building a data-driven infrastructure to both assist individual investigators and bring translational science to each element of the clinical investigation process, with the goal of both generating new knowledge and accelerating the uptake of that knowledge into practice.

Transparency of clinical trials in pancreatic cancer: An analysis of availability of trial results from the ClinicalTrials.gov database

Background

Pancreatic cancer (PC) is a highly malignant tumor of the digestive system. As clinical trials involving PC are increasingly being conducted, the transparency of the generated data has become an important issue of concern. In other areas of medicine, clinical trial transparency presents a worrying state of affairs. However, at present, there has been no study examining the transparency of data derived from PC clinical trials.

Methods

A comprehensive search was conducted in the ClinicalTrial.gov database for clinical trials investigating pancreatic cancer as of June 2022. We examined the availability of clinical trial results and recorded the characteristics of the trials.

Results

A total of 856 trials were included in this study, of which 668 were completed and 188 were terminated or suspended. The results of 626 trials (73.13%) were available, of these 230 trials (26.87%) did not disclose any information on the trial data in any form. The publication rate for trials with available results was 86.10%, but the report rate on ClinicalTrial.gov was only 39.78%.

Conclusion

Although approximately 90% of clinical trial investigating interventions on patients with PC have published study results, 30% of trials did not report any findings, and the disclosure of trial results from ClinicalTrial.gov was unsatisfactory. In general, there is still room for improvement in the transparency of PC clinical trials.

Availability of Results of Trials Studying Pancreatic Adenocarcinoma over the Past 10 Years

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is a lethal cancer with few therapeutic options. Availability of results is a crucial step in interventional research. Our aim was to evaluate results availability for trials in patients with PDAC and explore associated factors.

MATERIALS AND METHODS

We performed a retrospective cohort study and searched the ClinicalTrials.gov registry for trials evaluating PDAC management with a primary completion date between 1 January 2010 and 1 June 2020. Then, we searched for results submitted on ClinicalTrials.gov and/or published. Our primary outcome was the proportion of PDAC trials with available results: submitted on ClinicalTrials.gov (either publicly available or undergoing quality control check) and/or published in a full-text article. The association of predefined trial characteristics with results availability was assessed.

RESULTS

We identified 551 trials of which 386 (70%) had available results. The cumulative percentage of trials with available results was 21% (95% CI, 18-25%) at 12 months after the primary completion date, 44% (95% CI, 30-48%) at 24 months and 57% (95% CI, 53-61%) at 36 months. Applicable clinical trials, required to comply with the 2007 Food and Drug Administration Amendments Act 801 and its final rule on reporting of results on ClinicalTrials.gov, were more likely to have available results over time (HR 2.1 [95% CI 1.72-2.63], P < .001). Industry-funded, small sample size, and terminated trials were less likely to have available results. Other trial characteristics showed no association with results availability.

CONCLUSION

Our results highlight a waste in interventional research studying PDAC.

Availability of results of academic randomized trials involving cooperative groups in oncology in France: A systematic search of clinical trial registries

BACKGROUND

Cooperative groups' involvement is increasing in academic oncological research. We aimed to assess the impact of sponsoring by cooperative groups in France on the availability of results of academic randomized trials in oncology.

METHODS

We performed a systematic search using ClinicalTrials.gov and the European Clinical Trials Register. We searched for all academic randomized trials in oncology conducted in France between January 1, 2005 and January 1, 2015. The inclusion criteria were: completed or terminated, phase 2 or 3 randomized trials with an academic (non-industry) sponsor. The main outcome was the publication of the results of trial (either as a journal article or as posting results in a registry) across each type of sponsor.

RESULTS

We included 211 randomized trials, mainly phase 3 (n = 135, 64%) and evaluating pharmacological treatments (n = 149, 71%). French cooperative groups were involved in 69 trials (33%), as part of a collaboration in one third (n = 23) of instances. Seventy-one (34%) trials were run by oncologic hospitals, 50 (23%) by university hospitals, and 21 (10%) by European organizations. Seventy-seven randomized trials (36%) had available results (published n = 73, posted n = 6). Cooperative groups were involved in half of those that have been published (37/73). The cumulative probability of results availability was 57% for cooperative groups, 41% for European organizations, 32% for oncologic hospitals, and 17% for university hospital at 10 years from the beginning of trials (p = 0.0006). In the case of collaboration with cooperative groups, the cumulative probability of results availability achieved 59% for university hospitals and 74% for oncologic hospitals.

CONCLUSION

The availability of results of randomized trials in oncology remains limited and almost exclusively through publications, but is higher when cooperative groups are involved.

POLICY SUMMARY

Sponsoring by a cooperative group should become the rule in academic trials to increase availability of trial results.

Availability of results of interventional studies assessing colorectal cancer from 2013 to 2020

Colorectal cancer (CRC) is one of the most frequent cancers worldwide. Our aim was to evaluate the availability of results of interventional studies studying CRC. We searched the ClinicalTrials.gov registry for all interventional studies on CRC management in adults completed or terminated between 01/01/2013 and 01/01/2020. To identify results, we searched for results posted on the ClinicalTrials.gov registry and/or published in a full-text article. Our primary outcome was the proportion of CRC interventional studies with available results (i.e. posted on the ClinicalTrials.gov registry and/or published in a full-text article). Secondary outcomes were 1) median time between primary completion and earliest date of results availability, 2) the cumulative percentage of interventional studies with results available over time 3) the cumulative percentage of interventional studies with results posted on the ClinicalTrials.gov registry over time and 4) the percentage of results available in open access. We identified 763 eligible interventional studies in ClinicalTrials.gov, which included 679 198 patients. Of these, 286 (37%) trials, including 270 845 (40%) patients, did not have any results available. Median time for results availability was 32.6 months (IQ 16.1-unreached). The cumulative percentage of interventional studies with available results was 17% at 12 months, 39% at 24 months and 55% at 36 months. Results were more likely available for trials that were randomized, completed, had one trial site in the United States, and with mixed funding. The cumulative percentage of interventional studies with results posted on ClinicalTrials.gov was 2% at 12 months. Results were available in open access for 420 (420/477 = 88%) trials. Our results highlight an important waste in research for interventional studies studying CRC.

Evaluation of Oncology Trial Results Reporting Over a 10-Year Period

IMPORTANCE

Unreported clinical trial results represent a violation of human rights. Oncology trials account for nearly 30% of interventional biopharmaceutical clinical studies registered on ClinicalTrials.gov and are the most numerous among all disciplines.

OBJECTIVE

To analyze the reporting of results among all interventional oncology trials registered on ClinicalTrials.gov from 2007 through 2017.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study analyzed all clinical studies registered between June 1, 2007, and May 8, 2017, on ClinicalTrials.gov, the largest public clinical trial registry in the world. Trials with a recruitment status of completed or terminated and a primary completion date of on or before September 30, 2017, were selected. Data were analyzed between February 20, 2021, and February 26, 2021.

MAIN OUTCOMES AND MEASURES

The main outcome was the percentage of trials that reported results either on ClinicalTrials.gov or in journal publications within 24 months of the primary completion date. Journal publication was ascertained by searching ClinicalTrials.gov for a link to the publication, PubMed using national clinical trial number, and Embase using national clinical trial number and filters.

RESULTS

Of the 12 240 clinical trials registered in ClinicalTrials.gov, 7425 trials (60.7%; 95% CI, 60.0%-61.5%) reported results, with a 34.0% (95% CI, 30.3%-37.7%) increase in 24-month reporting rate from 2007 to 2017. Multivariable analyses confirmed that more recent trials (adjusted hazard ratio [HR], 1.11 per year increase; 95% CI, 1.10-1.13) and trials with larger sample sizes (51-100 patients: adjusted HR, 1.17 [95% CI, 1.09-1.24]; >100 patients: adjusted HR, 1.43 [95% CI, 1.33-1.54]) were more likely to report results. Terminated trials were less likely to report results compared with completed trials (adjusted HR, 0.88; 95% CI, 0.83-0.93). Compared with trials funded by industry, those funded by the National Institutes of Health were more likely to report results (adjusted HR, 1.39; 95% CI, 1.29-1.49), whereas those funded by other academic or nonprofit organizations were less likely to report results (adjusted HR, 0.66; 95% CI, 0.62-0.70). Among all 7425 trials, the results of 2807 trials (37.8%; 95% CI, 36.7%-38.9%) were posted only on ClinicalTrials.gov. These trials tended to be terminated early and to have small sample sizes (≤50 patients) compared with trials that published results in journals.

CONCLUSIONS AND RELEVANCE

This study found a gradual improvement in results reporting among oncology trials over a 10-year period. Trial registries could serve as a results reporting platform for unpublished trials and as a data source of trial outcomes for future studies.

Results of trials assessing transarterial chemoembolization for treating hepatocellular carcinoma are critically underreported

OBJECTIVE

We aimed to evaluate to what extent the results of registered randomized controlled trials (RCTs) assessing transarterial chemoembolization (TACE) for treating hepatocellular carcinoma (HCC) are publicly available.

METHODS

We searched the Cochrane Central Register of Controlled Trials, the International Clinical Trials Registry Platform, and primary registries for RCTs assessing TACE for treating HCC, registered between January 2008 and August 2018, that had exceeded their completion date by more than 1 year. We systematically searched PubMed, EMBASE, and Google Scholar for a publication as well as the registry for results. The main outcomes were the availability of results, and the time to the first availability of results (i.e., posted on the registry or published). Secondary outcomes were the proportion of results available at 12 and 36 months after completion.

RESULTS

Among 67 identified RCTs, including a total target number to 11,599 participants, 26 had publicly available results (39%; i.e., 42% of total target number of participants). Results of 25 RCTs (37%) were published, with only 3 having results posted on the registry and 2 with both published and posted results. The median (Q1-Q3) time from completion to the first public availability of results was 18 months (11-29). The cumulative percentages of RCTs with results available were 10% (95% CI, 3-17%) and 29% (95% CI, 17-39%) at 12 and 36 months, respectively, after completion.

CONCLUSIONS

Despite the ethical commitments and societal expectations for disclosure of results, the availability of results of RCTs on TACE for treating HCC is very limited.

KEY POINTS

• Underreporting of trial results is a major cause of wasted medical research since inaccessible research results fail to help both patients and clinicians. • Transarterial chemoembolization (TACE) is the most common treatment for hepatocellular carcinoma (HCC) and has called for considerable research efforts. • Yet, almost two-thirds of randomized controlled trials assessing TACE for treating HCC did not yield any public results, either on the registry platform or in scientific journals.

Clinical trials on drug-drug interactions registered in ClinicalTrials.gov reported incongruent safety data in published articles: an observational study

OBJECTIVE

To assess safety data of trials on drug-drug interactions (DDIs) reported in ClinicalTrials.gov and published in journal articles, since DDIs are a growing concern.

STUDY DESIGN AND SETTING

In an observational study of clinical trials retrieved by the search term "drug-drug interaction(s)," we collected the information on registration and on adverse events (AEs) from ClinicalTrials.gov and corresponding publications. Trials were included if they primarily investigated DDIs, had a National Clinical Trial identifier, and were closed and completed by October 16, 2015. Publication data were extracted until March 2017.

RESULTS

Among 1,110 eligible trials, most were in phase 1 (76.8%), industry-funded (68.8%), and started before registration (56.9%). Results were not reported in the registry for 86.8% and not published for 68.1% trials. Published AE data were completely identical to the data submitted to ClinicalTrials.gov for only 15.6% trials. Among 64 trials with results reported both in ClinicalTrials.gov and publications, 34.4% published concordant number for other AEs.

CONCLUSION

Discrepancies that emerge from incomplete or changed reporting of AEs in publications emphasize the need to amend and enforce regulatory requirements for timely and complete submission of results, clearer AE reporting for trials focusing on DDIs, and regular assessment of the congruence of AE data submitted to ClinicalTrials.gov and scientific journals during the publication process.

Factors associated with reporting results for pulmonary clinical trials in ClinicalTrials.gov

Background/aims The Food and Drug Administration Amendments Act mandates that applicable clinical trials report basic summary results to the ClinicalTrials.gov database within 1 year of trial completion or termination. We aimed to determine the proportion of pulmonary trials reporting basic summary results to ClinicalTrials.gov and assess factors associated with reporting. Methods We identified pulmonary clinical trials subject to the Food and Drug Administration Amendments Act (called highly likely applicable clinical trials) that were completed or terminated between 2008 and 2012 and reported results by September 2013. We estimated the cumulative percentage of applicable clinical trials reporting results by pulmonary disease category. Multivariable Cox regression modeling identified characteristics independently associated with results reporting. Results Of 1450 pulmonary highly likely applicable clinical trials, 380 (26%) examined respiratory neoplasms, 238 (16%) asthma, 175 (12%) chronic obstructive pulmonary disease, and 657 (45%) other respiratory diseases. Most (75%) were pharmaceutical highly likely applicable clinical trials and 71% were industry-funded. Approximately 15% of highly likely applicable clinical trials reported results within 1 year of trial completion, while 55% reported results over the 5-year study period. Earlier phase highly likely applicable clinical trials were less likely to report results compared to phase 4 highly likely applicable clinical trials (phases 1/2 and 2 (adjusted hazard ratio 0.41 (95% confidence interval: 0.31-0.54)), phases 2/3 and 3 (adjusted hazard ratio 0.55 (95% confidence interval: 0.42-0.72)) and phase not applicable (adjusted hazard ratio 0.43 (95% confidence interval: 0.29-0.63)). Pulmonary highly likely applicable clinical trials without Food and Drug Administration oversight were less likely to report results compared with those with oversight (adjusted hazard ratio 0.65 (95% confidence interval: 0.51-0.83)). Conclusion A total of 15% of pulmonary clinical highly likely applicable clinical trials report basic summary results to ClinicalTrials.gov within 1 year of trial completion. Strategies to improve reporting are needed within the pulmonary community.

Underreporting of Research Biopsies from Clinical Trials in Oncology

Purpose: Research biopsies are frequently incorporated within clinical trials in oncology and are often a mandatory requirement for trial enrollment. However, limited information is available regarding the extent and completeness of research biopsy reporting.Experimental Design: We identified a cohort of therapeutic clinical trials where research biopsies were performed between January 2005 and October 2010 from an IR database at our institution. Clinical trial protocols were compared with the highest level of corresponding publication as a manuscript or registry report.Results: A total of 866 research biopsies were performed across 46 clinical trials, with a median of 8 patients biopsied/trial and 19 biopsies collected/trial. After a median follow-up time of 4.3 years from trial completion, 36 of 46 trials (78%) reported trial results: published manuscripts (n = 35), or registry report (n = 1). A total of 635 conducted biopsies were reported in 18 of the 46 trials (39%). Six (33%) of these 18 trials underreported the number of biopsies performed. Of 33 trials with mandatory research biopsies, 13 (39%) trials reported on these biopsies. Biopsy complications occurred in 8 trials [n = 39 patients, 6 grade 3/4 adverse events (AE)] but only 1 trial reported these. Factors associated with biopsy reporting included a larger number of biopsies (P ≤ 0.001) and serial biopsies (P < 0.001). Twelve of 16 (75%) trials with >12 biopsies performed reported on these biopsies compared with only 20% (6/30) that performed ≤12 biopsies.Conclusions: Despite ethical obligations to report research biopsies, the majority (61%) of trials do not report results from research biopsies. Complications are rarely reported in these studies. Improved reporting of results and AEs from research biopsies is needed. Clin Cancer Res; 23(21); 6450-7. ©2017 AACR.

From Composition to Cure: A Systems Engineering Approach to Anticancer Drug Carriers

The molecular complexity and heterogeneity of cancer has led to a persistent, and as yet unsolved, challenge to develop cures for this disease. The pharmaceutical industry focuses the bulk of its efforts on the development of new drugs, but an alternative approach is to improve the delivery of existing drugs with drug carriers that can manipulate when, where, and how a drug exerts its therapeutic effect. For the treatment of solid tumors, systemically delivered drug carriers face significant challenges that are imposed by the pathophysiological barriers that lie between their site of administration and their site of therapeutic action in the tumor. Furthermore, drug carriers face additional challenges in their translation from preclinical validation to clinical approval and adoption. Addressing this diverse network of challenges requires a systems engineering approach for the rational design of optimized carriers that have a realistic prospect for translation from the laboratory to the patient.

[New applications for individual participant data meta-analyses of randomized trials]

Meta-analyses of randomized trials using individual-participant data, which represent the highest level of evidence for the evaluation of a treatment effect, are now used in different contexts in clinical research. This article aims at reviewing some of these new applications. Meta-analyses are increasingly used in economic evaluation, which implies new measure outcomes of the treatment effect, as well as in biomarkers evaluations thanks to their higher statistical power and the possibility to validate findings on independent data. This article also considers the perspectives opened up by new data sources, such as randomized trials registers, and data sharing policies.

Reporting of statistically significant results at ClinicalTrials.gov for completed superiority randomized controlled trials

BACKGROUND

Publication bias and other reporting bias have been well documented for journal articles, but no study has evaluated the nature of results posted at ClinicalTrials.gov. We aimed to assess how many randomized controlled trials (RCTs) with results posted at ClinicalTrials.gov report statistically significant results and whether the proportion of trials with significant results differs when no treatment effect estimate or p-value is posted.

METHODS

We searched ClinicalTrials.gov in June 2015 for all studies with results posted. We included completed RCTs with a superiority hypothesis and considered results for the first primary outcome with results posted. For each trial, we assessed whether a treatment effect estimate and/or p-value was reported at ClinicalTrials.gov and if yes, whether results were statistically significant. If no treatment effect estimate or p-value was reported, we calculated the treatment effect and corresponding p-value using results per arm posted at ClinicalTrials.gov when sufficient data were reported.

RESULTS

From the 17,536 studies with results posted at ClinicalTrials.gov, we identified 2823 completed phase 3 or 4 randomized trials with a superiority hypothesis. Of these, 1400 (50%) reported a treatment effect estimate and/or p-value. Results were statistically significant for 844 trials (60%), with a median p-value of 0.01 (Q1-Q3: 0.001-0.26). For the 1423 trials with no treatment effect estimate or p-value posted, we could calculate the treatment effect and corresponding p-value using results reported per arm for 929 (65%). For 494 trials (35%), p-values could not be calculated mainly because of insufficient reporting, censored data, or repeated measurements over time. For the 929 trials we could calculate p-values, we found statistically significant results for 342 (37%), with a median p-value of 0.19 (Q1-Q3: 0.005-0.59).

CONCLUSIONS

Half of the trials with results posted at ClinicalTrials.gov reported a treatment effect estimate and/or p-value, with significant results for 60% of these. p-values could be calculated from results reported per arm at ClinicalTrials.gov for only 65% of the other trials. The proportion of significant results was much lower for these trials, which suggests a selective posting of treatment effect estimates and/or p-values when results are statistically significant.

Publication status of contemporary oncology randomised controlled trials worldwide

BACKGROUND

Little is known about the extent of selective publication in contemporary oncology randomised controlled trials (RCTs) worldwide. This study aimed to evaluate the rates of publication and timely publication (within 24 months) for contemporary oncology RCTs from all over the world. We also investigated the trial characteristics associated with publication and timely publication.

PATIENTS AND METHODS

We identified all phase III oncology RCTs registered on ClinicalTrials.gov with a primary completion date between January 2008 and December 2012. We searched PubMed and EMBASE to identify publications. The final search date was 31 December 2015. Our primary outcome measure was the time to publication from the primary completion date to the date of primary publication in a peer-reviewed journal.

RESULTS

We identified 598 completed oncology RCTs; overall, 398 (66.6%) had been published. For published trials, the median time to publication was 25 months (interquartile range, 16-37 months). Only 192 trials (32.1%) were published within 24 months. Timely publication was independently associated with trials completed late in 2012. Trials conducted in Asia and other regions were less likely to have timely publication, but trials conducted in different locations were all equally likely to be published. Industry- and NIH-funded trials were equally likely to be published timely or at any time after trial completion. Among 391 published trials with clear primary outcomes, there was a trend for timely publication of positive trials compared with negative trials.

CONCLUSIONS

Despite the ethical obligations and societal expectations of disclosing findings promptly, oncology RCTs performed poorly.

Publication proportions for registered breast cancer trials: before and following the introduction of the ClinicalTrials.gov results database

Background

To limit selective and incomplete publication of the results of clinical trials, registries including ClinicalTrials.gov were introduced. The ClinicalTrials.gov registry added a results database in 2008 to enable researchers to post the results of their trials as stipulated by the Food and Drug Administration Amendment Act of 2007. This study aimed to determine the direction and magnitude of any change in publication proportions of registered breast cancer trials that occurred since the inception of the ClinicalTrials.gov results database.

Methods

A cross-sectional study design was employed using ClinicalTrials.gov, a publicly available registry/results database as the primary data source. Registry contents under the subcategories ‘Breast Neoplasms’ and ‘Breast Neoplasms, Male’ were downloaded on 1 August 2015. A literature search for included trials was afterwards conducted using MEDLINE and DISCOVER databases to determine publication status of the registered breast cancer trials.

Results

Nearly half (168/340) of the listed trials had been published, with a median time to publication of 24 months (Q1 = 14 months, Q3 = 42 months). Only 86 trials were published within 24 months of completion. There was no significant increase in publication proportions of trials that were completed before the introduction of the results database compared to those completed after (OR = 1.00, 95 % CI = .61 to 1.63; adjusted OR = 0.84, 95 % CI = .51 to 1.39). Characteristics associated with publication included trial type (observational versus interventional adjusted OR = .28, 95 % CI = .10 to .74) and completion/termination status (terminated versus completed adjusted OR = .22, 95 % CI = .09 to .51).

Conclusions

Less than a half of breast cancer trials registered in ClinicalTrials.gov are published in peer-reviewed journals.

Electronic supplementary material

The online version of this article (doi:10.1186/s41073-016-0017-4) contains supplementary material, which is available to authorized users.

Association between trial registration and treatment effect estimates: a meta-epidemiological study

BACKGROUND

To increase transparency in research, the International Committee of Medical Journal Editors required, in 2005, prospective registration of clinical trials as a condition to publication. However, many trials remain unregistered or retrospectively registered. We aimed to assess the association between trial prospective registration and treatment effect estimates.

METHODS

This is a meta-epidemiological study based on all Cochrane reviews published between March 2011 and September 2014 with meta-analyses of a binary outcome including three or more randomised controlled trials published after 2006. We extracted trial general characteristics and results from the Cochrane reviews. For each trial, we searched for registration in the report's full text, contacted the corresponding author if not reported and searched ClinicalTrials.gov and the International Clinical Trials Registry Platform in case of no response. We classified each trial as prospectively registered (i.e. registered before the start date); retrospectively registered, distinguishing trials registered before and after the primary completion date; and not registered. Treatment effect estimates of prospectively registered and other trials were compared by the ratio of odds ratio (ROR) (ROR <1 indicates larger effects in trials not prospectively registered).

RESULTS

We identified 67 meta-analyses (322 trials). Overall, 225/322 trials (70 %) were registered, 74 (33 %) prospectively and 142 (63 %) retrospectively; 88 were registered before the primary completion date and 54 after. Unregistered or retrospectively registered trials tended to show larger treatment effect estimates than prospectively registered trials (combined ROR = 0.81, 95 % CI 0.65-1.02, based on 32 contributing meta-analyses). Trials unregistered or registered after the primary completion date tended to show larger treatment effect estimates than those registered before this date (combined ROR = 0.84, 95 % CI 0.71-1.01, based on 43 contributing meta-analyses).

CONCLUSIONS

Lack of trial prospective registration may be associated with larger treatment effect estimates.

Evidence selection for a prescription drug's benefit-harm assessment: challenges and recommendations

OBJECTIVES

To describe challenges and make recommendations for researchers in how they select evidence to quantitatively assess a prescription drug's benefits and harms.

STUDY DESIGN AND SETTING

These challenges and recommendations are based on our recent experience conducting a benefit-harm assessment for the prescription drug roflumilast. We considered the selection of evidence to quantify (1) the drug's treatment effects in patients, (2) the patient population's baseline risks for beneficial and harmful outcomes without treatment, and (3) the patient population's preferences for these beneficial effects and harms. These are fundamental steps for most benefit-harm assessment methods.

RESULTS

We identify critical issues in selecting evidence for each of these steps. We justify in particular the need to incorporate (1) clinical trials for the drug's specific treatment effect; (2) observational studies with the most valid, precise, and applicable effect estimates for the baseline risk; and (3) flexible weighting approaches for balancing the drug benefits and harms.

CONCLUSION

We identify challenges and make recommendations for selecting evidence at the critical steps in a prescription drug's benefit-harm assessment. Our findings should assist other researchers conducting these assessments for prescription drugs, which could help regulators, medical professionals, and patients make better decisions about prescription drug use.

Media Reporting of Practice-Changing Clinical Trials in Oncology: A North American Perspective

INTRODUCTION

Media reporting of clinical trials impacts patient-oncologist interactions. We sought to characterize the accuracy of media and Internet reporting of practice-changing clinical trials in oncology.

MATERIALS AND METHODS

The first media articles referencing 17 practice-changing clinical trials were collected from 4 media outlets: newspapers, cable news, cancer websites, and industry websites. Measured outcomes were media reporting score, social media score, and academic citation score. The media reporting score was a measure of completeness of information detailed in media articles as scored by a 15-point scoring instrument. The social media score represented the ubiquity of social media presence referencing 17 practice-changing clinical trials in cancer as determined by the American Society of Clinical Oncology in its annual report, entitled Clinical Cancer Advances 2012; social media score was calculated from Twitter, Facebook, and Google searches. The academic citation score comprised total citations from Google Scholar plus the Scopus database, which represented the academic impact per clinical cancer advance.

RESULTS

From 170 media articles, 107 (63%) had sufficient data for analysis. Cohen's κ coefficient demonstrated reliability of the media reporting score instrument with a coefficient of determination of 94%. Per the media reporting score, information was most complete from industry, followed by cancer websites, newspapers, and cable news. The most commonly omitted items, in descending order, were study limitations, exclusion criteria, conflict of interest, and other. The social media score was weakly correlated with academic citation score.

CONCLUSION

Media outlets appear to have set a low bar for coverage of many practice-changing advances in oncology, with reports of scientific breakthroughs often omitting basic study facts and cautions, which may mislead the public. The media should be encouraged to use a standardized reporting template and provide accessible references to original source information whenever feasible.

Public availability of results of observational studies evaluating an intervention registered at ClinicalTrials.gov

BACKGROUND

Observational studies are essential for assessing safety. The aims of this study were to evaluate whether results of observational studies evaluating an intervention with safety outcome(s) registered at ClinicalTrials.gov were published and, if not, whether they were available through posting on ClinicalTrials.gov or the sponsor website.

METHODS

We identified a cohort of observational studies with safety outcome(s) registered on ClinicalTrials.gov after October 1, 2007, and completed between October 1, 2007, and December 31, 2011. We systematically searched PubMed for a publication, as well as ClinicalTrials.gov and the sponsor website for results. The main outcomes were the time to the first publication in journals and to the first public availability of the study results (i.e. published or posted on ClinicalTrials.gov or the sponsor website). For all studies with results publicly available, we evaluated the completeness of reporting (i.e. reported with the number of events per arm) of safety outcomes.

RESULTS

We identified 489 studies; 334 (68%) were partially or completely funded by industry. Results for only 189 (39%, i.e. 65% of the total target number of participants) were published at least 30 months after the study completion. When searching other data sources, we obtained the results for 53% (n = 158; i.e. 93% of the total target number of participants) of unpublished studies; 31% (n = 94) were posted on ClinicalTrials.gov and 21% (n = 64) on the sponsor website. As compared with non-industry-funded studies, industry-funded study results were less likely to be published but not less likely to be publicly available. Of the 242 studies with a primary outcome recorded as a safety issue, all these outcomes were adequately reported in 86% (114/133) when available in a publication, 91% (62/68) when available on ClinicalTrials.gov, and 80% (33/41) when available on the sponsor website.

CONCLUSIONS

Only 39% of observational studies evaluating an intervention with safety outcome(s) registered at ClinicalTrials.gov had their results published at least 30 months after study completion. The registration of these observational studies allowed searching other sources (results posted at ClinicalTrials.gov and sponsor website) and obtaining results for half of unpublished studies and 93% of the total target number of participants.

Trends in global clinical trial registration: an analysis of numbers of registered clinical trials in different parts of the world from 2004 to 2013

OBJECTIVES

To analyse developments (and their causes) in the number and proportion of clinical trials that were registered in different parts of the world after the International Committee of Medical Journal Editors (ICMJE) announced in 2004 that it would require registration of clinical trials as a condition for publication.

SETTING

The International Clinical Trials Registry Platform (ICTRP).

DESIGN

The ICTRP database was searched for all clinical trials that were registered up to 31 December 2013.

RESULTS

The ICTRP database contained data on 186,523 interventional clinical trials. The annual number of registered clinical trials increased from 3294 in 2004 to 23,384 in 2013. Relative to the number of clinical trial research publications, the global number of registered clinical trials increased fivefold between 2004 and 2013, rising particularly strongly between 2004 and 2005. In certain regions, especially Asia, the annual number of registered trials increased more gradually and continued to increase up to 2013. In India and Japan, two countries with marked but more gradual increases, these increases only happened after several local measures were implemented that encouraged and enforced registration. In most regions, there was a trend toward trials being registered at local registries.

CONCLUSIONS

Clinical trial registration has greatly improved transparency in clinical trial research. However, these improvements have not taken place equally in all parts of the world. Achieving compliance with registration requires a coalescence of global and local measures, and remains a key challenge in many countries. Poor quality of registered trial data and the inaccessibility of trial protocols, results and participant-level data further undermine the potential benefits of clinical trial registration. National and regional registries and the ICTRP have played a leading role in achieving the successes of trial registration to date and should be supported in addressing these challenges in the future.

Comparison of serious adverse events posted at ClinicalTrials.gov and published in corresponding journal articles

BACKGROUND

The reporting of serious adverse events (SAEs) in clinical trials is crucial to assess the balance between benefits and risks. For trials with serious adverse events posted at ClinicalTrials.gov, we assessed the consistency between SAEs posted at ClinicalTrials.gov and those published in corresponding journal articles.

METHODS

All records from ClinicalTrials.gov up to February 2014 were automatically exported in XML format. Among these, we identified all phase III or IV randomized controlled trials with at least one SAE posted. For a random sample of 300 of these trials, we searched for corresponding publications using MEDLINE via PubMed and extracted safety results from the articles.

RESULTS

Among the sample of 300 trials with SAEs posted at ClinicalTrials.gov, 78 (26%) did not have a corresponding publication, and 20 (7%) had a publication that did not match the ClinicalTrials.gov record. For the 202 remaining trials, 26 published articles (13%) did not mention SAEs, 4 (2%) reported no SAEs, and 33 (16%) did not report the total number of SAEs per treatment group. Among the remaining 139 trials, for 44 (32%), the number of SAEs per group published did not match those posted at ClinicalTrials.gov. For 31 trials, the number of SAEs was greater at ClinicalTrials.gov than in the published article, with a difference ≥30 % for at least one group for 21. Only 33 trials (11%) had a publication reporting matching numbers of SAE and describing the type of SAE.

CONCLUSIONS

Many trials with SAEs posted at ClinicalTrials.gov are not yet published, omit the reporting of these SAEs in corresponding publications, or report a discrepant number of SAEs as compared with ClinicalTrials.gov. These results underline the need to consult ClinicalTrials.gov for more information on serious harms.

Compliance with results reporting at ClinicalTrials.gov

BACKGROUND

The Food and Drug Administration Amendments Act (FDAAA) mandates timely reporting of results of applicable clinical trials to ClinicalTrials.gov. We characterized the proportion of applicable clinical trials with publicly available results and determined independent factors associated with the reporting of results.

METHODS

Using an algorithm based on input from the National Library of Medicine, we identified trials that were likely to be subject to FDAAA provisions (highly likely applicable clinical trials, or HLACTs) from 2008 through 2013. We determined the proportion of HLACTs that reported results within the 12-month interval mandated by the FDAAA or at any time during the 5-year study period. We used regression models to examine characteristics associated with reporting at 12 months and throughout the 5-year study period.

RESULTS

From all the trials at ClinicalTrials.gov, we identified 13,327 HLACTs that were terminated or completed from January 1, 2008, through August 31, 2012. Of these trials, 77.4% were classified as drug trials. A total of 36.9% of the trials were phase 2 studies, and 23.4% were phase 3 studies; 65.6% were funded by industry. Only 13.4% of trials reported summary results within 12 months after trial completion, whereas 38.3% reported results at any time up to September 27, 2013. Timely reporting was independently associated with factors such as FDA oversight, a later trial phase, and industry funding. A sample review suggested that 45% of industry-funded trials were not required to report results, as compared with 6% of trials funded by the National Institutes of Health (NIH) and 9% of trials that were funded by other government or academic institutions.

CONCLUSIONS

Despite ethical and legal obligations to disclose findings promptly, most HLACTs did not report results to ClinicalTrials.gov in a timely fashion during the study period. Industry-funded trials adhered to legal obligations more often than did trials funded by the NIH or other government or academic institutions. (Funded by the Clinical Trials Transformation Initiative and the NIH.).

Information on new drugs at market entry: retrospective analysis of health technology assessment reports versus regulatory reports, journal publications, and registry reports

BACKGROUND

When a new drug becomes available, patients and doctors require information on its benefits and harms. In 2011, Germany introduced the early benefit assessment of new drugs through the act on the reform of the market for medicinal products (AMNOG). At market entry, the pharmaceutical company responsible must submit a standardised dossier containing all available evidence of the drug's added benefit over an appropriate comparator treatment. The added benefit is mainly determined using patient relevant outcomes. The "dossier assessment" is generally performed by the Institute for Quality and Efficiency in Health Care (IQWiG) and then published online. It contains all relevant study information, including data from unpublished clinical study reports contained in the dossiers. The dossier assessment refers to the patient population for which the new drug is approved according to the summary of product characteristics. This patient population may comprise either the total populations investigated in the studies submitted to regulatory authorities in the drug approval process, or the specific subpopulations defined in the summary of product characteristics ("approved subpopulations").

OBJECTIVE

To determine the information gain from AMNOG documents compared with non-AMNOG documents for methods and results of studies available at market entry of new drugs. AMNOG documents comprise dossier assessments done by IQWiG and publicly available modules of company dossiers; non-AMNOG documents comprise conventional, publicly available sources-that is, European public assessment reports, journal publications, and registry reports. The analysis focused on the approved patient populations.

DESIGN

Retrospective analysis.

DATA SOURCES

All dossier assessments conducted by IQWiG between 1 January 2011 and 28 February 2013 in which the dossiers contained suitable studies allowing for a full early benefit assessment. We also considered all European public assessment reports, journal publications, and registry reports referring to these studies and included in the dossiers.

DATA ANALYSIS

We assessed reporting quality for each study and each available document for eight methods and 11 results items (three baseline characteristics and eight patient relevant outcomes), and dichotomised them as "completely reported" or "incompletely reported (including items not reported at all)." For each document type we calculated the proportion of items with complete reporting for methods and results, for each item and overall, and compared the findings.Results 15 out of 27 dossiers were eligible for inclusion and contained 22 studies. The 15 dossier assessments contained 28 individual assessments of 15 total study populations and 13 approved subpopulations. European public assessment reports were available for all drugs. Journal publications were available for 14 out of 15 drugs and 21 out of 22 studies. A registry report in ClinicalTrials.gov was available for all drugs and studies; however, only 11 contained results. In the analysis of total study populations, the AMNOG documents reached the highest grade of completeness, with about 90% of methods and results items completely reported. In non-AMNOG documents, the rate was 75% for methods and 52% for results items; journal publications achieved the best rates, followed by European public assessment reports and registry reports. The analysis of approved subpopulations showed poorer complete reporting of results items, particularly in non-AMNOG documents (non-AMNOG versus AMNOG: 11% v 71% for overall results items and 5% v 70% for patient relevant outcomes). The main limitation of our analysis is the small sample size.

CONCLUSION

Conventional, publicly available sources provide insufficient information on new drugs, especially on patient relevant outcomes in approved subpopulations. This type of information is largely available in AMNOG documents, albeit only partly in English. The AMNOG approach could be used internationally to develop a comprehensive publication model for clinical studies and thus represents a key open access measure.

How transparent are migraine clinical trials? Repository of Registered Migraine Trials (RReMiT)

Transparency in research requires public access to unbiased information prior to trial initiation and openly available results upon study completion. The Repository of Registered Migraine Trials is a global snapshot of registered migraine clinical trials and scorecard of results availability via the peer-reviewed literature, registry databases, and gray literature. The 295 unique clinical trials identified employed 447 investigational agents, with 30% of 154 acute migraine trials and 11% of 141 migraine prophylaxis trials testing combinations of agents. The most frequently studied categories in acute migraine trials were triptans, nonsteroidal anti-inflammatory drugs, antiemetics, calcitonin gene-related peptide antagonists, and acetaminophen. Migraine prophylaxis trials frequently studied anticonvulsants, β-blockers, complementary/alternative therapies, antidepressants, and botulinum toxin. Overall, 237 trials were eligible for a results search. Of 163 trials completed at least 12 months earlier, 57% had peer-reviewed literature results, and registries/gray literature added another 13%. Using logistic regression analysis, studies with a sample size below the median of 141 subjects were significantly less likely to have results, but the dominant factor associated with availability of results was time since study completion. In unadjusted models, trials registered on ClinicalTrials.gov and trials with industry primary sponsorship were significantly more likely to have results. Recently completed trials rarely have publicly available results; 2 years after completion, the peer-reviewed literature contains results for fewer than 60% of completed migraine trials. To avoid bias, evidence-based therapy algorithms should consider factors affecting results availability. As negative trials are less likely to be published, special caution should be exercised before recommending a therapy with a high proportion of missing trial results.

Impact of sending email reminders of the legal requirement for posting results on ClinicalTrials.gov: cohort embedded pragmatic randomized controlled trial

OBJECTIVE

To evaluate the impact of sending an email to responsible parties of completed trials that do not comply with the Food and Drug Administration Amendments Act 801 legislation, to remind them of the legal requirement to post results.

DESIGN

Cohort embedded pragmatic randomized controlled trial.

SETTING

Trials registered on ClinicalTrials.gov.

PARTICIPANTS

190 out of 379 trials randomly selected by computer generated randomization list to receive the intervention (personalized emails structured as a survey and sent by one of us to responsible parties of the trials, indirectly reminding them of the legal requirement and potential penalties for non-compliance).

MAIN OUTCOME MEASURES

The primary outcome was the proportion of results posted on ClinicalTrials.gov at three months. The secondary outcome was the proportion posted at six months. In a second step, two assessors blinded to the intervention group collected the date of the first results being received on ClinicalTrials.gov. A post hoc sensitivity analysis excluding trials wrongly included was performed.

RESULTS

Among 379 trials included, 190 were randomized to receive the email intervention. The rate of posting of results did not differ at three months between trials with or without the intervention: 36/190 (19%) v 24/189 (13%), respectively (relative risk 1.5, 95% confidence interval 0.9 to 2.4, P=0.096) but did at six months: 46/190 (24%) v 27/189 (14%), 1.7, 1.1 to 2.6, P=0.014. In the sensitivity analysis, which excluded 48/379 trials (13%), 26/190 (14%) and 22/189 (12%), respectively, results were significant at three months (relative risk 5.1, 1.1 to 22.9, P=0.02) and at six months (4.1, 1.3 to 10.6, P=0.001).

CONCLUSIONS

Sending email reminders about the FDA's legal requirement to post results at ClinicalTrials.gov improved significantly the posting rate at six months but not at three months.Trial registration ClinicalTrials.gov NCT01658254.

Evidence-informed frameworks for cost-effective cancer care and prevention in low, middle, and high-income countries

Evidence-informed frameworks for cost-effective cancer prevention and management are essential for delivering equitable outcomes and tackling the growing burden of cancer in all resource settings. Evidence can help address the demand side pressures (ie, pressures exerted by people who need care) faced by economies with high, middle, and low incomes, particularly in the context of transitioning towards (or sustaining) universal health-care coverage. Strong systems, as opposed to technology-based solutions, can drive the development and implementation of evidence-informed frameworks for prevention and management of cancer in an equitable and affordable way. For this to succeed, different stakeholders-including national governments, global donors, the commercial sector, and service delivery institutions-must work together to address the growing burden of cancer across economies of low, middle, and high income.

Surgical trials and trial registers: a cross-sectional study of randomized controlled trials published in journals requiring trial registration in the author instructions

Background

Trial registration and the reporting of trial results are essential to increase transparency in clinical research. Although both have been strongly promoted in recent years, it remains unclear whether they have been successfully implemented in surgery and surgery-related disciplines. In this cross-sectional study, we assessed whether randomized controlled trials (RCTs) published in surgery journals requiring trial registration in their author instructions were indeed registered, and whether the study results of registered RCTs had been submitted to the trial register and were thus publicly available.

Methods

The ten highest ranked surgery journals requiring trial registration by impact factor (Journal Citation Reports, JCR, 2011) were chosen. We then searched MEDLINE (in PubMed) for RCTs published in the selected journals between 1 June 2012 and 31 December 2012. Any trials recruiting participants before 2004 were excluded because the International Committee of Medical Journal Editors (ICMJE) first proposed trial registration in 2004. We then searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to assess whether the identified RCTs were indeed registered and whether the results of the registered RCTs were available in the register.

Results

The search retrieved 588 citations. Four hundred and sixty references were excluded in the first screening. A further 25 were excluded after full-text screening. A total of 103 RCTs were finally included. Eighty-five of these RCTs (83%) could be found via the ICTRP. For 7 of 59 (12%) RCTs, which were registered on ClinicalTrials.gov, summary study data had been posted in the results database.

Conclusions

Although still not fully implemented, trial registration in surgery has gained momentum. In general, however, the submission of summary study data to ClinicalTrials.gov remains poor.

Timing and completeness of trial results posted at ClinicalTrials.gov and published in journals

BACKGROUND

The US Food and Drug Administration Amendments Act requires results from clinical trials of Food and Drug Administration-approved drugs to be posted at ClinicalTrials.gov within 1 y after trial completion. We compared the timing and completeness of results of drug trials posted at ClinicalTrials.gov and published in journals.

METHODS AND FINDINGS

We searched ClinicalTrials.gov on March 27, 2012, for randomized controlled trials of drugs with posted results. For a random sample of these trials, we searched PubMed for corresponding publications. Data were extracted independently from ClinicalTrials.gov and from the published articles for trials with results both posted and published. We assessed the time to first public posting or publishing of results and compared the completeness of results posted at ClinicalTrials.gov versus published in journal articles. Completeness was defined as the reporting of all key elements, according to three experts, for the flow of participants, efficacy results, adverse events, and serious adverse events (e.g., for adverse events, reporting of the number of adverse events per arm, without restriction to statistically significant differences between arms for all randomized patients or for those who received at least one treatment dose). From the 600 trials with results posted at ClinicalTrials.gov, we randomly sampled 50% (n = 297) had no corresponding published article. For trials with both posted and published results (n = 202), the median time between primary completion date and first results publicly posted was 19 mo (first quartile = 14, third quartile = 30 mo), and the median time between primary completion date and journal publication was 21 mo (first quartile = 14, third quartile = 28 mo). Reporting was significantly more complete at ClinicalTrials.gov than in the published article for the flow of participants (64% versus 48% of trials, p<0.001), efficacy results (79% versus 69%, p = 0.02), adverse events (73% versus 45%, p<0.001), and serious adverse events (99% versus 63%, p<0.001). The main study limitation was that we considered only the publication describing the results for the primary outcomes.

CONCLUSIONS

Our results highlight the need to search ClinicalTrials.gov for both unpublished and published trials. Trial results, especially serious adverse events, are more completely reported at ClinicalTrials.gov than in the published article.