Early stopping in clinical PET studies: How to reduce expense and exposure.

Clinical positron emission tomography (PET) research is costly and entails exposing participants to radioactivity. Researchers should therefore aim to include just the number of subjects needed to fulfill the purpose of the study. In this tutorial we show how to apply sequential Bayes Factor testing in order to stop the recruitment of subjects in a clinical PET study as soon as enough data have been collected to make a conclusion. By using simulations, we demonstrate that it is possible to stop a study early, while keeping the number of erroneous conclusions low. We then apply sequential Bayes Factor testing to a real PET data set and show that it is possible to obtain support in favor of an effect while simultaneously reducing the sample size with 30%. Using this procedure allows researchers to reduce expense and radioactivity exposure for a range of effect sizes relevant for PET research.

A preliminary assessment of oral monepantel's tolerability and pharmacokinetics in individuals with treatment-refractory solid tumors.

PURPOSE: Monepantel is an approved veterinary anthelmintic with a strong safety profile. Preclinical evidence suggests novel mTOR pathway-associated anticancer activity. An open-label Phase I trial assessed tolerability, pharmacokinetics, pharmacodynamics and PET-CT imaging following oral Zolvix® monepantel administration to adults with treatment refractory, progressing and unresectable solid tumors. METHODS: Subjects were scheduled to daily home-based monepantel administration for 28 days in a 3 + 3 dose escalation study (5.0, 25.0 and 62.5 mg/kg bw). RESULTS: Of 41 reported drug-related AEs, 68% were Grade 1 and 24% were Grade 2; 35 AEs related to gastrointestinal effects including very poor palatability. DLT and MTD could not be determined due to early termination. Myelosuppression was not observed at the lowest level tested. Three of four Cohort 1 subjects had reduced mTOR pathway marker p-RPS6KB1 levels in PBMCs and achieved RECISTv1.1 SD by CT; one had progressive bony metastases by FDG-PET. One subject recorded PD on day 28, correlating with no detectable plasma monepantel from day 7. Monepantel sulfone dominated monepantel in pharmacokinetics. Both Cohort 2 subjects withdrew early due to AEs and the trial was terminated. CONCLUSIONS: Short-term 5 mg/kg bw monepantel administration provides a combined steady-state trough plasma monepantel and monepantel sulfone concentration of 0.5 µM. Gastrointestinal AEs including very poor palatability are concerning and suggested to be resolved by future drug product reformulation. RECISTv1.1, p-RPS6KB1 and plasma tumor marker outcomes provide preliminary evidence of anticancer activity.

Assessment of Hazard Ratios in Oncology Clinical Trials Terminated Early for Superiority: A Systematic Review.

Importance: Group sequential designs allow potential early trial termination at the interim analysis, before study completion. Traditional maximum likelihood estimate is commonly used to quantify the treatment effect in group sequential design trials; however, in published clinical trials, a bias-adjusted estimator has rarely been reported. Objective: To emphasize the need for considering overestimation of treatment effect by applying 2 bias-adjusted estimators to previously published, early-terminated oncology clinical trials. Evidence Review: Trials published from 2013 to 2017 were identified by searching MEDLINE and Embase on February 23, 2018. This review was restricted to oncology clinical trials using group sequential designs with a single preplanned interim analysis as well as 2-arm randomized clinical trials that were subsequently stopped for efficacy reasons. Each article was independently reviewed by 3 biostatisticians during text screening, and differences in opinion were resolved by discussion. This report presents the unadjusted hazard ratio (HR) of an experimental arm to a reference arm and 2 bias-adjusted HRs calculated by using the conditional mean-adjusted estimator (CMAE) and weighted CMAE (WCMAE). Findings: In total, 198 abstracts were screened for eligibility, of which, 19 eligible clinical trials were identified as applicable to the bias-adjusted estimators. Unadjusted HRs ranged from 0.203 (95% CI, 0.150-0.276) to 0.71 (95% CI, 0.60-0.84), number of events at the interim analysis from 58 to 540, and information time from 48% to 82%. In each study, the HRs adjusted by CMAE and WCMAE were higher than the unadjusted HR. Bias-adjusted estimates in large trials (243 and 414 events at the interim analysis) were similar to the unadjusted HR. However, in small trials (eg, with 58 events at the interim analysis), bias-adjusted estimates were highly disparate from the unadjusted HR. In trials with large treatment effects (eg, HRs of 0.20 and 0.22), the difference between unadjusted and bias-adjusted HRs was small even though the number of events at the interim analysis was small; larger differences were observed when the unadjusted HR was greater than 0.5. Conclusions and Relevance: In this systematic review of oncology clinical trials that were stopped for efficacy at the interim analysis, relatively large differences were noted between the unadjusted and adjusted HRs when the number of events at the interim analysis was small or when the unadjusted HR was close to the boundaries. These findings suggest presenting the 2 bias-adjusted HRs along with the unadjusted HR in the data monitoring committee meeting.

Add-On Therapies in Cardiovascular Disease: Reviewing ICER's Report and the Potential Effect on Payers.

DISCLOSURES: No outside funding supported this commentary. The authors have nothing to disclose.

Sensitivity analyses assessing the impact of early stopping on systematic reviews: Recommendations for interpreting guidelines.

The CONSORT Statement says that data-driven early stopping of a clinical trial is likely to weaken the inferences that can be drawn from the trial. The GRADE guidelines go further, saying that early stopping is a study limitation that carries the risk of bias, and recommending sensitivity analyses in which trials stopped early are omitted from evidence synthesis. Despite extensive debate in the literature over these issues, the existence of clear recommendations in high profile guidelines makes it inevitable that systematic reviewers will consider sensitivity analyses investigating the impact of early stopping. The purpose of this article is to assess methodologies for conducting such sensitivity analyses, and to make recommendations about how the guidelines should be interpreted. We begin with a clarifying overview of the impacts of early stopping on treatment effect estimation in single studies and meta-analyses. We then warn against naive approaches for conducting sensitivity analyses, including simply omitting trials stopped early from meta-analyses. This approach underestimates treatment effects, which may have serious implications if cost-effectiveness analyses determine whether treatments are made widely available. Instead, we discuss two unbiased approaches to sensitivity analysis, one of which is straightforward but statistically inefficient, and the other of which achieves greater statistical efficiency by making use of recent methodological developments in the analysis of clinical trials. We end with recommendations for interpreting: (a) the CONSORT Statement on reporting of reasons for early stopping, and (b) the GRADE guidelines on sensitivity analyses assessing the impact of early stopping.

Failure of an Innovative Low-Cost, Noninvasive Thermotherapy Device for Treating Cutaneous Leishmaniasis Caused by Leishmania tropica in Pakistan.

Cutaneous leishmaniasis (CL), a neglected parasitic skin disease, is endemic in Pakistan, where Leishmania tropica and Leishmania major are the causative protozoan species. Standard treatment with antimonial injections is long, painful, and costly; has toxic side effects; and is not always available in public hospitals. Small pilot studies have previously evaluated a low-cost and noninvasive hand-held exothermic crystallization thermotherapy for cutaneous leishmaniasis (HECT-CL) device. We aimed to further establish the effectiveness, safety, and feasibility of HECT-CL in L. tropica. In a prospective observational study, patients with parasitological confirmation of CL were treated using the HECT-CL heat pack for 3 minutes with an initial temperature of 52-53°C for 7 consecutive days. Dried blood spot samples were taken for species identification by polymerase chain reaction (PCR). Effectiveness was assessed by using medical photographs and measurements of the lesion size at baseline and subsequent follow-up visits, for up to 180 days. We intended to enroll 317 patients. The HECT-CL treatment was easy to apply and well tolerated. Species identification demonstrated the presence of L. tropica. Interim analysis of 56 patients showed a failure rate of 91% at follow-up (median 45 days after treatment, interquartile range 30-60 days). Enrollment of patients was prematurely suspended because of futility. This study showed a high failure rate for HECT-CL thermotherapy in this setting. Leishmania tropica is known to be less sensitive to antileishmanial drugs, more temperature-resistant, and spontaneous healing is slower than that in L. major. More research is needed to identify low-cost, effective, and more patient-friendly treatment for L. tropica.

Comparison of randomized controlled trials discontinued or revised for poor recruitment and completed trials with the same research question: a matched qualitative study.

BACKGROUND: More than a quarter of randomized controlled trials (RCTs) are prematurely discontinued, mostly due to poor recruitment of patients. In this study, we systematically compared RCTs discontinued or revised for poor recruitment and completed RCTs with the same underlying research question to better understand the causes of poor recruitment, particularly related to methodological aspects and context-specific study settings. METHODS: We compared RCTs that were discontinued or revised for poor recruitment to RCTs that were completed as planned, matching in terms of population and intervention. Based on an existing sample of RCTs discontinued or revised due to poor recruitment, we identified matching RCTs through a literature search for systematic reviews that cited the discontinued or revised RCT and matching completed RCTs without poor recruitment. Based on extracted data, we explored differences in the design, conduct, and study settings between RCTs with and without poor recruitment, separately for each research question using semi-structured discussions. RESULTS: We identified 15 separate research questions with a total of 29 RCTs discontinued or revised for poor recruitment and 48 RCTs completed as planned. Prominent research areas in the sample were cancer and acute care. The mean number of RCTs with poor recruitment per research question was 1.9 ranging from 1 to 4 suggesting clusters of research questions or settings prone to recruitment problems. The reporting quality of the recruitment process in RCT publications was generally low. We found that RCTs with poor recruitment often had narrower eligibility criteria, were investigator- rather than industry-sponsored, were associated with a higher burden for patients and recruiters, sometimes used outdated control interventions, and were often launched later in time than RCTs without poor recruitment compromising uncertainty about tested interventions through emerging evidence. Whether a multi- or single-center setting was advantageous for patient recruitment seemed to depend on the research context. CONCLUSIONS: Our study confirmed previously identified causes for poor recruitment, i.e., narrow eligibility criteria, investigator sponsorship, and a reduced motivation of patients and recruiters. Newly identified aspects were that researchers need to be aware of all other RCTs on a research question so that compromising effects on the recruitment can be minimized and that a larger number of centers is not always advantageous.

Applications of Bayesian statistical methodology to clinical trial design: A case study of a phase 2 trial with an interim futility assessment in patients with knee osteoarthritis.

Development of new pharmacological treatments for osteoarthritis that address unmet medical needs in a competitive market place is challenging. Bayesian approaches to trial design offer advantages in defining treatment benefits by addressing clinically relevant magnitude of effects relative to comparators and in optimizing efficiency in analysis. Such advantages are illustrated by a motivating case study, a proof of concept, and dose finding study in patients with osteoarthritis. Patients with osteoarthritis were randomized to receive placebo, celecoxib, or 1 of 4 doses of galcanezumab. Primary outcome measure was change from baseline WOMAC pain after 8 weeks of treatment. Literature review of clinical trials with targeted comparator therapies quantified treatment effects versus placebo. Two success criteria were defined: one to address superiority to placebo with adequate precision and another to ensure a clinically relevant treatment effect. Trial simulations used a Bayesian dose response and longitudinal model. An interim analysis for futility was incorporated. Simulations indicated the study had ≥85% power to detect a 14-mm improvement and ≤1% risk for a placebo-like drug to pass. The addition of the second success criterion substantially reduced the risk of an inadequate, weakly efficacious drug proceeding to future development. The study was terminated at the interim analysis due to inadequate analgesic efficacy. A Bayesian approach using probabilistic statements enables clear understanding of success criteria, leading to informed decisions for study conduct. Incorporating an interim analysis can effectively reduce sample size, save resources, and minimize exposure of patients to an inadequate treatment.

Lessons learnt from a discontinued randomised controlled trial: adalimumab injection compared with placebo for patients receiving physiotherapy treatment for sciatica (Subcutaneous Injection of Adalimumab Trial compared with Control: SCIATiC).

BACKGROUND: Adalimumab, a biological treatment targeting tumour necrosis factor α, might be useful in sciatica. This paper describes the challenges faced when developing a new treatment pathway for a randomised controlled trial of adalimumab for people with sciatica, as well as the reasons why the trial discussed was stopped early. METHODS: A pragmatic, parallel group, randomised controlled trial with blinded (masked) participants, clinicians, outcome assessment and statistical analysis was conducted in six UK sites. Participants were identified and recruited from general practices, musculoskeletal services and outpatient physiotherapy clinics. They were adults with persistent symptoms of sciatica of 1 to 6 months' duration with moderate to high level of disability. Eligibility was assessed by research physiotherapists according to clinical criteria, and participants were randomised to receive two doses of adalimumab (80 mg then 40 mg 2 weeks later) or saline placebo subcutaneous injections in the posterior lateral thigh. Both groups were referred for a course of physiotherapy. Outcomes were measured at baseline, 6-week, 6-month and 12-month follow-up. The main outcome measure was disability measured using the Oswestry Disability Index. The planned sample size was 332, with the first 50 in an internal pilot phase. RESULTS: The internal pilot phase was discontinued after 10 months from opening owing to low recruitment (two of the six sites active, eight participants recruited). There were several challenges: contractual delays; one site did not complete contract negotiations, and two sites signed contracts shortly before trial closure; site withdrawal owing to patient safety concerns; difficulties obtaining excess treatment costs; and in the two sites that did recruit, recruitment was slower than planned because of operational issues and low uptake by potential participants. CONCLUSIONS: Improved patient care requires robust clinical research within contexts in which treatments can realistically be provided. Step changes in treatment, such as the introduction of biologic treatments for severe sciatica, raise complex issues that can delay trial initiation and retard recruitment. Additional preparatory work might be required before testing novel treatments. A randomised controlled trial of tumour necrosis factor-α blockade is still needed to determine its cost-effectiveness in severe sciatica. TRIAL REGISTRATION: Current Controlled Trials, ISRCTN14569274 . Registered on 15 December 2014.

Discontinuation of surgical versus nonsurgical clinical trials: an analysis of 88,498 trials.

BACKGROUND: It has been previously reported that over 20% of surgical trials will be discontinued prematurely raising ethical and financial concerns. Previous studies have been limited in scope owing to the need for manual review of selected trials. To date, there has been no broad analysis comparing surgical and nonsurgical registered clinical trials. MATERIALS AND METHODS: ClinicalTrials.gov was queried October 7, 2017 for all US trials from 2005 to 2017. Trials were assigned to surgical or nonsurgical groups by automated sorting. The sorting algorithm was validated by comparison with manual assignments made by blinded investigators. Comparisons were made between trial status, funding sources, and trial design. The reasons for discontinuation were examined and tabulated. RESULTS: The database search yielded 82,719 nonsurgical and 5779 surgical trials after automatic assignment. The algorithm for assignments had an overall accuracy of 87.99% and a positive likelihood ratio of 6.09 and negative likelihood ratio of 0.093. Significant differences existed in trial status (nonsurgical versus surgical: completed: 55.51% versus 39.49%, P < 0.001 and discontinued: 11.07% versus 15.97%, P < 0.001). Discontinuation due to poor recruitment was more commonly cited by surgical trials (44.65% versus 34.74% P < 0.001). Industry funding predicted discontinuation for all trials (odds ratio 1.63 P < 0.001) and surgical trials independently (OR 1.25 P = 0.041). Patient enrollment, reporting results, and NIH funding were all protective against discontinuation. CONCLUSIONS: Surgical trials are more likely to prematurely discontinue than nonsurgical trials. Industry funding independently predicts trial discontinuation. Poor recruitment is a major cause of early trial discontinuation for all trials and is more pronounced in surgical trials.

Randomized controlled trials in pediatric patients had higher completion rates than adult trials: a cross-sectional study.

OBJECTIVE: Conduct of clinical trials is perceived to be more challenging in children than in adults. This study aimed to evaluate the impact of the age of participants on completion rates of randomized controlled trials (RCTs). STUDY DESIGN AND SETTING: A cross-sectional study on RCTs registered in the ClinicalTrials.gov database. All RCTs registered up to December 31, 2016, were extracted and were classified according to their recruitment status: active, completed, or discontinued and according to the age of participants: children (<17 years), adults (≥18 years), and mixed-age population. A logistic regression model was applied to assess the impact of participant's age category on trial completion while controlling for other relevant trial features. RESULTS: A total of 65,095 registered RCTs were identified. Among pediatric trials, 49.9% were completed and 8.5% were discontinued. Among adult and mixed age RCTs, respectively, 49.7% and 47.9% were completed whereas, 10.2% and 9.4% were discontinued. Overall, pediatric and mixed age RCTs were more likely to be registered as completed than adult RCTs (odds ratio: 1.16, 95% CI: 1.02-1.30; odds ratio: 1.15, 95% CI: 1.04-1.27, respectively). Also, funding source, type of intervention under evaluation, primary trial purpose, use of a blinding procedure, use of a placebo, and participants' assignment model were identified as independent predictors of RCT completion. CONCLUSION: Contrary to current perceptions and despite several specific challenges, recruitment of children and adolescents is not a limiting factor to completing a RCT. Other study features such as funding source, impact completeness and should be carefully considered before initiating research.

Facet-joint injections for non-specific low back pain: a feasibility RCT.

BACKGROUND: Pain of lumbar facet-joint origin is a common cause of low back pain in adults and may lead to chronic pain and disability, with associated health and socioeconomic implications. The socioeconomic burden includes an inability to return to work resulting in loss of productivity in addition to direct and indirect health-care utilisation costs. Lumbar facet-joints are paired synovial joints between the superior and inferior articular processes of consecutive lumbar vertebrae and between the fifth lumbar vertebra and the sacrum. Facet-joint pain is defined as pain that arises from any structure that is part of the facet-joints, including the fibrous capsule, synovial membrane, hyaline cartilage and bone. This pain may be treated by intra-articular injections with local anaesthetic and steroid, although this treatment is not standardised. At present, there is no definitive research to support the use of targeted lumbar facet-joint injections to manage this pain. Because of the lack of high-quality, robust clinical evidence, the National Institute for Health and Care Excellence (NICE) guidelines on the management of chronic low back pain [NICE. Low Back Pain in Adults: Early Management. Clinical guideline (CG88). London: NICE; 2009] did not recommend the use of spinal injections despite their perceived potential to reduce pain intensity and improve rehabilitation, with NICE calling for further research to be undertaken. The updated guidelines [NICE. Low Back Pain and Sciatica in Over 16s: Assessment and Management. NICE guideline (NG59). London: NICE; 2016] again do not recommend the use of spinal injections. OBJECTIVES: To assess the feasibility of carrying out a definitive study to evaluate the clinical effectiveness and cost-effectiveness of lumbar facet-joint injections compared with a sham procedure in patients with non-specific low back pain of > 3 months' duration. DESIGN: Blinded parallel two-arm pilot randomised controlled trial. SETTING: Initially planned as a multicentre study involving three NHS trusts in the UK, recruitment took place in the pain and spinal orthopaedic clinics at Barts Health NHS Trust only. PARTICIPANTS: Adult patients referred by their GP to the specialist clinics with non-specific low back pain of at least 3 months' duration despite NICE-recommended best non-invasive care (education and one of a physical exercise programme, acupuncture or manual therapy). Patients who had already received lumbar facet-joint injections or who had had previous back surgery were excluded. INTERVENTIONS: Participants who had a positive result following a diagnostic test (single medial branch nerve blocks) were randomised and blinded to receive either intra-articular lumbar facet-joint injections with steroids (intervention group) or a sham procedure (control group). All participants were invited to attend a group-based combined physical and psychological (CPP) programme. MAIN OUTCOME MEASURES: In addition to the primary outcome of feasibility, questionnaires were used to assess a range of pain-related (including the Brief Pain Inventory and Short-Form McGill Pain Questionnaire version 2) and disability-related (including the EuroQol-5 Dimensions five-level version and Oswestry Low Back Pain Questionnaire) issues. Health-care utilisation and cost data were also assessed. The questionnaire visits took place at baseline and at 6 weeks, 3 months and 6 months post randomisation. The outcome assessors were blinded to the allocation groups. RESULTS: Of 628 participants screened for eligibility, nine were randomised to receive the study intervention (intervention group, n = 5; sham group, n = 4), six completed the CPP programme and eight completed the study. LIMITATIONS: Failure to achieve our expected recruitment targets led to early closure of the study by the funder. CONCLUSIONS: Because of the small number of participants recruited to the study, we were unable to draw any conclusions about the clinical effectiveness or cost-effectiveness of intra-articular lumbar facet-joint injections in the management of non-specific low back pain. Although we did not achieve the target recruitment rate from the pain clinics, we demonstrated our ability to develop a robust study protocol and deliver the intended interventions safely to all nine randomised participants, thus addressing many of the feasibility objectives. FUTURE WORK: Stronger collaborations with primary care may improve the recruitment of patients earlier in their pain trajectory who are suitable for inclusion in a future trial. TRIAL REGISTRATION: EudraCT 2014-003187-20 and Current Controlled Trials ISRCTN12191542. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 74. See the NIHR Journals Library website for further project information.

Discontinuation and non-publication of clinical trials in cardiovascular medicine.

BACKGROUND: Appropriate dissemination of clinical data is crucial for minimising bias. Despite this, high rates of study discontinuation and non-publication have been reported among clinical trials. Cardiovascular medicine receives a substantial proportion of academic funding; however, predictors of non-publication among cardiovascular trials are not well-established. METHODS: The National Clinical Trials database was searched for cardiovascular trials completed between January 2010 and January 2014. Associated publications were identified in Medline or Embase. Relevant variables were extracted and subject to chi-squared and logistic regression to identify predictors of discontinuation and non-publication. RESULTS: After reviewing 2035 trials, 431 trials were included, of which 82.1% (n=354; 119,233 participants) were completed. Among completed trials, 70.3% (n=249; 99,095 participants) were published. Industry funding was associated with increased likelihood of non-publication (odds ratio [OR] 2.84; 95% confidence interval [CI] 1.47-5.51; P=0.002), while non-randomised studies were more likely to remain unpublished than randomised counterparts. Industry-funded studies were over three times more likely to be discontinued than those sponsored by academic institutions (OR 3.89; CI 1.54-9.83; P=0.004). Trials studying heart failure and atrial fibrillation were more likely to be discontinued compared to trials studying coronary artery disease (OR 2.83; CI 1.23-6.51; and OR 3.10; CI 1.21-7.96, respectively). Of the total 135,714 participants, 25,565 were recruited into unpublished studies. CONCLUSIONS: Discontinuation and non-publication of cardiovascular trials are common, resulting in data from thousands of participants remaining unpublished. Funding source and randomisation are strong predictors of non-publication, while sponsor type, phase and blinding status are key predictors of discontinuation.

Docetaxel plus gemcitabine versus gemcitabine in elderly patients with advanced non-small cell lung cancer and use of a geriatric assessment: Lessons from a prematurely closed Hellenic Oncology Research Group randomized phase III study.

OBJECTIVES: To compare first-line treatment with docetaxel plus gemcitabine (DG) versus gemcitabine (G) in elderly patients with advanced/metastatic non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Chemotherapy-naïve patients with inoperable stage IIIB/IV NSCLC, ≥70years, with an ECOG performance status (PS) of 0-2 were enrolled. Patients were stratified by PS and disease stage and randomized to either DG (docetaxel 30mg/m2 plus gemcitabine 900mg/m2 i.v.) or G (gemcitabine 1200mg/m2 i.v.) on days 1 and 8, every 3weeks. The study's primary end-point was overall survival (OS). RESULTS: In this prematurely closed study, 106 patients with a median age of 75years (range, 70-92) were enrolled (DG: n=54; G: n=52); 77 (73%) had stage IV disease and 18 (17%) a PS of 2. There was no difference in terms of median OS (14.6 vs 12.2months; p=0.121), progression-free survival (PFS) (3.4 vs 2.6months; p=0.757) and overall response rate (26.0% vs 15.4%; p=0.233) between DG and G arm, respectively. Patients with an Instrumental Activities of Daily Living (IADL) score<7 had significantly lower median OS (7.6 vs 15.4months; p=0.002) and median PFS (1.7 vs 4.4months; p=0.009) than patients with higher IADL score. The regimens were well tolerated with no significant difference in severe toxicity. CONCLUSION: DG and G demonstrated comparable efficacy in elderly patients with NSCLC and high IADL score was correlated with superior clinical outcome.

Discontinuation and Nonpublication of Randomized Clinical Trials Conducted in Children.

BACKGROUND: Trial discontinuation and nonpublication represent potential waste in research resources and lead to compromises in medical evidence. Pediatric trials may be particularly vulnerable to these outcomes given the challenges encountered in conducting trials in children. We aimed to determine the prevalence of discontinuation and nonpublication of randomized clinical trials (RCTs) conducted in pediatric populations. METHODS: Retrospective, cross-sectional study of pediatric RCTs registered in ClinicalTrials.gov from 2008 to 2010. Data were collected from the registry and associated publications identified (final search on September 1, 2015). RESULTS: Of 559 trials, 104 (19%) were discontinued early, accounting for an estimated 8369 pediatric participants. Difficulty with patient accrual (37%) was the most commonly cited reason for discontinuation. Trials were less likely to be discontinued if they were funded by industry compared with academic institutions (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.27-0.77). Of the 455 completed trials, 136 (30%) were not published, representing 69 165 pediatric participants. Forty-two unpublished trials posted results on ClinicalTrials.gov. Trials funded by industry were more than twice as likely to result in nonpublication at 24 and 36 months (OR 2.21, 95% CI 1.35-3.64; OR 3.12, 95% CI 1.6-6.08, respectively) and had a longer mean time to publication compared with trials sponsored by academia (33 vs 24 months, P < .001). CONCLUSIONS: In this sample of pediatric RCTs, discontinuation and nonpublication were common, with thousands of children exposed to interventions that did not lead to informative or published findings. Trial funding source was an important determinant of these outcomes, with both academic and industry sponsors contributing to inefficiencies.