Early Termination Of Trial Research Articles

Early termination of clinical trials in paediatrics.

Early termination of clinical trials in paediatrics.

Effect of Maternal Docosahexaenoic Acid Supplementation on Bronchopulmonary Dysplasia–Free Survival in Breastfed Preterm Infants

Maternal docosahexaenoic acid (DHA) supplementation may prevent bronchopulmonary dysplasia, but evidence remains inconclusive. To determine whether maternal DHA supplementation during the neonatal period improves bronchopulmonary dysplasia-free survival in breastfed infants born before 29 weeks of gestation. Superiority, placebo-controlled randomized clinical trial at 16 Canadian neonatal intensive care units (June 2015-April 2018 with last infant follow-up in July 2018). Lactating women who delivered before 29 weeks of gestation were enrolled within 72 hours of delivery. The trial intended to enroll 800 mothers, but was stopped earlier. There were 232 mothers (273 infants) assigned to oral capsules providing 1.2 g/d of DHA from randomization to 36 weeks' postmenstrual age and 229 mothers (255 infants) assigned to placebo capsules. The primary outcome was bronchopulmonary dysplasia-free survival in infants at 36 weeks' postmenstrual age. There were 22 secondary outcomes, including mortality and bronchopulmonary dysplasia. Enrollment was stopped early due to concern for harm based on interim data from this trial and from another trial that was published during the course of this study. Among 461 mothers and their 528 infants (mean gestational age, 26.6 weeks [SD, 1.6 weeks]; 253 [47.9%] females), 375 mothers (81.3%) and 523 infants (99.1%) completed the trial. Overall, 147 of 268 infants (54.9%) in the DHA group vs 157 of 255 infants (61.6%) in the placebo group survived without bronchopulmonary dysplasia (absolute difference, -5.0% [95% CI, -11.6% to 2.6%]; relative risk, 0.91 [95% CI, 0.80 to 1.04], P = .18). Mortality occurred in 6.0% of infants in the DHA group vs 10.2% of infants in the placebo group (absolute difference, -3.9% [95% CI, -6.8% to 1.4%]; relative risk, 0.61 [95% CI, 0.33 to 1.13], P = .12). Bronchopulmonary dysplasia occurred in 41.7% of surviving infants in the DHA group vs 31.4% in the placebo group (absolute difference, 11.5% [95% CI, 2.3% to 23.2%]; relative risk, 1.36 [95% CI, 1.07 to 1.73], P = .01). Of 22 prespecified secondary outcomes, 19 were not significantly different. Among breastfed preterm infants born before 29 weeks of gestation, maternal docosahexaenoic acid supplementation during the neonatal period did not significantly improve bronchopulmonary dysplasia-free survival at 36 weeks' postmenstrual age compared with placebo. Study interpretation is limited by early trial termination. ClinicalTrials.gov Identifier: NCT02371460.

Assessment of Hazard Ratios in Oncology Clinical Trials Terminated Early for Superiority

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. To emphasize the need for considering overestimation of treatment effect by applying 2 bias-adjusted estimators to previously published, early-terminated oncology clinical trials. 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). 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. 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.

Effect of Vancomycin or Daptomycin With vs Without an Antistaphylococcal β-Lactam on Mortality, Bacteremia, Relapse, or Treatment Failure in Patients With MRSA Bacteremia

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with mortality of more than 20%. Combining standard therapy with a β-lactam antibiotic has been associated with reduced mortality, although adequately powered randomized clinical trials of this intervention have not been conducted. To determine whether combining an antistaphylococcal β-lactam with standard therapy is more effective than standard therapy alone in patients with MRSA bacteremia. Open-label, randomized clinical trial conducted at 27 hospital sites in 4 countries from August 2015 to July 2018 among 352 hospitalized adults with MRSA bacteremia. Follow-up was complete on October 23, 2018. Participants were randomized to standard therapy (intravenous vancomycin or daptomycin) plus an antistaphylococcal β-lactam (intravenous flucloxacillin, cloxacillin, or cefazolin) (n = 174) or standard therapy alone (n = 178). Total duration of therapy was determined by treating clinicians and the β-lactam was administered for 7 days. The primary end point was a 90-day composite of mortality, persistent bacteremia at day 5, microbiological relapse, and microbiological treatment failure. Secondary outcomes included mortality at days 14, 42, and 90; persistent bacteremia at days 2 and 5; acute kidney injury (AKI); microbiological relapse; microbiological treatment failure; and duration of intravenous antibiotics. The data and safety monitoring board recommended early termination of the study prior to enrollment of 440 patients because of safety. Among 352 patients randomized (mean age, 62.2 [SD, 17.7] years; 121 women [34.4%]), 345 (98%) completed the trial. The primary end point was met by 59 (35%) with combination therapy and 68 (39%) with standard therapy (absolute difference, -4.2%; 95% CI, -14.3% to 6.0%). Seven of 9 prespecified secondary end points showed no significant difference. For the combination therapy vs standard therapy groups, all-cause 90-day mortality occurred in 35 (21%) vs 28 (16%) (difference, 4.5%; 95% CI, -3.7% to 12.7%); persistent bacteremia at day 5 was observed in 19 of 166 (11%) vs 35 of 172 (20%) (difference, -8.9%; 95% CI, -16.6% to -1.2%); and, excluding patients receiving dialysis at baseline, AKI occurred in 34 of 145 (23%) vs 9 of 145 (6%) (difference, 17.2%; 95% CI, 9.3%-25.2%). Among patients with MRSA bacteremia, addition of an antistaphylococcal β-lactam to standard antibiotic therapy with vancomycin or daptomycin did not result in significant improvement in the primary composite end point of mortality, persistent bacteremia, relapse, or treatment failure. Early trial termination for safety concerns and the possibility that the study was underpowered to detect clinically important differences in favor of the intervention should be considered when interpreting the findings. ClinicalTrials.gov Identifier: NCT02365493.

Updated Preliminary Results from a Phase II Study Combining Azacitidine and Pembrolizumab in Patients with Higher-Risk Myelodysplastic Syndrome

Updated Preliminary Results from a Phase II Study Combining Azacitidine and Pembrolizumab in Patients with Higher-Risk Myelodysplastic Syndrome

Association Between Low-Dose Rivaroxaban With or Without Aspirin and Ischemic Stroke Subtypes

The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) randomized clinical trial was stopped early owing to the efficacy of low-dose rivaroxaban plus aspirin in preventing major cardiovascular events. The main reason for early trial termination was the effect of combination therapy on reducing ischemic strokes. To analyze the association between low-dose rivaroxaban with or without aspirin and different ischemic stroke subtypes. This is a secondary analysis of a multicenter, double-blind, randomized, placebo-controlled study that was performed in 33 countries from March 12, 2013, to May 10, 2016. Patients with stable atherosclerotic vascular disease were eligible, and a total of 27 395 participants were randomized and followed up to February 6, 2017. All first ischemic strokes and uncertain strokes that occurred by this date were adjudicated using TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. The analysis of ischemic stroke subtypes was evaluated using an intention-to-treat principle. Statistical analysis was performed from March 12, 2013, to February 6, 2017. Participants received rivaroxaban (2.5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban (5 mg twice a day), or aspirin (100 mg once a day). Risk of ischemic stroke subtypes during follow-up. A total of 291 patients (66 women; mean [SD] age, 69.4 [8.5] years; 43 [14.8%] had a previous nonlacunar stroke) experienced an ischemic stroke. During the study, 49 patients (16.8%) received a diagnosis of atrial fibrillation. Applying TOAST criteria, 59 strokes (20.3%) were cardioembolic, 54 strokes (18.6%) were secondary to greater than 50% stenosis of the ipsilateral internal carotid artery, 42 strokes (14.4%) had a negative evaluation that met criteria for embolic stroke of undetermined source, and 21 strokes (7.2%) were secondary to small vessel disease. There were significantly fewer cardioembolic strokes (hazard ratio [HR], 0.40 [95% CI, 0.20-0.78]; P = .005) and embolic strokes of undetermined source (HR, 0.30 [95% CI, 0.12-0.74]; P = .006) in the combination therapy group compared with the aspirin-only group. A trend for reduction in strokes secondary to small vessel disease (HR, 0.36 [95% CI, 0.12-1.14]; P = .07) was not statistically significant. No significant difference was observed between the 2 groups in strokes secondary to greater than 50% carotid artery stenosis (HR, 0.85 [95% CI, 0.45-1.60]; P = .61). Rivaroxaban, 5 mg, twice daily showed a trend for reducing cardioembolic strokes compared with aspirin (HR, 0.57 [95% CI, 0.31-1.03]; P = .06) but was not associated with reducing other stroke subtypes. For patients with systemic atherosclerosis, low-dose rivaroxaban plus aspirin was associated with large, significant reductions in cardioembolic strokes and embolic strokes of undetermined source. However, these results of exploratory analysis need to be independently confirmed before influencing clinical practice. ClinicalTrials.gov identifier: NCT01776424.

Pembrolizumab plus lenalidomide and dexamethasone for patients with treatment-naive multiple myeloma (KEYNOTE-185): a randomised, open-label, phase 3 trial

Lenalidomide and dexamethasone has been a standard of care in transplant-ineligible patients with newly diagnosed multiple myeloma. The addition of a third drug to the combination is likely to improve treatment efficacy. KEYNOTE-185 assessed the efficacy and safety of lenalidomide and dexamethasone with and without pembrolizumab in patients with previously untreated multiple myeloma. Here, we present the results of an unplanned interim analysis done to assess the benefit-risk of the combination at the request of the US Food and Drug Administration (FDA). KEYNOTE-185 was a randomised, open-label, phase 3 trial done at 95 medical centres across 15 countries (Australia, Canada, France, Germany, Ireland, Israel, Italy, Japan, New Zealand, Norway, Russia, South Africa, Spain, UK, and USA). Transplantation-ineligible patients aged 18 years and older with newly diagnosed multiple myeloma, Eastern Cooperative Oncology Group performance status of 0 or 1, and who were treatment naive were enrolled, and randomly assigned 1:1 to receive either pembrolizumab plus lenalidomide and dexamethasone or lenalidomide and dexamethasone alone using an interactive voice or integrated web response system. Patients received oral lenalidomide 25 mg on days 1-21 and oral dexamethasone 40 mg on days 1, 8, 15, and 22 of repeated 28-day cycles, with or without intravenous pembrolizumab 200 mg every 3 weeks. The primary endpoint was progression-free survival, which was investigator-assessed because of early trial termination. Efficacy was analysed in all randomly assigned patients and safety was analysed in all patients who received at least one dose of study drug. This trial is registered at ClinicalTrials.gov, number NCT02579863, and it is closed for accrual. Between Jan 7, 2016, and June 9, 2017, 301 patients were randomly assigned to the pembrolizumab plus lenalidomide and dexamethasone group (n=151) or the lenalidomide and dexamethasone group (n=150). On July 3, 2017, the FDA decided to halt the study because of the imbalance in the proportion of death between groups. At database cutoff (June 2, 2017), with a median follow-up of 6·6 months (IQR 3·4-9·6), 149 patients in the pembrolizumab plus lenalidomide and dexamethasone group and 145 in the lenalidomide and dexamethasone group had received their assigned study drug. Median progression-free survival was not reached in either group; progression-free survival estimates at 6-months were 82·0% (95% CI 73·2-88·1) versus 85·0% (76·8-90·5; hazard ratio [HR] 1·22; 95% CI 0·67-2·22; p=0·75). Serious adverse events were reported in 81 (54%) patients in the pembrolizumab plus lenalidomide and dexamethasone group versus 57 (39%) patients in the lenalidomide and dexamethasone group; the most common serious adverse events were pneumonia (nine [6%]) and pyrexia (seven [5%]) in the pembrolizumab plus lenalidomide and dexamethasone group and pneumonia (eight [6%]) and sepsis (two [1%]) in the lenalidomide and dexamethasone group. Six (4%) treatment-related deaths occurred in the pembrolizumab plus lenalidomide and dexamethasone group (cardiac arrest, cardiac failure, myocarditis, large intestine perforation, pneumonia, and pulmonary embolism) and two (1%) in the lenalidomide and dexamethasone group (upper gastrointestinal haemorrhage and respiratory failure). The results from this unplanned, FDA-requested, interim analysis showed that the benefit-risk profile of pembrolizumab plus lenalidomide and dexamethasone is unfavourable for patients with newly diagnosed, previously untreated multiple myeloma. Long-term safety and survival follow-up is ongoing. Merck Sharp & Dohme, a subsidiary of Merck & Co, Inc (Kenilworth, NJ, USA).

PEP uP (Enhanced Protein-Energy Provision via the Enteral Route Feeding Protocol) in Surgical Patients-A Multicenter Pilot Randomized Controlled Trial.

The Enhanced Protein-Energy Provision via the Enteral Route Feeding Protocol (PEP uP) has been shown to be feasible, safe, and effective in delivering significantly more energy/protein, though it has not been well studied in surgical/trauma patients. We hypothesized that PEP uP will effectively increase energy/protein delivery to critically ill surgical/trauma patients. This multicenter, prospective, randomized pilot study included adult patients admitted to surgical service who were expected to require mechanical ventilation for >24hours and intensive care unit (ICU) care for >72hours. Subjects were randomized to PEP uP or standard care. The PEP uP protocol includes initiation at goal rate, semi-elemental formula, prophylactic prokinetic agents, 24-hour volume-based goals, and modular protein supplementation. The primary outcome was nutrition adequacy over the first 12 ICU days. Thirty-six subjects were enrolled. Slow recruitment resulted in early trial termination by the sponsor. There were no baseline differences between groups. PEP uP patients received more protein (106.8± 37.0 vs 78.5± 30.3 g/d, P = 0.02). Energy delivery was not significantly different (1400.0±409.5 vs 1237.9±459.1 kcal, P = 0.25). Vomiting was more common in the PEP uP patients (32% vs 12%, P = 0.03). PEP uP protocol violations included 2 patients (15.4%) not receiving pro-motility medications, 3 (23.1%) not receiving volume-based feeds as ordered, and 4 (30.8%) not receiving supplemental protein. In surgical/trauma patients, PEPuP seemed to improve protein delivery but was difficult to implement successfully and may increase vomiting rates.

A 5-day course of oral antibiotics followed by faecal transplantation to eradicate carriage of multidrug-resistant Enterobacteriaceae: a randomized clinical trial

ObjectivesIntestinal carriage with extended spectrum β-lactamase Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) can persist for months. We aimed to evaluate whether oral antibiotics followed by faecal microbiota transplantation (FMT) can eradicate intestinal carriage with ESBL-E/CPE. MethodsRandomized, open-label, superiority trial in four tertiary-care centres (Geneva (G), Paris (P), Utrecht (U), Tel Aviv (T)). Non-immunocompromised adult patients were randomized 1: 1 to either no intervention (control) or a 5-day course of oral antibiotics (colistin sulphate 2 × 106 IU 4×/day; neomycin sulphate 500 mg 4×/day) followed by frozen FMT obtained from unrelated healthy donors. The primary outcome was detectable intestinal carriage of ESBL-E/CPE by stool culture 35–48 days after randomization (V4). ClinicalTrials.govNCT02472600. The trial was funded by the European Commission (FP7). ResultsThirty-nine patients (G = 14; P = 16; U = 7; T = 2) colonized by ESBL-E (n = 36) and/or CPE (n = 11) were enrolled between February 2016 and June 2017. In the intention-to-treat analysis 9/22 (41%) patients assigned to the intervention arm were negative for ESBL-E/CPE at V4 (1/22 not receiving the intervention imputed as positive) whereas in the control arm 5/17 (29%) patients were negative (one lost to follow up imputed as negative) resulting in an OR for decolonization success of 1.7 (95% CI 0.4–6.4). Study drugs were well tolerated overall but three patients in the intervention group prematurely stopped the study antibiotics because of diarrhoea (all received FMT). ConclusionsNon-absorbable antibiotics followed by FMT slightly decreased ESBL-E/CPE carriage compared with controls; this difference was not statistically significant, potentially due to early trial termination. Further clinical investigations seem warranted.

Interim analysis of binary outcome data in clinical trials: a comparison of five estimators

ABSTRACT In clinical trials, where the outcome of interest is the occurrence of an event over a fixed time period, estimation of the event proportion at interim analysis can form a basis for decision-making such as early trial termination, sample size re-estimation, and/or dropping inferior treatment arms. In addition to derivation of mean squared error under an exponential time-to-event distribution, we performed a simulation study to examine the performance of five estimators of the event proportion when time to the event is assessable. The simulation results showed advantages of the Kaplan–Meier estimator over others in terms of robustness, and the bias and variability of the event proportion estimate. An example was given to illustrate how the estimators affect dropping treatment arms in a multi-arm multi-stage adaptive trial. We recommended the use of the Kaplan–Meier estimator and discourage the use of other estimators that discard the inherent time-to-event information.

Rivaroxaban or aspirin for patent foramen ovale and embolic stroke of undetermined source: a prespecified subgroup analysis from the NAVIGATE ESUS trial

Patent foramen ovale (PFO) is a contributor to embolic stroke of undetermined source (ESUS). Subgroup analyses from previous studies suggest that anticoagulation could reduce recurrent stroke compared with antiplatelet therapy. We hypothesised that anticoagulant treatment with rivaroxaban, an oral factor Xa inhibitor, would reduce the risk of recurrent ischaemic stroke compared with aspirin among patients with PFO enrolled in the NAVIGATE ESUS trial. NAVIGATE ESUS was a double-blinded, randomised, phase 3 trial done at 459 centres in 31 countries that assessed the efficacy and safety of rivaroxaban versus aspirin for secondary stroke prevention in patients with ESUS. For this prespecified subgroup analysis, cohorts with and without PFO were defined on the basis of transthoracic echocardiography (TTE) and transoesophageal echocardiography (TOE). The primary efficacy outcome was time to recurrent ischaemic stroke between treatment groups. The primary safety outcome was major bleeding, according to the criteria of the International Society of Thrombosis and Haemostasis. The primary analyses were based on the intention-to-treat population. Additionally, we did a systematic review and random-effects meta-analysis of studies in which patients with cryptogenic stroke and PFO were randomly assigned to receive anticoagulant or antiplatelet therapy. Between Dec 23, 2014, and Sept 20, 2017, 7213 participants were enrolled and assigned to receive rivaroxaban (n=3609) or aspirin (n=3604). Patients were followed up for a mean of 11 months because of early trial termination. PFO was reported as present in 534 (7·4%) patients on the basis of either TTE or TOE. Patients with PFO assigned to receive aspirin had a recurrent ischaemic stroke rate of 4·8 events per 100 person-years compared with 2·6 events per 100 person-years in those treated with rivaroxaban. Among patients with known PFO, there was insufficient evidence to support a difference in risk of recurrent ischaemic stroke between rivaroxaban and aspirin (hazard ratio [HR] 0·54; 95% CI 0·22-1·36), and the risk was similar for those without known PFO (1·06; 0·84-1·33; pinteraction=0·18). The risks of major bleeding with rivaroxaban versus aspirin were similar in patients with PFO detected (HR 2·05; 95% CI 0·51-8·18) and in those without PFO detected (HR 2·82; 95% CI 1·69-4·70; pinteraction=0·68). The random-effects meta-analysis combined data from NAVIGATE ESUS with data from two previous trials (PICSS and CLOSE) and yielded a summary odds ratio of 0·48 (95% CI 0·24-0·96; p=0·04) for ischaemic stroke in favour of anticoagulation, without evidence of heterogeneity. Among patients with ESUS who have PFO, anticoagulation might reduce the risk of recurrent stroke by about half, although substantial imprecision remains. Dedicated trials of anticoagulation versus antiplatelet therapy or PFO closure, or both, are warranted. Bayer and Janssen.

Optimal Patient Enrollment in Sequential Adaptive Clinical Trials with Binary Response

Adaptive clinical trials for new drugs or treatment options promise significant benefits to both trial sponsors and patients, but complicate resource allocation. We study the patient enrollment and trial termination decision in a Phase 3 group sequential adaptive trial, which allows for early trial termination due to established efficacy or anticipated futility. Our objective is to quantify the impact of interim analyses on key performance metrics, including the new drug’s misclassification risk and time-to-market, and the firm’s profit. To this end, we build a stochastic dynamic programming model that incorporates Bayesian updates on the drug’s efficacy. The patient enrollment decision in this setting is characterized by endogenous uncertainty, and a trade-off between the incentive to establish the drug’s efficacy early on (exploitation), due to a time-decreasing market revenue, and the benefit from collecting information on the drug’s performance (exploration) prior to committing a large amount of resources. We characterize important structural properties of an optimal patient enrollment policy and perform a numerical study utilizing realistic data. Our results suggest that sequential adaptive clinical trials, even with a single interim analysis, outperform their traditional counterparts (i.e., fixed sample size trials) across all metrics, because patient enrollment is re-optimized adaptively, based on updated information on the drug’s efficacy.

Premature Clinical Trial Discontinuation in the Era of Immune Checkpoint Inhibitors.

Clinical trial completion is critical for new cancer therapies. Premature trial termination or withdrawal is common and impairs progress. We assessed factors of early terminated/withdrawn oncology trials focusing on trials with immune checkpoint inhibitors (ICI), hypothesizing that the latter may be associated with lower rates of premature discontinuation. We reviewed all adult, intervention, oncology trials registered in ClinicalTrials.gov (November 16, 2011, to April 16, 2015) to identify all terminated/withdrawn trials and reasons for termination. Logistics regression model was used to identify factors associated with early termination/withdrawal. Discontinuation rate was compared in trials with and without ICI. We identified 12,875 trials (35% industry funded, 12% federal funded), of which 8.5% were prematurely terminated (5%) or withdrawn (3.5%); the main reasons were poor accrual (33%) and logistical (24%). ICI trials (n = 350) had a nonsignificant lower rate of termination or withdrawal compared with all other oncology trials (5.4% vs. 8.5%; p = .9) and were less likely to discontinue due to poor accrual (nonsignificant difference: 21% vs. 33%; p = .4). ICI trials were also less likely to discontinue compared with all other oncology drug trials (e.g., chemotherapy, targeted inhibitors, antiangiogenesis, biologics; 5.4% vs. 7.9%, respectively, nonsignificant difference). The 4-year cumulative incidence of failing to complete for reasons unrelated to toxicity or efficacy was 18% (95% confidence interval 16%-20%). There was no association between annual incidence across different tumor types or accrual goal and rate of trial termination. Poor accrual represents the main cause of early cancer trial termination. Premature termination/withdrawal rate was not significantly lower in ICI compared with other trials. Clinical trial completion remains a high priority and can be influenced by provider and patient factors. Clinical trial completion is critical for new cancer therapies. Premature trial termination or withdrawal is common and impairs progress. This study assessed factors of early terminated/withdrawn oncology trials, focusing on trials with immune checkpoint inhibitors (ICI), and found that poor accrual represents the main cause of early cancer trial termination. Premature termination/withdrawal rate was not significantly lower in immune checkpoint inhibitor trials compared to other trials. The discussion herein is focused on measures taken by the National Cancer Institute and other institutions to improve clinical trial accrual and prevent premature clinical trial discontinuation.

The independent statistician model: How well is it working?

With the initiation in the late 1960s of the data and safety monitoring board or equivalently the data monitoring committee in randomized clinical trials came the need for interim statistical reports for these committees to review for study conduct and early evidence of harm or overwhelming evidence of benefit, perhaps leading to early trial termination. Initially, the statistical team was part of the data coordinating center for the trial. Later, starting in the early 1990s in many industry-sponsored trials, this statistical unit was separated organizationally from the team that collected and managed the data. This unit, often referred to as the statistical data analysis center, prepares reports for the data monitoring committee, which cover study conduct, data quality and completeness, primary and secondary outcomes, and safety measures by study arm in an unblinded fashion. The role of the statistical data analysis center is critical to any well-functioning data monitoring committee. With the proliferation of data monitoring committees has grown the need for many more well-trained and experienced statistical data analysis centers. In my experience, some such units perform their tasks extremely well but many do not. There is a tremendous need and opportunity to provide training for statistical data analysis centers, and what sponsors and data monitoring committees should expect from statistical data analysis centers.

Practical characteristics of adaptive design in phase 2 and 3 clinical trials.

Adaptive design methods are expected to be ethical, reflect real medical practice, increase the likelihood of research and development success and reduce the allocation of patients into ineffective treatment groups by the early termination of clinical trials. However, the comprehensive details regarding which types of clinical trials will include adaptive designs remain unclear. We examined the practical characteristics of adaptive design used in clinical trials. We conducted a literature search of adaptive design clinical trials published from 2012 to 2015 using PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, with common search terms related to adaptive design. We systematically assessed the types and characteristics of adaptive designs and disease areas employed in the adaptive design trials. Our survey identified 245 adaptive design clinical trials. The number of trials by the publication year increased from 2012 to 2013 and did not greatly change afterwards. The most frequently used adaptive design was group sequential design (n=222, 90.6%), especially for neoplasm or cardiovascular disease trials. Among the other types of adaptive design, adaptive dose/treatment group selection (n=21, 8.6%) and adaptive sample-size adjustment (n=19, 7.8%) were frequently used. The adaptive randomization (n=8, 3.3%) and adaptive seamless design (n=6, 2.4%) were less frequent. Adaptive dose/treatment group selection and adaptive sample-size adjustment were frequently used (up to 23%) in "certain infectious and parasitic diseases," "diseases of nervous system," and "mental and behavioural disorders" in comparison with "neoplasms" (<6.6%). For "mental and behavioural disorders," adaptive randomization was used in two trials of eight trials in total (25%). Group sequential design and adaptive sample-size adjustment were used frequently in phase 3 trials or in trials where study phase was not specified, whereas the other types of adaptive designs were used more in phase 2 trials. Approximately 82% (202 of 245 trials) resulted in early termination at the interim analysis. Among the 202 trials, 132 (54% of 245 trials) had fewer randomized patients than initially planned. This result supports the motive to use adaptive design to make study durations shorter and include a smaller number of subjects. We found that adaptive designs have been applied to clinical trials in various therapeutic areas and interventions. The applications were frequently reported in neoplasm or cardiovascular clinical trials. The adaptive dose/treatment group selection and sample-size adjustment are increasingly common, and these adaptations generally follow the Food and Drug Administration's (FDA's) recommendations.

Decision on performing interim analysis for comparative clinical trials.

In randomized-controlled trials, interim analyses are often planned for possible early trial termination to claim superiority or futility of a new therapy. While unblinding is necessary to conduct the formal interim analysis in blinded studies, blinded data also have information about the potential treatment difference between the groups. We developed a blinded data monitoring tool that enables investigators to predict whether they observe such an unblinded interim analysis results that supports early termination of the trial. Investigators may skip some of the planned interim analyses if an early termination is unlikely. We specifically focused on blinded, randomized-controlled studies to compare binary endpoints of a new treatment with a control. Assuming one interim analysis is planned for early termination for superiority or futility, we conducted extensive simulation studies to assess the impact of the implementation of our tool on the size, power, expected number of interim analyses, and bias in the treatment effect. The numerical study showed the proposed monitoring tool does not affect size or power, but dramatically reduces the expected number of interim analyses when the effect of the treatment difference is small. The tool serves as a useful reference when interpreting the summary of the blinded data throughout the course of the trial, without losing integrity of the study. This tool could potentially save the study resources and budget by avoiding unnecessary interim analyses.

Effect of Azithromycin on Airflow Decline–Free Survival After Allogeneic Hematopoietic Stem Cell Transplant

Bronchiolitis obliterans syndrome has been associated with increased morbidity and mortality after allogeneic hematopoietic stem cell transplant (HSCT). Previous studies have suggested that azithromycin may reduce the incidence of post-lung transplant bronchiolitis obliterans syndrome. To evaluate if the early administration of azithromycin can improve airflow decline-free survival after allogeneic HSCT. The ALLOZITHRO parallel-group trial conducted in 19 French academic transplant centers and involving participants who were at least 16 years old, had undergone allogeneic HSCT for a hematological malignancy, and had available pretransplant pulmonary function test results. Enrollment was from February 2014 to August 2015 with follow-up through April 26, 2017. Patients were randomly assigned to receive 3 times a week either 250 mg of azithromycin (n = 243) or placebo (n = 237) for 2 years, starting at the time of the conditioning regimen. The primary efficacy end point was airflow decline-free survival at 2 years after randomization. Main secondary end points were overall survival and bronchiolitis obliterans syndrome at 2 years. Thirteen months after enrollment, the independent data and safety monitoring board detected an unanticipated imbalance across blinded groups in the number of hematological relapses, and the treatment was stopped December 26, 2016. Among 480 randomized participants, 465 (97%) were included in the modified intention-to-treat analysis (mean age, 52 [SD, 14] years; 75 women [35%]). At the time of data cutoff, 104 patients (22%; 54 azithromycin vs 50 placebo) had experienced an airflow decline; 138 patients (30%) died (78 azithromycin vs 60 placebo). Two-year airflow decline-free survival was 32.8% (95% CI, 25.9%-41.7%) with azithromycin and 41.3% (95% CI, 34.1%-50.1%) with placebo (unadjusted hazard ratio [HR], 1.3; 95% CI, 1.02-1.70; P = .03). Of the 22 patients (5%) who experienced bronchiolitis obliterans syndrome, 15 (6%) were in the azithromycin group and 7 (3%) in the placebo group (P = .08). The azithromycin group had increased mortality, with a 2-year survival of 56.6% (95% CI, 50.2%-63.7%) vs 70.1% (95% CI, 64.2%-76.5%) in the placebo group (unadjusted HR, 1.5; 95% CI, 1.1-2.0; P = .02). In a post hoc analysis, the 2-year cumulative incidence of hematological relapse was 33.5% (95% CI, 27.3%-39.7%) with azithromycin vs 22.3% (95% CI, 16.4%-28.2%) with placebo (unadjusted cause-specific HR, 1.7; 95% CI, 1.2-2.4; P = .002). Among patients undergoing allogeneic HSCT for hematological malignancy, early administration of azithromycin resulted in worse airflow decline-free survival than did placebo; these findings are limited by early trial termination. The potential for harm related to relapse requires further investigation. clinicaltrials.gov Identifier: NCT01959100.

Early termination of cardiovascular trials as a consequence of poor accrual: analysis of ClinicalTrials.gov 2006–2015

ObjectivesTo present a snapshot of experimental cardiovascular research with a focus on geographical and temporal patterns of early termination due to poor accrual.SettingThe Aggregate Analysis of ClinicalTrials.gov (AACT) database, reflecting...

Premature clinical trial discontinuation in all and genitourinary (GU) cancers in the era of immune checkpoint inhibitors (ICI).

394 Background: Clinical trial completion is critical for evaluating new therapies. Premature termination or withdrawal of clinical trials is common, impairs progress and results in waste of resources. We assessed features and reasons of early terminated and withdrawn cancer trials focusing on trials with ICI (anti-CTLA-4, anti-PD-1, anti-PD-L1). Methods: We reviewed all adult, intervention, cancer clinical trials registered in ClinicalTrials.gov from November 16, 2011 to April 16, 2015 to identify all early terminated and withdrawn trials. Reasons for termination were captured. Logistics regression model was used to identify factors associated with early termination or withdrawal. Discontinuation rate was compared between ICI and all trials (χ2); p &lt; 0.05 was set as significant. Results: We identified 12875 clinical trials (35% industry-funded, 12% federal-funded; 772 in prostate and 386 in non-prostate GU cancers); 8.5% of all trials were prematurely terminated (5%) or withdrawn (3.5%); main reason for discontinuation was poor accrual (33%) followed by logistical reasons (26%). When comparing trials with ICI (n = 350) to all cancer trials, lower rate of termination or withdrawal was noted with ICI [5.4% vs 8.5%, p = 0.05]. Trials with ICI were less likely to discontinue due to poor accrual compared to all trials, but the difference was not significant (21% vs 33%, p = 0.4). Of the 1158 GU cancers trials, 75 (6.5%) were prematurely terminated and 56 (4.8%) withdrawn; reasons for discontinuation are shown in the table. Conclusions: Poor accrual represents the main cause of early termination of all cancer clinical trials. Premature termination/withdrawal rate appears lower in ICI trials which may be attributed to accrual differences. Clinical trial completion remains a high priority. [Table: see text]

Eltrombopag versus placebo for low-risk myelodysplastic syndromes with thrombocytopenia (EQoL-MDS): phase 1 results of a single-blind, randomised, controlled, phase 2 superiority trial

In myelodysplastic syndromes, thrombocytopenia is associated with mortality, but treatments in this setting are scarce. We tested whether eltrombopag, a thrombopoietin receptor agonist, might be effective in improving thrombocytopenia in lower-risk myelodysplastic syndromes and severe thrombocytopenia. EQoL-MDS was a single-blind, randomised, controlled, phase 2 superiority trial of adult patients with low-risk or International Prognostic Scoring System intermediate-1-risk myelodysplastic syndromes and severe thrombocytopenia. Patients with a stable platelet count of lower than 30 × 109 platelets per L, aged at least 18 years, with refractoriness, ineligibility to receive treatment with alternative medications, or relapse while receiving treatment with alternative medications were included in this trial. Patients were randomly assigned (2:1) to receive eltrombopag (50 mg to 300 mg) or placebo for at least 24 weeks and until disease progression and were masked to treatment allocation. Here, we report the results in the intention-to-treat population of the first phase of the trial, for which the primary endpoints were the proportion of patients achieving a platelet response within 24 weeks and safety. The interim analysis presented here was protocol-specified and used a two-sided significance level of 0·001 and a p value at or below this limit for both primary endpoints to indicate the need for early trial termination. Duration of platelet transfusion independence, duration of response, overall survival, leukaemia-free survival, and pharmacokinetics will be reported at the end of the phase 2 portion of the trial. This trial is registered with EudraCT, number 2010-022890-33. Between June 13, 2011, and June 17, 2016, we enrolled 90 participants for the first phase of the trial. The median follow-up time to assess platelet responses was 11 weeks (IQR 4-24). Platelet responses occurred in 28 (47%) of 59 patients in the eltrombopag group versus one (3%) of 31 patients in the placebo group (odds ratio 27·1 [95% CI 3·5-211·9], p=0·0017). During the follow-up, 21 patients had at least one severe bleeding event (WHO bleeding score ≥2). There were a higher number of bleeders in the placebo (13 [42%] of 31 patients) than in the eltrombopag arm (eight [14%] of 59 patients; p=0·0025). 52 grade 3-4 adverse events occurred in 27 (46%) of 59 patients in the eltrombopag group versus nine events in five (16%) of 31 patients in the placebo group (χ2=7·8, p=0·0053, stopping rule not reached). The outcome acute myeloid leukaemia evolution or disease progression occurred in seven (12%) of 59 patients in the eltrombopag group versus five (16%) of 31 patients in the placebo group (χ2=0·06, p=0·81). Eltrombopag is well-tolerated in patients with lower-risk myelodysplastic syndromes and severe thrombocytopenia and is clinically effective in raising platelet counts and reducing bleeding events. The assessment of long-term safety and efficacy of eltrombopag and its effect on survival (phase 2 part of study) is still ongoing. Associazione QOL-ONE.