scholarly journals Estimation of ascertainment bias and its effect on power in clinical trials with time‐to‐event outcomes

2020 ◽  
Author(s):  
Erich J. Greene ◽  
Peter Peduzzi ◽  
James Dziura ◽  
Can Meng ◽  
Michael E. Miller ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Ascertainment Bias ◽  
Time To Event

A systematic review of noninferiority margins in oncology clinical trials

2021 ◽  
Vol 10 (6) ◽  
pp. 443-455
Author(s):  
Mahmoud Hashim ◽  
Talitha Vincken ◽  
Florint Kroi ◽  
Samron Gebregergish ◽  
Mike Spencer ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Absolute Rate ◽  
Time To Event ◽  
End Points ◽  
Patients With Cancer ◽  
Randomized Controlled ◽  
Noninferiority Trials ◽  
Oncology Clinical Trials ◽  
Noninferiority Margin

Aim: A systematic literature review was conducted to identify and characterize noninferiority margins for relevant end points in oncology clinical trials. Materials & methods: Randomized, controlled, noninferiority trials of patients with cancer were identified in PubMed and Embase. Results: Of 2284 publications identified, 285 oncology noninferiority clinical trials were analyzed. The median noninferiority margin was a hazard ratio of 1.29 (mean: 1.32; range: 1.05–2.05) for studies that reported time-to-event end points (n = 192). The median noninferiority margin was 13.0% (mean: 12.7%; range: 5.0–20.0%) for studies that reported response end points as absolute rate differences (n = 31). Conclusion: Although there was consistency in the noninferiority margins’ scale, variability was evident in noninferiority margins across trials. Increased transparency may improve consistency in noninferiority margin application in oncology clinical trials.

scholarly journals Sizing clinical trials when comparing bivariate time-to-event outcomes

2017 ◽  
Vol 36 (9) ◽  
pp. 1363-1382 ◽  
Author(s):  
Tomoyuki Sugimoto ◽  
Toshimitsu Hamasaki ◽  
Scott R. Evans ◽  
Takashi Sozu
Keyword(s):  
Clinical Trials ◽  
Time To Event

Control arm heterogeneity in trials for unselected advanced triple-negative breast cancer (aTNBC).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1082-1082
Author(s):  
Kinisha Gala ◽  
Ankit Kalucha ◽  
Samuel Martinet ◽  
Anushri Goel ◽  
Kalpana Devi Narisetty ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Sample Size ◽  
Single Agent ◽  
Progression Free Survival ◽  
Sample Sizes ◽  
Time To Event ◽  
Sample Size Calculations ◽  
Subgroup Analyses ◽  
Combination Regimens

1082 Background: Primary endpoints of clinical trials frequently include subgroup-analyses. Several solid cancers such as aTNBC are heterogeneous, which can lead to unpredictable control arm performance impairing accurate assumptions for sample size calculations. We explore the value of a comprehensive clinical trial results repository in assessing control arm heterogeneity with aTNBC as the pilot. Methods: We identified P2/3 trials reporting median overall survival (mOS) and/or median progression-free survival (mPFS) in unselected aTNBC through a systematic search of PubMed, clinical trials databases and conference proceedings. Trial arms with sample sizes ≤25 or evaluating drugs no longer in development were excluded. Due to inconsistency among PD-L1 assays, PD-L1 subgroup analyses were not assessed separately. The primary aim was a descriptive analysis of control arm mOS and mPFS across all randomized trials in first line (1L) aTNBC. Secondary aims were to investigate time-to-event outcomes in control arms in later lines and to assess time-trends in aTNBC experimental and control arm outcomes. Results: We included 33 trials published between June 2013-Feb 2021. The mOS of control arms in 1L was 18.7mo (range 12.6-22.8) across 5 trials with single agent (nab-) paclitaxel [(n)P], and 18.1mo (similar range) for 7 trials including combination regimens (Table). The mPFS of control arms in 1L was 4.9mo (range 3.8-5.6) across 5 trials with single-agent (n)P, and 5.6mo (range 3.8-6.1) across 8 trials including combination regimens. Control arm mOS was 13.1mo (range 9.4-17.4) for 3 trials in first and second line (1/2L) and 8.7mo (range 6.7-10.8) across 5 trials in 2L and beyond. R2 for the mOS best-fit lines across control and experimental arms over time was 0.09, 0.01 and 0.04 for 1L, 1/2L and 2L and beyond, respectively. Conclusions: Median time-to-event outcomes of control arms in 1L aTNBC show considerable heterogeneity, even among trials with comparable regimens and large sample sizes. Disregarding important prognostic factors at stratification can lead to imbalances between arms, which may jeopardize accurate sample size calculations, trial results and interpretation. Optimizing stratification and assumptions for power calculations is of utmost importance in aTNBC and beyond. A digitized trial results repository with precisely defined patient populations and treatment settings could improve accuracy of assumptions during clinical trial design.[Table: see text]

A Bayesian approach for event predictions in clinical trials with time‐to‐event outcomes

2021 ◽  
Author(s):  
Paul Aubel ◽  
Marine Antigny ◽  
Ronan Fougeray ◽  
Frédéric Dubois ◽  
Gaëlle Saint‐Hilary
Keyword(s):  
Clinical Trials ◽  
Bayesian Approach ◽  
Time To Event
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