Estimating the rate and reasons of clinical trial failure in urologic oncology
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Published on: December 9, 2015
Kristian D Stensland1, Krystal DePorto2, James Ryan2
1Department of Urology, University of Michigan, Ann Arbor, MI; Lahey Hospital and Medical Center, Burlington, MA.
Objectives:
Clinical trials are pillars of modern clinical evidence generation. However, the clinical trial enterprise can be inefficient, and trials often fail before their planned endpoint is reached. We sought to estimate how often urologic oncology trials fail, why trials fail, and associations with trial failure.
Methods:
We queried phase 2/3 urologic clinical trial data from ClinicalTrials.gov registered between 2007 and 2019, with status marked as active, completed, or terminated. We extracted relevant trial data, including anticipated and actual accrual, from trial records and ClinicalTrials.gov archives. We manually coded reasons given in the "why stopped" free text field for trial failure into categories (poor accrual, interim results, toxicity/adverse events, study agent unavailable, canceled by the sponsor, inadequate budget, logistics, trial no longer needed, principal investigator left, no reason given, or other). We considered trials terminated for safety or efficacy to be completed trials. Trials marked as terminated for other reasons were considered failed trials. We then estimated the rate of trial failure using competing risks methods. Finally, we assessed associations with trial failure using a Cox proportional hazards model.
Results:
A total of 1,869 urologic oncology trials were included. Of these, 225 (12.0%) failed, and 51 (2.7%) were terminated for "good" reasons (e.g., toxicity, efficacy). Of the 225 failed trials, 122 (54%) failed due to poor accrual. Failed trials had a lower anticipated accrual than successfully completed trials (55 vs. 63 patients, P<0.001). A total of 6,832 patients were actually accrued to failed trials. The 10-year estimated risk of trial failure was 17% (95% CI 15%-22%). Single center trials, phase 3 trials, drug trials, and trials with exclusively USA sites were more likely to fail.
Conclusion:
We estimate that 17%, or roughly 1 in 6, of urologic oncology trials fail, most frequently for poor accrual. Further investigations are needed into systemic, trial, and site-specific factors that may impact accrual and successful trial completion.
Insights
Approximately 17% of urologic oncology clinical trials fail, with poor patient accrual being the most common reason. Understanding these failures is crucial for improving cancer research efficiency.
Area of Science:
- Urologic Oncology
- Clinical Trial Methodology
- Evidence-Based Medicine
Background:
- Clinical trials are essential for advancing medical knowledge and patient care.
- Inefficiencies within the clinical trial process can lead to premature trial termination.
- Understanding the reasons for trial failure is critical for optimizing future research endeavors.
Purpose of the Study:
- To determine the failure rate of urologic oncology clinical trials.
- To identify the primary reasons behind trial failures in this field.
- To explore factors associated with an increased risk of trial failure.
Main Methods:
- Analysis of phase 2/3 urologic oncology trial data from ClinicalTrials.gov (2007-2019).
- Manual coding of reasons for trial termination from free-text fields.
- Estimation of trial failure rates using competing risks methods and assessment of associated factors via Cox proportional hazards models.
Main Results:
- A total of 1,869 trials were analyzed; 12.0% (225) failed, and 2.7% were terminated for positive outcomes.
- Poor patient accrual was the leading cause of failure, accounting for 54% of failed trials.
- The estimated 10-year risk of trial failure was 17%. Single-center, phase 3, drug-specific, and US-only trials showed higher failure rates.
Conclusions:
- An estimated 17% of urologic oncology trials fail, predominantly due to insufficient patient enrollment.
- Further research is warranted to address systemic, trial-specific, and site-specific factors influencing accrual and successful completion.
- Improving trial design and recruitment strategies is vital for enhancing the efficiency of cancer clinical research.
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