Estimating the size and scope of the urologic oncology clinical trials enterprise

INTRODUCTION

Clinical trials are a cornerstone of urologic science and practice, both advancing and delivering optimal care. While enrollment in a trial is considered standard of care for some conditions (e.g., cancer per NCCN guidelines) and we invest billions of dollars annually in trials, clinical trials still struggle to reach their goals.¹

In urology, many clinical trials fail to reach their primary endpoint, wasting patient and investigator time and resources.^2,3 While clinical trials may seem a niche topic, the number of urologic oncology patients involved in trials may be higher than with certain urologic conditions. Better understanding the size and scope of the urologic oncology trials enterprise could encourage engagement with trials and trial improvement from urologists, sponsors, funders, and patients. In other words, highlighting the large number of urologic oncology patients involved in trials emphasizes that clinical trials should be important and of interest to urologists.

While there has been recent interest in trial conduct from the urologic community, such as educational clinical trial sessions at the American Urological Association and Society of Urologic Oncology annual conferences, more attention to the scope and implementation of clinical trials is needed to improve their conduct and impact. For these reasons, we analyzed enrollment data for urologic oncology trials to contextualize the urologic oncology clinical trials enterprise.

METHODS

On January 19, 2023, we extracted records of all interventional urologic oncology trials registered on ClinicalTrials.gov since 2007 through the Aggregate Analysis of ClinicalTrials.gov (AACT) database. We excluded trials with suspended/withdrawn/unknown status, missing enrollment information, and trials reporting enrollment of over 1,000 patients as these trials were considered either erroneously entered or unrepresentative of “standard” trials (Figure).

Figure.

Flow diagram of included urologic oncology clinical trials

We calculated cumulative actual enrollment for completed trials and terminated trials, and anticipated enrollment (i.e., goal enrollment) for ongoing trials. We calculated a simple average based on the 17-year study period (2007–2023) for patients enrolled per year (total patients / 17 years) and per day (total patients / 17 years / 52 weeks / 5 workdays).

RESULTS

We identified a total of 10,600 registered urologic oncology trials, comprising 4,709 completed, 1,474 terminated, and 4,417 ongoing trials. A total of 472,983 patients were enrolled to completed or terminated trials, of which 53,500 patients were enrolled in terminated trials (i.e., trials that failed to reach their anticipated endpoint). On average, 27,822 patients per year, or 107 patients per workday, were enrolled in urologic oncology clinical trials. A median of 40 patients (interquartile range (IQR) 20–95) were enrolled in each completed trial and 12 patients (IQR 5–29) were enrolled in each terminated trial. A total of 589,929 participants (median 60 patients (IQR 30–155) per trial) are needed to complete enrollment for all currently registered ongoing urologic oncology trials. Median patients/trial decreased over time based on trial start year (2007–2010: 34, 2011–2014: 32, 2015–2018: 30, 2019–2023: 25).

DISCUSSION

Nearly half a million patients have been enrolled in urologic oncology clinical trials over the past 17 years, with an average of 107 patients per day enrolling in a trial. With nearly 28,000 patients enrolled annually in urologic oncology trials, there are more patients enrolled in urologic oncology trials each year than there are new cases of testicular, penile, and ureteral cancer combined.⁴

This rate of urology trial participation highlights a central role of clinical trials in urology. While some increased attention has been paid to trials recently, more robust investment and interest in developing our urologic trial infrastructure could positively influence tens of thousands of urology patients annually. Additionally, we found that thousands of patients are enrolled in urologic oncology trials that fail to reach their endpoint, suggesting these trials are noninformative and not advancing science as was promised during the trial consent and enrollment process. We must improve how we design and run our trials to increase the pace of innovation, decrease costs of drug development, and ensure we meet our moral obligation to maximize the likelihood of trial success for patients who have agreed to participate in trials. Approaches to improving trial design and conduct are direly needed.

Partnering with groups such as the SUO Clinical Trials Consortium, ASCO, and clinical trial cooperative groups (e.g., SWOG) and investing in trial improvement research could greatly benefit urology patients directly while also advancing science more efficiently. In addition, efforts to advertise clinical trials, both as a general concept and for specific trials, should be increased. Clinical trial enrollment should be highlighted and encouraged in all feasible settings, especially as trial infrastructure is expanded. With improved engagement from urologists and patients in varied settings, the urologic care we deliver can be optimized more efficiently through streamlined trials.

CONCLUSION

Tens of thousands of urologic oncology patients are enrolled in clinical trials every year. Efforts to advertise and improve clinical trials are needed to ensure patient, investigator, and urologist time and resources are optimally invested.