Enrollment Success, Factors, and Prediction Models in Cancer Trials (2008-2019).

Area of Science:

• Oncology
• Clinical Trial Management
• Biostatistics

Background:

• Enrollment success is crucial for advancing cancer research and drug development.
• Understanding factors influencing enrollment rates is key to optimizing clinical trial design and execution.

Purpose of the Study:

• To investigate the enrollment success rate of cancer clinical trials between 2008 and 2019.
• To identify factors associated with lower enrollment success in these trials.

Main Methods:

• A cross-sectional study analyzing 4,004 cancer clinical trials (breast, lung, colorectal) registered on ClinicalTrials.gov.
• Enrollment success defined as achieving ≥85% of the estimated enrollment goal.
• Multivariable logistic regression used to evaluate associations between trial characteristics and enrollment success.

Main Results:

• The overall enrollment success rate was 49.1%, with a notable decline from 2014-2019.
• Factors associated with lower success included later activation year, earlier phase trials (I, I/II, II vs. III), government sponsorship, no healthy volunteers, and larger enrollment targets.
• Trials with placebo comparators, multiple locations (≥5), and more secondary endpoints (≥5) showed higher success rates.

Conclusions:

• Cancer clinical trial enrollment success rates have decreased over the study period.
• Identifying key factors influencing enrollment can guide the development of improved recruitment strategies for future cancer trials.