Slow Cancer Trial Accrual Rates Prevent Clinical Translation of Goals

A new study from the MD Anderson Cancer Center has identified factors that influence cancer clinical trial accrual rates—slow enrollments in cancer clinical trials often result in delayed clinical translation of the trial goals and also increase healthcare costs.

“Clinical trials are the gold standard for evaluating treatments and for new drug approval; however, conducting a clinical trial is a very costly process, so it is important to ensure that the effort is successful,” said J. Jack Lee, PhD, DDS, senior author on the study.

Nearly 4270 clinical studies at the MD Anderson Cancer Center met the following inclusion criteria of the study:

• Activated phase 1-3 trials
• At least 10 participants
• Activation prior to March 2011

These trials, which were activated between January 5, 1981, and March 25, 2011, enrolled a total of 145,214 participants. Median enrollment for trials was 16, and the average annual enrollment rate was 8.7 participants. The authors identified 755 (18%) trials as slow accruing, and these trials had strong associations with:

• National cooperative group trials (odds ratio, OR = 4.16; P<.0001 vs. industry sponsored)
• Time from trial activation to first enrollment (OR = 1.13 per month, P<.0001), which may depend on the nature of the study, complexity of the trial, multiple trials for the same patient groups, and available resources

Highest odds of slow enrollment were for trials that needed more than 70 days between activation and first enrollment. The authors also found that phase 2-3 and phase 3 trials had a much slower rate of accrual than phase 1 and phase 2 trials.

According to Lee, lack of funding might be the primary challenge for patient accrual in national cooperative group trials. “Doctors and hospitals need to carefully vet the feasibility of a successful study accrual before opening a trial and be more mindful of investing in the areas of highest potential impact in order to maximize the utilization of available resources,” he added.

Lee emphasized the global impact of a failed trial, explaining that the time and resources invested to develop, write, review, and approve a trial and then to open and maintain it, costs money. Dearth of patient enrollment prevents the trial from collecting meaningful data that could meet the trial objectives and impact treatment.

The authors acknowledge that their study was limited to trials conducted at a single institution, so the findings are not generalizable. Additionally, MD Anderson Cancer Center is a large tertiary cancer center, and so trial findings cannot be generalized to community hospitals.

The study has been published in Clinical Cancer Research.