The impact of delay: assessing the early indicators of development time and accrual milestones on oncology clinical trial success

Abstract

This research discovers if there are early indicators of the conduct of clinical trials that related to predicting the success of a clinical trial. Successful trials were those achieving at least 100% of the minimum projected accrual goal necessary to statistically support the scientific objective. Two primary aspects of a clinical trial are investigated that influence success are identified as 1) factors related to the design and development stage of a trial and 2) factors that are observed once a clinical trial is implemented, or available for patient enrollment. The research is conducted using National Cancer Institute (NCI) – Cancer Therapy Evaluation Program (CTEP) sponsored trials for all therapeutic Phase I, I/II, II and III trials between January 1, 2000 and December 31, 2007. Overall observations of the trials in the sample uncover that approximately two out of every five therapeutic studies conducted through NCI-CTEP will fail to achieve the minimum accrual goal. Furthermore, it is observed that phase III clinical trials are unique from non-phase III clinical trials; Phase III trials have longer development times, greater trial size with respect to accrual goals, and a higher rate failure in terms of inability to achieve the accrual goal. The findings of the research suggest that studies with shorter development time have a higher likelihood of achieving accrual success at trial closure; inversely, studies with longer development time have a decreased likelihood of achieving accrual success. Both the time-to-first accrual and the accrual performance at the expected period are both identified as potential accrual milestone indicators of predicting eventual accrual success. Finally, clinical trial characteristics, particularly the number of scientific reviews, can be used to explain the variance in the development time.