An analysis of 7,776 adult cancer clinical trials registered on Clinicaltrials.gov showed that approximately 20 percent of trials failed to complete (for reasons unrelated to the efficacy or side effects of the intervention).

In 2010, a report from the Institute of Medicine entitled “A National Clinical Trials System for the 21st Century” called attention to this potential problem, indicating that about 40 percent of the clinical trials initiated by the NCI Cooperative Groups are never finished.

However, NCI cooperative trials account for a small proportion of all cancer clinical trials and the scope of this problem within the larger clinical trials enterprise had not previously been comprehensively examined, providing the rationale for the current analysis.

“When we consider what prevents the translation of clinical trials to new standard treatments for our patients, we generally think of two things – an experimental intervention doesn’t work and/or the side effects are too severe,” said senior author Matthew Galsky, MD, associate professor of medicine at the Icahn School of Medicine at Mount Sinai and the director of the Genitourinary Medical Oncology Program at the Tisch Cancer Institute. “However, our findings reveal a third major barrier to progress in cancer care – that a large proportion of initiated clinical trials are not completed at all, failing to contribute to our understanding of how best to care for patients.”

In this study researchers analysed data from Clinicaltrials.gov for all phase II and III adult cancer clinical that were registered between 2005 and 2011. They identified 7,776 trials. Those that were designated as “stopped early” in the registry were classified as failing to complete. Using statistical methods to account for the different time frames during which trials were initiated and closed, they determined that approximately 20 percent failed to complete.

Overall, poor accrual was the most common cause of trials failing to complete, accounting for almost 40 percent of these trials. The researchers initially became interested in studying this topic after noting that a series of clinical trials in bladder cancer failed to complete, leading to a poor level of evidence to guide treatment decisions in this disease. However, in the current study, they found that genitourinary cancer trials, including bladder cancer trials, were no more likely to fail to complete than trials in other cancer types. Researchers found that trials conducted at a single location, trials with industry sponsors, and trials with study locations only inside the United States were more likely to fail to complete.

According to Dr. Galsky, “clinical trials that fail to complete waste financial resources and human capital. The results of this study further highlight the wide-ranging impact of poor accrual to cancer clinical trials in the United States.” As a clinical trialist himself, he notes that this is not an indictment of any other single stakeholder in the system but hopes that these findings will facilitate broader conversations regarding the need for new approaches to how trials are conducted and improve communication and collaboration among stakeholders to increase the efficiency of the system.

Source: ASCO