Core limitations in clinical trials leading to anticancer drug approvals by the U.S. Food and Drug Administration.

Abstract

2057 Background: To date, a comprehensive evaluation of core limitations in clinical trials leading to anti-cancer drug approvals by the US Food and Drug Administration (FDA) has not been undertaken.The aim of this analysis was to assess the percentage of clinical trials with core limitations, defined as lack of randomization, lack of overall survival data, inappropriate use of crossover, and use of sub-optimal control arms that led to FDA approvals from 2014 to 2019. Methods: This observational analysis included all approved anti-cancer drug indications by the FDA from July 2014 through July 2019. All indications were investigated and each clinical trial evaluated for design, enrollment period, primary endpoints, and presence of core limitations. The standard of care therapy was determined by evaluating the literature and published guidelines 1-year prior to start of clinical trial enrollment. Crossover was examined and evaluated for optimal use. We then calculated the percentage of approvals based on clinical trials with any or all core limitations. Results: A total of 187 anti-cancer approvals were evaluated. The number of anti-cancer drug approvals doubled over time with 68 in first half of study period (June 2014 to December 2016) to 119 in second half of study period (January 2017 to July 2019). Of those, 125 (67%) were based on a clinical trial with at least one core limitation. 64 (34%) approvals were based on a single-arm clinical trial. Of the remaining 123 approvals based on randomized trials, 60 (32%) had a core limitation. Of all randomized trials, 37 (30%) lacked overall survival benefit, 31 (25%) had a sub-optimal control, and 17 (14%) used crossover inappropriately. Conclusions: The majority of cancer drugs are approved based on clinical trials with core limitations. Efforts to minimize core limitations at the time of clinical trial design are essential to ensure that new anti-cancer drugs being marketed truly improve patient outcomes over current standards.