Monitoring for Lack of Benefit: A Critical Component of a Randomized Clinical Trial

To balance patient interests against the need for acquiring evidence, ongoing randomized clinical trials are formally monitored for early convincing indication of benefit or lack of benefit. In lethal diseases like cancer, where new therapies are often toxic and may have limited preliminary efficacy data, monitoring for lack of benefit is particularly important. We review the complex nature of stopping a randomized trial for lack of benefit and...