In English | En español
Questions About Cancer? 1-800-4-CANCER

Learn About Clinical Trials

  • Updated: 11/02/2012

Page Options

  • Print This Page
  • Email This Document

Ending Trials Early

Most clinical trials run as planned from beginning to end. But sometimes trials are stopped early. For example, the IRB and DSMB may stop a trial if participants are experiencing unexpected and severe side effects or if there is clear evidence that the harms are outweighing the benefits.

In some cases, a trial might be stopped because:

  • It is going very well. If there is clear evidence early-on that a new treatment or intervention is effective, then the trial may be halted so that the new treatment can be made widely available as soon as possible.
  • Enough patients cannot be recruited
  • The results of other trials are published that answer the question or make it irrelevant