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