What enrollment failure means
Enrollment failure means a trial could not recruit or accrue enough participants to continue as planned. That can happen before treatment starts, during active recruitment, or after trial conditions change.
Common source language includes slow accrual, insufficient accrual, unable to recruit, enrollment goals not met, poor recruitment, or sites not recruiting as planned.
Why it is different from drug failure
An enrollment stop often tells you more about feasibility than biology. The intervention may not have been tested enough to conclude whether it worked, failed, or created safety problems.
That does not make enrollment failure unimportant. Recruitment problems can reveal narrow eligibility, competitive pressure, trial burden, site execution issues, or patient population problems.
How to analyze enrollment stops
The most useful workflow is to compare enrollment stops by phase, disease area, sponsor, and condition. A single enrollment stop may be noise. Repeated enrollment stops in the same niche can be a meaningful development signal.
Use this page as a starting point, then verify the source NCT records and look for protocol amendments, enrollment targets, actual enrollment, site footprint, and competing trials.