GlobalData analysed all terminated trials within the Clinical Trials Database to determine the major reasons for terminations. When “Other” and “Unspecified” were removed from the dataset, the single highest reason for trial termination, at 55% of the total trials, is low accrual rate (Figure 1). This is distantly followed by lack of efficacy (15%), adverse events (11%), financial issues (6%), and rounding out the top five, a tie between business/strategic decisions and product discontinuation (4% each).

Reasons for clinical trial termination

Because low accrual rate is the biggest reason for trial termination, it is not surprising that the average enrollment efficiency (the number of subjects planned divided by the number of subjects actually enrolled) in these trials for every phase is below 40%. The lowest enrollment efficiency in any phase occurred in Phase III at 32.1%, and the highest occurred in Phase IV at 39.8%. The average number of patients enrolled also suffered, ranging from 19.1 in Phase I up to only 79.9 in Phase III.

Go deeper with GlobalData

Data Insights

The gold standard of business intelligence.

Find out more

Related Company Profiles

View all

Reasons for Trial Termination. Source: GlobalData

This data underscores the need for addressing issues of poor enrollment in clinical trials, especially in Oncology indications, which were the most often terminated therapy area, with low accrual being the reason for this. Clinical trial feasibility planning to minimise risk, account for competitive activity, and ultimately select the right geographic location, sites, and investigators for a trial are paramount.