Terminated clinical trials

Terminated clinical trials: search reasons and failure patterns

Terminated clinical trials are a critical source of development intelligence, but termination does not always mean scientific failure. This guide explains how to interpret terminated trial records and compare termination reasons.

Termination status versus failure reason

A terminated clinical trial ended before its planned completion. The reason may be scientific, such as futility or safety, but it may also be practical, financial, strategic, or operational.

That distinction matters. Treating every terminated trial as a drug failure can lead to poor conclusions, especially in areas with recruitment challenges or rapidly changing standards of care.

How termination reasons are grouped

The database groups stop reasons into buckets such as efficacy/futility, safety, enrollment, funding, regulatory, strategic, operational, and other/unknown.

This makes it easier to scan large numbers of terminated records and decide which records deserve deeper primary-source review.

Using terminated trial data in research

Terminated trial patterns can inform competitive intelligence, diligence, portfolio strategy, clinical operations planning, and landscape reviews.

The most useful analyses compare termination reasons across phases, sponsors, disease areas, and interventions rather than relying on a single trial record.

Original dataset signals

What termination records show

The terminated-trials slice is the largest status group in the database. It is useful for SEO and research because users often search termination status directly, but the dataset shows why termination must be paired with reason classification.

Terminated records16,085

Trials with overall status TERMINATED in the current dataset.

Biological failures1,677

Terminated records classified as efficacy/futility or safety signals.

Biological share10%

Termination is not the same as scientific failure.

Termination reason buckets

Operational
8,613
Other/unknown
5,749
Efficacy/futility
1,043
Safety
634

Top terminated-trial phases

Phase 2
7,513
Phase 1
4,612
Phase 3
2,819
Phase 4
1,811

Example records to verify

NCT07014735

Effect of Hyperglycaemia and Moxifloxacin on QTc Interval in T2DM

Efficacy/futility

A terminated record whose stop language directly references futility, illustrating why the reason field is more informative than status alone.

Open trial record
NCT05999968

Abemaciclib plus darolutamide in prostate cancer after initial treatment

Efficacy/futility

A terminated oncology-related record connected to a related study missing its primary endpoint.

Open trial record
NCT04867837

OCTAPLEX in patients with acute major bleeding on DOAC therapy

Efficacy/futility

This terminated trial references interim-analysis futility, a stronger scientific signal than termination status alone.

Open trial record

Termination counts are based on the ClinicalTrials.gov overall status field. The interpretation of why a terminated trial stopped comes from sponsor-provided stop text and the site's reason-bucket classification.

Frequently asked questions

Does terminated mean the drug failed?

Not always. Termination can reflect scientific, operational, financial, strategic, regulatory, or enrollment reasons.

Where can I see the original reason?

Open a trial detail page from Explore and use the ClinicalTrials.gov source link for the primary record.

Should terminated trial pages be used for medical advice?

No. This site is for research support and should not be used as medical advice.