Industry Trials Stopped for Safety or Efficacy (% of Stops)

## What this measures

Of the company-led interventional trials terminated over the last 12 months, the share whose stated reason cites safety findings or the drug not working (futility, missed endpoints, lack of efficacy, an interim analysis or a data monitoring committee), in percent.

## Why it matters

These are the scientific failures. Their share shows how often stops are about the drug itself rather than money or logistics.

## How to read it

Higher means a larger part of early stops cite this reason. A stop can cite several reasons and count in more than one share; stops that give no reason, or only "sponsor decision", count in none.

## What it does not say

A registration is a plan, not a result: some registered trials never start, and size, cost and odds of success differ widely. Being listed does not mean a study was reviewed by the U.S. government.

## How it's built

Sponsors give a short free-text reason when they mark a trial terminated ("why stopped"). Palanor labels each reason with fixed word rules, published in its code (src/lib/clinicaltrials/reasons.ts), not a model. Phrases that deny a reason are removed first, because sponsors often add "not related to safety or efficacy" to business stops. The share is labelled stops divided by all terminated trials. Company-led interventional trials that ended with an actual completion date, counted in the month they ended and summed over the 12 months to the month shown (so each point is a 12-month window). Trials report their ending late, so the newest three complete months are not published, and the latest points can still move a little as reports arrive. Records are read from the API each week. History from January 2010.

## Source

ClinicalTrials.gov (U.S. National Library of Medicine), API v2, refreshed weekly by /api/cron/clinicaltrials-pipeline-sync. Palanor counts and classifies the records as described above; it does not change them. ClinicalTrials.gov disclaimer: the U.S. government does not review or approve the safety and science of all studies listed; sponsors and investigators are responsible for their listings.