# Endpoint

Source: https://onco.cc/terms/endpoint/  
OnCo record `endpoint` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The specific outcome a trial is designed to measure, fixed in advance: for example how long patients live, or how long before their cancer grows. A trial 'meets its endpoint' when the new treatment beats the comparison on that measure.

## Summary

The primary endpoint determines the trial's size and its verdict; secondary endpoints (response rate, quality of life, safety, overall survival if not primary) add context but are not what the trial was powered to prove. Overall survival is the gold standard because it is unambiguous and matters most, but it takes years and is muddied when control patients later receive the new drug; progression-free survival, response rate and pathologic complete response are faster surrogates that may or may not translate into living longer. Choosing endpoints, and whether regulators should accept surrogates, is one of the most contested areas in oncology.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: endpoints; end point; end points; primary endpoint; primary endpoints; secondary endpoint; secondary endpoints; co-primary; dual primary; met its primary endpoint; primary outcome; outcome measure; outcome measures; exploratory endpoint; exploratory endpoints; statistically significant; statistical significance

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Clinical_endpoint
- Wikipedia: https://en.wikipedia.org/wiki/Clinical_endpoint

## Connected records

- terms: [Blinded trial](https://onco.cc/terms/blinding/), [Clinical trial](https://onco.cc/terms/clinical-trial/), [Confidence interval](https://onco.cc/terms/confidence-interval/), [Event-free / disease-free survival (EFS, DFS, iDFS, RFS)](https://onco.cc/terms/efs/), [Hazard ratio (HR)](https://onco.cc/terms/hazard-ratio/), [Objective response rate (ORR)](https://onco.cc/terms/orr/), [Overall survival (OS)](https://onco.cc/terms/os/), [P-value](https://onco.cc/terms/p-value/), [Pathologic complete response (pCR)](https://onco.cc/terms/pcr/), [Phase 1, 2 and 3 trials](https://onco.cc/terms/trial-phases/), [Primary, secondary and co-primary endpoints](https://onco.cc/terms/primary-endpoint/), [Progression-free survival (PFS)](https://onco.cc/terms/pfs/), [Quality of life](https://onco.cc/terms/quality-of-life/), [Quality of life and patient-reported outcomes (QoL, PRO)](https://onco.cc/terms/qol-pro/), [Quality-adjusted survival (QALYs and Q-TWiST)](https://onco.cc/terms/quality-adjusted-survival/), [Randomised trial](https://onco.cc/terms/randomised-trial/), [Reading a hazard ratio](https://onco.cc/terms/hazard-ratio-basics/), [Surrogate endpoint](https://onco.cc/terms/surrogate-endpoint/), [Surrogate endpoint validation: which stand-ins have earned trust](https://onco.cc/terms/surrogate-validation/)

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JSON: https://onco.cc/api/v1/entities/endpoint.json