# Time to treatment failure and quality of life as co-primary endpoints in non-curative trials

Source: https://onco.cc/ideas/idea-tr1-ttf-and-qol-coprimary/  
OnCo record `idea-tr1-ttf-and-qol-coprimary` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

For treatments that will not cure, what matters is how long the treatment keeps working without becoming unbearable, and how the person feels. Trials should measure both of those as their main results.

## Summary

In palliative-intent settings, trials adopt time to treatment failure (progression, death or discontinuation for toxicity or patient choice) together with a validated QoL instrument (EORTC QLQ-C30 or disease module) analysed as time to definitive deterioration, as co-primary endpoints, with OS as the principal secondary endpoint. PFS alone rewards drugs that delay scan progression while making patients feel worse.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Trials with TTF plus QoL co-primaries will more often identify regimens that patients continue and prefer, and drugs approved on these endpoints will show better real-world persistence than drugs approved on PFS alone.
- Rationale: Discontinuation for toxicity is common with modern combinations and invisible in PFS. Regulators have accepted QoL-based labels in some settings; the co-primary structure protects against approving effective-but-intolerable regimens.
- Proposed test: Re-analyse completed phase 3 trials with available PRO data under the co-primary framework and identify decisions that would have changed; then run a prospective trial in a common palliative setting with the new endpoints.
- Maturity: speculative
- Actor: regulator

## Sources

- EORTC Quality of Life Group (QLQ-C30): https://qol.eortc.org/

## Connected records

- companies: [EORTC](https://onco.cc/companies/curie-nki-eortc/)
- terms: [Overall survival (OS)](https://onco.cc/terms/os/), [Progression-free survival (PFS)](https://onco.cc/terms/pfs/)
- bottlenecks: [Patients lack understanding, navigation and agency](https://onco.cc/bottlenecks/b-patient-voice/), [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/), [Trial design, endpoints and cost](https://onco.cc/bottlenecks/b-trial-design/)

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