# Record what happens when doctors use cancer drugs off-label

Source: https://onco.cc/ideas/idea-tr2-off-label-outcome-registry/  
OnCo record `idea-tr2-off-label-outcome-registry` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cancer drugs are often prescribed outside their approved use based on hope or small studies. Capturing outcomes of these uses would reveal which ones fail so they can be stopped.

## Summary

Off-label use is common in oncology, particularly for targeted agents matched to molecular alterations in other cancers. Structured outcome capture at the point of off-label prescribing (indication, rationale, response, duration, toxicity) through a simple registry, as the Dutch DRUP trial and the US TAPUR study do within trial frameworks, but extended to routine practice, would document failures that are otherwise invisible.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: A national off-label registry will identify at least five drug-alteration-cancer combinations with response rates below 10% in over 50 patients within three years, leading to guideline statements against their use.
- Rationale: DRUP and TAPUR have both closed cohorts for futility, generating negative evidence that changed practice. Most off-label use happens outside such studies and is never counted.
- Proposed test: Mandate registry entry as a condition of off-label reimbursement in one health system; report cohort response rates annually.
- Maturity: early-clinical
- Actor: clinic

## Sources

- Bottleneck evidence (Failures are hidden): Anderson et al., Compliance with results reporting at ClinicalTrials.gov (NEJM 2015): https://doi.org/10.1056/NEJMsa1409364

## Connected records

- ideas: [Payers cover off-label combinations only inside registry-randomised trials](https://onco.cc/ideas/idea-tr2-payer-combo-cwe/)
- terms: [Real-world evidence](https://onco.cc/terms/real-world-evidence/), [Tumour-agnostic (tissue-agnostic) approval](https://onco.cc/terms/tumour-agnostic/)
- bottlenecks: [Failures are hidden](https://onco.cc/bottlenecks/b-negative-results/), [Weak real-world evidence and registries](https://onco.cc/bottlenecks/b-real-world-evidence/)
- key papers: [Compliance with results reporting at ClinicalTrials.gov](https://onco.cc/key-papers/paper-anderson-n-engl-j-med/)

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