# Relapsed / refractory (R/R)

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

## TL;DR

Relapsed means the cancer came back after responding; refractory means it never responded or grew during treatment. 'R/R' is the label on most trials of new blood cancer drugs.

## Summary

The distinction matters for prognosis and drug choice: refractory disease is biologically more resistant, and the interval to relapse (early relapse within 12 months of chemoimmunotherapy in lymphoma, platinum-resistant relapse within 6 months in ovarian cancer) is itself a stratification factor. Regulators define trial populations by prior lines and drug classes, so terms such as 'triple-class refractory' (myeloma resistant to a proteasome inhibitor, an immunomodulator and a CD38 antibody) or 'BCG-unresponsive' bladder cancer describe specific unmet needs that new drugs are approved for. Most accelerated approvals are in R/R settings before drugs move to earlier lines.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: R/R; relapsed/refractory; relapsed or refractory; relapsed and refractory; refractory; relapsed; primary refractory; chemorefractory; chemo-refractory; treatment-refractory; heavily pretreated; pretreated; previously treated; triple-class refractory; penta-refractory; BCG-refractory; double-refractory

## Sources

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

## Connected records

- terms: [Accelerated approval](https://onco.cc/terms/accelerated-approval/), [Drug resistance (primary and acquired)](https://onco.cc/terms/resistance/), [Lines of therapy](https://onco.cc/terms/first-line/), [Platinum-sensitive / platinum-resistant](https://onco.cc/terms/platinum-sensitivity/), [Salvage therapy](https://onco.cc/terms/salvage-therapy/)
- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/)
- journals: [The Lancet Haematology](https://onco.cc/journals/lancet-haematology/)

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