# Duration of response

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

## TL;DR

How long a tumour stays shrunk once it has responded to a drug. A response that lasts two years is worth far more than one that lasts two months, so this is reported alongside response rate.

## Summary

Measured from the first documented response to progression or death, and usually reported as a median plus the proportion of responders still responding at 6, 12 or 24 months. Immunotherapy's signature is not a high response rate but a long duration of response, with responses lasting years in a subset; conversely, many chemotherapy responses are brisk but short. Regulators weigh response rate and durability together when granting accelerated approval on single-arm data, and the durable-response tail is what turns survival curves into a plateau.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: DoR; durable response; durable responses; durability; long-lasting responses; median duration of response

## Sources

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

## Connected records

- terms: [Accelerated approval](https://onco.cc/terms/accelerated-approval/), [Complete response](https://onco.cc/terms/complete-response/), [Immunotherapy](https://onco.cc/terms/immunotherapy-term/), [Objective response rate (ORR)](https://onco.cc/terms/orr/), [Partial response](https://onco.cc/terms/partial-response/), [Progression-free survival (PFS)](https://onco.cc/terms/pfs/)

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JSON: https://onco.cc/api/v1/entities/duration-of-response.json