PFS

Also known as: Progression-Free Survival

Time from treatment start until disease progression or death.

Definition

Progression-Free Survival (PFS) is time from randomisation until disease progression (by RECIST or other measure) or death. PFS reads out faster than OS and is the primary endpoint in most modern oncology Phase 3 trials. Surrogate validation varies by disease — strong in some cancers (CRC, HER2+ breast), weaker in others.

See also

• OS — Time from treatment start (or randomisation) until death from any cause.
• ORR — The proportion of patients with a complete or partial tumour response.
• RECIST — The standardised criteria for measuring tumour response on imaging in solid-tumour oncology trials.

Other clinical terms

• Phase 1 trial
• Phase 2 trial
• Phase 3 trial
• Primary endpoint
• Surrogate endpoint
• CDx