OS

Also known as: Overall Survival

Time from treatment start (or randomisation) until death from any cause.

Definition

Overall Survival (OS) is the gold-standard efficacy endpoint in oncology: time from randomisation to death from any cause. Median OS and the hazard ratio for OS are the most credible measures of clinical benefit. OS is patient-centric, objective, and unambiguous — but it requires long trial follow-up.

See also

• PFS — Time from treatment start until disease progression or death.
• ORR — The proportion of patients with a complete or partial tumour response.
• HR — The relative risk of an event (progression, death) in the treatment vs. control arm.

Other clinical terms

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