Clinical Endpoints
Overall Survival
Also known as: OS, Survival
Definition
Time from treatment start until death from any cause, considered the gold standard clinical trial endpoint.
Detailed Explanation
OS is the most definitive endpoint but requires longer follow-up and larger sample sizes. Not all treatments that improve PFS improve OS due to crossover, subsequent therapies, or competing mortality. Median OS means half of patients survived longer than this time. Used for definitive approval in most cancer types.