In clinical trials, overall survival (OS), defined as the time from randomisation (assignment of clinical trial participants to treatment groups) until death from any cause, remains a robust measure of the clinical benefit of cancer medicines. Its objectivity, suitability for comparing treatment regimens and relevance to patients have made it the preferred measure of clinical efficacy in regulatory and HTA body / payer decision-making. However, reliance on OS data in regulatory and HTA body / payer decisions has its limitations. Namely, it fails to capture health-related quality of life (HRQoL) outcomes, is more vulnerable to confounding than other endpoints, and may lead to increased cost and delayed patient access to novel medicines as time to measure OS benefit increases in many treatment settings.