Efficacy Endpoints in Oncology Clinical Trials
The following table shows a number of efficacy endpoints. Each of these endpoints is associated with certain advantages and limitations. Although the endpoint definitions provided here are from FDA guidance, please note that individual clinical trials may use different definitions.
Commonly used efficacy endpoints in oncology clinical trials: advantages and limitations1
|Overall survival (OS)||Time from randomization* until death from any cause||
|Progression-free survival (PFS)||Time from randomization* until disease progression or death|| || |
|Time to progression (TTP)||Time from randomization* until objective tumor progression; does not include deaths|
|Time to treatment failure (TTF)||Time from randomization* to discontinuation of treatment for any reason, including disease progression, treatment toxicity, and death|| || |
|Event-free survival (EFS)||Time from randomization* to disease progression, death, or discontinuation of treatment for any reason (eg, toxicity, patient preference, or initiation of a new treatment without documented progression)|| || |
|Time to next treatment (TTNT)||Time from end of primary treatment to institution of next therapy|| || |
|Objective response rate (ORR)||Proportion of patients with reduction in tumor burden of a predefined amount||
|Duration of response (DoR)||Time from documentation of tumor response to disease progression|
*Not all trials are randomized. In nonrandomized trials, time from study enrollment is commonly used.
- U.S. Department of Health and Human Services Food and Drug Administration Center for Drug Evaluation and Research (CDER), Center for Biologics Evaluation and Research (CBER). Guidance for industry: clinical trial endpoints for the approval of cancer drugs and biologics. http://www.fda.gov/downloads/Drugs/.../Guidances/ucm071590.pdf. Published May 2007. Accessed June 4, 2018.