Table 1.

Clinical End Point Key Concepts Defined

Concept	Abbreviation	Definition
Progression-free survival	PFS	“The length of time during and after the treatment of a disease, such as cancer, that a patient lives with the disease that may or may not shrink but it’s increase in size does not meet the criteria of progressive disease according to the protocol criteria used” [27]
“PFS deferred,” “PFS delayed,” “tandem PFS,” or “PFS version 2.0”	PFS2	“time from randomisation to objective tumor progression on next-line treatment or death from any cause. In some cases, time on next-line therapy may be used as proxy for PFS” [8]
Time to tumor progression	TTP	“The length of time from the date of diagnosis or the start of treatment for a disease until the disease starts to get worse or spread to other parts of the body.” In the context of pivotal clinical studies, this is the time from randomization to objective tumor progression [27].
Time to treatment failure	TTF	“TTF is defined as a composite endpoint measuring time from randomization to discontinuation of treatment for any reason, including disease progression, treatment toxicity, and death.” [28]
Duration of response	DOR	“Time from documentation of objective tumor response to objective disease progression” [29]
Duration of disease control	DDC	“DDC is defined as the sum of the PFS of each sequence, except when progressive disease is observed at either reintroduction or second-therapy (DDC = PFS1 + PFS2 if treatment 2 achieved stabilization or response).” [30]