From: Validating ORR and PFS as surrogate endpoints in phase II and III clinical trials for NSCLC patients: difference exists in the strength of surrogacy in various trial settings
Treatment effect of surrogate endpoint
Treatment effect of true endpoint
No. of trials
rs
95% CI
ΔORR
HR of OS
112
0.462
0.303, 0.597
HR of PFS
114
0.764
0.675, 0.831
138
0.584
0.462, 0.684