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

Table 2 Arm-level association of all included arms

Surrogate endpoint	True endpoint	No. of arms	r_s	95%CI
ORR	Median OS	254	0.700	0.631,0.758
ORR	Median PFS	271	0.831	0.790,0.864
Median PFS	Median OS	306	0.755	0.702,0.799

ISSN: 1471-2407